From fd005be844d91f821eb4ecd69c40f08afba7ae28 Mon Sep 17 00:00:00 2001
From: cosmic-snow <134004613+cosmic-snow@users.noreply.github.com>
Date: Tue, 9 Jul 2024 19:08:20 +0200
Subject: [PATCH] GPT4All Chat server API: add errors 405 Method Not Allowed
 (#2615)

Add a HTTP status code 405 Method Not Allowed for each of the four handlers
when the wrong method (GET/POST) is used. This mimics the OpenAI API response.

Signed-off-by: cosmic-snow <134004613+cosmic-snow@users.noreply.github.com>
---
 gpt4all-chat/server.cpp | 47 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/gpt4all-chat/server.cpp b/gpt4all-chat/server.cpp
index 9b5819a4..af11663a 100644
--- a/gpt4all-chat/server.cpp
+++ b/gpt4all-chat/server.cpp
@@ -147,6 +147,53 @@ void Server::start()
         }
     );
 
+    // Respond with code 405 to wrong HTTP methods:
+    m_server->route("/v1/models",  QHttpServerRequest::Method::Post,
+        [](const QHttpServerRequest &request) {
+            if (!MySettings::globalInstance()->serverChat())
+                return QHttpServerResponse(QHttpServerResponder::StatusCode::Unauthorized);
+            return QHttpServerResponse(
+                QJsonDocument::fromJson("{\"error\": {\"message\": \"Not allowed to POST on /v1/models."
+                    " (HINT: Perhaps you meant to use a different HTTP method?)\","
+                    " \"type\": \"invalid_request_error\", \"param\": null, \"code\": null}}").object(),
+                QHttpServerResponder::StatusCode::MethodNotAllowed);
+        }
+    );
+
+    m_server->route("/v1/models/<arg>", QHttpServerRequest::Method::Post,
+        [](const QString &model, const QHttpServerRequest &request) {
+            if (!MySettings::globalInstance()->serverChat())
+                return QHttpServerResponse(QHttpServerResponder::StatusCode::Unauthorized);
+            return QHttpServerResponse(
+                QJsonDocument::fromJson("{\"error\": {\"message\": \"Not allowed to POST on /v1/models/*."
+                    " (HINT: Perhaps you meant to use a different HTTP method?)\","
+                    " \"type\": \"invalid_request_error\", \"param\": null, \"code\": null}}").object(),
+                QHttpServerResponder::StatusCode::MethodNotAllowed);
+        }
+    );
+
+    m_server->route("/v1/completions", QHttpServerRequest::Method::Get,
+        [](const QHttpServerRequest &request) {
+            if (!MySettings::globalInstance()->serverChat())
+                return QHttpServerResponse(QHttpServerResponder::StatusCode::Unauthorized);
+            return QHttpServerResponse(
+                QJsonDocument::fromJson("{\"error\": {\"message\": \"Only POST requests are accepted.\","
+                    " \"type\": \"invalid_request_error\", \"param\": null, \"code\": \"method_not_supported\"}}").object(),
+                QHttpServerResponder::StatusCode::MethodNotAllowed);
+        }
+    );
+
+    m_server->route("/v1/chat/completions", QHttpServerRequest::Method::Get,
+        [](const QHttpServerRequest &request) {
+            if (!MySettings::globalInstance()->serverChat())
+                return QHttpServerResponse(QHttpServerResponder::StatusCode::Unauthorized);
+            return QHttpServerResponse(
+                QJsonDocument::fromJson("{\"error\": {\"message\": \"Only POST requests are accepted.\","
+                    " \"type\": \"invalid_request_error\", \"param\": null, \"code\": \"method_not_supported\"}}").object(),
+                QHttpServerResponder::StatusCode::MethodNotAllowed);
+        }
+    );
+
     m_server->afterRequest([] (QHttpServerResponse &&resp) {
         resp.addHeader("Access-Control-Allow-Origin", "*");
         return std::move(resp);