feat: add @langchain/openrouter provider support

- Create OpenRouter provider with static createInstance() factory
- Add env vars: OPENROUTER_MODEL, OPENROUTER_API_KEY, OPENROUTER_TEMPERATURE, OPENROUTER_BASE_URL
- Update LLMProviderType union to include ChatOpenRouter
- Add package.json exports and typesVersions entries

Co-authored-by: opencode <opencode-agent[bot]@users.noreply.github.com>

Author: sf-sahil-jassal

package-lock.json

@@ -41,6 +41,10 @@
       "type": "./dist/sub-modules/providers/groq/index.d.ts",
       "default": "./dist/sub-modules/providers/groq/index.js"
     },
+    "./openrouter": {
+      "type": "./dist/sub-modules/providers/openrouter/index.d.ts",
+      "default": "./dist/sub-modules/providers/openrouter/index.js"
+    },
     "./pg": {
       "type": "./dist/sub-modules/providers/pg/index.d.ts",
       "default": "./dist/sub-modules/providers/pg/index.js"
@@ -77,6 +81,9 @@
       "groq": [
         "dist/sub-modules/providers/groq/index.d.ts"
       ],
+      "openrouter": [
+        "dist/sub-modules/providers/openrouter/index.d.ts"
+      ],
       "pg": [
         "dist/sub-modules/providers/pg/index.d.ts"
       ],
@@ -153,6 +160,7 @@
     "@langchain/groq": "^1.2.0",
     "@langchain/ollama": "^1.2.6",
     "@langchain/openai": "^1.4.4",
+    "@langchain/openrouter": "^0.2.2",
     "@langfuse/core": "^5.1.0",
     "@langfuse/langchain": "^5.1.0",
     "@loopback/build": "^11.0.9",

package.json

@@ -0,0 +1 @@
+export * from './llms';

src/sub-modules/providers/openrouter/index.ts

@@ -0,0 +1 @@
+export * from './openrouter.provider';

src/sub-modules/providers/openrouter/llms/index.ts

@@ -0,0 +1,30 @@
+import {Provider} from '@loopback/core';
+import {ChatOpenRouter} from '@langchain/openrouter';
+import {LLMProvider} from '../../../../types';
+import {OpenRouterInstanceConfig} from '../types';
+
+export class OpenRouter implements Provider<LLMProvider> {
+  static createInstance(config: OpenRouterInstanceConfig): ChatOpenRouter {
+    return new ChatOpenRouter({
+      model: config.model,
+      ...config.config,
+    });
+  }
+  value(): LLMProvider {
+    if (!process.env.OPENROUTER_MODEL || !process.env.OPENROUTER_API_KEY) {
+      throw new Error(
+        'OPENROUTER_MODEL and OPENROUTER_API_KEY environment variables must be set.',
+      );
+    }
+    return OpenRouter.createInstance({
+      model: process.env.OPENROUTER_MODEL,
+      config: {
+        apiKey: process.env.OPENROUTER_API_KEY,
+        temperature: Number.parseFloat(
+          process.env.OPENROUTER_TEMPERATURE ?? '0',
+        ),
+        baseURL: process.env.OPENROUTER_BASE_URL,
+      },
+    });
+  }
+}

src/sub-modules/providers/openrouter/llms/openrouter.provider.ts

@@ -0,0 +1,6 @@
+import {ChatOpenRouterInput} from '@langchain/openrouter';
+
+export type OpenRouterInstanceConfig = {
+  model: string;
+  config: Omit<ChatOpenRouterInput, 'model'>;
+};

src/sub-modules/providers/openrouter/types.ts

@@ -12,6 +12,7 @@ import {Provider} from '@loopback/core';
 import {AnyObject} from '@loopback/repository';
 import {IGraphTool} from './graphs/types';
 import {ChatGroq} from '@langchain/groq';
+import {ChatOpenRouter} from '@langchain/openrouter';
 
 export enum SupportedDBs {
   PostgreSQL = 'PostgreSQL',
@@ -43,7 +44,8 @@ export type LLMProviderType =
   | ChatAnthropic
   | ChatBedrockConverse
   | ChatGoogleGenerativeAI
-  | ChatGroq;
+  | ChatGroq
+  | ChatOpenRouter;
 
 export type LLMProvider = LLMProviderType & {
   getFile?: FileMessageBuilder;