---
title: Gateway quickstart
description: Get AI Gateway access, create a key, and point Claude Code, Codex, the OpenAI or Anthropic SDK, or curl at https://api.agentlab.cresclab.com. Copyable steps.
url: https://agentlab.cresclab.com/docs/en/gateway/quickstart
language: en
updated: 2026-10-28
---

# Gateway quickstart

Get AI Gateway access, create a key, and point Claude Code, Codex, the OpenAI or Anthropic SDK, or curl at https://api.agentlab.cresclab.com. Copyable steps.

## Before you start

1. **Open the Gateway** Sign up in the [Agent Lab console](https://app.agentlab.cresclab.com/) and open **AI Gateway** in your workspace. If the Gateway is not on yet, request access on the [AI Gateway page](https://agentlab.cresclab.com/en/gateway#demo) and we turn it on for your workspace; the console page says the same.
2. **Create a key** On the **Get started** tab, select **Create API key** and give it a name. The key is shown once; copy it now.
3. **Pick a client** Follow one of the sections below. The console's **Get started** tab shows the same steps with your key and your workspace's models filled in.

Every example reads the key from the `AGENTLAB_API_KEY` environment variable:

```bash
export AGENTLAB_API_KEY=<your API key>
```

Model names come from `GET /v1/models`, which lists `auto` and every model your workspace allows. The names below are examples.

## Claude Code

Claude Code speaks Anthropic Messages and adds `/v1/messages` itself, so its base URL has no `/v1`. It checks the model name before sending, so it keeps a Claude model name and asks for `auto` with a header.

```bash
export ANTHROPIC_BASE_URL=https://api.agentlab.cresclab.com
export ANTHROPIC_AUTH_TOKEN=$AGENTLAB_API_KEY
export ANTHROPIC_MODEL=claude-sonnet-5-5
export ANTHROPIC_CUSTOM_HEADERS="X-AgentLab-Routing: auto"
export ANTHROPIC_DEFAULT_HAIKU_MODEL=claude-haiku-5-5
claude
```

Leave out the `ANTHROPIC_CUSTOM_HEADERS` line to always use the model you named. The haiku line sends Claude Code's small background calls to a cheap model.

## Codex

Codex speaks OpenAI Responses. Add a provider to `~/.codex/config.toml`:

```toml ~/.codex/config.toml
model = "gpt-5.6-luna"
model_provider = "agentlab"

[model_providers.agentlab]
name = "Agent Lab"
base_url = "https://api.agentlab.cresclab.com/v1"
wire_api = "responses"
env_key = "AGENTLAB_API_KEY"
http_headers = { "X-AgentLab-Routing" = "auto" }
```

Then run it:

```bash
codex
```

Remove the `http_headers` line to always use the model you named.

## OpenAI SDK

```bash
pip install openai
```

```python
import os
from openai import OpenAI

client = OpenAI(base_url="https://api.agentlab.cresclab.com/v1", api_key=os.environ["AGENTLAB_API_KEY"])
reply = client.chat.completions.create(
    model="auto",
    messages=[{"role": "user", "content": "Hello"}],
)
print(reply.model, reply.choices[0].message.content)
```

`reply.model` is the model that answered.

## Anthropic SDK

```bash
pip install anthropic
```

```python
import os
from anthropic import Anthropic

client = Anthropic(base_url="https://api.agentlab.cresclab.com", api_key=os.environ["AGENTLAB_API_KEY"])
reply = client.messages.create(
    model="auto",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}],
)
print(reply.model, reply.content[0].text)
```

## curl

Chat Completions:

```bash
curl https://api.agentlab.cresclab.com/v1/chat/completions \
  -H "Authorization: Bearer $AGENTLAB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "auto", "messages": [{"role": "user", "content": "Hello"}]}'
```

Anthropic Messages:

```bash
curl https://api.agentlab.cresclab.com/v1/messages \
  -H "Authorization: Bearer $AGENTLAB_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{"model": "auto", "max_tokens": 1024, "messages": [{"role": "user", "content": "Hello"}]}'
```

OpenAI Responses:

```bash
curl https://api.agentlab.cresclab.com/v1/responses \
  -H "Authorization: Bearer $AGENTLAB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "auto", "input": "Hello"}'
```

## Tag requests

To see spend by team, feature or customer, add the `X-AgentLab-Metadata` header with one JSON object of string values, such as `{"team": "support"}`. It works with every endpoint above. See [tags](https://agentlab.cresclab.com/docs/en/gateway/usage.md#tags) for the limits and where they show up.

## Check it worked

Open **AI Gateway › Usage** in the console. The request is listed with its key, the model that answered and its cost. If a request was refused, its code is in [Errors](https://agentlab.cresclab.com/docs/en/gateway/errors.md).