graphql-engine/README.md

# Hasura GraphQL Engine

[![Docs](https://img.shields.io/badge/docs-v1.0-brightgreen.svg?style=flat)](https://docs.hasura.io)
[![CircleCI](https://circleci.com/gh/hasura/graphql-engine.svg?style=shield)](https://circleci.com/gh/hasura/graphql-engine)


<a href="https://discord.gg/vBPpJkS"><img src="https://img.shields.io/badge/chat-discord-brightgreen.svg?logo=discord&style=flat"></a>
<a href="https://twitter.com/intent/follow?screen_name=HasuraHQ"><img src="https://img.shields.io/badge/Follow-HasuraHQ-blue.svg?style=flat&logo=twitter"></a>
<a href="https://eepurl.com/dBUfJ5"><img src="https://img.shields.io/badge/newsletter-subscribe-yellow.svg?style=flat"></a>

Hasura GraphQL Engine is a blazing-fast GraphQL server that gives you **instant, realtime GraphQL APIs over Postgres**, with [**webhook triggers**](event-triggers.md) on database events, and [**remote schemas**](remote-schemas.md) for business logic.

Hasura helps you build GraphQL apps backed by Postgres or incrementally move to GraphQL for existing applications using Postgres.

Read more at [hasura.io](https://hasura.io) and the [docs](https://docs.hasura.io).

------------------

![Hasura GraphQL Engine Demo](assets/demo.gif)

------------------

![Hasura GraphQL Engine Realtime Demo](assets/realtime.gif)

-------------------

## Features

* **Make powerful queries**: Built-in filtering, pagination, pattern search, bulk insert, update, delete mutations
* **Realtime**: Convert any GraphQL query to a live query by using subscriptions
* **Merge remote schemas**: Access custom GraphQL schemas for business logic via a single GraphQL Engine endpoint. [**Read more**](remote-schemas.md).
* **Trigger webhooks or serverless functions**: On Postgres insert/update/delete events ([read more](event-triggers.md))
* **Works with existing, live databases**: Point it to an existing Postgres database to instantly get a ready-to-use GraphQL API
* **Fine-grained access control**: Dynamic access control that integrates with your auth system (eg: auth0, firebase-auth)
* **High-performance & low-footprint**: ~15MB docker image; ~50MB RAM @ 1000 req/s; multi-core aware
* **Admin UI & Migrations**: Admin UI & Rails-inspired schema migrations
* **Postgres** ❤️: Supports Postgres types (PostGIS/geo-location, etc.), turns views to *graphs*, trigger stored functions or procedures with mutations

Read more at [hasura.io](https://hasura.io) and the [docs](https://docs.hasura.io).

## Table of contents
<!-- markdown-toc start - Don't edit this section. Run M-x markdown-toc-refresh-toc -->
**Table of Contents**

- [Quickstart:](#quickstart)
    - [One-click deployment on Heroku](#one-click-deployment-on-heroku)
    - [Other deployment methods](#other-deployment-methods)
- [Architecture](#architecture)
- [Client-side tooling](#client-side-tooling)
- [Add business logic](#add-business-logic)
    - [Remote schemas](#remote-schemas)
    - [Trigger webhooks on database events](#trigger-webhooks-on-database-events)
- [Demos](#demos)
    - [Realtime applications](#realtime-applications)
    - [Videos](#videos)
- [Support & Troubleshooting](#support--troubleshooting)
- [Contributing](#contributing)
- [Brand assets](#brand-assets)
- [License](#license)
- [Translations](#translations)

<!-- markdown-toc end -->

## Quickstart:

### One-click deployment on Heroku

The fastest way to try Hasura out is via Heroku.

1. Click on the following button to deploy GraphQL Engine on Heroku with the free Postgres add-on:

    [![Deploy to Heroku](https://www.herokucdn.com/deploy/button.svg)](https://heroku.com/deploy?template=https://github.com/hasura/graphql-engine-heroku)

2. Open the Hasura console

   Visit `https://<app-name>.herokuapp.com` (*replace \<app-name\> with your app name*) to open the admin console.

3. Make your first GraphQL query

   Create a table and instantly run your first query. Follow this [simple guide](https://docs.hasura.io/1.0/graphql/manual/getting-started/first-graphql-query.html).

### Other one-click deployment options

Check out the instructions for the following one-click deployment options:

| **Infra provider** | **One-click link** | **Additional information** |
|:------------------:|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------:|:-------------------------------------------------------------------------------------------------------------------------------------------------:|
| DigitalOcean | [![Deploy to DigitalOcean](https://graphql-engine-cdn.hasura.io/img/create_hasura_droplet_200px.png)](https://marketplace.digitalocean.com/apps/hasura?action=deploy&refcode=c4d9092d2c48&utm_source=hasura&utm_campaign=readme) | [docs](https://docs.hasura.io/1.0/graphql/manual/guides/deployment/digital-ocean-one-click.html#hasura-graphql-engine-digitalocean-one-click-app) |
| Azure | [![Deploy to Azure](http://azuredeploy.net/deploybutton.png)](https://portal.azure.com/#create/Microsoft.Template/uri/https%3a%2f%2fraw.githubusercontent.com%2fhasura%2fgraphql-engine%2fmaster%2finstall-manifests%2fazure-container-with-pg%2fazuredeploy.json) | [docs](https://docs.hasura.io/1.0/graphql/manual/guides/deployment/azure-container-instances-postgres.html) |

### Other deployment methods

For Docker-based deployment and advanced configuration options, see [deployment
guides](https://docs.hasura.io/1.0/graphql/manual/getting-started/index.html) or
[install manifests](install-manifests).

## Architecture

The Hasura GraphQL Engine fronts a Postgres database instance and can accept GraphQL requests from your client apps. It can be configured to work with your existing auth system and can handle access control using field-level rules with dynamic variables from your auth system.

You can also merge remote GraphQL schemas and provide a unified GraphQL API.

![Hasura GraphQL Engine architecture](assets/hasura-arch.svg)

## Client-side tooling

Hasura works with any GraphQL client. We recommend using [Apollo Client](https://github.com/apollographql/apollo-client). See [awesome-graphql](https://github.com/chentsulin/awesome-graphql) for a list of clients.

## Add business logic

GraphQL Engine provides easy-to-reason, scalable and performant methods for adding custom business logic to your backend:

### Remote schemas

Add custom resolvers in a remote schema in addition to Hasura's Postgres-based GraphQL schema. Ideal for use-cases like implementing a payment API, or querying data that is not in your database - [read more](remote-schemas.md).

### Trigger webhooks on database events

Add asynchronous business logic that is triggered based on database events.
Ideal for notifications, data-pipelines from Postgres or asynchronous
processing - [read more](event-triggers.md).

### Derived data or data transformations

Transform data in Postgres or run business logic on it to derive another dataset that can be queried using GraphQL Engine - [read more](https://docs.hasura.io/1.0/graphql/manual/queries/derived-data.html).

## Demos

Check out all the example applications in the
[community/examples](community/examples) directory.

### Realtime applications

- Group Chat application built with React, includes a typing indicator, online users & new
  message notifications.
  - [Try it out](https://realtime-chat.demo.hasura.app/)
  - [Tutorial](community/examples/realtime-chat)
  - [Browse APIs](https://realtime-chat.demo.hasura.app/console)

- Live location tracking app that shows a running vehicle changing current GPS
  coordinates moving on a map.
  - [Try it out](https://realtime-location-tracking.demo.hasura.app/)
  - [Tutorial](community/examples/realtime-location-tracking)
  - [Browse APIs](https://realtime-location-tracking.demo.hasura.app/console)

- A realtime dashboard for data aggregations on continuously changing data.
  - [Try it out](https://realtime-poll.demo.hasura.app/)
  - [Tutorial](community/examples/realtime-poll)
  - [Browse APIs](https://realtime-poll.demo.hasura.app/console)

### Videos

* [Add GraphQL to a self-hosted GitLab instance](https://www.youtube.com/watch?v=a2AhxKqd82Q) (*3:44 mins*)
* [Todo app with Auth0 and GraphQL backend](https://www.youtube.com/watch?v=15ITBYnccgc) (*4:00 mins*)
* [GraphQL on GitLab integrated with GitLab auth](https://www.youtube.com/watch?v=m1ChRhRLq7o) (*4:05 mins*)
* [Dashboard for 10million rides with geo-location (PostGIS, Timescale)](https://www.youtube.com/watch?v=tsY573yyGWA) (*3:06 mins*)


## Support & Troubleshooting

The documentation and community will help you troubleshoot most issues. If you have encountered a bug or need to get in touch with us, you can contact us using one of the following channels:

* Support & feedback: [Discord](https://discord.gg/vBPpJkS)
* Issue & bug tracking: [GitHub issues](https://github.com/hasura/graphql-engine/issues)
* Follow product updates: [@HasuraHQ](https://twitter.com/hasurahq)
* Talk to us on our [website chat](https://hasura.io)

We are committed to fostering an open and welcoming environment in the community. Please see the [Code of Conduct](code-of-conduct.md).

If you want to report a security issue, please [read this](SECURITY.md).

## Contributing

Check out our [contributing guide](CONTRIBUTING.md) for more details.

## Brand assets

Hasura brand assets (logos, the Hasura mascot, powered by badges etc.) can be
found in the [assets/brand](assets/brand) folder. Feel free to use them in your
application/website etc. We'd be thrilled if you add the "Powered by Hasura"
badge to your applications built using Hasura. ❤️

<div style="display: flex;">
  <img src="assets/brand/powered_by_hasura_blue.svg" width="150px"/>
  <img src="assets/brand/powered_by_hasura_white.svg" width="150px"/>
</div>

```html
<!-- For light backgrounds -->
<a href="https://hasura.io">
  <img width="150px" src="https://graphql-engine-cdn.hasura.io/img/powered_by_hasura_blue.svg" />
</a>

<!-- For dark backgrounds -->
<a href="https://hasura.io">
  <img width="150px" src="https://graphql-engine-cdn.hasura.io/img/powered_by_hasura_white.svg" />
</a>
```

## License

The core GraphQL Engine is available under the [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0) (Apache-2.0).

All **other contents** (except those in [`server`](server), [`cli`](cli) and
[`console`](console) directories) are available under the [MIT License](LICENSE-community).
This includes everything in the [`docs`](docs) and [`community`](community)
directories.

## Translations

This readme is available in the following translations:

- [Japanese :jp:](translations/README.japanese.md) (:pray: [@moksahero](https://github.com/moksahero))
- [French :fr:](translations/README.french.md) (:pray: [@l0ck3](https://github.com/l0ck3))

Translations for other files can be found [here](translations).