Authentication

All requests to the gateway must be authenticated with a Bearer token — your MetrixLLM API key.

Creating a key

Open your Workspace

Log into app.metrixllm.com and select the workspace you want to create a key for.

Go to API Keys

Click API Keys in the left sidebar.

Create and copy

Click Create API Key, give it a name (e.g. Backend - Production), and click Create. Copy the key immediately — it is shown only once.

API keys are displayed only at the moment of creation. If you lose a key, revoke it and create a new one. Never commit keys to source control — use environment variables.

Key format

MetrixLLM API keys always start with mtx_. This prefix makes them easy to identify and never confused with a raw provider key like sk-....

Using your key

Pass the key as a Bearer token in the Authorization header:

from openai import OpenAI

client = OpenAI(
    base_url="https://gateway.metrixllm.com/openai/v1",
    api_key="mtx_..."
)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://gateway.metrixllm.com/openai/v1",
  apiKey: "mtx_...",
});

curl https://gateway.metrixllm.com/openai/v1/chat/completions \
  -H "Authorization: Bearer mtx_..." \
  -H "Content-Type: application/json" \
  -d '{"model": "gpt-4o", "messages": [{"role": "user", "content": "Hello"}]}'

Revoking a key

Navigate to API Keys in your workspace and click Revoke next to any key. It is invalidated immediately — active requests using it will fail with 401 Unauthorized within seconds.

Key scoping

Keys are scoped to the workspace they were created in. A key from your Production workspace cannot access logs or routing rules from Staging. For additional role restrictions, see RBAC.

Overview

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Gateway API Reference

Creating a key

Key format

Using your key

Revoking a key

Key scoping

​Creating a key

​Key format

​Using your key

​Revoking a key

​Key scoping

Creating a key

Key format

Using your key

Revoking a key

Key scoping