add new rate-limited getChatCompletion for compat with AI SDK

Author: vkarpov15

netlify/functions/getChatCompletion.js

@@ -0,0 +1,5 @@
+'use strict';
+
+const extrovert = require('extrovert');
+
+module.exports = extrovert.toNetlifyFunction(require('../../src/actions/getChatCompletion'));

src/actions/getChatCompletion.js

@@ -0,0 +1,66 @@
+'use strict';
+
+const Archetype = require('archetype');
+const connect = require('../../src/db');
+
+const CreateChatMessageParams = new Archetype({
+  messages: [{
+    role: {
+      $type: 'string'
+    },
+    content: [{
+      type: {
+        $type: 'string',
+        $required: true
+      },
+      text: {
+        $type: 'string'
+      }
+    }]
+  }],
+  model: {
+    $type: 'string',
+    $enum: ['gpt-4o', 'gpt-4.1-nano']
+  }
+}).compile('CreateChatMessageParams');
+
+module.exports = async function createChatMessage(params) {
+  const { messages, model } = new CreateChatMessageParams(params);
+
+  if (!messages) {
+    throw new Error('Missing messages');
+  }
+
+  const db = await connect();
+  const { RateLimit } = db.models;
+
+  await RateLimit.checkRateLimit('openai', 1000);
+
+  const res = await getChatCompletion(messages, { model });
+
+  return {
+    response: res.choices?.[0]?.message?.content
+  };
+};
+
+async function getChatCompletion(messages, options = {}) {
+  const response = await fetch('https://api.openai.com/v1/chat/completions', {
+    method: 'POST',
+    headers: {
+      Authorization: `Bearer ${process.env.OPENAI_API_KEY}`,
+      'Content-Type': 'application/json'
+    },
+    body: JSON.stringify({
+      max_tokens: 2500,
+      ...options,
+      model: options?.model || 'gpt-4o',
+      messages
+    })
+  });
+
+  if (!response.ok) {
+    throw new Error(`OpenAI API request failed with status ${response.status}: ${await response.text()}`);
+  }
+
+  return await response.json();
+}