OpenAI

Route your OpenAI requests through Metrion to track token usage, costs, and latency — with a one-line SDK change.

Use Metrion as a drop-in proxy for OpenAI’s API. Point the OpenAI SDK at Metrion’s endpoint and use your sk-metrion-xxx token as the API key. Everything else stays the same.

Prerequisites

• A Metrion account with your sk-metrion-xxx token (find it on the Integrate page)
• An OpenAI API key saved in Metrion’s Integrate page

Setup

Direct HTTP

curl https://www.metrion.dev/api/proxy/openai/v1/chat/completions \
  -H 'Authorization: Bearer sk-metrion-xxx' \
  -H 'content-type: application/json' \
  -d '{
    "model": "gpt-4o",
    "max_tokens": 1024,
    "messages": [{"role": "user", "content": "Hello, world!"}]
  }'

Supported models

Model ID	Notes
gpt-4o	Latest multimodal flagship
gpt-4o-mini	Fast and cost-efficient
gpt-4-turbo	High-context window
gpt-3.5-turbo	Low-cost general purpose
o1	Advanced reasoning
o3-mini	Compact reasoning model

Metrion uses prefix matching for versioned model IDs (e.g. gpt-4o-mini-2024-07-18 resolves to gpt-4o-mini pricing).

Pass-through mode

To use your own OpenAI key without storing it in Metrion, pass it in Authorization: Bearer and identify your Metrion account with the x-metrion-token header:

TypeScript

import OpenAI from 'openai'

const client = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY,      // your OpenAI key directly
  baseURL: 'https://www.metrion.dev/api/proxy/openai',
  defaultHeaders: {
    'x-metrion-token': 'sk-metrion-xxx',   // identifies your Metrion account
  },
})

In pass-through mode, your OpenAI key is forwarded directly to OpenAI’s API and is never stored by Metrion.

Track requests by user or service

Add the optional x-metrion-user header to tag individual requests. These labels appear in your Metrion logs and dashboards.

Use x-metrion-user to break down costs by team member, bot, or application — for example "x-metrion-user": "agent-classifier" or "x-metrion-user": "user-99".

TypeScript

const client = new OpenAI({
  apiKey: 'sk-metrion-xxx',
  baseURL: 'https://www.metrion.dev/api/proxy/openai',
  defaultHeaders: {
    'x-metrion-user': 'user-99',
  },
})