OpenRouter

OpenRouter is a meta-API that provides access to models from multiple providers through a single interface. You can use OpenAI, Cohere, and other models without separate accounts for each—just one API key and one billing relationship. This is useful when you want flexibility to switch models without changing credentials, or when you want to compare different providers.

OpenRouter uses its own SDK rather than the AI SDK, so the setup is slightly different from other providers.

Setup

Install the OpenRouter SDK package:

bun add @openrouter/sdk

Set your API key in the environment:

OPENROUTER_API_KEY="..."

Configure the provider in your unrag.config.ts:

import { defineUnragConfig } from "./lib/unrag/core";

export const unrag = defineUnragConfig({
  // ...
  embedding: {
    provider: "openrouter",
    config: {
      model: "text-embedding-3-small",
      timeoutMs: 15_000,
    },
  },
} as const);

Configuration options

model specifies which model to use. OpenRouter routes your request to the appropriate provider. If not set, the provider checks the OPENROUTER_EMBEDDING_MODEL environment variable, then falls back to text-embedding-3-small.

timeoutMs sets the request timeout in milliseconds.

apiKey optionally sets the API key in code rather than through environment variables.

baseURL overrides the OpenRouter API URL.

headers adds custom headers to requests.

referer sets the HTTP-Referer header. OpenRouter uses this for analytics and rate limiting.

title sets a title for your application, which appears in OpenRouter's dashboard.

embedding: {
  provider: "openrouter",
  config: {
    model: "text-embedding-3-small",
    referer: "https://myapp.com",
    title: "MyApp Search",
    timeoutMs: 20_000,
  },
},

Available models

OpenRouter provides access to embedding models from various providers. The specific models available depend on OpenRouter's current offerings—check their documentation for the current list.

Common choices include OpenAI's embedding models (text-embedding-3-small, text-embedding-3-large) routed through OpenRouter's infrastructure.

Environment variables

OPENROUTER_API_KEY (required): Your OpenRouter API key.

OPENROUTER_EMBEDDING_MODEL (optional): Overrides the model specified in code.

# .env
OPENROUTER_API_KEY="..."

When to use OpenRouter

Choose OpenRouter when you want a single API key that provides access to multiple providers, or when you're experimenting with different models and want easy switching. It's also useful if you prefer OpenRouter's pricing or billing model.

For production applications with stable model choices, you might prefer going directly to the provider for simpler infrastructure and potentially lower latency.