Proxy Endpoints

Complete reference for Metrion’s proxy endpoints.

Metrion acts as a transparent proxy between your application and AI providers. All proxy endpoints accept the same request body as the original provider API — Metrion forwards your request and returns the original response unchanged.

Endpoints

Provider	Method	Endpoint	SDK base URL
Anthropic (SDK)	POST	https://www.metrion.dev/api/proxy/v1/messages	https://www.metrion.dev/api/proxy
Anthropic (direct)	POST	https://www.metrion.dev/api/proxy/messages	— for curl / direct HTTP requests
OpenAI	POST	https://www.metrion.dev/api/proxy/openai/v1/chat/completions	https://www.metrion.dev/api/proxy/openai
Google Gemini	POST	https://www.metrion.dev/api/proxy/gemini/v1/chat/completions	https://www.metrion.dev/api/proxy/gemini
Mistral	POST	https://www.metrion.dev/api/proxy/mistral/v1/chat/completions	https://www.metrion.dev/api/proxy/mistral
Grok (xAI)	POST	https://www.metrion.dev/api/proxy/grok/v1/chat/completions	https://www.metrion.dev/api/proxy/grok

Request body

Send the same request body you would send directly to the provider. Metrion does not modify your request payload.

// Anthropic example
{
  "model": "claude-opus-4-6",
  "max_tokens": 1024,
  "messages": [{ "role": "user", "content": "Hello" }]
}

// OpenAI-compatible example (OpenAI, Gemini, Mistral, Grok)
{
  "model": "gpt-4o",
  "messages": [{ "role": "user", "content": "Hello" }]
}

Response body

The response body is identical to what the provider returns. Metrion only reads usage metadata (token counts, latency) from the response — it does not alter the response structure or content.

Streaming

Streaming is supported for all providers. Pass stream: true in the request body exactly as you would with the provider’s API directly — no additional configuration is needed.

{
  "model": "gpt-4o",
  "stream": true,
  "messages": [{ "role": "user", "content": "Hello" }]
}

Limits

Parameter	Value
Rate limit	100 requests per minute, per Metrion token
Timeout	30 seconds
Free plan monthly cap	10,000 requests per month

If you exceed the monthly cap on the Free plan, the proxy returns a 429 Too Many Requests response. Your counter resets on the first of each month. To remove the monthly cap, upgrade to Pro.