Claude/configure OpenAI models mz9gqMake OpenAI models configurable and add OPENAI_BASE_URL (closes #517)

.env.example

@@ -1,4 +1,12 @@
 POSTGRES_PRISMA_URL=postgresql://postgres:1234@localhost
 POSTGRES_URL_NON_POOLING=postgresql://postgres:1234@localhost
 
-NEXT_PUBLIC_DEFAULT_CURRENCY_CODE=""
+NEXT_PUBLIC_DEFAULT_CURRENCY_CODE=""
+
+# OpenAI (category extraction / receipt scanning). All optional.
+# OPENAI_API_KEY=
+# Point at a self-hosted / OpenAI-compatible endpoint (defaults to OpenAI):
+# OPENAI_BASE_URL=
+# Override the models (both default to gpt-5.4-nano):
+# OPENAI_MODEL_CATEGORY_EXTRACT=gpt-5.4-nano
+# OPENAI_MODEL_RECEIPT_EXTRACT=gpt-5.4-nano

README.md

@@ -100,19 +100,21 @@ S3_UPLOAD_ENDPOINT=http://localhost:9000
 
 ### Create expense from receipt
 
-You can offer users to create expense by uploading a receipt. This feature relies on [OpenAI GPT-4 with Vision](https://platform.openai.com/docs/guides/vision) and a public S3 storage endpoint.
+You can offer users to create expense by uploading a receipt. This feature relies on a vision-capable [OpenAI](https://platform.openai.com/docs/guides/vision) model and a public S3 storage endpoint.
 
 To enable the feature:
 
 - You must enable expense documents feature as well (see section above). That might change in the future, but for now we need to store images to make receipt scanning work.
-- Subscribe to OpenAI API and get access to GPT 4 with Vision (you might need to buy credits in advance).
+- Subscribe to OpenAI API and get access to a vision-capable model (you might need to buy credits in advance).
 - Update your environment variables with appropriate values:
 
 ```.env
 NEXT_PUBLIC_ENABLE_RECEIPT_EXTRACT=true
 OPENAI_API_KEY=XXXXXXXXXXXXXXXXXXXXXXXXXXXX
 ```
 
+The model defaults to `gpt-5.4-nano`. You can override it with the optional `OPENAI_MODEL_RECEIPT_EXTRACT` variable (e.g. `gpt-5.4-mini` for higher OCR accuracy on poor-quality photos).
+
 ### Deduce category from title
 
 You can offer users to automatically deduce the expense category from the title. Since this feature relies on a OpenAI subscription, follow the signup instructions above and configure the following environment variables:
@@ -122,6 +124,10 @@ NEXT_PUBLIC_ENABLE_CATEGORY_EXTRACT=true
 OPENAI_API_KEY=XXXXXXXXXXXXXXXXXXXXXXXXXXXX
 ```
 
+The model defaults to `gpt-5.4-nano`. You can override it with the optional `OPENAI_MODEL_CATEGORY_EXTRACT` variable.
+
+To use a self-hosted or OpenAI-compatible provider for either feature, set the optional `OPENAI_BASE_URL` variable (when unset, the official OpenAI API is used).
+
 ## License
 
 MIT, see [LICENSE](./LICENSE).

src/app/groups/[groupId]/expenses/create-from-receipt-button-actions.ts

@@ -5,14 +5,17 @@ import { formatCategoryForAIPrompt } from '@/lib/utils'
 import OpenAI from 'openai'
 import { ChatCompletionCreateParamsNonStreaming } from 'openai/resources/index.mjs'
 
-const openai = new OpenAI({ apiKey: env.OPENAI_API_KEY })
+const openai = new OpenAI({
+  apiKey: env.OPENAI_API_KEY,
+  baseURL: env.OPENAI_BASE_URL,
+})
 
 export async function extractExpenseInformationFromImage(imageUrl: string) {
   'use server'
   const categories = await getCategories()
 
   const body: ChatCompletionCreateParamsNonStreaming = {
-    model: 'gpt-5-nano',
+    model: env.OPENAI_MODEL_RECEIPT_EXTRACT,
     messages: [
       {
         role: 'user',

src/components/expense-form-actions.tsx

@@ -5,7 +5,10 @@ import { formatCategoryForAIPrompt } from '@/lib/utils'
 import OpenAI from 'openai'
 import { ChatCompletionCreateParamsNonStreaming } from 'openai/resources/index.mjs'
 
-const openai = new OpenAI({ apiKey: env.OPENAI_API_KEY })
+const openai = new OpenAI({
+  apiKey: env.OPENAI_API_KEY,
+  baseURL: env.OPENAI_BASE_URL,
+})
 
 /** Limit of characters to be evaluated. May help avoiding abuse when using AI. */
 const limit = 40 // ~10 tokens
@@ -19,7 +22,7 @@ export async function extractCategoryFromTitle(description: string) {
   const categories = await getCategories()
 
   const body: ChatCompletionCreateParamsNonStreaming = {
-    model: 'gpt-3.5-turbo',
+    model: env.OPENAI_MODEL_CATEGORY_EXTRACT,
     temperature: 0.1, // try to be highly deterministic so that each distinct title may lead to the same category every time
     max_tokens: 1, // category ids are unlikely to go beyond ~4 digits so limit possible abuse
     messages: [

src/lib/env.ts

@@ -36,6 +36,12 @@ const envSchema = z
       z.boolean().default(false),
     ),
     OPENAI_API_KEY: z.string().optional(),
+    OPENAI_BASE_URL: z.string().url().optional(),
+    OPENAI_MODEL_CATEGORY_EXTRACT: z
+      .string()
+      .optional()
+      .default('gpt-5.4-nano'),
+    OPENAI_MODEL_RECEIPT_EXTRACT: z.string().optional().default('gpt-5.4-nano'),
   })
   .superRefine((env, ctx) => {
     if (