OpenRouter

OpenRouter provides a unified API to access various AI models from different providers. You can use GenSX with OpenRouter by configuring the OpenAI client with OpenRouter’s API endpoint.

Installation

To use OpenRouter with GenSX, you need to install the @gensx/openai package:


npm install @gensx/openai

Configuration

Configure the OpenAI client with your OpenRouter API key and the OpenRouter base URL:


import { OpenAI } from "@gensx/openai";
 
const client = new OpenAI({
  apiKey: process.env.OPENROUTER_API_KEY,
  baseURL: "https://openrouter.ai/api/v1",
});

Example Usage

Here’s a complete example of using OpenRouter with GenSX:


import { OpenAI } from "@gensx/openai";
 
interface RespondProps {
  userInput: string;
}
type RespondOutput = string;
 
const GenerateText = gensx.Component<RespondProps, RespondOutput>(
  "GenerateText",
  async ({ userInput }) => {
    const result = await client.chat.completions.create({
      model: "anthropic/claude-sonnet-4",
      messages: [
        {
          role: "system",
          content: "You are a helpful assistant. Respond to the user's input.",
        },
        { role: "user", content: userInput },
      ],
      provider: {
        ignore: ["Anthropic"],
      },
    });
    return result.choices[0].message.content ?? "";
  },
);
 
const OpenRouterWorkflow = gensx.Component<{ userInput: string }, string>(
  "OpenRouter",
  async ({ userInput }: { userInput: string }) => {
    const result = await GenerateText({ userInput });
    return result;
  },
);
 
const result = await OpenRouterWorkflow.run({
  userInput: "Hi there! Write me a short story about a cat that can fly.",
});

Specifying Models

When using OpenRouter, you can specify models using their full identifiers:

anthropic/claude-sonnet-4
openai/gpt-4.1
google/gemini-2.5-pro-preview
meta-llama/llama-3.3-70b-instruct

Check the OpenRouter documentation for a complete list of available models.

Provider Options

You can use the provider property in the openai.chat.completions.create method to specify OpenRouter-specific options:


openai.chat.completions.create({
  model: "anthropic/claude-sonnet-4",
  messages: [
    /* your messages */
  ],
  provider: {
    ignore: ["Anthropic"], // Ignore specific providers
    route: "fallback", // Use fallback routing strategy
  },
});