> ## Documentation Index
> Fetch the complete documentation index at: https://braintrust.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Baseten

> Baseten model provider configuration and integration guide

If you are a coding agent, prefer the Braintrust [`bt` CLI](/reference/cli/quickstart) for repeatable, scriptable work: running evals, instrumenting code, querying logs, syncing data, managing functions, and configuring coding agents. Use the MCP server for reasoning over Braintrust data in conversation, such as ad-hoc lookups and exploration from your IDE.

Baseten provides scalable infrastructure for deploying and serving machine learning models, including language models and custom AI applications. Braintrust integrates seamlessly with Baseten through direct API access, wrapper functions for automatic tracing, and proxy support.

## Setup

To use Baseten models, configure your Baseten API key in Braintrust.

1. Get a Baseten API key from the [Baseten console](https://app.baseten.co/settings/api-keys).
2. Add the Baseten API key as an [organization or project AI provider](/admin/ai-providers).
3. Optional: Set **API base URL** if your models are served from a custom Baseten deployment endpoint (for example, a [dedicated deployment](https://docs.baseten.co/deployments/dedicated)).

   If you leave this blank, Braintrust uses the default Baseten endpoint.
4. Set the Baseten API key and your Braintrust API key as environment variables.

```bash title=".env" theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
BASETEN_API_KEY=<your-baseten-api-key>
BRAINTRUST_API_KEY=<your-braintrust-api-key>

# For organizations on the EU data plane, use https://api-eu.braintrust.dev
# For self-hosted deployments, use your data plane URL
# BRAINTRUST_API_URL=<your-braintrust-api-url>
```

<Note>
  API keys are stored as one-way cryptographic hashes, never in plaintext.
</Note>

## Use Baseten with Braintrust gateway

The [Braintrust gateway](/deploy/gateway) allows you to access Baseten models through a unified interface. Use any [supported provider's SDK](/integrations/ai-providers) to call Baseten models.

Install the `braintrust` and `openai` packages.

<CodeGroup>
  ```bash Typescript theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  # pnpm
  pnpm add braintrust openai
  # npm
  npm install braintrust openai
  ```

  ```bash Python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  pip install braintrust openai
  ```
</CodeGroup>

Then, initialize the client and make a request to a Baseten model via the Braintrust gateway.

<CodeGroup dropdown>
  ```typescript theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import { OpenAI } from "openai";

  const client = new OpenAI({
    baseURL: "https://gateway.braintrust.dev/v1",
    apiKey: process.env.BRAINTRUST_API_KEY,
  });

  const response = await client.chat.completions.create({
    model: "gpt-oss-120b",
    messages: [{ role: "user", content: "Hello, world!" }],
  });
  ```

  ```python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import os

  from openai import OpenAI

  client = OpenAI(
      base_url="https://gateway.braintrust.dev/v1",
      api_key=os.environ["BRAINTRUST_API_KEY"],
  )

  response = client.chat.completions.create(
      model="gpt-oss-120b",
      messages=[{"role": "user", "content": "Hello, world!"}],
  )
  ```
</CodeGroup>

## Trace logs with Baseten

Trace your Baseten LLM calls for observability and monitoring.

When using the Braintrust gateway, API calls are automatically logged to the specified project.

<CodeGroup dropdown>
  ```typescript theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import { OpenAI } from "openai";
  import { initLogger } from "braintrust";

  initLogger({
    projectName: "My Project",
    apiKey: process.env.BRAINTRUST_API_KEY,
  });

  const client = new OpenAI({
    baseURL: "https://gateway.braintrust.dev/v1",
    apiKey: process.env.BRAINTRUST_API_KEY,
  });

  // All API calls are automatically logged
  const result = await client.chat.completions.create({
    model: "gpt-oss-120b",
    messages: [{ role: "user", content: "What is machine learning?" }],
  });
  ```

  ```python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import os

  from braintrust import init_logger
  from openai import OpenAI

  init_logger(project="My Project")

  client = OpenAI(
      base_url="https://gateway.braintrust.dev/v1",
      api_key=os.environ["BRAINTRUST_API_KEY"],
  )

  # All API calls are automatically logged
  result = client.chat.completions.create(
      model="gpt-oss-120b",
      messages=[{"role": "user", "content": "What is machine learning?"}],
  )
  ```
</CodeGroup>

<Tip>
  The Braintrust gateway is not required. For more control, learn how to [customize traces](/instrument/advanced-tracing).
</Tip>

## Evaluate with Baseten

Evaluations distill the non-deterministic outputs of Baseten models into an effective feedback loop that enables you to ship more reliable, higher quality products. Braintrust `Eval` is a simple function composed of a dataset of user inputs, a task, and a set of scorers. To learn more about evaluations, check out the [Experiments](/evaluate/run-evaluations) guide.

<CodeGroup dropdown>
  ```typescript theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import { Eval } from "braintrust";
  import { OpenAI } from "openai";

  const client = new OpenAI({
    baseURL: "https://gateway.braintrust.dev/v1",
    apiKey: process.env.BRAINTRUST_API_KEY,
  });

  Eval("Baseten Evaluation", {
    data: () => [
      { input: "What is 2+2?", expected: "4" },
      { input: "What is the capital of France?", expected: "Paris" },
    ],
    task: async (input) => {
      const response = await client.chat.completions.create({
        model: "openai/gpt-oss-120b",
        messages: [{ role: "user", content: input }],
      });
      return response.choices[0].message.content;
    },
    scores: [
      {
        name: "accuracy",
        scorer: (args) => (args.output === args.expected ? 1 : 0),
      },
    ],
  });
  ```

  ```python theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
  import os

  from braintrust import Eval
  from openai import OpenAI

  client = OpenAI(
      base_url="https://gateway.braintrust.dev/v1",
      api_key=os.environ["BRAINTRUST_API_KEY"],
  )


  def task(input):
      response = client.chat.completions.create(
          model="openai/gpt-oss-120b",
          messages=[{"role": "user", "content": input}],
      )
      return response.choices[0].message.content


  def accuracy_scorer(output, expected, **kwargs):
      return 1 if output == expected else 0


  Eval(
      "Baseten Evaluation",
      data=[
          {"input": "What is 2+2?", "expected": "4"},
          {"input": "What is the capital of France?", "expected": "Paris"},
      ],
      task=task,
      scores=[accuracy_scorer],
  )
  ```
</CodeGroup>

<Tip>
  To learn more about tool use, multimodal support, attachments, and masking sensitive data with Baseten, visit the [customize traces](/instrument/advanced-tracing) guide.
</Tip>