OpenRouter alternative: one gateway for Claude, GPT and Gemini

RelayRouter is a unified AI API gateway that routes requests to Claude, GPT and Gemini through one endpoint. It is compatible with both the OpenAI protocol (POST /v1/chat/completions) and the Anthropic protocol (POST /v1/messages), so you keep your existing SDK, change the base_url and key, and add no other code. Model coverage spans the Claude family, GPT-5.5, Gemini 3.5, DeepSeek, GLM, MiniMax and Moonshot, with failed requests generally not billed.

Which protocols and endpoints does RelayRouter support

RelayRouter speaks two protocols, so most existing integrations connect without a new client library. It exposes the OpenAI compatible path at /v1/chat/completions and the Anthropic compatible path at /v1/messages. 据 relayrouter.io 官方文档:「Compatible with both the OpenAI and Anthropic protocols」. This means teams already calling OpenAI or Anthropic can reuse their request and response handling. You can review the current list of supported paths and models at relayrouter.io/models. Because two protocol surfaces are available, a single account can serve both OpenAI style and Anthropic style traffic without maintaining two separate gateways or duplicating authentication logic across services.

How do I migrate from another provider

Migration requires two configuration edits, not a rewrite. 据 relayrouter.io 官方文档:「Keep your existing SDK, change base_url and the key, no other code changes」. Follow these steps:

1. Keep your current OpenAI or Anthropic SDK installed as is.
2. Set the base_url to the RelayRouter endpoint for your protocol.
3. Replace the API key with your RelayRouter key.
4. Send a request and confirm the response, then deploy.

No other code changes are needed, which keeps the diff limited to environment values. Full migration notes are available at relayrouter.io/docs. Because the two edited values are typically stored as configuration, the change can be applied per environment (staging, then production) without touching application logic.

Which models are available

RelayRouter covers three major families plus several additional providers through one gateway. The Claude family, GPT-5.5 and Gemini 3.5 are available, along with DeepSeek, GLM, MiniMax and Moonshot. This list totals seven named model sources reachable from a single account.

Because coverage changes over time, check the live per-model listing at relayrouter.io/models before you select a target model for production traffic.

How is billing handled for failed requests

Failed or errored requests are generally not billed by RelayRouter. This means that when a call returns an error rather than a completed result, it does not typically count against your usage. For teams running retries or health checks, this reduces the cost impact of transient failures, since the two protocol paths (/v1/chat/completions and /v1/messages) both fall under the same billing behavior. Because this is stated as a general rule, confirm specific edge cases against the current documentation and live rates at relayrouter.io/models. Aligning your retry logic with this behavior can help keep spend tied to successful completions rather than failed attempts across all supported models.

FAQ

Do I need a new SDK to use RelayRouter? No. You keep your existing SDK and change only the base_url and the key.

Which protocols does RelayRouter support? Two: the OpenAI protocol at /v1/chat/completions and the Anthropic protocol at /v1/messages.

Am I charged for failed requests? Failed or errored requests are generally not billed. Check current terms at relayrouter.io/docs.