Merge branch 'master' into phantom-builder

2024-11-24 06:54:03 +03:00 · 2020-05-11 10:40:58 -07:00 · 2020-05-11 10:40:58 -07:00 · 3a61933d81
commit 3a61933d81
parent a6dcde5dde bca521a9af
44 changed files with 5404 additions and 2919 deletions
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@ -40,6 +40,15 @@
      "contributions": [
        "code"
      ]
+    },
+    {
+      "login": "lukewestby",
+      "name": "Luke Westby",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/1508245?v=4",
+      "profile": "https://sunrisemovement.com",
+      "contributions": [
+        "code"
+      ]
    }
  ],
  "contributorsPerLine": 7,
@ -47,5 +56,6 @@
  "projectOwner": "dillonkearns",
  "repoType": "github",
  "repoHost": "https://github.com",
-  "skipCi": true
+  "skipCi": true,
+  "commitConvention": "none"
 }
--- a/CHANGELOG-NPM.md
+++ b/CHANGELOG-NPM.md
@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.

 ## [Unreleased]

-## [1.2.12] - 2020-03-28
+## [1.3.0] - 2020-03-28

 ### Added
 - You can now host your `elm-pages` site in a sub-directory. For example, you could host it at mysite.com/blog, where the top-level mysite.com/ is hosting a different app.
--- a/README.md
+++ b/README.md
@ -1,9 +1,7 @@
 # `elm-pages` [![Netlify Status](https://api.netlify.com/api/v1/badges/8ee4a674-4f37-4f16-b99e-607c0a02ee75/deploy-status)](https://app.netlify.com/sites/elm-pages/deploys) [![Build Status](https://github.com/dillonkearns/elm-pages/workflows/Elm%20CI/badge.svg)](https://github.com/dillonkearns/elm-pages/actions?query=branch%3Amaster) [![npm](https://img.shields.io/npm/v/elm-pages.svg)](https://npmjs.com/package/elm-pages) [![Elm package](https://img.shields.io/elm-package/v/dillonkearns/elm-pages.svg)](https://package.elm-lang.org/packages/dillonkearns/elm-pages/latest/)

 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-
-[![All Contributors](https://img.shields.io/badge/all_contributors-3-orange.svg?style=flat-square)](#contributors-)
-
+[![All Contributors](https://img.shields.io/badge/all_contributors-5-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->

 [![Deploy to Netlify](https://www.netlify.com/img/deploy/button.svg)](https://app.netlify.com/start/deploy?repository=https://github.com/dillonkearns/elm-pages-starter)
@ -165,12 +163,12 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
    <td align="center"><a href="https://citric.id"><img src="https://avatars1.githubusercontent.com/u/296665?v=4" width="100px;" alt=""/><br /><sub><b>Steven Vandevelde</b></sub></a><br /><a href="https://github.com/dillonkearns/elm-pages/commits?author=icidasset" title="Code">💻</a></td>
    <td align="center"><a href="https://github.com/Y0hy0h"><img src="https://avatars0.githubusercontent.com/u/11377826?v=4" width="100px;" alt=""/><br /><sub><b>Johannes Maas</b></sub></a><br /><a href="#userTesting-Y0hy0h" title="User Testing">📓</a></td>
    <td align="center"><a href="https://github.com/vViktorPL"><img src="https://avatars1.githubusercontent.com/u/2961541?v=4" width="100px;" alt=""/><br /><sub><b>Wiktor Toporek</b></sub></a><br /><a href="https://github.com/dillonkearns/elm-pages/commits?author=vViktorPL" title="Code">💻</a></td>
+    <td align="center"><a href="https://sunrisemovement.com"><img src="https://avatars1.githubusercontent.com/u/1508245?v=4" width="100px;" alt=""/><br /><sub><b>Luke Westby</b></sub></a><br /><a href="https://github.com/dillonkearns/elm-pages/commits?author=lukewestby" title="Code">💻</a></td>
  </tr>
 </table>

 <!-- markdownlint-enable -->
 <!-- prettier-ignore-end -->
-
 <!-- ALL-CONTRIBUTORS-LIST:END -->

 This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification. Contributions of any kind welcome!
--- a/elm.json
+++ b/elm.json
@ -7,6 +7,8 @@
    "exposed-modules": [
        "Head",
        "Head.Seo",
+        "OptimizedDecoder",
+        "OptimizedDecoder.Pipeline",
        "Pages.ImagePath",
        "Pages.PagePath",
        "Pages.StaticHttp",
@ -31,7 +33,6 @@
        "elm-community/list-extra": "8.2.2 <= v < 9.0.0",
        "elm-community/result-extra": "2.2.1 <= v < 3.0.0",
        "lukewestby/elm-string-interpolate": "1.0.4 <= v < 2.0.0",
-        "mdgriffith/elm-markup": "3.0.1 <= v < 4.0.0",
        "mgold/elm-nonempty-list": "4.0.2 <= v < 5.0.0",
        "miniBill/elm-codec": "1.2.0 <= v < 2.0.0",
        "noahzgordon/elm-color-extra": "1.0.2 <= v < 2.0.0",
@ -43,4 +44,4 @@
        "elm-explorations/test": "1.2.2 <= v < 2.0.0",
        "jgrenat/elm-html-test-runner": "1.0.3 <= v < 2.0.0"
    }
-}
+}
--- a/examples/docs/content/blog/static-http.md
+++ b/examples/docs/content/blog/static-http.md
@ -3,7 +3,7 @@
  "type": "blog",
  "author": "Dillon Kearns",
  "title": "A is for API - Introducing Static HTTP Requests",
-  "description": "",
+  "description": "The new StaticHttp API lets you fetch data when your site is built. That lets you remove loading spinners, and even access environment variables.",
  "image": "images/article-covers/static-http.jpg",
  "published": "2019-12-10",
 }
--- a/examples/docs/content/docs/core-concepts.md
+++ b/examples/docs/content/docs/core-concepts.md
@ -0,0 +1,7 @@
+---
+title: Core Concepts
+type: doc
+---
+## StaticHttp
+
+Gives you a way to pull in data during the build step. This data changes every time you run a build. You won't see a loading spinner or error with this data in your built production site. You might get a build error that you can fix.
--- a/examples/docs/elm.json
+++ b/examples/docs/elm.json
@ -31,7 +31,6 @@
            "elm-explorations/markdown": "1.0.0",
            "justinmimbs/date": "3.2.0",
            "lukewestby/elm-string-interpolate": "1.0.4",
-            "mdgriffith/elm-markup": "3.0.1",
            "mdgriffith/elm-ui": "1.1.5",
            "miniBill/elm-codec": "1.2.0",
            "noahzgordon/elm-color-extra": "1.0.2",
@ -59,4 +58,4 @@
        },
        "indirect": {}
    }
-}
+}
--- a/examples/docs/src/Main.elm
+++ b/examples/docs/src/Main.elm
@ -17,10 +17,12 @@ import Head.Seo as Seo
 import Html exposing (Html)
 import Html.Attributes as Attr
 import Index
-import Json.Decode.Exploration as D
+import Json.Decode as Decode exposing (Decoder)
+import Json.Encode
 import MarkdownRenderer
 import Metadata exposing (Metadata)
 import MySitemap
+import OptimizedDecoder as D
 import Pages exposing (images, pages)
 import Pages.Directory as Directory exposing (Directory)
 import Pages.ImagePath as ImagePath exposing (ImagePath)
@ -34,6 +36,7 @@ import Rss
 import RssPlugin
 import Secrets
 import Showcase
+import StructuredData


 manifest : Manifest.Config Pages.PathKey
@ -202,7 +205,7 @@ view siteMetadata page =
                                    ]
                            }
                                |> wrapBody stars page model
-                    , head = head page.frontmatter
+                    , head = head page.path page.frontmatter
                    }
                )
                (StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-pages")
@ -219,49 +222,11 @@ view siteMetadata page =
                            \model viewForPage ->
                                pageView stars model siteMetadata page viewForPage
                                    |> wrapBody stars page model
-                        , head = head page.frontmatter
+                        , head = head page.path page.frontmatter
                        }
                    )


-
--let
--    viewFn =
--        case page.frontmatter of
--            Metadata.Page metadata ->
--                StaticHttp.map3
--                    (\elmPagesStars elmPagesStarterStars netlifyStars ->
--                        { view =
--                            \model viewForPage ->
--                                { title = metadata.title
--                                , body =
--                                    "elm-pages ⭐️'s: "
--                                        ++ String.fromInt elmPagesStars
--                                        ++ "\n\nelm-pages-starter ⭐️'s: "
--                                        ++ String.fromInt elmPagesStarterStars
--                                        ++ "\n\nelm-markdown ⭐️'s: "
--                                        ++ String.fromInt netlifyStars
--                                        |> Element.text
--                                        |> wrapBody
--                                }
--                        , head = head page.frontmatter
--                        }
--                    )
--                    (StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-pages")
--                        (D.field "stargazers_count" D.int)
--                    )
--                    (StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-pages-starter")
--                        (D.field "stargazers_count" D.int)
--                    )
--                    (StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-markdown")
--                        (D.field "stargazers_count" D.int)
--                    )
--
--            _ ->
--                    StaticHttp.withData "https://api.github.com/repos/dillonkearns/elm-pages"
--                        (Decode.field "stargazers_count" Decode.int)
-
-
 pageView :
    Int
    -> Model
@ -535,8 +500,8 @@ highlightableLink currentPath linkDirectory displayName =
 <https://html.spec.whatwg.org/multipage/semantics.html#standard-metadata-names>
 <https://ogp.me/>
 -}
-head : Metadata -> List (Head.Tag Pages.PathKey)
-head metadata =
+head : PagePath Pages.PathKey -> Metadata -> List (Head.Tag Pages.PathKey)
+head currentPath metadata =
    case metadata of
        Metadata.Page meta ->
            Seo.summary
@ -571,26 +536,45 @@ head metadata =
                |> Seo.website

        Metadata.Article meta ->
-            Seo.summaryLarge
-                { canonicalUrlOverride = Nothing
-                , siteName = "elm-pages"
-                , image =
-                    { url = meta.image
-                    , alt = meta.description
-                    , dimensions = Nothing
-                    , mimeType = Nothing
-                    }
-                , description = meta.description
-                , locale = Nothing
-                , title = meta.title
-                }
-                |> Seo.article
-                    { tags = []
-                    , section = Nothing
-                    , publishedTime = Just (Date.toIsoString meta.published)
-                    , modifiedTime = Nothing
-                    , expirationTime = Nothing
+            Head.structuredData
+                (StructuredData.article
+                    { title = meta.title
+                    , description = meta.description
+                    , author = StructuredData.person { name = meta.author.name }
+                    , publisher = StructuredData.person { name = "Dillon Kearns" }
+                    , url = canonicalSiteUrl ++ "/" ++ PagePath.toString currentPath
+                    , imageUrl = canonicalSiteUrl ++ "/" ++ ImagePath.toString meta.image
+                    , datePublished = Date.toIsoString meta.published
+                    , mainEntityOfPage =
+                        StructuredData.softwareSourceCode
+                            { codeRepositoryUrl = "https://github.com/dillonkearns/elm-pages"
+                            , description = "A statically typed site generator for Elm."
+                            , author = "Dillon Kearns"
+                            , programmingLanguage = StructuredData.elmLang
+                            }
                    }
+                )
+                :: (Seo.summaryLarge
+                        { canonicalUrlOverride = Nothing
+                        , siteName = "elm-pages"
+                        , image =
+                            { url = meta.image
+                            , alt = meta.description
+                            , dimensions = Nothing
+                            , mimeType = Nothing
+                            }
+                        , description = meta.description
+                        , locale = Nothing
+                        , title = meta.title
+                        }
+                        |> Seo.article
+                            { tags = []
+                            , section = Nothing
+                            , publishedTime = Just (Date.toIsoString meta.published)
+                            , modifiedTime = Nothing
+                            , expirationTime = Nothing
+                            }
+                   )

        Metadata.Author meta ->
            let
--- a/examples/docs/src/Metadata.elm
+++ b/examples/docs/src/Metadata.elm
@ -91,7 +91,7 @@ decoder =
                            |> Decode.map Article

                    _ ->
-                        Decode.fail <| "Unexpected page type " ++ pageType
+                        Decode.fail <| "Unexpected page \"type\" " ++ pageType
            )


--- a/examples/docs/src/Showcase.elm
+++ b/examples/docs/src/Showcase.elm
@ -4,7 +4,7 @@ import Element
 import Element.Border
 import Element.Font
 import FontAwesome
-import Json.Decode.Exploration as Decode
+import OptimizedDecoder as Decode
 import Pages.Secrets as Secrets
 import Pages.StaticHttp as StaticHttp
 import Palette
--- a/examples/external-data/elm.json
+++ b/examples/external-data/elm.json
@ -27,7 +27,6 @@
            "elm-explorations/markdown": "1.0.0",
            "justinmimbs/date": "3.1.2",
            "lukewestby/elm-string-interpolate": "1.0.4",
-            "mdgriffith/elm-markup": "3.0.1",
            "mdgriffith/elm-ui": "1.1.5",
            "mgold/elm-nonempty-list": "4.0.2",
            "miniBill/elm-codec": "1.2.0",
@ -51,4 +50,4 @@
        },
        "indirect": {}
    }
-}
+}
--- a/generator/src/Main.elm
+++ b/generator/src/Main.elm
@ -95,20 +95,13 @@ import Dict exposing (Dict)

 content : { markdown : List ( List String, { frontMatter : String, body : Maybe String } ), markup : List ( List String, String ) }
 content =
-    { markdown = markdown, markup = markup }
+    { markdown = markdown }


 markdown : List ( List String, { frontMatter : String, body : Maybe String } )
 markdown =
    [ {1}
    ]
-
-
-markup : List ( List String, String )
-markup =
-    [
-    {0}
-    ]
 """
        [ List.map generatePage content |> String.join "\n  ,"
        , List.map generateMarkdownPage markdownContent |> String.join "\n  ,"
--- a/generator/src/add-files-plugin.js
+++ b/generator/src/add-files-plugin.js
@ -2,6 +2,7 @@ const path = require("path");
 const fs = require("fs");
 const globby = require("globby");
 const parseFrontmatter = require("./frontmatter.js");
+const webpack = require('webpack')

 function unpackFile(filePath) {
  const { content, data } = parseFrontmatter(
@ -15,52 +16,74 @@ function unpackFile(filePath) {

  return {
    baseRoute,
-    content
+    content,
+    filePath
  };
 }

 module.exports = class AddFilesPlugin {
-  constructor(data, filesToGenerate) {
-    this.pagesWithRequests = data;
-    this.filesToGenerate = filesToGenerate;
-  }
-  apply(compiler) {
-    compiler.hooks.emit.tap("AddFilesPlugin", compilation => {
-      const files = globby
-        .sync(["content/**/*.*", "!content/**/*.emu"], {})
-        .map(unpackFile);
+  apply(/** @type {webpack.Compiler} */ compiler) {

-      files.forEach(file => {
-        // Couldn't find this documented in the webpack docs,
-        // but I found the example code for it here:
-        // https://github.com/jantimon/html-webpack-plugin/blob/35a154186501fba3ecddb819b6f632556d37a58f/index.js#L470-L478
+    (global.mode === "dev" ? compiler.hooks.emit : compiler.hooks.make).tapAsync("AddFilesPlugin", (compilation, callback) => {

-        let route = file.baseRoute.replace(/\/$/, '');
-        const staticRequests = this.pagesWithRequests[route];

-        const filename = path.join(file.baseRoute, "content.json");
-        compilation.fileDependencies.add(filename);
-        const rawContents = JSON.stringify({
-          body: file.content,
-          staticData: staticRequests || {}
-        });
+      const files = globby.sync("content").map(unpackFile);

-        compilation.assets[filename] = {
-          source: () => rawContents,
-          size: () => rawContents.length
-        };
-      });

-      (this.filesToGenerate || []).forEach(file => {
-        // Couldn't find this documented in the webpack docs,
-        // but I found the example code for it here:
-        // https://github.com/jantimon/html-webpack-plugin/blob/35a154186501fba3ecddb819b6f632556d37a58f/index.js#L470-L478
-        compilation.assets[file.path] = {
-          source: () => file.content,
-          size: () => file.content.length
-        };
-      });
+      let staticRequestData = {}
+      global.pagesWithRequests.then(payload => {

+        if (payload.type === 'error') {
+          compilation.errors.push(new Error(payload.message))
+        } else if (payload.errors && payload.errors.length > 0) {
+          compilation.errors.push(new Error(payload.errors[0]))
+        }
+        else {
+          staticRequestData = payload.pages
+        }
+      })
+        .finally(() => {
+
+          files.forEach(file => {
+            // Couldn't find this documented in the webpack docs,
+            // but I found the example code for it here:
+            // https://github.com/jantimon/html-webpack-plugin/blob/35a154186501fba3ecddb819b6f632556d37a58f/index.js#L470-L478
+
+            let route = file.baseRoute.replace(/\/$/, '');
+            const staticRequests = staticRequestData[route];
+
+            const filename = path.join(file.baseRoute, "content.json");
+            if (compilation.contextDependencies) {
+              compilation.contextDependencies.add('content')
+            }
+            // compilation.fileDependencies.add(filename);
+            if (compilation.fileDependencies) {
+              compilation.fileDependencies.add(path.resolve(file.filePath));
+            }
+            const rawContents = JSON.stringify({
+              body: file.content,
+              staticData: staticRequests || {}
+            });
+
+            compilation.assets[filename] = {
+              source: () => rawContents,
+              size: () => rawContents.length
+            };
+          });
+
+          (global.filesToGenerate || []).forEach(file => {
+            // Couldn't find this documented in the webpack docs,
+            // but I found the example code for it here:
+            // https://github.com/jantimon/html-webpack-plugin/blob/35a154186501fba3ecddb819b6f632556d37a58f/index.js#L470-L478
+            compilation.assets[file.path] = {
+              source: () => file.content,
+              size: () => file.content.length
+            };
+          });
+
+          callback()
+
+        })

    });
  }
--- a/generator/src/compile-elm.js
+++ b/generator/src/compile-elm.js
@ -1,33 +1,36 @@
-const { compileToString } = require("../node-elm-compiler/index.js");
+const { compileToStringSync } = require("../node-elm-compiler/index.js");
 XMLHttpRequest = require("xhr2");

 module.exports = runElm;
-function runElm(/** @type string */ mode, /** @type any */ callback) {
-  const elmBaseDirectory = "./elm-stuff/elm-pages";
-  const mainElmFile = "../../src/Main.elm";
-  const startingDir = process.cwd();
-  process.chdir(elmBaseDirectory);
-  compileToString([mainElmFile], {}).then(function(data) {
-    (function() {
+function runElm(/** @type string */ mode) {
+  return new Promise((resolve, reject) => {
+    const elmBaseDirectory = "./elm-stuff/elm-pages";
+    const mainElmFile = "../../src/Main.elm";
+    const startingDir = process.cwd();
+    process.chdir(elmBaseDirectory);
+    const data = compileToStringSync([mainElmFile], {});
+    process.chdir(startingDir);
+    (function () {
      const warnOriginal = console.warn;
-      console.warn = function() {};
+      console.warn = function () { };
      eval(data.toString());
      const app = Elm.Main.init({
-        flags: { secrets: process.env, mode }
+        flags: { secrets: process.env, mode, staticHttpCache: global.staticHttpCache }
      });

      app.ports.toJsPort.subscribe(payload => {
-        process.chdir(startingDir);

        if (payload.tag === "Success") {
-          callback(payload.args[0]);
+          global.staticHttpCache = payload.args[0].staticHttpCache;
+          resolve(payload.args[0])
        } else {
-          console.log(payload.args[0]);
-          process.exit(1);
+          reject(payload.args[0])
        }
        delete Elm;
        console.warn = warnOriginal;
      });
    })();
+
+
  });
 }
--- a/generator/src/develop.js
+++ b/generator/src/develop.js
@ -1,5 +1,4 @@
 const webpack = require("webpack");
-const middleware = require("webpack-dev-middleware");
 const path = require("path");
 const HTMLWebpackPlugin = require("html-webpack-plugin");
 const ScriptExtHtmlWebpackPlugin = require('script-ext-html-webpack-plugin');
@ -14,14 +13,27 @@ const imageminMozjpeg = require("imagemin-mozjpeg");
 const express = require("express");
 const ClosurePlugin = require("closure-webpack-plugin");
 const readline = require("readline");
+const webpackDevMiddleware = require("webpack-dev-middleware");
+const PluginGenerateElmPagesBuild = require('./plugin-generate-elm-pages-build')
+
+const hotReloadIndicatorStyle = `
+<style>
+  @keyframes lds-default {
+    0%, 20%, 80%, 100% {
+      transform: scale(1);
+    }
+    50% {
+      transform: scale(1.5);
+    }
+  }
+</style>
+    `

 module.exports = { start, run };
-function start({ routes, debug, customPort, manifestConfig, routesWithRequests, filesToGenerate }) {
+function start({ routes, debug, customPort, manifestConfig }) {
  const config = webpackOptions(false, routes, {
    debug,
-    manifestConfig,
-    routesWithRequests,
-    filesToGenerate
+    manifestConfig
  });

  const compiler = webpack(config);
@ -39,27 +51,31 @@ function start({ routes, debug, customPort, manifestConfig, routesWithRequests,
  app.use('/images', express.static(path.resolve(process.cwd(), "./images")));


-  app.use(require("webpack-dev-middleware")(compiler, options));
+  app.use(webpackDevMiddleware(compiler, options));
  app.use(require("webpack-hot-middleware")(compiler, {
    log: console.log, path: '/__webpack_hmr'
  }))

-  app.use("*", function(req, res, next) {
+  app.get('/elm-pages-dev-server-options', function (req, res) {
+    res.json({ elmDebugger: debug });
+  });
+
+  app.use("*", function (req, res, next) {
    // don't know why this works, but it does
    // see: https://github.com/jantimon/html-webpack-plugin/issues/145#issuecomment-170554832
    const filename = path.join(compiler.outputPath, "index.html");
    const route = req.originalUrl.replace(/(\w)\/$/, "$1").replace(/^\//, "");
    const isPage = routes.includes(route);

-    compiler.outputFileSystem.readFile(filename, function(err, result) {
-      const contents = isPage
-        ? replaceBaseAndLinks(result.toString(), route)
-        : result
-
+    compiler.outputFileSystem.readFile(filename, function (err, result) {
      if (err) {
        return next(err);
      }

+      const contents = isPage
+        ? replaceBaseAndLinks(result.toString(), route)
+        : result
+
      res.set("content-type", "text/html");
      res.send(contents);
      res.end();
@ -74,20 +90,18 @@ function start({ routes, debug, customPort, manifestConfig, routesWithRequests,
  // app.use(express.static(__dirname + "/path-to-static-folder"));
 }

-function run({ routes, manifestConfig, routesWithRequests, filesToGenerate }, callback) {
+function run({ routes, manifestConfig }) {
  webpack(
    webpackOptions(true, routes, {
      debug: false,
      manifestConfig,
-      routesWithRequests,
-      filesToGenerate
    })
  ).run((err, stats) => {
    if (err) {
      console.error(err);
      process.exit(1);
    } else {
-      callback();
+      // done
    }

    console.log(
@ -128,12 +142,13 @@ function printProgress(progress, message) {
 function webpackOptions(
  production,
  routes,
-  { debug, manifestConfig, routesWithRequests, filesToGenerate }
+  { debug, manifestConfig }
 ) {
  const common = {
    mode: production ? "production" : "development",
    plugins: [
-      new AddFilesPlugin(routesWithRequests, filesToGenerate),
+      new PluginGenerateElmPagesBuild(),
+      new AddFilesPlugin(),
      new CopyPlugin([
        {
          from: "static/**/*",
@ -167,7 +182,33 @@ function webpackOptions(

      new HTMLWebpackPlugin({
        inject: "head",
-        template: path.resolve(__dirname, "template.html")
+        templateContent: `<!DOCTYPE html>
+<html lang="en">
+
+<head>
+  <link rel="preload" href="content.json" as="fetch" crossorigin />
+
+  <base href="/" />
+
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1" />
+
+  <script>
+    if ("serviceWorker" in navigator) {
+      window.addEventListener("load", () => {
+        navigator.serviceWorker.register("service-worker.js");
+      });
+    } else {
+      console.log("No service worker registered.");
+    }
+  </script>
+  ${production ? '' : hotReloadIndicatorStyle}
+</head>
+
+<body></body>
+
+
+</html>`
      }),
      new ScriptExtHtmlWebpackPlugin({
        preload: /\.js$/,
@ -234,10 +275,10 @@ function webpackOptions(
          /assets\//
        ],
        swDest: "service-worker.js"
-      })
+      }),
      // comment this out to do performance profiling
      // (drag-and-drop `events.json` file into Chrome performance tab)
-      // , new webpack.debug.ProfilingPlugin()
+      // new webpack.debug.ProfilingPlugin()
    ],
    output: {},
    resolve: {
@ -249,7 +290,7 @@ function webpackOptions(
        // process.cwd prefixed node_modules above).
        path.resolve(path.dirname(require.resolve('webpack')), '../../'),

-    ],
+      ],
      extensions: [".js", ".elm", ".scss", ".png", ".html"]
    },
    module: {
@ -323,7 +364,7 @@ function webpackOptions(
          renderer: new PrerenderSPAPlugin.PuppeteerRenderer({
            renderAfterDocumentEvent: "prerender-trigger",
            headless: true,
-            devtools: false
+            devtools: false,
          }),

          postProcess: renderedRoute => {
@ -354,14 +395,14 @@ function webpackOptions(
  } else {
    return merge(common, {
      entry: [
-        require.resolve("webpack-hot-middleware/client"),
+        hmrClientPath(),
        "./index.js",
-        ],
+      ],
      plugins: [
        new webpack.NamedModulesPlugin(),
+        new webpack.HotModuleReplacementPlugin(),
        // Prevents compilation errors causing the hot loader to lose state
        new webpack.NoEmitOnErrorsPlugin(),
-        new webpack.HotModuleReplacementPlugin()
      ],
      module: {
        rules: [
@ -385,6 +426,42 @@ function webpackOptions(
  }
 }

+function hmrClientPath() {
+  var ansiColors = {
+    reset: ['ffffff', 'transparent'], // [FOREGROUD_COLOR, BACKGROUND_COLOR]
+    black: '000',
+    red: 'c91b00',
+    green: '00c200',
+    yellow: 'c7c400',
+    blue: '0225c7',
+    magenta: 'c930c7',
+    cyan: '00c5c7',
+    lightgrey: 'f0f0f0',
+    darkgrey: '888'
+  };
+  var overlayStyles = {
+    // options from https://github.com/webpack-contrib/webpack-hot-middleware/blob/master/client-overlay.js
+
+    background: 'rgba(0,0,0,0.90)',
+    color: '#e8e8e8',
+    lineHeight: '1.6',
+    whiteSpace: 'pre-wrap',
+    fontFamily: 'Menlo, Consolas, monospace',
+    fontSize: '16px',
+    // position: 'fixed',
+    // zIndex: 9999,
+    // padding: '10px',
+    // left: 0,
+    // right: 0,
+    // top: 0,
+    // bottom: 0,
+    // overflow: 'auto',
+    // dir: 'ltr',
+    // textAlign: 'left',
+  };
+  return `${require.resolve("webpack-hot-middleware/client")}?ansiColors=${encodeURIComponent(JSON.stringify(ansiColors))}&overlayStyles=${encodeURIComponent(JSON.stringify(overlayStyles))}`;
+}
+

 function cleanRoute(route) {
  return route.replace(/(^\/|\/$)/, "")
@ -395,10 +472,10 @@ function pathToRoot(cleanedRoute) {
  return cleanedRoute === ""
    ? cleanedRoute
    : cleanedRoute
-        .split("/")
-        .map(_ => "..")
-        .join("/")
-        .replace(/\.$/, "./")
+      .split("/")
+      .map(_ => "..")
+      .join("/")
+      .replace(/\.$/, "./")
 }


--- a/generator/src/elm-file-constants.js
+++ b/generator/src/elm-file-constants.js
@ -1,9 +1,9 @@
 generateRawContent = require("./generate-raw-content.js");
 const exposingList =
-  "(PathKey, allPages, allImages, internals, images, isValidRoute, pages, builtAt)";
+    "(PathKey, allPages, allImages, internals, images, isValidRoute, pages, builtAt)";

 function staticRouteStuff(staticRoutes) {
-  return `
+    return `


 ${staticRoutes.allRoutes}
@ -41,8 +41,8 @@ isValidRoute route =
 `;
 }

-function elmPagesUiFile(staticRoutes, markdownContent, markupContent) {
-  return `port module Pages exposing ${exposingList}
+function elmPagesUiFile(staticRoutes, markdownContent) {
+    return `port module Pages exposing ${exposingList}

 import Color exposing (Color)
 import Pages.Internal
@ -50,7 +50,6 @@ import Head
 import Html exposing (Html)
 import Json.Decode
 import Json.Encode
-import Mark
 import Pages.Platform
 import Pages.Manifest exposing (DisplayMode, Orientation)
 import Pages.Manifest.Category as Category exposing (Category)
@ -92,23 +91,26 @@ directoryWithoutIndex path =

 port toJsPort : Json.Encode.Value -> Cmd msg

+port fromJsPort : (Json.Decode.Value -> msg) -> Sub msg
+

 internals : Pages.Internal.Internal PathKey
 internals =
    { applicationType = Pages.Internal.Browser
    , toJsPort = toJsPort
+    , fromJsPort = fromJsPort identity
    , content = content
    , pathKey = PathKey
    }

 ${staticRouteStuff(staticRoutes)}

-${generateRawContent(markdownContent, markupContent, false)}
+${generateRawContent(markdownContent, false)}
 `;
 }

-function elmPagesCliFile(staticRoutes, markdownContent, markupContent) {
-  return `port module Pages exposing ${exposingList}
+function elmPagesCliFile(staticRoutes, markdownContent) {
+    return `port module Pages exposing ${exposingList}

 import Color exposing (Color)
 import Pages.Internal
@ -116,7 +118,6 @@ import Head
 import Html exposing (Html)
 import Json.Decode
 import Json.Encode
-import Mark
 import Pages.Platform
 import Pages.Manifest exposing (DisplayMode, Orientation)
 import Pages.Manifest.Category as Category exposing (Category)
@ -159,10 +160,14 @@ directoryWithoutIndex path =
 port toJsPort : Json.Encode.Value -> Cmd msg


+port fromJsPort : (Json.Decode.Value -> msg) -> Sub msg
+
+
 internals : Pages.Internal.Internal PathKey
 internals =
    { applicationType = Pages.Internal.Cli
    , toJsPort = toJsPort
+    , fromJsPort = fromJsPort identity
    , content = content
    , pathKey = PathKey
    }
@ -170,7 +175,7 @@ internals =

 ${staticRouteStuff(staticRoutes)}

-${generateRawContent(markdownContent, markupContent, true)}
+${generateRawContent(markdownContent, true)}
 `;
 }
 module.exports = { elmPagesUiFile, elmPagesCliFile };
--- a/generator/src/elm-pages.js
+++ b/generator/src/elm-pages.js
@ -5,67 +5,38 @@ const { version } = require("../../package.json");
 const fs = require("fs");
 const globby = require("globby");
 const develop = require("./develop.js");
-const chokidar = require("chokidar");
-const doCliStuff = require("./generate-elm-stuff.js");
-const { elmPagesUiFile } = require("./elm-file-constants.js");
-const generateRecords = require("./generate-records.js");
 const parseFrontmatter = require("./frontmatter.js");
-const path = require("path");
-const { ensureDirSync, deleteIfExists } = require('./file-helpers.js')
+const generateRecords = require("./generate-records.js");
+const doCliStuff = require("./generate-elm-stuff.js");
 global.builtAt = new Date();
-
-const contentGlobPath = "content/**/*.emu";
-
-let watcher = null;
-let devServerRunning = false;
+global.staticHttpCache = {};

 function unpackFile(path) {
  return { path, contents: fs.readFileSync(path).toString() };
 }

-function unpackMarkup(path) {
-  const separated = parseFrontmatter(path, fs.readFileSync(path).toString());
-  return {
-    path,
-    metadata: separated.matter,
-    body: separated.content,
-    extension: "emu"
-  };
-}

 function parseMarkdown(path, fileContents) {
  const { content, data } = parseFrontmatter(path, fileContents);
  return {
    path,
    metadata: JSON.stringify(data),
-    body: content,
-    extension: "md"
+    body: content
  };
 }

 function run() {
-  console.log("Running elm-pages...");
-  const content = globby.sync([contentGlobPath], {}).map(unpackMarkup);
-  const staticRoutes = generateRecords();
-
  const markdownContent = globby
-    .sync(["content/**/*.*", "!content/**/*.emu"], {})
+    .sync(["content/**/*.*"], {})
    .map(unpackFile)
    .map(({ path, contents }) => {
      return parseMarkdown(path, contents);
    });

-  const images = globby
-    .sync("images/**/*", {})
-    .filter(imagePath => !fs.lstatSync(imagePath).isDirectory());
-
  let app = Elm.Main.init({
    flags: {
      argv: process.argv,
      versionMessage: version,
-      content,
-      markdownContent,
-      images
    }
  });

@ -79,89 +50,51 @@ function run() {
    process.exit(1);
  });

-  app.ports.writeFile.subscribe(contents => {
-    const routes = toRoutes(markdownContent.concat(content));
+  app.ports.writeFile.subscribe(cliOptions => {
+
+
+    const markdownContent = globby
+      .sync(["content/**/*.*"], {})
+      .map(unpackFile)
+      .map(({ path, contents }) => {
+        return parseMarkdown(path, contents);
+      });
+    const routes = toRoutes(markdownContent);
+
+    global.mode = cliOptions.watch ? "dev" : "prod"
+    const staticRoutes = generateRecords();

    doCliStuff(
-      contents.watch ? "dev" : "prod",
+      global.mode,
      staticRoutes,
-      markdownContent,
-      content,
-      function(payload) {
-        if (contents.watch) {
-          startWatchIfNeeded();
-          if (!devServerRunning) {
-            devServerRunning = true;
-            develop.start({
-              routes,
-              debug: contents.debug,
-              manifestConfig: payload.manifest,
-              routesWithRequests: payload.pages,
-              filesToGenerate: payload.filesToGenerate,
-              customPort: contents.customPort
-            });
-          }
-        } else {
-          if (payload.errors && payload.errors.length > 0) {
-            printErrorsAndExit(payload.errors);
-          }
+      markdownContent
+    ).then((payload) => {
+    if (cliOptions.watch) {
+      develop.start({
+        routes,
+        debug: cliOptions.debug,
+          customPort: cliOptions.customPort,
+          manifestConfig: payload.manifest,

-          develop.run(
-            {
-              routes,
-              manifestConfig: payload.manifest,
-              routesWithRequests: payload.pages,
-              filesToGenerate: payload.filesToGenerate
-            },
-            () => {}
-          );
-        }
+      });
+    } else {
+      develop.run({
+        routes,
+        debug: cliOptions.debug,
+          customPort: cliOptions.customPort,
+          manifestConfig: payload.manifest,
+      });
+    }

-        ensureDirSync("./gen");
+    })

-        // prevent compilation errors if migrating from previous elm-pages version
-        deleteIfExists("./gen/Pages/ContentCache.elm");
-        deleteIfExists("./gen/Pages/Platform.elm");

-        fs.writeFileSync(
-          "./gen/Pages.elm",
-          elmPagesUiFile(staticRoutes, markdownContent, content)
-        );
-        console.log("elm-pages DONE");

-      }
-    );
  });
 }

 run();

-function printErrorsAndExit(errors) {
-  console.error(
-    "Found errors. Exiting. Fix your content or parsers and re-run, or run in dev mode with `elm-pages develop`."
-  );
-  console.error(errors.join("\n\n"));
-  process.exit(1);
-}
-
-function startWatchIfNeeded() {
-  if (!watcher) {
-    console.log("Watching...");
-    watcher = chokidar
-      .watch(["content/**/*.*"], {
-        awaitWriteFinish: {
-          stabilityThreshold: 500
-        },
-        ignoreInitial: true
-      })
-      .on("all", function(event, filePath) {
-        console.log(`Rerunning for ${filePath}...`);
-        run();
-        console.log("Done!");
-      });
-  }
-}
-
 function toRoutes(entries) {
  return entries.map(toRoute);
 }
--- a/generator/src/frontmatter.js
+++ b/generator/src/frontmatter.js
@ -1,23 +1,5 @@
-const path = require("path");
 const matter = require("gray-matter");

 module.exports = function parseFrontmatter(filePath, fileContents) {
-  return path.extname(filePath) === ".emu"
-    ? matter(fileContents, markupFrontmatterOptions)
-    : matter(fileContents);
-};
-
-const markupFrontmatterOptions = {
-  language: "markup",
-  engines: {
-    markup: {
-      parse: function(string) {
-        return string;
-      },
-
-      stringify: function(string) {
-        return string;
-      }
-    }
-  }
+  return matter(fileContents);
 };
--- a/generator/src/generate-elm-stuff.js
+++ b/generator/src/generate-elm-stuff.js
@ -1,35 +1,57 @@
 const fs = require("fs");
 const runElm = require("./compile-elm.js");
 const copyModifiedElmJson = require("./rewrite-elm-json.js");
-const { elmPagesCliFile } = require("./elm-file-constants.js");
+const { elmPagesCliFile, elmPagesUiFile } = require("./elm-file-constants.js");
 const path = require("path");
 const { ensureDirSync, deleteIfExists } = require('./file-helpers.js')
+let wasEqualBefore = false


 module.exports = function run(
  mode,
  staticRoutes,
-  markdownContent,
-  markupContent,
-  callback
+  markdownContent
 ) {
  ensureDirSync("./elm-stuff");
+  ensureDirSync("./gen");
  ensureDirSync("./elm-stuff/elm-pages");

  // prevent compilation errors if migrating from previous elm-pages version
  deleteIfExists("./elm-stuff/elm-pages/Pages/ContentCache.elm");
  deleteIfExists("./elm-stuff/elm-pages/Pages/Platform.elm");
-  
+
+
+  const uiFileContent = elmPagesUiFile(staticRoutes, markdownContent)
+
+  // TODO should just write it once, but webpack doesn't seem to pick up the changes
+  // so this wasEqualBefore code causes it to get written twice to make sure the changes come through for HMR
+  if (wasEqualBefore) {
+    fs.writeFileSync(
+      "./gen/Pages.elm",
+      uiFileContent
+    );
+  }
+  if (global.previousUiFileContent === uiFileContent) {
+    wasEqualBefore = false
+  } else {
+    wasEqualBefore = true
+    fs.writeFileSync(
+      "./gen/Pages.elm",
+      uiFileContent
+    );
+  }
+
+  global.previousUiFileContent = uiFileContent

  // write `Pages.elm` with cli interface
  fs.writeFileSync(
    "./elm-stuff/elm-pages/Pages.elm",
-    elmPagesCliFile(staticRoutes, markdownContent, markupContent)
+    elmPagesCliFile(staticRoutes, markdownContent)
  );

  // write modified elm.json to elm-stuff/elm-pages/
  copyModifiedElmJson();

  // run Main.elm from elm-stuff/elm-pages with `runElm`
-  runElm(mode, callback);
+  return runElm(mode);
 };
--- a/generator/src/generate-raw-content.js
+++ b/generator/src/generate-raw-content.js
@ -1,9 +1,9 @@
 const path = require("path");

-module.exports = function(markdown, markup, includeBody) {
+module.exports = function (markdown, includeBody) {
  return `content : List ( List String, { extension: String, frontMatter : String, body : Maybe String } )
 content =
-    [ ${markdown.concat(markup).map(entry => toEntry(entry, includeBody))}
+    [ ${markdown.map(entry => toEntry(entry, includeBody))}
    ]`;
 };

--- a/generator/src/generate-records.js
+++ b/generator/src/generate-records.js
@ -1,5 +1,4 @@
 const path = require("path");
-const matter = require("gray-matter");
 const dir = "content/";
 const glob = require("glob");
 const fs = require("fs");
@ -138,14 +137,14 @@ function allImageAssetNames() {
    });
 }
 function toPascalCase(str) {
-  var pascal = str.replace(/(\-\w)/g, function(m) {
+  var pascal = str.replace(/(\-\w)/g, function (m) {
    return m[1].toUpperCase();
  });
  return pascal.charAt(0).toUpperCase() + pascal.slice(1);
 }

 function toCamelCase(str) {
-  var pascal = str.replace(/(\-\w)/g, function(m) {
+  var pascal = str.replace(/(\-\w)/g, function (m) {
    return m[1].toUpperCase();
  });
  return pascal.charAt(0).toLowerCase() + pascal.slice(1);
@ -180,14 +179,14 @@ function formatRecord(directoryPath, rec, asType, level) {
    } else {
      keyVals.push(
        key +
-          " =\n" +
-          formatRecord(directoryPath.concat(key), val, asType, level + 1)
+        " =\n" +
+        formatRecord(directoryPath.concat(key), val, asType, level + 1)
      );
    }
  }
  keyVals.push(
    `directory = ${
-      keys.includes("index") ? "directoryWithIndex" : "directoryWithoutIndex"
+    keys.includes("index") ? "directoryWithIndex" : "directoryWithoutIndex"
    } [${directoryPath.map(pathFragment => `"${pathFragment}"`).join(", ")}]`
  );
  const indentationDelimiter = `\n${indentation}, `;
--- a/generator/src/plugin-generate-elm-pages-build.js
+++ b/generator/src/plugin-generate-elm-pages-build.js
@ -0,0 +1,62 @@
+const fs = require('fs')
+const path = require('path')
+const doCliStuff = require("./generate-elm-stuff.js");
+const webpack = require('webpack')
+const parseFrontmatter = require("./frontmatter.js");
+const generateRecords = require("./generate-records.js");
+const globby = require("globby");
+
+module.exports = class PluginGenerateElmPagesBuild {
+    constructor() {
+    }
+
+    apply(/** @type {webpack.Compiler} */ compiler) {
+        compiler.hooks.beforeCompile.tap('PluginGenerateElmPagesBuild', (compilation) => {
+            const staticRoutes = generateRecords();
+
+            const markdownContent = globby
+                .sync(["content/**/*.*"], {})
+                .map(unpackFile)
+                .map(({ path, contents }) => {
+                    return parseMarkdown(path, contents);
+                });
+
+            let resolvePageRequests;
+            let rejectPageRequests;
+            global.pagesWithRequests = new Promise(function (resolve, reject) {
+                resolvePageRequests = resolve;
+                rejectPageRequests = reject;
+            });
+
+            doCliStuff(
+                global.mode,
+                staticRoutes,
+                markdownContent
+            ).then((payload) => {
+                // console.log('PROMISE RESOLVED doCliStuff');
+
+                resolvePageRequests(payload);
+                global.filesToGenerate = payload.filesToGenerate;
+
+            }).catch(function (errorPayload) {
+                resolvePageRequests({ type: 'error', message: errorPayload });
+            })
+
+        });
+    };
+
+}
+
+
+function unpackFile(path) {
+    return { path, contents: fs.readFileSync(path).toString() };
+}
+
+function parseMarkdown(path, fileContents) {
+    const { content, data } = parseFrontmatter(path, fileContents);
+    return {
+        path,
+        metadata: JSON.stringify(data),
+        body: content,
+    };
+}
--- a/generator/src/template.html
+++ b/generator/src/template.html
@ -1,23 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-  <head>
-    <link rel="preload" href="content.json" as="fetch" crossorigin />
-
-    <base href="/" />
-
-    <meta charset="UTF-8" />
-    <meta name="viewport" content="width=device-width, initial-scale=1" />
-
-    <script>
-      if ("serviceWorker" in navigator) {
-        window.addEventListener("load", () => {
-          navigator.serviceWorker.register("service-worker.js");
-        });
-      } else {
-        console.log("No service worker registered.");
-      }
-    </script>
-  </head>
-
-  <body></body>
-</html>
--- a/index.js
+++ b/index.js
@ -11,9 +11,9 @@ module.exports = function pagesInit(
  prefetchedPages = [window.location.pathname];
  initialLocationHash = document.location.hash.replace(/^#/, "");

-  return new Promise(function(resolve, reject) {
+  return new Promise(function (resolve, reject) {
    document.addEventListener("DOMContentLoaded", _ => {
-      new MutationObserver(function() {
+      new MutationObserver(function () {
        elmViewRendered = true;
        if (headTagsAdded) {
          document.dispatchEvent(new Event("prerender-trigger"));
@ -32,48 +32,98 @@ function loadContentAndInitializeApp(/** @type { init: any  } */ mainElmModule)
  const isPrerendering = navigator.userAgent.indexOf("Headless") >= 0
  const path = window.location.pathname.replace(/(\w)$/, "$1/")

-  return httpGet(`${window.location.origin}${path}content.json`).then(function(/** @type JSON */ contentJson) {
+  return Promise.all([
+    getConfig(),
+    httpGet(`${window.location.origin}${path}content.json`)]).then(function (/** @type {[DevServerConfig?, JSON]} */[devServerConfig, contentJson]) {
+      console.log('devServerConfig', devServerConfig);

-    const app = mainElmModule.init({
-      flags: {
-        secrets: null,
-        baseUrl: isPrerendering
-          ? window.location.origin
-          : document.baseURI,
-        isPrerendering: isPrerendering,
-        contentJson
-      }
-    });
-
-    app.ports.toJsPort.subscribe((
-      /** @type { { head: HeadTag[], allRoutes: string[] } }  */ fromElm
-    ) => {
-      appendTag({
-        name: "meta",
-        attributes: [
-          ["name", "generator"],
-          ["content", `elm-pages v${elmPagesVersion}`]
-        ]
+      const app = mainElmModule.init({
+        flags: {
+          secrets: null,
+          baseUrl: isPrerendering
+            ? window.location.origin
+            : document.baseURI,
+          isPrerendering: isPrerendering,
+          isDevServer: !!module.hot,
+          isElmDebugMode: devServerConfig ? devServerConfig.elmDebugger : false,
+          contentJson,
+        }
      });

-      window.allRoutes = fromElm.allRoutes.map(route => new URL(route, document.baseURI).href);
-
-      if (navigator.userAgent.indexOf("Headless") >= 0) {
-        fromElm.head.forEach(headTag => {
-          appendTag(headTag);
+      app.ports.toJsPort.subscribe((
+      /** @type { { head: SeoTag[], allRoutes: string[] } }  */ fromElm
+      ) => {
+        appendTag({
+          type: 'head',
+          name: "meta",
+          attributes: [
+            ["name", "generator"],
+            ["content", `elm-pages v${elmPagesVersion}`]
+          ]
        });
+
+        window.allRoutes = fromElm.allRoutes.map(route => new URL(route, document.baseURI).href);
+
+        if (navigator.userAgent.indexOf("Headless") >= 0) {
+          fromElm.head.forEach(headTag => {
+            if (headTag.type === 'head') {
+              appendTag(headTag);
+            } else if (headTag.type === 'json-ld') {
+              appendJsonLdTag(headTag);
+            } else {
+              throw new Error(`Unknown tag type #{headTag}`)
+            }
+          });
          headTagsAdded = true;
          if (elmViewRendered) {
            document.dispatchEvent(new Event("prerender-trigger"));
          }
-      } else {
-        setupLinkPrefetching();
+        } else {
+          setupLinkPrefetching();
+        }
+      });
+
+
+      if (module.hot) {
+
+        // found this trick in the next.js source code
+        // https://github.com/zeit/next.js/blob/886037b1bac4bdbfeb689b032c1612750fb593f7/packages/next/client/dev/error-overlay/eventsource.js
+        // https://github.com/zeit/next.js/blob/886037b1bac4bdbfeb689b032c1612750fb593f7/packages/next/client/dev/dev-build-watcher.js
+        // more details about this API at https://www.html5rocks.com/en/tutorials/eventsource/basics/
+        let source = new window.EventSource('/__webpack_hmr')
+        // source.addEventListener('open', () => { console.log('open!!!!!') })
+        source.addEventListener('message', (e) => {
+          // console.log('message!!!!!', e)
+          // console.log(e.data.action)
+          // console.log('ACTION', e.data.action);
+          // if (e.data && e.data.action)
+
+          if (event.data === '\uD83D\uDC93') {
+            // heartbeat
+          } else {
+            const obj = JSON.parse(event.data)
+            // console.log('obj.action', obj.action);
+
+            if (obj.action === 'building') {
+              app.ports.fromJsPort.send({ thingy: 'hmr-check' });
+            } else if (obj.action === 'built') {
+              // console.log('httpGet start');
+
+              let currentPath = window.location.pathname.replace(/(\w)$/, "$1/")
+              httpGet(`${window.location.origin}${currentPath}content.json`).then(function (/** @type JSON */ contentJson) {
+                // console.log('httpGet received');
+
+                app.ports.fromJsPort.send({ contentJson: contentJson });
+              });
+            }
+
+          }
+        })
+
      }
+
+      return app
    });
-
-    return app
-
-  });
 }

 function setupLinkPrefetching() {
@ -132,7 +182,7 @@ function setupLinkPrefetchingHelp(
  const links = document.querySelectorAll("a");
  links.forEach(link => {
    // console.log(link.pathname);
-    link.addEventListener("mouseenter", function(event) {
+    link.addEventListener("mouseenter", function (event) {
      if (
        event &&
        event.target &&
@ -166,7 +216,9 @@ function prefetchIfNeeded(/** @type {HTMLAnchorElement} */ target) {
  }
 }

-/** @typedef {{ name: string; attributes: string[][]; }} HeadTag */
+/** @typedef {HeadTag | JsonLdTag} SeoTag */
+
+/** @typedef {{ name: string; attributes: string[][]; type: 'head' }} HeadTag */
 function appendTag(/** @type {HeadTag} */ tagDetails) {
  const meta = document.createElement(tagDetails.name);
  tagDetails.attributes.forEach(([name, value]) => {
@ -175,15 +227,36 @@ function appendTag(/** @type {HeadTag} */ tagDetails) {
  document.getElementsByTagName("head")[0].appendChild(meta);
 }

+/** @typedef {{ contents: Object; type: 'json-ld' }} JsonLdTag */
+function appendJsonLdTag(/** @type {JsonLdTag} */ tagDetails) {
+  let jsonLdScript = document.createElement('script');
+  jsonLdScript.type = "application/ld+json";
+  jsonLdScript.innerHTML = JSON.stringify(tagDetails.contents);
+  document.getElementsByTagName("head")[0].appendChild(jsonLdScript);
+}
+
 function httpGet(/** @type string */ theUrl) {
-  return new Promise(function(resolve, reject) {
+  return new Promise(function (resolve, reject) {
    const xmlHttp = new XMLHttpRequest();
-    xmlHttp.onreadystatechange = function() {
-        if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
-            resolve(JSON.parse(xmlHttp.responseText));
+    xmlHttp.onreadystatechange = function () {
+      if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
+        resolve(JSON.parse(xmlHttp.responseText));
    }
    xmlHttp.onerror = reject;
    xmlHttp.open("GET", theUrl, true); // true for asynchronous
    xmlHttp.send(null);
  })
 }
+
+/**
+* @returns { Promise<DevServerConfig?>}
+*/
+function getConfig() {
+  if (module.hot) {
+    return httpGet(`/elm-pages-dev-server-options`)
+  } else {
+    return Promise.resolve(null)
+  }
+}
+
+/** @typedef { {  elmDebugger : boolean } } DevServerConfig */
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@ -22,9 +22,9 @@
    "@babel/core": "^7.5.5",
    "@babel/preset-env": "^7.5.5",
    "babel-loader": "^8.0.6",
-    "chokidar": "^2.1.5",
    "closure-webpack-plugin": "^2.0.1",
    "copy-webpack-plugin": "^5.0.4",
+    "cross-spawn": "6.0.5",
    "css-loader": "^3.2.0",
    "elm": "^0.19.1-3",
    "elm-hot-webpack-loader": "^1.1.2",
@ -32,30 +32,29 @@
    "express": "^4.17.1",
    "favicons-webpack-plugin": "^3.0.0",
    "file-loader": "^4.2.0",
+    "find-elm-dependencies": "2.0.2",
    "globby": "^10.0.1",
    "google-closure-compiler": "^20190909.0.0",
    "gray-matter": "^4.0.2",
-    "html-webpack-plugin": "^4.0.0-beta.11",
+    "html-webpack-plugin": "^4.2.0",
    "imagemin-mozjpeg": "^8.0.0",
    "imagemin-webpack-plugin": "^2.4.2",
+    "lodash": "4.17.15",
    "node-sass": "^4.12.0",
    "prerender-spa-plugin": "^3.4.0",
+    "raw-loader": "^4.0.0",
    "sass-loader": "^8.0.0",
    "script-ext-html-webpack-plugin": "^2.1.4",
    "style-loader": "^1.0.0",
-    "webpack": "^4.41.5",
+    "temp": "^0.9.0",
+    "webpack": "4.42.1",
    "webpack-dev-middleware": "^3.7.0",
    "webpack-hot-middleware": "^2.25.0",
    "webpack-merge": "^4.2.1",
    "workbox-webpack-plugin": "^4.3.1",
-    "xhr2": "^0.2.0",
-    "cross-spawn": "6.0.5",
-    "find-elm-dependencies": "2.0.2",
-    "lodash": "4.17.15",
-    "temp": "^0.9.0"
+    "xhr2": "^0.2.0"
  },
  "devDependencies": {
-    "@types/chokidar": "^2.1.3",
    "@types/express": "^4.17.0",
    "@types/node": "^12.7.7",
    "@types/webpack": "^4.32.1",
--- a/src/Head.elm
+++ b/src/Head.elm
@ -1,6 +1,7 @@
 module Head exposing
    ( Tag, metaName, metaProperty
    , rssLink, sitemapLink
+    , structuredData
    , AttributeValue
    , currentPageFullUrl, fullImageUrl, fullPageUrl, raw
    , toJson, canonicalLink
@ -19,6 +20,11 @@ writing a plugin package to extend `elm-pages`.
@docs rssLink, sitemapLink


+## Structured Data
+
+@docs structuredData
+
+
 ## `AttributeValue`s

@docs AttributeValue
@ -42,6 +48,7 @@ through the `head` function.
 -}
 type Tag pathKey
    = Tag (Details pathKey)
+    | StructuredData Json.Encode.Value


 type alias Details pathKey =
@ -50,6 +57,100 @@ type alias Details pathKey =
    }


+{-| You can learn more about structured data in [Google's intro to structured data](https://developers.google.com/search/docs/guides/intro-structured-data).
+
+When you add a `structuredData` item to one of your pages in `elm-pages`, it will add `json-ld` data to your document that looks like this:
+
+```html
+<script type="application/ld+json">
+{
+   "@context":"http://schema.org/",
+   "@type":"Article",
+   "headline":"Extensible Markdown Parsing in Pure Elm",
+   "description":"Introducing a new parser that extends your palette with no additional syntax",
+   "image":"https://elm-pages.com/images/article-covers/extensible-markdown-parsing.jpg",
+   "author":{
+      "@type":"Person",
+      "name":"Dillon Kearns"
+   },
+   "publisher":{
+      "@type":"Person",
+      "name":"Dillon Kearns"
+   },
+   "url":"https://elm-pages.com/blog/extensible-markdown-parsing-in-elm",
+   "datePublished":"2019-10-08",
+   "mainEntityOfPage":{
+      "@type":"SoftwareSourceCode",
+      "codeRepository":"https://github.com/dillonkearns/elm-pages",
+      "description":"A statically typed site generator for Elm.",
+      "author":"Dillon Kearns",
+      "programmingLanguage":{
+         "@type":"ComputerLanguage",
+         "url":"http://elm-lang.org/",
+         "name":"Elm",
+         "image":"http://elm-lang.org/",
+         "identifier":"http://elm-lang.org/"
+      }
+   }
+}
+</script>
+```
+
+To get that data, you would write this in your `elm-pages` head tags:
+
+    import Json.Encode as Encode
+
+    {-| <https://schema.org/Article>
+    -}
+    encodeArticle :
+        { title : String
+        , description : String
+        , author : StructuredData { authorMemberOf | personOrOrganization : () } authorPossibleFields
+        , publisher : StructuredData { publisherMemberOf | personOrOrganization : () } publisherPossibleFields
+        , url : String
+        , imageUrl : String
+        , datePublished : String
+        , mainEntityOfPage : Encode.Value
+        }
+        -> Head.Tag pathKey
+    encodeArticle info =
+        Encode.object
+            [ ( "@context", Encode.string "http://schema.org/" )
+            , ( "@type", Encode.string "Article" )
+            , ( "headline", Encode.string info.title )
+            , ( "description", Encode.string info.description )
+            , ( "image", Encode.string info.imageUrl )
+            , ( "author", encode info.author )
+            , ( "publisher", encode info.publisher )
+            , ( "url", Encode.string info.url )
+            , ( "datePublished", Encode.string info.datePublished )
+            , ( "mainEntityOfPage", info.mainEntityOfPage )
+            ]
+            |> Head.structuredData
+
+Take a look at this [Google Search Gallery](https://developers.google.com/search/docs/guides/search-gallery)
+to see some examples of how structured data can be used by search engines to give rich search results. It can help boost
+your rankings, get better engagement for your content, and also make your content more accessible. For example,
+voice assistant devices can make use of structured data. If you're hosting a conference and want to make the event
+date and location easy for attendees to find, this can make that information more accessible.
+
+For the current version of API, you'll need to make sure that the format is correct and contains the required and recommended
+structure.
+
+Check out <https://schema.org> for a comprehensive listing of possible data types and fields. And take a look at
+Google's [Structured Data Testing Tool](https://search.google.com/structured-data/testing-tool)
+too make sure that your structured data is valid and includes the recommended values.
+
+In the future, `elm-pages` will likely support a typed API, but schema.org is a massive spec, and changes frequently.
+And there are multiple sources of information on the possible and recommended structure. So it will take some time
+for the right API design to evolve. In the meantime, this allows you to make use of this for SEO purposes.
+
+-}
+structuredData : Json.Encode.Value -> Tag pathKey
+structuredData value =
+    StructuredData value
+
+
 {-| Create a raw `AttributeValue` (as opposed to some kind of absolute URL).
 -}
 raw : String -> AttributeValue pathKey
@ -196,11 +297,20 @@ node name attributes =
 code will run this for you to generate your `manifest.json` file automatically!
 -}
 toJson : String -> String -> Tag pathKey -> Json.Encode.Value
-toJson canonicalSiteUrl currentPagePath (Tag tag) =
-    Json.Encode.object
-        [ ( "name", Json.Encode.string tag.name )
-        , ( "attributes", Json.Encode.list (encodeProperty canonicalSiteUrl currentPagePath) tag.attributes )
-        ]
+toJson canonicalSiteUrl currentPagePath tag =
+    case tag of
+        Tag headTag ->
+            Json.Encode.object
+                [ ( "name", Json.Encode.string headTag.name )
+                , ( "attributes", Json.Encode.list (encodeProperty canonicalSiteUrl currentPagePath) headTag.attributes )
+                , ( "type", Json.Encode.string "head" )
+                ]
+
+        StructuredData value ->
+            Json.Encode.object
+                [ ( "contents", value )
+                , ( "type", Json.Encode.string "json-ld" )
+                ]


 encodeProperty : String -> String -> ( String, AttributeValue pathKey ) -> Json.Encode.Value
--- a/src/Internal/OptimizedDecoder.elm
+++ b/src/Internal/OptimizedDecoder.elm
@ -0,0 +1,18 @@
+module Internal.OptimizedDecoder exposing (OptimizedDecoder(..), jd, jde)
+
+import Json.Decode
+import Json.Decode.Exploration
+
+
+type OptimizedDecoder a
+    = OptimizedDecoder (Json.Decode.Decoder a) (Json.Decode.Exploration.Decoder a)
+
+
+jd : OptimizedDecoder a -> Json.Decode.Decoder a
+jd (OptimizedDecoder jd_ jde_) =
+    jd_
+
+
+jde : OptimizedDecoder a -> Json.Decode.Exploration.Decoder a
+jde (OptimizedDecoder jd_ jde_) =
+    jde_
--- a/src/OptimizedDecoder.elm
+++ b/src/OptimizedDecoder.elm
@ -0,0 +1,769 @@
+module OptimizedDecoder exposing
+    ( Error, errorToString
+    , Decoder, string, bool, int, float, Value
+    , nullable, list, array, dict, keyValuePairs
+    , field, at, index
+    , maybe, oneOf
+    , lazy, value, null, succeed, fail, andThen
+    , map, map2, map3, map4, map5, map6, map7, map8, andMap
+    , decodeString, decodeValue, decoder
+    )
+
+{-| This module allows you to build decoders that `elm-pages` can optimize for you in your `StaticHttp` requests.
+It does this by stripping of unused fields during the CLI build step. When it runs in production, it will
+just run a plain `elm/json` decoder, so you're fetching and decoding the stripped-down data, but without any
+performance penalty.
+
+For convenience, this library also includes a `Json.Decode.Exploration.Pipeline`
+module which is largely a copy of [`NoRedInk/elm-decode-pipeline`][edp].
+
+[edp]: http://package.elm-lang.org/packages/NoRedInk/elm-decode-pipeline/latest
+
+
+## Dealing with warnings and errors
+
+@docs Error, errorToString
+
+
+# Primitives
+
+@docs Decoder, string, bool, int, float, Value
+
+
+# Data Structures
+
+@docs nullable, list, array, dict, keyValuePairs
+
+
+# Object Primitives
+
+@docs field, at, index
+
+
+# Inconsistent Structure
+
+@docs maybe, oneOf
+
+
+# Fancy Decoding
+
+@docs lazy, value, null, succeed, fail, andThen
+
+
+# Mapping
+
+**Note:** If you run out of map functions, take a look at [the pipeline module][pipe]
+which makes it easier to handle large objects.
+
+[pipe]: http://package.elm-lang.org/packages/zwilias/json-decode-exploration/latest/Json-Decode-Exploration-Pipeline
+
+@docs map, map2, map3, map4, map5, map6, map7, map8, andMap
+
+
+# Directly Running Decoders
+
+Usually you'll be passing your decoders to
+
+@docs decodeString, decodeValue, decoder
+
+-}
+
+import Array exposing (Array)
+import Dict exposing (Dict)
+import Internal.OptimizedDecoder exposing (OptimizedDecoder(..))
+import Json.Decode as JD
+import Json.Decode.Exploration as JDE
+
+
+{-| A decoder that will be optimized in your production bundle.
+-}
+type alias Decoder a =
+    OptimizedDecoder a
+
+
+{-| A simple type alias for `Json.Decode.Value`.
+-}
+type alias Value =
+    JD.Value
+
+
+{-| A simple type alias for `Json.Decode.Error`.
+-}
+type alias Error =
+    JD.Error
+
+
+{-| A simple wrapper for `Json.Decode.errorToString`.
+-}
+errorToString : JD.Error -> String
+errorToString =
+    JD.errorToString
+
+
+{-| Usually you'll want to directly pass your `OptimizedDecoder` to `StaticHttp` or other `elm-pages` APIs.
+But if you want to re-use your decoder somewhere else, it may be useful to turn it into a plain `elm/json` decoder.
+-}
+decoder : Decoder a -> JD.Decoder a
+decoder (OptimizedDecoder jd jde) =
+    jd
+
+
+{-| A simple wrapper for `Json.Decode.errorToString`.
+
+This will directly call the raw `elm/json` decoder that is stored under the hood.
+
+-}
+decodeString : Decoder a -> String -> Result Error a
+decodeString (OptimizedDecoder jd jde) =
+    JD.decodeString jd
+
+
+{-| A simple wrapper for `Json.Decode.errorToString`.
+
+This will directly call the raw `elm/json` decoder that is stored under the hood.
+
+-}
+decodeValue : Decoder a -> Value -> Result Error a
+decodeValue (OptimizedDecoder jd jde) =
+    JD.decodeValue jd
+
+
+{-| A decoder that will ignore the actual JSON and succeed with the provided
+value. Note that this may still fail when dealing with an invalid JSON string.
+
+If a value in the JSON ends up being ignored because of this, this will cause a
+warning.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ null """
+        |> decodeString (value |> andThen (\_ -> succeed "hello world"))
+    --> Success "hello world"
+
+
+    """ null """
+        |> decodeString (succeed "hello world")
+    --> WithWarnings
+    -->     (Nonempty (Here <| UnusedValue Encode.null) [])
+    -->     "hello world"
+
+
+    """ foo """
+        |> decodeString (succeed "hello world")
+    --> BadJson
+
+-}
+succeed : a -> Decoder a
+succeed a =
+    OptimizedDecoder (JD.succeed a) (JDE.succeed a)
+
+
+{-| Ignore the json and fail with a provided message.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+    """ "hello" """
+        |> decodeString (fail "failure")
+    --> Errors (Nonempty (Here <| Failure "failure" (Just <| Encode.string "hello")) [])
+
+-}
+fail : String -> Decoder a
+fail message =
+    OptimizedDecoder (JD.fail message) (JDE.fail message)
+
+
+{-| Decode a string.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ "hello world" """
+        |> decodeString string
+    --> Success "hello world"
+
+
+    """ 123 """
+        |> decodeString string
+    --> Errors (Nonempty (Here <| Expected TString (Encode.int 123)) [])
+
+-}
+string : Decoder String
+string =
+    OptimizedDecoder JD.string JDE.string
+
+
+{-| Extract a piece without actually decoding it.
+
+If a structure is decoded as a `value`, everything _in_ the structure will be
+considered as having been used and will not appear in `UnusedValue` warnings.
+
+    import Json.Encode as Encode
+
+
+    """ [ 123, "world" ] """
+        |> decodeString value
+    --> Success (Encode.list identity [ Encode.int 123, Encode.string "world" ])
+
+-}
+value : Decoder Value
+value =
+    OptimizedDecoder JD.value JDE.value
+
+
+{-| Decode a number into a `Float`.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ 12.34 """
+        |> decodeString float
+    --> Success 12.34
+
+
+    """ 12 """
+        |> decodeString float
+    --> Success 12
+
+
+    """ null """
+        |> decodeString float
+    --> Errors (Nonempty (Here <| Expected TNumber Encode.null) [])
+
+-}
+float : Decoder Float
+float =
+    OptimizedDecoder JD.float JDE.float
+
+
+{-| Decode a number into an `Int`.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ 123 """
+        |> decodeString int
+    --> Success 123
+
+
+    """ 0.1 """
+        |> decodeString int
+    --> Errors <|
+    -->   Nonempty
+    -->     (Here <| Expected TInt (Encode.float 0.1))
+    -->     []
+
+-}
+int : Decoder Int
+int =
+    OptimizedDecoder JD.int JDE.int
+
+
+{-| Decode a boolean value.
+
+    """ [ true, false ] """
+        |> decodeString (list bool)
+    --> Success [ True, False ]
+
+-}
+bool : Decoder Bool
+bool =
+    OptimizedDecoder JD.bool JDE.bool
+
+
+{-| Decode a `null` and succeed with some value.
+
+    """ null """
+        |> decodeString (null "it was null")
+    --> Success "it was null"
+
+Note that `undefined` and `null` are not the same thing. This cannot be used to
+verify that a field is _missing_, only that it is explicitly set to `null`.
+
+    """ { "foo": null } """
+        |> decodeString (field "foo" (null ()))
+    --> Success ()
+
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ { } """
+        |> decodeString (field "foo" (null ()))
+    --> Errors <|
+    -->   Nonempty
+    -->     (Here <| Expected (TObjectField "foo") (Encode.object []))
+    -->     []
+
+-}
+null : a -> Decoder a
+null val =
+    OptimizedDecoder (JD.null val) (JDE.null val)
+
+
+{-| Decode a list of values, decoding each entry with the provided decoder.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ [ "foo", "bar" ] """
+        |> decodeString (list string)
+    --> Success [ "foo", "bar" ]
+
+
+    """ [ "foo", null ] """
+        |> decodeString (list string)
+    --> Errors <|
+    -->   Nonempty
+    -->     (AtIndex 1 <|
+    -->       Nonempty (Here <| Expected TString Encode.null) []
+    -->     )
+    -->     []
+
+-}
+list : Decoder a -> Decoder (List a)
+list (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.list jd) (JDE.list jde)
+
+
+{-| _Convenience function._ Decode a JSON array into an Elm `Array`.
+
+    import Array
+
+    """ [ 1, 2, 3 ] """
+        |> decodeString (array int)
+    --> Success <| Array.fromList [ 1, 2, 3 ]
+
+-}
+array : Decoder a -> Decoder (Array a)
+array (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.array jd) (JDE.array jde)
+
+
+{-| _Convenience function._ Decode a JSON object into an Elm `Dict String`.
+
+    import Dict
+
+
+    """ { "foo": "bar", "bar": "hi there" } """
+        |> decodeString (dict string)
+    --> Success <| Dict.fromList
+    -->   [ ( "bar", "hi there" )
+    -->   , ( "foo", "bar" )
+    -->   ]
+
+-}
+dict : Decoder v -> Decoder (Dict String v)
+dict (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.dict jd) (JDE.dict jde)
+
+
+{-| Decode a specific index using a specified `Decoder`.
+
+    import List.Nonempty exposing (Nonempty(..))
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ [ "hello", 123 ] """
+        |> decodeString (map2 Tuple.pair (index 0 string) (index 1 int))
+    --> Success ( "hello", 123 )
+
+
+    """ [ "hello", "there" ] """
+        |> decodeString (index 1 string)
+    --> WithWarnings (Nonempty (AtIndex 0 (Nonempty (Here (UnusedValue (Encode.string "hello"))) [])) [])
+    -->   "there"
+
+-}
+index : Int -> Decoder a -> Decoder a
+index idx (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.index idx jd) (JDE.index idx jde)
+
+
+{-| Decode a JSON object into a list of key-value pairs. The decoder you provide
+will be used to decode the values.
+
+    """ { "foo": "bar", "hello": "world" } """
+        |> decodeString (keyValuePairs string)
+    --> Success [ ( "foo", "bar" ), ( "hello", "world" ) ]
+
+-}
+keyValuePairs : Decoder a -> Decoder (List ( String, a ))
+keyValuePairs (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.keyValuePairs jd) (JDE.keyValuePairs jde)
+
+
+{-| Decode the content of a field using a provided decoder.
+
+    import List.Nonempty as Nonempty
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+    """ { "foo": "bar" } """
+        |> decodeString (field "foo" string)
+    --> Success "bar"
+
+
+    """ [ { "foo": "bar" }, { "foo": "baz", "hello": "world" } ] """
+        |> decodeString (list (field "foo" string))
+    --> WithWarnings expectedWarnings [ "bar", "baz" ]
+
+
+    expectedWarnings : Warnings
+    expectedWarnings =
+        UnusedField "hello"
+            |> Here
+            |> Nonempty.fromElement
+            |> AtIndex 1
+            |> Nonempty.fromElement
+
+-}
+field : String -> Decoder a -> Decoder a
+field fieldName (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.field fieldName jd) (JDE.field fieldName jde)
+
+
+{-| Decodes a value at a certain path, using a provided decoder. Essentially,
+writing `at [ "a", "b", "c" ]  string` is sugar over writing
+`field "a" (field "b" (field "c" string))`}.
+
+    """ { "a": { "b": { "c": "hi there" } } } """
+        |> decodeString (at [ "a", "b", "c" ] string)
+    --> Success "hi there"
+
+-}
+at : List String -> Decoder a -> Decoder a
+at fields (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.at fields jd) (JDE.at fields jde)
+
+
+
+-- Choosing
+
+
+{-| Tries a bunch of decoders. The first one to not fail will be the one used.
+
+If all fail, the errors are collected into a `BadOneOf`.
+
+    import List.Nonempty as Nonempty
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+    """ [ 12, "whatever" ] """
+        |> decodeString (list <| oneOf [ map String.fromInt int, string ])
+    --> Success [ "12", "whatever" ]
+
+
+    """ null """
+        |> decodeString (oneOf [ string, map String.fromInt int ])
+    --> Errors <| Nonempty.fromElement <| Here <| BadOneOf
+    -->   [ Nonempty.fromElement <| Here <| Expected TString Encode.null
+    -->   , Nonempty.fromElement <| Here <| Expected TInt Encode.null
+    -->   ]
+
+-}
+oneOf : List (Decoder a) -> Decoder a
+oneOf decoders =
+    let
+        jds =
+            List.map
+                (\(OptimizedDecoder jd jde) ->
+                    jd
+                )
+                decoders
+
+        jdes =
+            List.map
+                (\(OptimizedDecoder jd jde) ->
+                    jde
+                )
+                decoders
+    in
+    OptimizedDecoder (JD.oneOf jds) (JDE.oneOf jdes)
+
+
+{-| Decodes successfully and wraps with a `Just`, handling failure by succeeding
+with `Nothing`.
+
+    import List.Nonempty as Nonempty
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+
+
+    """ [ "foo", 12 ] """
+        |> decodeString (list <| maybe string)
+    --> WithWarnings expectedWarnings [ Just "foo", Nothing ]
+
+
+    expectedWarnings : Warnings
+    expectedWarnings =
+        UnusedValue (Encode.int 12)
+            |> Here
+            |> Nonempty.fromElement
+            |> AtIndex 1
+            |> Nonempty.fromElement
+
+-}
+maybe : Decoder a -> Decoder (Maybe a)
+maybe (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.maybe jd) (JDE.maybe jde)
+
+
+{-| Decodes successfully and wraps with a `Just`. If the values is `null`
+succeeds with `Nothing`.
+
+    """ [ { "foo": "bar" }, { "foo": null } ] """
+        |> decodeString (list <| field "foo" <| nullable string)
+    --> Success [ Just "bar", Nothing ]
+
+-}
+nullable : Decoder a -> Decoder (Maybe a)
+nullable (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.nullable jd) (JDE.nullable jde)
+
+
+
+--
+
+
+{-| Required when using (mutually) recursive decoders.
+-}
+lazy : (() -> Decoder a) -> Decoder a
+lazy toDecoder =
+    let
+        jd : JD.Decoder a
+        jd =
+            (\() ->
+                case toDecoder () of
+                    OptimizedDecoder jd_ jde_ ->
+                        jd_
+            )
+                |> JD.lazy
+
+        jde : JDE.Decoder a
+        jde =
+            (\() ->
+                case toDecoder () of
+                    OptimizedDecoder jd_ jde_ ->
+                        jde_
+            )
+                |> JDE.lazy
+    in
+    OptimizedDecoder
+        jd
+        jde
+
+
+{-| Useful for checking a value in the JSON matches the value you expect it to
+have. If it does, succeeds with the second decoder. If it doesn't it fails.
+
+This can be used to decode union types:
+
+    type Pet = Cat | Dog | Rabbit
+
+    petDecoder : Decoder Pet
+    petDecoder =
+        oneOf
+            [ check string "cat" <| succeed Cat
+            , check string "dog" <| succeed Dog
+            , check string "rabbit" <| succeed Rabbit
+            ]
+
+    """ [ "dog", "rabbit", "cat" ] """
+        |> decodeString (list petDecoder)
+    --> Success [ Dog, Rabbit, Cat ]
+
+-}
+check : Decoder a -> a -> Decoder b -> Decoder b
+check checkDecoder expectedVal actualDecoder =
+    checkDecoder
+        |> andThen
+            (\actual ->
+                if actual == expectedVal then
+                    actualDecoder
+
+                else
+                    fail "Verification failed"
+            )
+
+
+
+-- Mapping and chaining
+
+
+{-| Useful for transforming decoders.
+
+    """ "foo" """
+        |> decodeString (map String.toUpper string)
+    --> Success "FOO"
+
+-}
+map : (a -> b) -> Decoder a -> Decoder b
+map f (OptimizedDecoder jd jde) =
+    OptimizedDecoder (JD.map f jd) (JDE.map f jde)
+
+
+{-| Chain decoders where one decoder depends on the value of another decoder.
+-}
+andThen : (a -> Decoder b) -> Decoder a -> Decoder b
+andThen toDecoderB (OptimizedDecoder jd jde) =
+    OptimizedDecoder
+        (JD.andThen (toDecoderB >> Internal.OptimizedDecoder.jd) jd)
+        (JDE.andThen (toDecoderB >> Internal.OptimizedDecoder.jde) jde)
+
+
+{-| Combine 2 decoders.
+-}
+map2 : (a -> b -> c) -> Decoder a -> Decoder b -> Decoder c
+map2 f (OptimizedDecoder jdA jdeA) (OptimizedDecoder jdB jdeB) =
+    OptimizedDecoder
+        (JD.map2 f jdA jdB)
+        (JDE.map2 f jdeA jdeB)
+
+
+{-| Decode an argument and provide it to a function in a decoder.
+
+    decoder : Decoder String
+    decoder =
+        succeed (String.repeat)
+            |> andMap (field "count" int)
+            |> andMap (field "val" string)
+
+
+    """ { "val": "hi", "count": 3 } """
+        |> decodeString decoder
+    --> Success "hihihi"
+
+-}
+andMap : Decoder a -> Decoder (a -> b) -> Decoder b
+andMap =
+    map2 (|>)
+
+
+{-| Combine 3 decoders.
+-}
+map3 :
+    (a -> b -> c -> d)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+map3 f decoderA decoderB decoderC =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+
+
+{-| Combine 4 decoders.
+-}
+map4 :
+    (a -> b -> c -> d -> e)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+    -> Decoder e
+map4 f decoderA decoderB decoderC decoderD =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+        |> andMap decoderD
+
+
+{-| Combine 5 decoders.
+-}
+map5 :
+    (a -> b -> c -> d -> e -> f)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+    -> Decoder e
+    -> Decoder f
+map5 f decoderA decoderB decoderC decoderD decoderE =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+        |> andMap decoderD
+        |> andMap decoderE
+
+
+{-| Combine 6 decoders.
+-}
+map6 :
+    (a -> b -> c -> d -> e -> f -> g)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+    -> Decoder e
+    -> Decoder f
+    -> Decoder g
+map6 f decoderA decoderB decoderC decoderD decoderE decoderF =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+        |> andMap decoderD
+        |> andMap decoderE
+        |> andMap decoderF
+
+
+{-| Combine 7 decoders.
+-}
+map7 :
+    (a -> b -> c -> d -> e -> f -> g -> h)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+    -> Decoder e
+    -> Decoder f
+    -> Decoder g
+    -> Decoder h
+map7 f decoderA decoderB decoderC decoderD decoderE decoderF decoderG =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+        |> andMap decoderD
+        |> andMap decoderE
+        |> andMap decoderF
+        |> andMap decoderG
+
+
+{-| Combine 8 decoders.
+-}
+map8 :
+    (a -> b -> c -> d -> e -> f -> g -> h -> i)
+    -> Decoder a
+    -> Decoder b
+    -> Decoder c
+    -> Decoder d
+    -> Decoder e
+    -> Decoder f
+    -> Decoder g
+    -> Decoder h
+    -> Decoder i
+map8 f decoderA decoderB decoderC decoderD decoderE decoderF decoderG decoderH =
+    map f decoderA
+        |> andMap decoderB
+        |> andMap decoderC
+        |> andMap decoderD
+        |> andMap decoderE
+        |> andMap decoderF
+        |> andMap decoderG
+        |> andMap decoderH
--- a/src/OptimizedDecoder/Pipeline.elm
+++ b/src/OptimizedDecoder/Pipeline.elm
@ -0,0 +1,333 @@
+module OptimizedDecoder.Pipeline exposing
+    ( required, requiredAt, optional, optionalAt, hardcoded, custom
+    , decode, resolve
+    )
+
+{-|
+
+
+# Json.Decode.Pipeline
+
+Use the `(|>)` operator to build JSON decoders.
+
+
+## Decoding fields
+
+@docs required, requiredAt, optional, optionalAt, hardcoded, custom
+
+
+## Beginning and ending pipelines
+
+@docs decode, resolve
+
+
+### Verified docs
+
+The examples all expect imports set up like this:
+
+    import Json.Decode.Exploration exposing (..)
+    import Json.Decode.Exploration.Pipeline exposing (..)
+    import Json.Decode.Exploration.Located exposing (Located(..))
+    import Json.Encode as Encode
+    import List.Nonempty as Nonempty
+
+For automated verification of these examples, this import is also required.
+Please ignore it.
+
+    import DocVerificationHelpers exposing (User)
+
+-}
+
+import OptimizedDecoder as Decode exposing (Decoder)
+
+
+{-| Decode a required field.
+
+    import Json.Decode.Exploration exposing (..)
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> required "name" string
+            |> required "email" string
+
+    """ {"id": 123, "email": "sam@example.com", "name": "Sam"} """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "Sam", email = "sam@example.com" }
+
+-}
+required : String -> Decoder a -> Decoder (a -> b) -> Decoder b
+required key valDecoder decoder =
+    decoder |> Decode.andMap (Decode.field key valDecoder)
+
+
+{-| Decode a required nested field.
+
+    import Json.Decode.Exploration exposing (..)
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> requiredAt [ "profile", "name" ] string
+            |> required "email" string
+
+    """
+    {
+        "id": 123,
+        "email": "sam@example.com",
+        "profile": { "name": "Sam" }
+    }
+    """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "Sam", email = "sam@example.com" }
+
+-}
+requiredAt : List String -> Decoder a -> Decoder (a -> b) -> Decoder b
+requiredAt path valDecoder decoder =
+    decoder |> Decode.andMap (Decode.at path valDecoder)
+
+
+{-| Decode a field that may be missing or have a null value. If the field is
+missing, then it decodes as the `fallback` value. If the field is present,
+then `valDecoder` is used to decode its value. If `valDecoder` fails on a
+`null` value, then the `fallback` is used as if the field were missing
+entirely.
+
+    import Json.Decode.Exploration exposing (..)
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> optional "name" string "blah"
+            |> required "email" string
+
+    """ { "id": 123, "email": "sam@example.com" } """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "blah", email = "sam@example.com" }
+
+Because `valDecoder` is given an opportunity to decode `null` values before
+resorting to the `fallback`, you can distinguish between missing and `null`
+values if you need to:
+
+    userDecoder2 =
+        decode User
+            |> required "id" int
+            |> optional "name" (oneOf [ string, null "NULL" ]) "MISSING"
+            |> required "email" string
+
+Note also that this behaves _slightly_ different than the stock pipeline
+package.
+
+In the stock pipeline package, running the following decoder with an array as
+the input would _succeed_.
+
+    fooDecoder =
+        decode identity
+            |> optional "foo" (maybe string) Nothing
+
+In this package, such a decoder will error out instead, saying that it expected
+the input to be an object. The _key_ `"foo"` is optional, but it really does
+have to be an object before we even consider trying your decoder or returning
+the fallback.
+
+-}
+optional : String -> Decoder a -> a -> Decoder (a -> b) -> Decoder b
+optional key valDecoder fallback decoder =
+    -- source: https://github.com/NoRedInk/elm-json-decode-pipeline/blob/d9c10a2b388176569fe3e88ef0e2b6fc19d9beeb/src/Json/Decode/Pipeline.elm#L113
+    custom (optionalDecoder (Decode.field key Decode.value) valDecoder fallback) decoder
+
+
+{-| Decode an optional nested field.
+-}
+optionalAt : List String -> Decoder a -> a -> Decoder (a -> b) -> Decoder b
+optionalAt path valDecoder fallback decoder =
+    custom (optionalDecoder (Decode.at path Decode.value) valDecoder fallback) decoder
+
+
+
+-- source: https://github.com/NoRedInk/elm-json-decode-pipeline/blob/d9c10a2b388176569fe3e88ef0e2b6fc19d9beeb/src/Json/Decode/Pipeline.elm#L116-L148
+
+
+optionalDecoder : Decode.Decoder Decode.Value -> Decoder a -> a -> Decoder a
+optionalDecoder pathDecoder valDecoder fallback =
+    let
+        nullOr decoder =
+            Decode.oneOf [ decoder, Decode.null fallback ]
+
+        handleResult input =
+            case Decode.decodeValue pathDecoder input of
+                Ok rawValue ->
+                    -- The field was present, so now let's try to decode that value.
+                    -- (If it was present but fails to decode, this should and will fail!)
+                    case Decode.decodeValue (nullOr valDecoder) rawValue of
+                        Ok finalResult ->
+                            Decode.succeed finalResult
+
+                        Err finalErr ->
+                            -- TODO is there some way to preserve the structure
+                            -- of the original error instead of using toString here?
+                            Decode.fail (Decode.errorToString finalErr)
+
+                Err _ ->
+                    -- The field was not present, so use the fallback.
+                    Decode.succeed fallback
+    in
+    Decode.value
+        |> Decode.andThen handleResult
+
+
+{-| Rather than decoding anything, use a fixed value for the next step in the
+pipeline. `harcoded` does not look at the JSON at all.
+
+    import Json.Decode.Exploration exposing (..)
+
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> hardcoded "Alex"
+            |> required "email" string
+
+    """ { "id": 123, "email": "sam@example.com" } """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "Alex", email = "sam@example.com" }
+
+-}
+hardcoded : a -> Decoder (a -> b) -> Decoder b
+hardcoded =
+    Decode.andMap << Decode.succeed
+
+
+{-| Run the given decoder and feed its result into the pipeline at this point.
+
+Consider this example.
+
+    import Json.Decode.Exploration exposing (..)
+
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> custom (at [ "profile", "name" ] string)
+            |> required "email" string
+
+    """
+    {
+        "id": 123,
+        "email": "sam@example.com",
+        "profile": {"name": "Sam"}
+    }
+    """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "Sam", email = "sam@example.com" }
+
+-}
+custom : Decoder a -> Decoder (a -> b) -> Decoder b
+custom =
+    Decode.andMap
+
+
+{-| Convert a `Decoder (Result x a)` into a `Decoder a`. Useful when you want
+to perform some custom processing just before completing the decoding operation.
+
+    import Json.Decode.Exploration exposing (..)
+
+    type alias User =
+        { id : Int
+        , name : String
+        , email : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        let
+            -- toDecoder gets run *after* all the
+            -- (|> required ...) steps are done.
+            toDecoder : Int -> String -> String -> Int -> Decoder User
+            toDecoder id name email version =
+                if version >= 2 then
+                    succeed (User id name email)
+                else
+                    fail "This JSON is from a deprecated source. Please upgrade!"
+        in
+        decode toDecoder
+            |> required "id" int
+            |> required "name" string
+            |> required "email" string
+            |> required "version" int
+            -- version is part of toDecoder,
+            -- but it is not a part of User
+            |> resolve
+
+    """
+    {
+        "id": 123,
+        "name": "Sam",
+        "email": "sam@example.com",
+        "version": 3
+    }
+    """
+        |> decodeString userDecoder
+    --> Success { id = 123, name = "Sam", email = "sam@example.com" }
+
+-}
+resolve : Decoder (Decoder a) -> Decoder a
+resolve =
+    Decode.andThen identity
+
+
+{-| Begin a decoding pipeline. This is a synonym for [Json.Decode.succeed](http://package.elm-lang.org/packages/elm-lang/core/latest/Json-Decode#succeed),
+intended to make things read more clearly.
+
+    type alias User =
+        { id : Int
+        , email : String
+        , name : String
+        }
+
+    userDecoder : Decoder User
+    userDecoder =
+        decode User
+            |> required "id" int
+            |> required "email" string
+            |> optional "name" string ""
+
+-}
+decode : a -> Decoder a
+decode =
+    Decode.succeed
--- a/src/Pages/ContentCache.elm
+++ b/src/Pages/ContentCache.elm
@ -21,16 +21,12 @@ import Html exposing (Html)
 import Html.Attributes as Attr
 import Http
 import Json.Decode as Decode
-import Mark
-import Mark.Error
 import Pages.Document as Document exposing (Document)
 import Pages.Internal.String as String
 import Pages.PagePath as PagePath exposing (PagePath)
-import Result.Extra
 import Task exposing (Task)
 import TerminalText as Terminal
 import Url exposing (Url)
-import Url.Builder


 type alias Content =
@ -283,16 +279,6 @@ type alias Page metadata view pathKey =
    }


-renderErrors : ( List String, List Mark.Error.Error ) -> Html msg
-renderErrors ( path, errors ) =
-    Html.div []
-        [ Html.text (String.join "/" path)
-        , errors
-            |> List.map (Mark.Error.toHtml Mark.Error.Light)
-            |> Html.div []
-        ]
-
-
 combineTupleResults :
    List ( List String, Result error success )
    -> Result (List error) (List ( List String, success ))
--- a/src/Pages/Document.elm
+++ b/src/Pages/Document.elm
@ -1,6 +1,6 @@
 module Pages.Document exposing
    ( Document, DocumentHandler
-    , parser, markupParser
+    , parser
    , fromList, get
    )

@ -80,7 +80,7 @@ Hello!!!
                )

@docs Document, DocumentHandler
-@docs parser, markupParser
+@docs parser


 ## Functions for use by generated code
@ -92,8 +92,6 @@ Hello!!!
 import Dict exposing (Dict)
 import Html exposing (Html)
 import Json.Decode
-import Mark
-import Mark.Error


 {-| Represents all of the `DocumentHandler`s. You register a handler for each
@ -157,54 +155,3 @@ parser { extension, body, metadata } =
                    |> Result.mapError Json.Decode.errorToString
        }
    )
-
-
-{-| Register an [`elm-markup`](https://github.com/mdgriffith/elm-markup/)
-parser for your `.emu` files.
-}
-markupParser :
-    Mark.Document metadata
-    -> Mark.Document view
-    -> ( String, DocumentHandler metadata view )
-markupParser metadataParser markBodyParser =
-    ( "emu"
-    , DocumentHandler
-        { contentParser = renderMarkup markBodyParser
-        , frontmatterParser =
-            \frontMatter ->
-                Mark.compile metadataParser
-                    frontMatter
-                    |> (\outcome ->
-                            case outcome of
-                                Mark.Success parsedMetadata ->
-                                    Ok parsedMetadata
-
-                                Mark.Failure failure ->
-                                    Err "Failure"
-
-                                Mark.Almost failure ->
-                                    Err "Almost failure"
-                       )
-        }
-    )
-
-
-renderMarkup : Mark.Document view -> String -> Result String view
-renderMarkup markBodyParser markupBody =
-    Mark.compile
-        markBodyParser
-        (markupBody |> String.trimLeft)
-        |> (\outcome ->
-                case outcome of
-                    Mark.Success renderedView ->
-                        Ok renderedView
-
-                    Mark.Failure failures ->
-                        failures
-                            |> List.map Mark.Error.toString
-                            |> String.join "\n"
-                            |> Err
-
-                    Mark.Almost failure ->
-                        Err "TODO almost failure"
-           )
--- a/src/Pages/Internal.elm
+++ b/src/Pages/Internal.elm
@ -13,11 +13,12 @@ that is in the generated `Pages` module (see <Pages.Platform>).

 -}

+import Json.Decode
 import Json.Encode
 import Pages.Internal.Platform


-{-| Internal detial to track whether to run the CLI step or the runtime step in the browser.
+{-| Internal detail to track whether to run the CLI step or the runtime step in the browser.
 -}
 type ApplicationType
    = Browser
@ -31,4 +32,5 @@ type alias Internal pathKey =
    , content : Pages.Internal.Platform.Content
    , pathKey : pathKey
    , toJsPort : Json.Encode.Value -> Cmd Never
+    , fromJsPort : Sub Json.Decode.Value
    }
--- a/src/Pages/Internal/ApplicationType.elm
+++ b/src/Pages/Internal/ApplicationType.elm
@ -0,0 +1,6 @@
+module Pages.Internal.ApplicationType exposing (ApplicationType(..))
+
+
+type ApplicationType
+    = Browser
+    | Cli
--- a/src/Pages/Internal/HotReloadLoadingIndicator.elm
+++ b/src/Pages/Internal/HotReloadLoadingIndicator.elm
@ -0,0 +1,108 @@
+module Pages.Internal.HotReloadLoadingIndicator exposing (..)
+
+import Html exposing (Html)
+import Html.Attributes exposing (..)
+
+
+circle : List (Html.Attribute msg) -> Html msg
+circle attrs =
+    Html.div
+        (style "animation" "lds-default 1.2s linear infinite"
+            :: style "background" "#000"
+            :: style "position" "absolute"
+            :: style "width" "6px"
+            :: style "height" "6px"
+            :: style "border-radius" "50%"
+            :: attrs
+        )
+        []
+
+
+view : Bool -> Bool -> Html msg
+view isDebugMode display =
+    Html.div
+        [ id "__elm-pages-loading"
+        , class "lds-default"
+        , style "position" "fixed"
+        , style "bottom" "10px"
+        , style "right"
+            (if isDebugMode then
+                "110px"
+
+             else
+                "10px"
+            )
+        , style "width" "80px"
+        , style "height" "80px"
+        , style "background-color" "white"
+        , style "box-shadow" "0 8px 15px 0 rgba(0, 0, 0, 0.25), 0 2px 10px 0 rgba(0, 0, 0, 0.12)"
+        , style "display"
+            (case display of
+                True ->
+                    "block"
+
+                False ->
+                    "none"
+            )
+        ]
+        [ circle
+            [ style "animation-delay" "0s"
+            , style "top" "37px"
+            , style "left" "66px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.1s"
+            , style "top" "22px"
+            , style "left" "62px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.2s"
+            , style "top" "11px"
+            , style "left" "52px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.3s"
+            , style "top" "7px"
+            , style "left" "37px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.4s"
+            , style "top" "11px"
+            , style "left" "22px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.5s"
+            , style "top" "22px"
+            , style "left" "11px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.6s"
+            , style "top" "37px"
+            , style "left" "7px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.7s"
+            , style "top" "52px"
+            , style "left" "11px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.8s"
+            , style "top" "62px"
+            , style "left" "22px"
+            ]
+        , circle
+            [ style "animation-delay" "-0.9s"
+            , style "top" "66px"
+            , style "left" "37px"
+            ]
+        , circle
+            [ style "animation-delay" "-1s"
+            , style "top" "62px"
+            , style "left" "52px"
+            ]
+        , circle
+            [ style "animation-delay" "-1.1s"
+            , style "top" "52px"
+            , style "left" "62px"
+            ]
+        ]
--- a/src/Pages/Internal/Platform.elm
+++ b/src/Pages/Internal/Platform.elm
@ -1,4 +1,4 @@
-module Pages.Internal.Platform exposing (Content, Flags, Model, Msg, Page, Parser, Program, application, cliApplication)
+module Pages.Internal.Platform exposing (Content, Flags, Model, Msg, Page, Program, application, cliApplication)

 import Browser
 import Browser.Dom as Dom
@ -6,14 +6,15 @@ import Browser.Navigation
 import Dict exposing (Dict)
 import Head
 import Html exposing (Html)
-import Html.Attributes
+import Html.Attributes exposing (style)
+import Html.Lazy
 import Http
 import Json.Decode as Decode
 import Json.Encode
-import List.Extra
-import Mark
 import Pages.ContentCache as ContentCache exposing (ContentCache)
 import Pages.Document
+import Pages.Internal.ApplicationType as ApplicationType
+import Pages.Internal.HotReloadLoadingIndicator as HotReloadLoadingIndicator
 import Pages.Internal.Platform.Cli
 import Pages.Internal.String as String
 import Pages.Manifest as Manifest
@ -122,7 +123,7 @@ pageViewOrError pathKey viewFn model cache =
                                     -- TODO handle error better
                                    )
                                |> (\request ->
-                                        StaticHttpRequest.resolve request viewResult.staticData
+                                        StaticHttpRequest.resolve ApplicationType.Browser request viewResult.staticData
                                   )
                    in
                    case viewResult.body of
@ -146,6 +147,12 @@ pageViewOrError pathKey viewFn model cache =
                                                    [ Html.text "I'm missing some StaticHttp data for this page:"
                                                    , Html.pre [] [ Html.text missingKey ]
                                                    ]
+
+                                            StaticHttpRequest.UserCalledStaticHttpFail message ->
+                                                Html.div []
+                                                    [ Html.text "I ran into a call to `Pages.StaticHttp.fail` with message:"
+                                                    , Html.pre [] [ Html.text message ]
+                                                    ]
                                    }

                        Err error ->
@ -198,10 +205,28 @@ view pathKey content viewFn model =
    , body =
        [ onViewChangeElement model.url
        , body |> Html.map UserMsg |> Html.map AppMsg
+        , Html.Lazy.lazy2 loadingView model.phase model.hmrStatus
        ]
    }


+loadingView : Phase -> HmrStatus -> Html msg
+loadingView phase hmrStatus =
+    case phase of
+        DevClient isDebugMode ->
+            (case hmrStatus of
+                HmrLoading ->
+                    True
+
+                _ ->
+                    False
+            )
+                |> HotReloadLoadingIndicator.view isDebugMode
+
+        _ ->
+            Html.text ""
+
+
 onViewChangeElement currentUrl =
    -- this is a hidden tag
    -- it is used from the JS-side to reliably
@ -224,6 +249,13 @@ type alias ContentJson =
    }


+contentJsonDecoder : Decode.Decoder ContentJson
+contentJsonDecoder =
+    Decode.map2 ContentJson
+        (Decode.field "body" Decode.string)
+        (Decode.field "staticData" (Decode.dict Decode.string))
+
+
 init :
    pathKey
    -> String
@ -273,12 +305,6 @@ init pathKey canonicalSiteUrl document toJsPort viewFn content initUserModel fla
                |> Decode.decodeValue (Decode.field "contentJson" contentJsonDecoder)
                |> Result.toMaybe

-        contentJsonDecoder : Decode.Decoder ContentJson
-        contentJsonDecoder =
-            Decode.map2 ContentJson
-                (Decode.field "body" Decode.string)
-                (Decode.field "staticData" (Decode.dict Decode.string))
-
        baseUrl =
            flags
                |> Decode.decodeValue (Decode.field "baseUrl" Decode.string)
@ -295,15 +321,26 @@ init pathKey canonicalSiteUrl document toJsPort viewFn content initUserModel fla
        Ok okCache ->
            let
                phase =
-                    case Decode.decodeValue (Decode.field "isPrerendering" Decode.bool) flags of
-                        Ok True ->
+                    case
+                        Decode.decodeValue
+                            (Decode.map3 (\a b c -> ( a, b, c ))
+                                (Decode.field "isPrerendering" Decode.bool)
+                                (Decode.field "isDevServer" Decode.bool)
+                                (Decode.field "isElmDebugMode" Decode.bool)
+                            )
+                            flags
+                    of
+                        Ok ( True, _, _ ) ->
                            Prerender

-                        Ok False ->
-                            Client
+                        Ok ( False, True, isElmDebugMode ) ->
+                            DevClient isElmDebugMode
+
+                        Ok ( False, False, _ ) ->
+                            ProdClient

                        Err _ ->
-                            Client
+                            DevClient False

                ( userModel, userCmd ) =
                    maybePagePath
@ -347,6 +384,7 @@ init pathKey canonicalSiteUrl document toJsPort viewFn content initUserModel fla
              , userModel = userModel
              , contentCache = contentCache
              , phase = phase
+              , hmrStatus = HmrLoaded
              }
            , cmd
            )
@ -361,7 +399,8 @@ init pathKey canonicalSiteUrl document toJsPort viewFn content initUserModel fla
              , baseUrl = baseUrl
              , userModel = userModel
              , contentCache = contentCache
-              , phase = Client
+              , phase = DevClient False
+              , hmrStatus = HmrLoaded
              }
            , Cmd.batch
                [ userCmd |> Cmd.map UserMsg
@ -389,7 +428,10 @@ type AppMsg userMsg metadata view
    | UserMsg userMsg
    | UpdateCache (Result Http.Error (ContentCache metadata view))
    | UpdateCacheAndUrl Url (Result Http.Error (ContentCache metadata view))
+    | UpdateCacheForHotReload (Result Http.Error (ContentCache metadata view))
    | PageScrollComplete
+    | HotReloadComplete ContentJson
+    | StartingHotReload


 type Model userModel userMsg metadata view
@ -404,16 +446,19 @@ type alias ModelDetails userModel metadata view =
    , contentCache : ContentCache metadata view
    , userModel : userModel
    , phase : Phase
+    , hmrStatus : HmrStatus
    }


 type Phase
    = Prerender
-    | Client
+    | DevClient Bool
+    | ProdClient


 update :
-    List String
+    Content
+    -> List String
    -> String
    ->
        (List ( PagePath pathKey, metadata )
@ -442,7 +487,7 @@ update :
    -> Msg userMsg metadata view
    -> ModelDetails userModel metadata view
    -> ( ModelDetails userModel metadata view, Cmd (AppMsg userMsg metadata view) )
-update allRoutes canonicalSiteUrl viewFunction pathKey maybeOnPageChangeMsg toJsPort document userUpdate msg model =
+update content allRoutes canonicalSiteUrl viewFunction pathKey maybeOnPageChangeMsg toJsPort document userUpdate msg model =
    case msg of
        AppMsg appMsg ->
            case appMsg of
@ -535,7 +580,7 @@ update allRoutes canonicalSiteUrl viewFunction pathKey maybeOnPageChangeMsg toJs
                                        )
                                        { path = pagePath, frontmatter = frontmatter }
                                        |> (\request ->
-                                                StaticHttpRequest.resolve request staticDataThing
+                                                StaticHttpRequest.resolve ApplicationType.Browser request staticDataThing
                                           )
                            in
                            ( { model | contentCache = updatedCache }
@ -584,18 +629,42 @@ update allRoutes canonicalSiteUrl viewFunction pathKey maybeOnPageChangeMsg toJs
                            -- TODO handle error
                            ( { model | url = url }, Cmd.none )

+                UpdateCacheForHotReload cacheUpdateResult ->
+                    case cacheUpdateResult of
+                        Ok updatedCache ->
+                            ( { model | contentCache = updatedCache }, Cmd.none )
+
+                        Err _ ->
+                            -- TODO handle error
+                            ( model, Cmd.none )
+
                PageScrollComplete ->
                    ( model, Cmd.none )

+                HotReloadComplete contentJson ->
+                    ( { model
+                        | contentCache = ContentCache.init document content (Just { contentJson = contentJson, initialUrl = model.url })
+                        , hmrStatus = HmrLoaded
+                      }
+                    , Cmd.none
+                      -- ContentCache.init document content (Maybe.map (\cj -> { contentJson = contentJson, initialUrl = model.url }) Nothing)
+                      --|> ContentCache.lazyLoad document
+                      --    { currentUrl = model.url
+                      --    , baseUrl = model.baseUrl
+                      --    }
+                      --|> Task.attempt UpdateCacheForHotReload
+                    )
+
+                StartingHotReload ->
+                    ( { model | hmrStatus = HmrLoading }, Cmd.none )
+
        CliMsg _ ->
            ( model, Cmd.none )


-type alias Parser metadata view =
-    Dict String String
-    -> List String
-    -> List ( List String, metadata )
-    -> Mark.Document view
+type HmrStatus
+    = HmrLoading
+    | HmrLoaded


 application :
@ -622,6 +691,7 @@ application :
    , document : Pages.Document.Document metadata view
    , content : Content
    , toJsPort : Json.Encode.Value -> Cmd Never
+    , fromJsPort : Sub Decode.Value
    , manifest : Manifest.Config pathKey
    , generateFiles :
        List
@ -678,7 +748,7 @@ application config =
                                    Prerender ->
                                        noOpUpdate

-                                    Client ->
+                                    _ ->
                                        config.update

                            noOpUpdate =
@ -690,7 +760,7 @@ application config =
                                    |> List.map Tuple.first
                                    |> List.map (String.join "/")
                        in
-                        update allRoutes config.canonicalSiteUrl config.view config.pathKey config.onPageChange config.toJsPort config.document userUpdate msg model
+                        update config.content allRoutes config.canonicalSiteUrl config.view config.pathKey config.onPageChange config.toJsPort config.document userUpdate msg model
                            |> Tuple.mapFirst Model
                            |> Tuple.mapSecond (Cmd.map AppMsg)

@ -700,9 +770,27 @@ application config =
            \outerModel ->
                case outerModel of
                    Model model ->
-                        config.subscriptions model.userModel
-                            |> Sub.map UserMsg
-                            |> Sub.map AppMsg
+                        Sub.batch
+                            [ config.subscriptions model.userModel
+                                |> Sub.map UserMsg
+                                |> Sub.map AppMsg
+                            , config.fromJsPort
+                                |> Sub.map
+                                    (\decodeValue ->
+                                        case decodeValue |> Decode.decodeValue (Decode.field "thingy" Decode.string) of
+                                            Ok "hmr-check" ->
+                                                AppMsg StartingHotReload
+
+                                            _ ->
+                                                case decodeValue |> Decode.decodeValue (Decode.field "contentJson" contentJsonDecoder) of
+                                                    Ok contentJson ->
+                                                        AppMsg (HotReloadComplete contentJson)
+
+                                                    Err error ->
+                                                        -- TODO should be no message here
+                                                        AppMsg StartingHotReload
+                                    )
+                            ]

                    CliModel _ ->
                        Sub.none
@ -735,6 +823,7 @@ cliApplication :
    , document : Pages.Document.Document metadata view
    , content : Content
    , toJsPort : Json.Encode.Value -> Cmd Never
+    , fromJsPort : Sub Decode.Value
    , manifest : Manifest.Config pathKey
    , generateFiles :
        List
--- a/src/Pages/Internal/Platform/Cli.elm
+++ b/src/Pages/Internal/Platform/Cli.elm
@ -26,6 +26,7 @@ import Pages.ContentCache as ContentCache exposing (ContentCache)
 import Pages.Document
 import Pages.Http
 import Pages.ImagePath as ImagePath
+import Pages.Internal.ApplicationType as ApplicationType exposing (ApplicationType)
 import Pages.Internal.StaticHttpBody as StaticHttpBody
 import Pages.Manifest as Manifest
 import Pages.PagePath as PagePath exposing (PagePath)
@ -47,6 +48,7 @@ type alias ToJsSuccessPayload pathKey =
    { pages : Dict String (Dict String String)
    , manifest : Manifest.Config pathKey
    , filesToGenerate : List FileToGenerate
+    , staticHttpCache : Dict String String
    , errors : List String
    }

@ -65,8 +67,8 @@ toJsCodec =
                Errors errorList ->
                    errorsTag errorList

-                Success { pages, manifest, filesToGenerate, errors } ->
-                    success (ToJsSuccessPayload pages manifest filesToGenerate errors)
+                Success { pages, manifest, filesToGenerate, errors, staticHttpCache } ->
+                    success (ToJsSuccessPayload pages manifest filesToGenerate staticHttpCache errors)
        )
        |> Codec.variant1 "Errors" Errors Codec.string
        |> Codec.variant1 "Success"
@ -115,6 +117,9 @@ successCodec =
                )
                (Decode.succeed [])
            )
+        |> Codec.field "staticHttpCache"
+            .staticHttpCache
+            (Codec.dict Codec.string)
        |> Codec.field "errors" .errors (Codec.list Codec.string)
        |> Codec.buildObject

@ -178,6 +183,7 @@ type alias Config pathKey userMsg userModel metadata view =
    , document : Pages.Document.Document metadata view
    , content : Content
    , toJsPort : Json.Encode.Value -> Cmd Never
+    , fromJsPort : Sub Decode.Value
    , manifest : Manifest.Config pathKey
    , generateFiles :
        List
@ -320,13 +326,20 @@ init :
 init toModel contentCache siteMetadata config flags =
    case
        Decode.decodeValue
-            (Decode.map2 Tuple.pair
+            (Decode.map3 (\a b c -> ( a, b, c ))
                (Decode.field "secrets" SecretsDict.decoder)
                (Decode.field "mode" modeDecoder)
+                (Decode.field "staticHttpCache"
+                    (Decode.dict
+                        (Decode.string
+                            |> Decode.map Just
+                        )
+                    )
+                )
            )
            flags
    of
-        Ok ( secrets, mode ) ->
+        Ok ( secrets, mode, staticHttpCache ) ->
            case contentCache of
                Ok _ ->
                    case ContentCache.pagesWithErrors contentCache of
@ -343,14 +356,14 @@ init toModel contentCache siteMetadata config flags =
                                staticResponses =
                                    case requests of
                                        Ok okRequests ->
-                                            staticResponsesInit siteMetadata config okRequests
+                                            staticResponsesInit staticHttpCache siteMetadata config okRequests

                                        Err errors ->
                                            -- TODO need to handle errors better?
-                                            staticResponsesInit siteMetadata config []
+                                            staticResponsesInit staticHttpCache siteMetadata config []

                                ( updatedRawResponses, effect ) =
-                                    sendStaticResponsesIfDone config siteMetadata mode secrets Dict.empty [] staticResponses
+                                    sendStaticResponsesIfDone config siteMetadata mode secrets staticHttpCache [] staticResponses
                            in
                            ( Model staticResponses secrets [] updatedRawResponses mode |> toModel
                            , effect
@ -369,11 +382,11 @@ init toModel contentCache siteMetadata config flags =
                                staticResponses =
                                    case requests of
                                        Ok okRequests ->
-                                            staticResponsesInit siteMetadata config okRequests
+                                            staticResponsesInit staticHttpCache siteMetadata config okRequests

                                        Err errors ->
                                            -- TODO need to handle errors better?
-                                            staticResponsesInit siteMetadata config []
+                                            staticResponsesInit staticHttpCache siteMetadata config []
                            in
                            updateAndSendPortIfDone
                                config
@ -382,7 +395,7 @@ init toModel contentCache siteMetadata config flags =
                                    staticResponses
                                    secrets
                                    pageErrors
-                                    Dict.empty
+                                    staticHttpCache
                                    mode
                                )
                                toModel
@ -394,7 +407,7 @@ init toModel contentCache siteMetadata config flags =
                        (Model Dict.empty
                            secrets
                            (metadataParserErrors |> List.map Tuple.second)
-                            Dict.empty
+                            staticHttpCache
                            mode
                        )
                        toModel
@ -528,7 +541,7 @@ performStaticHttpRequests allRawResponses secrets staticRequests =
            (\( pagePath, request ) ->
                allRawResponses
                    |> dictCompact
-                    |> StaticHttpRequest.resolveUrls request
+                    |> StaticHttpRequest.resolveUrls ApplicationType.Cli request
                    |> Tuple.second
            )
        |> List.concat
@ -580,18 +593,23 @@ cliDictKey =
    "////elm-pages-CLI////"


-staticResponsesInit : Result (List BuildError) (List ( PagePath pathKey, metadata )) -> Config pathKey userMsg userModel metadata view -> List ( PagePath pathKey, StaticHttp.Request value ) -> StaticResponses
-staticResponsesInit siteMetadata config list =
+staticResponsesInit : Dict String (Maybe String) -> Result (List BuildError) (List ( PagePath pathKey, metadata )) -> Config pathKey userMsg userModel metadata view -> List ( PagePath pathKey, StaticHttp.Request value ) -> StaticResponses
+staticResponsesInit staticHttpCache siteMetadataResult config list =
    let
-        foo : StaticHttp.Request (List (Result String { path : List String, content : String }))
-        foo =
-            config.generateFiles thing2
+        generateFilesRequest : StaticHttp.Request (List (Result String { path : List String, content : String }))
+        generateFilesRequest =
+            config.generateFiles siteMetadataWithContent

        generateFilesStaticRequest =
-            ( cliDictKey, NotFetched (foo |> StaticHttp.map (\_ -> ())) Dict.empty )
+            ( -- we don't want to include the CLI-only StaticHttp responses in the production bundle
+              -- since that data is only needed to run these functions during the build step
+              -- in the future, this could be refactored to have a type to represent this more clearly
+              cliDictKey
+            , NotFetched (generateFilesRequest |> StaticHttp.map (\_ -> ())) Dict.empty
+            )

-        thing2 =
-            siteMetadata
+        siteMetadataWithContent =
+            siteMetadataResult
                |> Result.withDefault []
                |> List.map
                    (\( pagePath, metadata ) ->
@ -625,8 +643,26 @@ staticResponsesInit siteMetadata config list =
    list
        |> List.map
            (\( path, staticRequest ) ->
+                let
+                    entry =
+                        NotFetched (staticRequest |> StaticHttp.map (\_ -> ())) Dict.empty
+
+                    updatedEntry =
+                        staticHttpCache
+                            |> dictCompact
+                            |> Dict.toList
+                            |> List.foldl
+                                (\( hashedRequest, response ) entrySoFar ->
+                                    entrySoFar
+                                        |> addEntry
+                                            staticHttpCache
+                                            hashedRequest
+                                            (Ok response)
+                                )
+                                entry
+                in
                ( PagePath.toString path
-                , NotFetched (staticRequest |> StaticHttp.map (\_ -> ())) Dict.empty
+                , updatedEntry
                )
            )
        |> List.append [ generateFilesStaticRequest ]
@ -654,7 +690,7 @@ staticResponsesUpdate newEntry model =
                                realUrls =
                                    updatedAllResponses
                                        |> dictCompact
-                                        |> StaticHttpRequest.resolveUrls request
+                                        |> StaticHttpRequest.resolveUrls ApplicationType.Cli request
                                        |> Tuple.second
                                        |> List.map Secrets.maskedLookup
                                        |> List.map HashRequest.hash
@ -681,6 +717,36 @@ staticResponsesUpdate newEntry model =
    }


+addEntry : Dict String (Maybe String) -> String -> Result () String -> StaticHttpResult -> StaticHttpResult
+addEntry globalRawResponses hashedRequest rawResponse ((NotFetched request rawResponses) as entry) =
+    let
+        realUrls =
+            globalRawResponses
+                |> dictCompact
+                |> StaticHttpRequest.resolveUrls ApplicationType.Cli request
+                |> Tuple.second
+                |> List.map Secrets.maskedLookup
+                |> List.map HashRequest.hash
+
+        includesUrl =
+            List.member
+                hashedRequest
+                realUrls
+    in
+    if includesUrl then
+        let
+            updatedRawResponses =
+                Dict.insert
+                    hashedRequest
+                    rawResponse
+                    rawResponses
+        in
+        NotFetched request updatedRawResponses
+
+    else
+        entry
+
+
 isJust : Maybe a -> Bool
 isJust maybeValue =
    case maybeValue of
@ -721,7 +787,7 @@ sendStaticResponsesIfDone config siteMetadata mode secrets allRawResponses error

                                    hasPermanentError =
                                        usableRawResponses
-                                            |> StaticHttpRequest.permanentError request
+                                            |> StaticHttpRequest.permanentError ApplicationType.Cli request
                                            |> isJust

                                    hasPermanentHttpError =
@ -737,7 +803,9 @@ sendStaticResponsesIfDone config siteMetadata mode secrets allRawResponses error
                                    --                False
                                    --    )
                                    ( allUrlsKnown, knownUrlsToFetch ) =
-                                        StaticHttpRequest.resolveUrls request
+                                        StaticHttpRequest.resolveUrls
+                                            ApplicationType.Cli
+                                            request
                                            (rawResponses |> Dict.map (\key value -> value |> Result.withDefault ""))

                                    fetchedAllKnownUrls =
@ -773,7 +841,9 @@ sendStaticResponsesIfDone config siteMetadata mode secrets allRawResponses error
                                        )

                            maybePermanentError =
-                                StaticHttpRequest.permanentError request
+                                StaticHttpRequest.permanentError
+                                    ApplicationType.Cli
+                                    request
                                    usableRawResponses

                            decoderErrors =
@ -893,7 +963,8 @@ sendStaticResponsesIfDone config siteMetadata mode secrets allRawResponses error

            mythingy2 : Result StaticHttpRequest.Error (List (Result String { path : List String, content : String }))
            mythingy2 =
-                StaticHttpRequest.resolve (config.generateFiles metadataForGenerateFiles)
+                StaticHttpRequest.resolve ApplicationType.Cli
+                    (config.generateFiles metadataForGenerateFiles)
                    (allRawResponses |> Dict.Extra.filterMap (\key value -> value))

            generatedOkayFiles : List { path : List String, content : String }
@ -938,11 +1009,19 @@ sendStaticResponsesIfDone config siteMetadata mode secrets allRawResponses error
            (encodeStaticResponses mode staticResponses)
            config.manifest
            generatedOkayFiles
+            allRawResponses
            allErrors
        )


-toJsPayload encodedStatic manifest generated allErrors =
+toJsPayload :
+    Dict String (Dict String String)
+    -> Manifest.Config pathKey
+    -> List FileToGenerate
+    -> Dict String (Maybe String)
+    -> List { title : String, message : List Terminal.Text, fatal : Bool }
+    -> Effect pathKey
+toJsPayload encodedStatic manifest generated allRawResponses allErrors =
    SendJsData <|
        if allErrors |> List.filter .fatal |> List.isEmpty then
            Success
@ -950,6 +1029,15 @@ toJsPayload encodedStatic manifest generated allErrors =
                    encodedStatic
                    manifest
                    generated
+                    (allRawResponses
+                        |> Dict.toList
+                        |> List.filterMap
+                            (\( key, maybeValue ) ->
+                                maybeValue
+                                    |> Maybe.map (\value -> ( key, value ))
+                            )
+                        |> Dict.fromList
+                    )
                    (List.map BuildError.errorToString allErrors)
                )

@ -980,7 +1068,7 @@ encodeStaticResponses mode staticResponses =
                            strippedResponses : Dict String String
                            strippedResponses =
                                -- TODO should this return an Err and handle that here?
-                                StaticHttpRequest.strippedResponses request relevantResponses
+                                StaticHttpRequest.strippedResponses ApplicationType.Cli request relevantResponses
                        in
                        case mode of
                            Dev ->
--- a/src/Pages/Platform.elm
+++ b/src/Pages/Platform.elm
@ -322,6 +322,7 @@ application config =
        , content = config.internals.content
        , generateFiles = config.generateFiles
        , toJsPort = config.internals.toJsPort
+        , fromJsPort = config.internals.fromJsPort
        , manifest = config.manifest
        , canonicalSiteUrl = config.canonicalSiteUrl
        , onPageChange = config.onPageChange
--- a/src/Pages/StaticHttp.elm
+++ b/src/Pages/StaticHttp.elm
@ -1,7 +1,7 @@
 module Pages.StaticHttp exposing
    ( Request, RequestDetails
    , get, request
-    , map, succeed
+    , map, succeed, fail
    , Body, emptyBody, stringBody, jsonBody
    , andThen, resolve, combine
    , map2, map3, map4, map5, map6, map7, map8, map9
@ -40,7 +40,7 @@ in [this article introducing StaticHttp requests and some concepts around it](ht

@docs Request, RequestDetails
@docs get, request
-@docs map, succeed
+@docs map, succeed, fail


 ## Building a StaticHttp Request Body
@ -76,9 +76,12 @@ your decoders. This can significantly reduce download sizes for your StaticHttp

 import Dict exposing (Dict)
 import Dict.Extra
+import Internal.OptimizedDecoder
 import Json.Decode
-import Json.Decode.Exploration as Decode exposing (Decoder)
+import Json.Decode.Exploration
 import Json.Encode as Encode
+import OptimizedDecoder as Decode exposing (Decoder)
+import Pages.Internal.ApplicationType as ApplicationType exposing (ApplicationType)
 import Pages.Internal.StaticHttpBody as Body
 import Pages.Secrets
 import Pages.StaticHttp.Request as HashRequest
@ -155,8 +158,8 @@ map fn requestInfo =
        Request ( urls, lookupFn ) ->
            Request
                ( urls
-                , \rawResponses ->
-                    lookupFn rawResponses
+                , \appType rawResponses ->
+                    lookupFn appType rawResponses
                        |> Result.map (\( partiallyStripped, nextRequest ) -> ( partiallyStripped, map fn nextRequest ))
                )

@ -238,24 +241,24 @@ map2 fn request1 request2 =
    case ( request1, request2 ) of
        ( Request ( urls1, lookupFn1 ), Request ( urls2, lookupFn2 ) ) ->
            let
-                value : Dict String String -> Result Pages.StaticHttpRequest.Error ( Dict String String, Request c )
-                value rawResponses =
+                value : ApplicationType -> Dict String String -> Result Pages.StaticHttpRequest.Error ( Dict String String, Request c )
+                value appType rawResponses =
                    let
                        value1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.second

                        value2 =
-                            lookupFn2 rawResponses
+                            lookupFn2 appType rawResponses
                                |> Result.map Tuple.second

                        dict1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.first
                                |> Result.withDefault Dict.empty

                        dict2 =
-                            lookupFn2 rawResponses
+                            lookupFn2 appType rawResponses
                                |> Result.map Tuple.first
                                |> Result.withDefault Dict.empty
                    in
@ -274,14 +277,14 @@ map2 fn request1 request2 =
        ( Request ( urls1, lookupFn1 ), Done value2 ) ->
            Request
                ( urls1
-                , \rawResponses ->
+                , \appType rawResponses ->
                    let
                        value1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.second

                        dict1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.first
                                |> Result.withDefault Dict.empty
                    in
@ -296,14 +299,14 @@ map2 fn request1 request2 =
        ( Done value2, Request ( urls1, lookupFn1 ) ) ->
            Request
                ( urls1
-                , \rawResponses ->
+                , \appType rawResponses ->
                    let
                        value1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.second

                        dict1 =
-                            lookupFn1 rawResponses
+                            lookupFn1 appType rawResponses
                                |> Result.map Tuple.first
                                |> Result.withDefault Dict.empty
                    in
@ -336,14 +339,14 @@ combineReducedDicts dict1 dict2 =
            )


-lookup : Pages.StaticHttpRequest.Request value -> Dict String String -> Result Pages.StaticHttpRequest.Error ( Dict String String, value )
-lookup requestInfo rawResponses =
+lookup : ApplicationType -> Pages.StaticHttpRequest.Request value -> Dict String String -> Result Pages.StaticHttpRequest.Error ( Dict String String, value )
+lookup appType requestInfo rawResponses =
    case requestInfo of
        Request ( urls, lookupFn ) ->
-            lookupFn rawResponses
+            lookupFn appType rawResponses
                |> Result.andThen
                    (\( strippedResponses, nextRequest ) ->
-                        lookup
+                        lookup appType
                            (addUrls urls nextRequest)
                            strippedResponses
                    )
@ -393,8 +396,8 @@ andThen : (a -> Request b) -> Request a -> Request b
 andThen fn requestInfo =
    Request
        ( lookupUrls requestInfo
-        , \rawResponses ->
-            lookup
+        , \appType rawResponses ->
+            lookup appType
                requestInfo
                rawResponses
                |> (\result ->
@ -436,11 +439,22 @@ succeed : a -> Request a
 succeed value =
    Request
        ( []
-        , \rawResponses ->
+        , \appType rawResponses ->
            Ok ( rawResponses, Done value )
        )


+{-| TODO
+-}
+fail : String -> Request a
+fail errorMessage =
+    Request
+        ( []
+        , \appType rawResponses ->
+            Err (Pages.StaticHttpRequest.UserCalledStaticHttpFail errorMessage)
+        )
+
+
 {-| A simplified helper around [`StaticHttp.request`](#request), which builds up a StaticHttp GET request.

    import Json.Decode as Decode exposing (Decoder)
@ -575,70 +589,104 @@ unoptimizedRequest requestWithSecrets expect =
        ExpectJson decoder ->
            Request
                ( [ requestWithSecrets ]
-                , \rawResponseDict ->
-                    rawResponseDict
-                        |> Dict.get (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
-                        |> (\maybeResponse ->
-                                case maybeResponse of
-                                    Just rawResponse ->
-                                        Ok
-                                            ( rawResponseDict
-                                              --                                        |> Dict.update url (\maybeValue -> Just """{"fake": 123}""")
-                                            , rawResponse
-                                            )
+                , \appType rawResponseDict ->
+                    case appType of
+                        ApplicationType.Cli ->
+                            rawResponseDict
+                                |> Dict.get (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
+                                |> (\maybeResponse ->
+                                        case maybeResponse of
+                                            Just rawResponse ->
+                                                Ok
+                                                    ( rawResponseDict
+                                                    , rawResponse
+                                                    )

-                                    Nothing ->
-                                        Secrets.maskedLookup requestWithSecrets
-                                            |> requestToString
-                                            |> Pages.StaticHttpRequest.MissingHttpResponse
-                                            |> Err
-                           )
-                        |> Result.andThen
-                            (\( strippedResponses, rawResponse ) ->
-                                let
-                                    reduced =
-                                        Decode.stripString decoder rawResponse
-                                            |> Result.withDefault "TODO"
-                                in
-                                rawResponse
-                                    |> Decode.decodeString decoder
-                                    --                                                        |> Result.mapError Json.Decode.Exploration.errorsToString
-                                    |> (\decodeResult ->
-                                            case decodeResult of
-                                                Decode.BadJson ->
-                                                    Pages.StaticHttpRequest.DecoderError "Payload sent back invalid JSON" |> Err
+                                            Nothing ->
+                                                Secrets.maskedLookup requestWithSecrets
+                                                    |> requestToString
+                                                    |> Pages.StaticHttpRequest.MissingHttpResponse
+                                                    |> Err
+                                   )
+                                |> Result.andThen
+                                    (\( strippedResponses, rawResponse ) ->
+                                        let
+                                            reduced =
+                                                Json.Decode.Exploration.stripString (Internal.OptimizedDecoder.jde decoder) rawResponse
+                                                    |> Result.withDefault "TODO"
+                                        in
+                                        rawResponse
+                                            |> Json.Decode.Exploration.decodeString (decoder |> Internal.OptimizedDecoder.jde)
+                                            |> (\decodeResult ->
+                                                    case decodeResult of
+                                                        Json.Decode.Exploration.BadJson ->
+                                                            Pages.StaticHttpRequest.DecoderError "Payload sent back invalid JSON" |> Err

-                                                Decode.Errors errors ->
-                                                    errors
-                                                        |> Decode.errorsToString
-                                                        |> Pages.StaticHttpRequest.DecoderError
-                                                        |> Err
+                                                        Json.Decode.Exploration.Errors errors ->
+                                                            errors
+                                                                |> Json.Decode.Exploration.errorsToString
+                                                                |> Pages.StaticHttpRequest.DecoderError
+                                                                |> Err

-                                                Decode.WithWarnings warnings a ->
-                                                    --                                            Pages.StaticHttpRequest.DecoderError "" |> Err
-                                                    Ok a
+                                                        Json.Decode.Exploration.WithWarnings warnings a ->
+                                                            Ok a

-                                                Decode.Success a ->
-                                                    Ok a
-                                       )
-                                    --                            |> Result.mapError Pages.StaticHttpRequest.DecoderError
-                                    |> Result.map Done
-                                    |> Result.map
-                                        (\finalRequest ->
-                                            ( strippedResponses
-                                                |> Dict.insert
-                                                    (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
-                                                    reduced
-                                            , finalRequest
-                                            )
-                                        )
-                            )
+                                                        Json.Decode.Exploration.Success a ->
+                                                            Ok a
+                                               )
+                                            |> Result.map Done
+                                            |> Result.map
+                                                (\finalRequest ->
+                                                    ( strippedResponses
+                                                        |> Dict.insert
+                                                            (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
+                                                            reduced
+                                                    , finalRequest
+                                                    )
+                                                )
+                                    )
+
+                        ApplicationType.Browser ->
+                            rawResponseDict
+                                |> Dict.get (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
+                                |> (\maybeResponse ->
+                                        case maybeResponse of
+                                            Just rawResponse ->
+                                                Ok
+                                                    ( rawResponseDict
+                                                    , rawResponse
+                                                    )
+
+                                            Nothing ->
+                                                Secrets.maskedLookup requestWithSecrets
+                                                    |> requestToString
+                                                    |> Pages.StaticHttpRequest.MissingHttpResponse
+                                                    |> Err
+                                   )
+                                |> Result.andThen
+                                    (\( strippedResponses, rawResponse ) ->
+                                        rawResponse
+                                            |> Json.Decode.decodeString (decoder |> Internal.OptimizedDecoder.jd)
+                                            |> (\decodeResult ->
+                                                    case decodeResult of
+                                                        Err _ ->
+                                                            Pages.StaticHttpRequest.DecoderError "Payload sent back invalid JSON" |> Err
+
+                                                        Ok a ->
+                                                            Ok a
+                                               )
+                                            |> Result.map Done
+                                            |> Result.map
+                                                (\finalRequest ->
+                                                    ( strippedResponses, finalRequest )
+                                                )
+                                    )
                )

        ExpectUnoptimizedJson decoder ->
            Request
                ( [ requestWithSecrets ]
-                , \rawResponseDict ->
+                , \appType rawResponseDict ->
                    rawResponseDict
                        |> Dict.get (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
                        |> (\maybeResponse ->
@ -664,7 +712,10 @@ unoptimizedRequest requestWithSecrets expect =
                                    |> (\decodeResult ->
                                            case decodeResult of
                                                Err error ->
-                                                    Pages.StaticHttpRequest.DecoderError "Payload sent back invalid JSON" |> Err
+                                                    error
+                                                        |> Decode.errorToString
+                                                        |> Pages.StaticHttpRequest.DecoderError
+                                                        |> Err

                                                Ok a ->
                                                    Ok a
@ -685,7 +736,7 @@ unoptimizedRequest requestWithSecrets expect =
        ExpectString mapStringFn ->
            Request
                ( [ requestWithSecrets ]
-                , \rawResponseDict ->
+                , \appType rawResponseDict ->
                    rawResponseDict
                        |> Dict.get (Secrets.maskedLookup requestWithSecrets |> HashRequest.hash)
                        |> (\maybeResponse ->
--- a/src/Pages/StaticHttpRequest.elm
+++ b/src/Pages/StaticHttpRequest.elm
@ -2,26 +2,27 @@ module Pages.StaticHttpRequest exposing (Error(..), Request(..), permanentError,

 import BuildError exposing (BuildError)
 import Dict exposing (Dict)
+import Pages.Internal.ApplicationType as ApplicationType exposing (ApplicationType)
 import Pages.StaticHttp.Request
 import Secrets
 import TerminalText as Terminal


 type Request value
-    = Request ( List (Secrets.Value Pages.StaticHttp.Request.Request), Dict String String -> Result Error ( Dict String String, Request value ) )
+    = Request ( List (Secrets.Value Pages.StaticHttp.Request.Request), ApplicationType -> Dict String String -> Result Error ( Dict String String, Request value ) )
    | Done value


-strippedResponses : Request value -> Dict String String -> Dict String String
-strippedResponses request rawResponses =
+strippedResponses : ApplicationType -> Request value -> Dict String String -> Dict String String
+strippedResponses appType request rawResponses =
    case request of
        Request ( list, lookupFn ) ->
-            case lookupFn rawResponses of
+            case lookupFn appType rawResponses of
                Err error ->
                    rawResponses

                Ok ( partiallyStrippedResponses, followupRequest ) ->
-                    strippedResponses followupRequest partiallyStrippedResponses
+                    strippedResponses appType followupRequest partiallyStrippedResponses

        Done value ->
            rawResponses
@ -30,6 +31,7 @@ strippedResponses request rawResponses =
 type Error
    = MissingHttpResponse String
    | DecoderError String
+    | UserCalledStaticHttpFail String


 urls : Request value -> List (Secrets.Value Pages.StaticHttp.Request.Request)
@ -65,14 +67,24 @@ toBuildError path error =
            , fatal = True
            }

+        UserCalledStaticHttpFail decodeErrorMessage ->
+            { title = "Called Static Http Fail"
+            , message =
+                [ Terminal.text path
+                , Terminal.text "\n\n"
+                , Terminal.text <| "I ran into a call to `Pages.StaticHttp.fail` with message: " ++ decodeErrorMessage
+                ]
+            , fatal = True
+            }

-permanentError : Request value -> Dict String String -> Maybe Error
-permanentError request rawResponses =
+
+permanentError : ApplicationType -> Request value -> Dict String String -> Maybe Error
+permanentError appType request rawResponses =
    case request of
        Request ( urlList, lookupFn ) ->
-            case lookupFn rawResponses of
+            case lookupFn appType rawResponses of
                Ok ( partiallyStrippedResponses, nextRequest ) ->
-                    permanentError nextRequest rawResponses
+                    permanentError appType nextRequest rawResponses

                Err error ->
                    case error of
@ -82,17 +94,20 @@ permanentError request rawResponses =
                        DecoderError _ ->
                            Just error

+                        UserCalledStaticHttpFail string ->
+                            Just error
+
        Done value ->
            Nothing


-resolve : Request value -> Dict String String -> Result Error value
-resolve request rawResponses =
+resolve : ApplicationType -> Request value -> Dict String String -> Result Error value
+resolve appType request rawResponses =
    case request of
        Request ( urlList, lookupFn ) ->
-            case lookupFn rawResponses of
+            case lookupFn appType rawResponses of
                Ok ( partiallyStrippedResponses, nextRequest ) ->
-                    resolve nextRequest rawResponses
+                    resolve appType nextRequest rawResponses

                Err error ->
                    Err error
@ -101,13 +116,13 @@ resolve request rawResponses =
            Ok value


-resolveUrls : Request value -> Dict String String -> ( Bool, List (Secrets.Value Pages.StaticHttp.Request.Request) )
-resolveUrls request rawResponses =
+resolveUrls : ApplicationType -> Request value -> Dict String String -> ( Bool, List (Secrets.Value Pages.StaticHttp.Request.Request) )
+resolveUrls appType request rawResponses =
    case request of
        Request ( urlList, lookupFn ) ->
-            case lookupFn rawResponses of
+            case lookupFn appType rawResponses of
                Ok ( partiallyStrippedResponses, nextRequest ) ->
-                    resolveUrls nextRequest rawResponses
+                    resolveUrls appType nextRequest rawResponses
                        |> Tuple.mapSecond ((++) urlList)

                Err error ->
--- a/src/StructuredData.elm
+++ b/src/StructuredData.elm
@ -0,0 +1,234 @@
+module StructuredData exposing (..)
+
+import Json.Encode as Encode
+
+
+{-| <https://schema.org/SoftwareSourceCode>
+-}
+softwareSourceCode :
+    { codeRepositoryUrl : String
+    , description : String
+    , author : String
+    , programmingLanguage : Encode.Value
+    }
+    -> Encode.Value
+softwareSourceCode info =
+    Encode.object
+        [ ( "@type", Encode.string "SoftwareSourceCode" )
+        , ( "codeRepository", Encode.string info.codeRepositoryUrl )
+        , ( "description", Encode.string info.description )
+        , ( "author", Encode.string info.author )
+        , ( "programmingLanguage", info.programmingLanguage )
+        ]
+
+
+{-| <https://schema.org/ComputerLanguage>
+-}
+computerLanguage : { url : String, name : String, imageUrl : String, identifier : String } -> Encode.Value
+computerLanguage info =
+    Encode.object
+        [ ( "@type", Encode.string "ComputerLanguage" )
+        , ( "url", Encode.string info.url )
+        , ( "name", Encode.string info.name )
+        , ( "image", Encode.string info.imageUrl )
+        , ( "identifier", Encode.string info.identifier )
+        ]
+
+
+elmLang : Encode.Value
+elmLang =
+    computerLanguage
+        { url = "http://elm-lang.org/"
+        , name = "Elm"
+        , imageUrl = "http://elm-lang.org/"
+        , identifier = "http://elm-lang.org/"
+        }
+
+
+{-| <https://schema.org/Article>
+-}
+article :
+    { title : String
+    , description : String
+    , author : StructuredData { authorMemberOf | personOrOrganization : () } authorPossibleFields
+    , publisher : StructuredData { publisherMemberOf | personOrOrganization : () } publisherPossibleFields
+    , url : String
+    , imageUrl : String
+    , datePublished : String
+    , mainEntityOfPage : Encode.Value
+    }
+    -> Encode.Value
+article info =
+    Encode.object
+        [ ( "@context", Encode.string "http://schema.org/" )
+        , ( "@type", Encode.string "Article" )
+        , ( "headline", Encode.string info.title )
+        , ( "description", Encode.string info.description )
+        , ( "image", Encode.string info.imageUrl )
+        , ( "author", encode info.author )
+        , ( "publisher", encode info.publisher )
+        , ( "url", Encode.string info.url )
+        , ( "datePublished", Encode.string info.datePublished )
+        , ( "mainEntityOfPage", info.mainEntityOfPage )
+        ]
+
+
+type StructuredData memberOf possibleFields
+    = StructuredData String (List ( String, Encode.Value ))
+
+
+{-| <https://schema.org/Person>
+-}
+person :
+    { name : String
+    }
+    ->
+        StructuredData { personOrOrganization : () }
+            { additionalName : ()
+            , address : ()
+            , affiliation : ()
+            }
+person info =
+    StructuredData "Person" [ ( "name", Encode.string info.name ) ]
+
+
+additionalName : String -> StructuredData memberOf { possibleFields | additionalName : () } -> StructuredData memberOf possibleFields
+additionalName value (StructuredData typeName fields) =
+    StructuredData typeName (( "additionalName", Encode.string value ) :: fields)
+
+
+{-| <https://schema.org/Article>
+-}
+article_ :
+    { title : String
+    , description : String
+    , author : String
+    , publisher : StructuredData { personOrOrganization : () } possibleFieldsPublisher
+    , url : String
+    , imageUrl : String
+    , datePublished : String
+    , mainEntityOfPage : Encode.Value
+    }
+    -> Encode.Value
+article_ info =
+    Encode.object
+        [ ( "@context", Encode.string "http://schema.org/" )
+        , ( "@type", Encode.string "Article" )
+        , ( "headline", Encode.string info.title )
+        , ( "description", Encode.string info.description )
+        , ( "image", Encode.string info.imageUrl )
+        , ( "author", Encode.string info.author )
+        , ( "publisher", encode info.publisher )
+        , ( "url", Encode.string info.url )
+        , ( "datePublished", Encode.string info.datePublished )
+        , ( "mainEntityOfPage", info.mainEntityOfPage )
+        ]
+
+
+encode : StructuredData memberOf possibleFieldsPublisher -> Encode.Value
+encode (StructuredData typeName fields) =
+    Encode.object
+        (( "@type", Encode.string typeName ) :: fields)
+
+
+
+--example : StructuredData { personOrOrganization : () } { address : (), affiliation : () }
+
+
+example =
+    person { name = "Dillon Kearns" }
+        |> additionalName "Cornelius"
+
+
+
+--organization :
+--    {}
+--    -> StructuredData { personOrOrganization : () }
+--organization info =
+--    StructuredData "Organization" []
+--needsPersonOrOrg : StructuredData {}
+--needsPersonOrOrg =
+--    StructuredData "" []
+
+
+{-|
+
+```json
+   {
+      "@context": "http://schema.org/",
+      "@type": "PodcastSeries",
+      "image": "https://www.relay.fm/inquisitive_artwork.png",
+      "url": "http://www.relay.fm/inquisitive",
+      "name": "Inquisitive",
+      "description": "Inquisitive is a show for the naturally curious. Each week, Myke Hurley takes a look at what makes creative people successful and what steps they have taken to get there.",
+      "webFeed": "http://www.relay.fm//inquisitive/feed",
+      "author": {
+        "@type": "Person",
+        "name": "Myke Hurley"
+      }
+    }
+   }
+```
+
+-}
+series : Encode.Value
+series =
+    Encode.object
+        [ ( "@context", Encode.string "http://schema.org/" )
+        , ( "@type", Encode.string "PodcastSeries" )
+        , ( "image", Encode.string "TODO" )
+        , ( "url", Encode.string "http://elm-radio.com/episode/getting-started-with-elm-pages" )
+        , ( "name", Encode.string "Elm Radio" )
+        , ( "description", Encode.string "TODO" )
+        , ( "webFeed", Encode.string "https://elm-radio.com/feed.xml" )
+        ]
+
+
+{-|
+
+```json
+   {
+      "@context": "http://schema.org/",
+      "@type": "PodcastEpisode",
+      "url": "http://elm-radio.com/episode/getting-started-with-elm-pages",
+     "name": "001: Getting Started with elm-pages",
+      "datePublished": "2015-02-18",
+      "timeRequired": "PT37M",
+      "description": "In the first episode of “Behind the App”, a special series of Inquisitive, we take a look at the beginnings of iOS app development, by focusing on the introduction of the iPhone and the App Store.",
+      "associatedMedia": {
+        "@type": "MediaObject",
+        "contentUrl": "https://cdn.simplecast.com/audio/6a206b/6a206baa-9c8e-4c25-9037-2b674204ba84/ca009f6e-1710-4518-b869-ca34cb0b7d17/001-getting-started-elm-pages_tc.mp3 "
+      },
+      "partOfSeries": {
+        "@type": "PodcastSeries",
+        "name": "Elm Radio",
+        "url": "https://elm-radio.com"
+      }
+    }
+```
+
+-}
+episode : Encode.Value
+episode =
+    Encode.object
+        [ ( "@context", Encode.string "http://schema.org/" )
+        , ( "@type", Encode.string "PodcastEpisode" )
+        , ( "url", Encode.string "http://elm-radio.com/episode/getting-started-with-elm-pages" )
+        , ( "name", Encode.string "Getting Started with elm-pages" )
+        , ( "datePublished", Encode.string "2015-02-18" )
+        , ( "timeRequired", Encode.string "PT37M" )
+        , ( "description", Encode.string "TODO" )
+        , ( "associatedMedia"
+          , Encode.object
+                [ ( "@type", Encode.string "MediaObject" )
+                , ( "contentUrl", Encode.string "https://cdn.simplecast.com/audio/6a206b/6a206baa-9c8e-4c25-9037-2b674204ba84/ca009f6e-1710-4518-b869-ca34cb0b7d17/001-getting-started-elm-pages_tc.mp3" )
+                ]
+          )
+        , ( "partOfSeries"
+          , Encode.object
+                [ ( "@type", Encode.string "PodcastSeries" )
+                , ( "name", Encode.string "Elm Radio" )
+                , ( "url", Encode.string "https://elm-radio.com" )
+                ]
+          )
+        ]
--- a/src/TerminalText.elm
+++ b/src/TerminalText.elm
@ -68,10 +68,10 @@ colorToString color =
                "[34m"

            Green ->
-                "[32;1m"
+                "[32m"

            Yellow ->
-                "[33;1m"
+                "[33m"

            Cyan ->
                "[36m"
--- a/tests/StaticHttpRequestsTests.elm
+++ b/tests/StaticHttpRequestsTests.elm
@ -5,7 +5,9 @@ import Dict exposing (Dict)
 import Expect
 import Html
 import Json.Decode as JD
-import Json.Decode.Exploration as Decode exposing (Decoder)
+import Json.Decode.Exploration
+import Json.Encode as Encode
+import OptimizedDecoder as Decode exposing (Decoder)
 import Pages.ContentCache as ContentCache
 import Pages.Document as Document
 import Pages.Http
@ -604,11 +606,68 @@ Body: """)
                            ]
                          )
                        ]
+        , describe "staticHttpCache"
+            [ test "it doesn't perform http requests that are provided in the http cache flag" <|
+                \() ->
+                    startWithHttpCache
+                        [ ( { url = "https://api.github.com/repos/dillonkearns/elm-pages"
+                            , method = "GET"
+                            , headers = []
+                            , body = StaticHttpBody.EmptyBody
+                            }
+                          , """{"stargazer_count":86}"""
+                          )
+                        ]
+                        [ ( []
+                          , StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-pages") starDecoder
+                          )
+                        ]
+                        |> expectSuccess
+                            [ ( ""
+                              , [ ( get "https://api.github.com/repos/dillonkearns/elm-pages"
+                                  , """{"stargazer_count":86}"""
+                                  )
+                                ]
+                              )
+                            ]
+            , test "it ignores unused cache" <|
+                \() ->
+                    startWithHttpCache
+                        [ ( { url = "https://this-is-never-used.example.com/"
+                            , method = "GET"
+                            , headers = []
+                            , body = StaticHttpBody.EmptyBody
+                            }
+                          , """{"stargazer_count":86}"""
+                          )
+                        ]
+                        [ ( []
+                          , StaticHttp.get (Secrets.succeed "https://api.github.com/repos/dillonkearns/elm-pages") starDecoder
+                          )
+                        ]
+                        |> ProgramTest.simulateHttpOk
+                            "GET"
+                            "https://api.github.com/repos/dillonkearns/elm-pages"
+                            """{ "stargazer_count": 86 }"""
+                        |> expectSuccess
+                            [ ( ""
+                              , [ ( get "https://api.github.com/repos/dillonkearns/elm-pages"
+                                  , """{"stargazer_count":86}"""
+                                  )
+                                ]
+                              )
+                            ]
+            ]
        ]


 start : List ( List String, StaticHttp.Request a ) -> ProgramTest Main.Model Main.Msg (Main.Effect PathKey)
 start pages =
+    startWithHttpCache [] pages
+
+
+startWithHttpCache : List ( Request.Request, String ) -> List ( List String, StaticHttp.Request a ) -> ProgramTest Main.Model Main.Msg (Main.Effect PathKey)
+startWithHttpCache staticHttpCache pages =
    let
        document =
            Document.fromList
@ -637,6 +696,7 @@ start pages =

        config =
            { toJsPort = toJsPort
+            , fromJsPort = fromJsPort
            , manifest = manifest
            , generateFiles = \_ -> StaticHttp.succeed []
            , init = \_ -> ( (), Cmd.none )
@ -669,6 +729,30 @@ start pages =
            , pathKey = PathKey
            , onPageChange = \_ -> ()
            }
+
+        encodedFlags =
+            --{"secrets":
+            --        {"API_KEY": "ABCD1234","BEARER": "XYZ789"}, "mode": "prod", "staticHttpCache": {}
+            --        }
+            Encode.object
+                [ ( "secrets"
+                  , [ ( "API_KEY", "ABCD1234" )
+                    , ( "BEARER", "XYZ789" )
+                    ]
+                        |> Dict.fromList
+                        |> Encode.dict identity Encode.string
+                  )
+                , ( "mode", Encode.string "prod" )
+                , ( "staticHttpCache", encodedStaticHttpCache )
+                ]
+
+        encodedStaticHttpCache =
+            staticHttpCache
+                |> List.map
+                    (\( request, httpResponseString ) ->
+                        ( Request.hash request, Encode.string httpResponseString )
+                    )
+                |> Encode.object
    in
    {-
       (Model -> model)
@ -684,9 +768,7 @@ start pages =
        , view = \_ -> { title = "", body = [] }
        }
        |> ProgramTest.withSimulatedEffects simulateEffects
-        |> ProgramTest.start (flags """{"secrets":
-        {"API_KEY": "ABCD1234","BEARER": "XYZ789"}, "mode": "prod"
-        }""")
+        |> ProgramTest.start (flags (Encode.encode 0 encodedFlags))


 flags : String -> JD.Value
@ -780,6 +862,10 @@ toJsPort foo =
    Cmd.none


+fromJsPort =
+    Sub.none
+
+
 type PathKey
    = PathKey

@ -831,27 +917,31 @@ expectSuccess expectedRequests previous =
        |> ProgramTest.expectOutgoingPortValues
            "toJsPort"
            (Codec.decoder Main.toJsCodec)
-            (Expect.equal
-                [ Main.Success
-                    { pages =
-                        expectedRequests
-                            |> List.map
-                                (\( url, requests ) ->
-                                    ( url
-                                    , requests
-                                        |> List.map
-                                            (\( request, response ) ->
-                                                ( Request.hash request, response )
+            (\value ->
+                case value of
+                    [ Main.Success portPayload ] ->
+                        portPayload.pages
+                            |> Expect.equal
+                                (expectedRequests
+                                    |> List.map
+                                        (\( url, requests ) ->
+                                            ( url
+                                            , requests
+                                                |> List.map
+                                                    (\( request, response ) ->
+                                                        ( Request.hash request, response )
+                                                    )
+                                                |> Dict.fromList
                                            )
-                                        |> Dict.fromList
-                                    )
+                                        )
+                                    |> Dict.fromList
                                )
-                            |> Dict.fromList
-                    , manifest = manifest
-                    , filesToGenerate = []
-                    , errors = []
-                    }
-                ]
+
+                    [ _ ] ->
+                        Expect.fail "Expected success port."
+
+                    _ ->
+                        Expect.fail ("Expected ports to be called once, but instead there were " ++ String.fromInt (List.length value) ++ " calls.")
            )


--- a/tests/StaticHttpUnitTests.elm
+++ b/tests/StaticHttpUnitTests.elm
@ -2,7 +2,9 @@ module StaticHttpUnitTests exposing (all)

 import Dict exposing (Dict)
 import Expect
-import Json.Decode.Exploration as Decode
+import Json.Decode.Exploration
+import OptimizedDecoder as Decode
+import Pages.Internal.ApplicationType as ApplicationType
 import Pages.StaticHttp as StaticHttp
 import Pages.StaticHttp.Request as Request
 import Pages.StaticHttpRequest as StaticHttpRequest
@ -42,11 +44,11 @@ all =
                StaticHttp.get (Secrets.succeed "first") (Decode.succeed "NEXT")
                    |> StaticHttp.andThen
                        (\continueUrl ->
-                            --                                        StaticHttp.get continueUrl (Decode.succeed ())
                            getWithoutSecrets "NEXT" (Decode.succeed ())
                        )
                    |> (\request ->
-                            StaticHttpRequest.resolveUrls request
+                            StaticHttpRequest.resolveUrls ApplicationType.Cli
+                                request
                                (requestsDict
                                    [ ( get "first", "null" )
                                    , ( get "NEXT", "null" )
@ -63,7 +65,8 @@ all =
                            getWithoutSecrets "NEXT" (Decode.succeed ())
                        )
                    |> (\request ->
-                            StaticHttpRequest.resolveUrls request
+                            StaticHttpRequest.resolveUrls ApplicationType.Cli
+                                request
                                (requestsDict
                                    [ ( get "NEXT", "null" )
                                    ]
@ -81,7 +84,8 @@ all =
                        )
                    |> StaticHttp.map (\_ -> ())
                    |> (\request ->
-                            StaticHttpRequest.resolveUrls request
+                            StaticHttpRequest.resolveUrls ApplicationType.Cli
+                                request
                                (requestsDict
                                    [ ( get "first", "null" )
                                    , ( get "NEXT", "null" )
@ -98,7 +102,8 @@ all =
                            getWithoutSecrets "NEXT" (Decode.succeed ())
                        )
                    |> (\request ->
-                            StaticHttpRequest.resolveUrls request
+                            StaticHttpRequest.resolveUrls ApplicationType.Cli
+                                request
                                (requestsDict
                                    [ ( get "first", "null" )
                                    ]
@ -119,7 +124,8 @@ all =
                                    )
                        )
                    |> (\request ->
-                            StaticHttpRequest.resolveUrls request
+                            StaticHttpRequest.resolveUrls ApplicationType.Cli
+                                request
                                (requestsDict
                                    [ ( get "first", "1" )
                                    ]