feat: Add support for OpenRouter as an LLM provider.

.env.example

@@ -15,6 +15,9 @@ GOOGLE_API_KEY=""
 MISTRAL_MODEL_NAME="mistral-medium-latest"
 MISTRAL_API_KEY=""
 
+OPENROUTER_MODEL_NAME="openai/gpt-4.1-mini"
+OPENROUTER_API_KEY=""
+
 # Auth Config
 BETTER_AUTH_SECRET="random-secret-key"  # please use any long random string here
 

README.md

@@ -40,7 +40,7 @@ Snap a photo of any receipt or upload an invoice PDF, and TaxHacker will automat
 - **Auto-categorization**: Transactions are automatically sorted into relevant categories based on their content
 - **Item splitting**: Extract individual items from invoices and split them into separate transactions when needed
 - **Structured storage**: Everything gets saved in an organized database for easy filtering and retrieval
-- **Customizable AI providers**: Choose from OpenAI, Google Gemini, or Mistral (local LLM support coming soon)
+- **Customizable AI providers**: Choose from OpenAI, Google Gemini, Mistral and OpenRouter (local LLM support coming soon)
 
 TaxHacker works with a wide variety of documents, including store receipts, restaurant bills, invoices, bank statements, letters, even handwritten receipts. It handles any language and any currency with ease.
 
@@ -163,6 +163,7 @@ You can also configure LLM provider settings in the application or via environme
 - **OpenAI**: `OPENAI_MODEL_NAME` and `OPENAI_API_KEY`
 - **Google Gemini**: `GOOGLE_MODEL_NAME` and `GOOGLE_API_KEY`
 - **Mistral**: `MISTRAL_MODEL_NAME` and `MISTRAL_API_KEY`
+- **OpenRouter**: `OPENROUTER_MODEL_NAME` and `OPENROUTER_API_KEY`
 
 ## ⌨️ Local Development
 

ai/providers/llmProvider.ts

@@ -3,7 +3,7 @@ import { ChatGoogleGenerativeAI } from "@langchain/google-genai"
 import { ChatMistralAI } from "@langchain/mistralai"
 import { BaseMessage, HumanMessage } from "@langchain/core/messages"
 
-export type LLMProvider = "openai" | "google" | "mistral"
+export type LLMProvider = "openai" | "google" | "mistral" | "openrouter"
 
 export interface LLMConfig {
   provider: LLMProvider
@@ -50,6 +50,15 @@ async function requestLLMUnified(config: LLMConfig, req: LLMRequest): Promise<LL
         model: config.model,
         temperature: temperature,
       })
+    } else if (config.provider === "openrouter") {
+      model = new ChatOpenAI({
+        apiKey: config.apiKey,
+        model: config.model,
+        temperature: temperature,
+        configuration: {
+          baseURL: "https://openrouter.ai/api/v1",
+        },
+      })
     } else {
       return {
         output: {},

app/(app)/unsorted/page.tsx

@@ -41,7 +41,8 @@ export default async function UnsortedPage() {
       {config.selfHosted.isEnabled &&
         !settings.openai_api_key &&
         !settings.google_api_key &&
-        !settings.mistral_api_key && (
+        !settings.mistral_api_key &&
+        !settings.openrouter_api_key && (
           <Alert>
             <Settings className="h-4 w-4 mt-2" />
             <div className="flex flex-row justify-between pt-2">

app/(auth)/actions.ts

@@ -16,7 +16,8 @@ export async function selfHostedGetStartedAction(formData: FormData) {
   const apiKeys = [
     "openai_api_key",
     "google_api_key",
-    "mistral_api_key"
+    "mistral_api_key",
+    "openrouter_api_key"
   ]
 
   for (const key of apiKeys) {

app/(auth)/self-hosted/page.tsx

@@ -37,6 +37,7 @@ export default async function SelfHostedWelcomePage() {
     openai: config.ai.openaiApiKey ?? "",
     google: config.ai.googleApiKey ?? "",
     mistral: config.ai.mistralApiKey ?? "",
+    openrouter: config.ai.openrouterApiKey ?? "",
   }
 
   return (

components/settings/llm-settings-form.tsx

@@ -30,7 +30,7 @@ import { PROVIDERS } from "@/lib/llm-providers";
 function getInitialProviderOrder(settings: Record<string, string>) {
   let order: string[] = []
   if (!settings.llm_providers) {
-    order = ['openai', 'google', 'mistral']
+    order = ['openai', 'google', 'mistral', 'openrouter']
   } else {
     order = settings.llm_providers.split(",").map(p => p.trim())
   }

forms/settings.ts

@@ -12,7 +12,9 @@ export const settingsFormSchema = z.object({
   google_model_name: z.string().default("gemini-2.5-flash"),
   mistral_api_key: z.string().optional(),
   mistral_model_name: z.string().default("mistral-medium-latest"),
-  llm_providers: z.string().default('openai,google,mistral'),
+  openrouter_api_key: z.string().optional(),
+  openrouter_model_name: z.string().default("openai/gpt-4o-mini"),
+  llm_providers: z.string().default('openai,google,mistral,openrouter'),
   prompt_analyse_new_file: z.string().optional(),
   is_welcome_message_hidden: z.string().optional(),
 })

lib/config.ts

@@ -10,6 +10,8 @@ const envSchema = z.object({
   GOOGLE_MODEL_NAME: z.string().default("gemini-2.5-flash"),
   MISTRAL_API_KEY: z.string().optional(),
   MISTRAL_MODEL_NAME: z.string().default("mistral-medium-latest"),
+  OPENROUTER_API_KEY: z.string().optional(),
+  OPENROUTER_MODEL_NAME: z.string().default("gpt-4o-mini"),
   BETTER_AUTH_SECRET: z
     .string()
     .min(16, "Auth secret must be at least 16 characters")
@@ -59,6 +61,8 @@ const config = {
     googleModelName: env.GOOGLE_MODEL_NAME,
     mistralApiKey: env.MISTRAL_API_KEY,
     mistralModelName: env.MISTRAL_MODEL_NAME,
+    openrouterApiKey: env.OPENROUTER_API_KEY,
+    openrouterModelName: env.OPENROUTER_MODEL_NAME,
   },
   auth: {
     secret: env.BETTER_AUTH_SECRET,

lib/llm-providers.ts

@@ -44,4 +44,19 @@ export const PROVIDERS = [
     },
     logo: "/logo/mistral.svg"
   },
+  {
+    key: "openrouter",
+    label: "OpenRouter",
+    apiKeyName: "openrouter_api_key",
+    modelName: "openrouter_model_name",
+    defaultModelName: "openai/gpt-4.1-mini",
+    apiDoc: "https://openrouter.ai/keys",
+    apiDocLabel: "OpenRouter Keys",
+    placeholder: "sk-or-...",
+    help: {
+      url: "https://openrouter.ai/keys",
+      label: "OpenRouter Keys"
+    },
+    logo: "/logo/openrouter.svg"
+  },
 ]

models/settings.ts

@@ -9,28 +9,37 @@ export type SettingsMap = Record<string, string>
  * Helper to extract LLM provider settings from SettingsMap.
  */
 export function getLLMSettings(settings: SettingsMap) {
-  const priorities = (settings.llm_providers || "openai,google,mistral").split(",").map(p => p.trim()).filter(Boolean)
+  const priorities = (settings.llm_providers || "openai,google,mistral,openrouter").split(",").map(p => p.trim()).filter(Boolean)
 
   const providers = priorities.map((provider) => {
+    const providerConfig = PROVIDERS.find(p => p.key === provider)
+
     if (provider === "openai") {
       return {
         provider: provider as LLMProvider,
         apiKey: settings.openai_api_key || "",
-        model: settings.openai_model_name || PROVIDERS[0]['defaultModelName'],
+        model: settings.openai_model_name || providerConfig?.defaultModelName || "gpt-4o-mini",
       }
     }
     if (provider === "google") {
       return {
         provider: provider as LLMProvider,
         apiKey: settings.google_api_key || "",
-        model: settings.google_model_name || PROVIDERS[1]['defaultModelName'],
+        model: settings.google_model_name || providerConfig?.defaultModelName || "gemini-2.5-flash",
       }
     }
     if (provider === "mistral") {
       return {
         provider: provider as LLMProvider,
         apiKey: settings.mistral_api_key || "",
-        model: settings.mistral_model_name || PROVIDERS[2]['defaultModelName'],
+        model: settings.mistral_model_name || providerConfig?.defaultModelName || "mistral-medium-latest",
+      }
+    }
+    if (provider === "openrouter") {
+      return {
+        provider: provider as LLMProvider,
+        apiKey: settings.openrouter_api_key || "",
+        model: settings.openrouter_model_name || providerConfig?.defaultModelName || "openai/gpt-4.1-mini",
       }
     }
     return null