> ## Documentation Index
> Fetch the complete documentation index at: https://langchain-5e9cc07a-preview-docsde-1785859450-e55f5fa.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# LLM Gateway

> Access models across providers with one LangSmith API key while tracing calls and enforcing spend and data-protection policies.

Use one [LangSmith API key](/langsmith/create-account-api-key) to call models across configured providers. Switch providers by changing the model ID, while the LLM Gateway traces every call and applies centralized governance policies.

<Note>
  **Beta:** The LLM Gateway is in [beta](/langsmith/release-stages).
</Note>

## Make your first request

<Info>
  An administrator must [enable the gateway, add a provider secret, and grant access](/langsmith/llm-gateway-admin-setup) once for your workspace. After setup, developers need only a workspace-scoped LangSmith API key.
</Info>

Set your key and make a standard Chat Completions request. This example assumes the workspace has an Anthropic provider secret:

```bash theme={null}
export LANGSMITH_API_KEY="lsv2_..._....cbed3e"

curl https://gateway.smith.langchain.com/v1/chat/completions \
    -H "Authorization: Bearer $LANGSMITH_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"model":"anthropic/claude-sonnet-4-6","messages":[{"role":"user","content":"Hello!"}]}'
```

A `200` response confirms that the gateway, your LangSmith API key, permissions, and the selected provider secret are configured correctly. For Python, TypeScript, alternative API formats, and troubleshooting, follow the [quickstart](/langsmith/llm-gateway-quickstart).

## What the gateway provides

* **One key, multiple providers:** Developers authenticate with a LangSmith API key instead of storing provider keys locally.
* **One request format, multiple models:** Use Chat Completions, Messages, or Responses with models across configured providers.
* **Built-in observability:** Every gateway call appears as a [LangSmith trace](/langsmith/llm-gateway-access).
* **Central governance:** Apply [spend limits](/langsmith/llm-gateway-spend-policies), [rate limits](/langsmith/llm-gateway-rate-limit-policies), and [data-protection policies](/langsmith/llm-gateway-data-protection).

## Use the standard API

Choose the request format already used by your application. The format does not limit which configured provider you can call.

| API format              | Endpoint                    |
| ----------------------- | --------------------------- |
| OpenAI Chat Completions | `POST /v1/chat/completions` |
| Anthropic Messages      | `POST /v1/messages`         |
| OpenAI Responses        | `POST /v1/responses`        |

Set `model` to a provider-prefixed bring-your-own-key ID such as `openai/gpt-5.4-mini` or `anthropic/claude-opus-5`, or use a [Gateway Credits](/langsmith/llm-gateway-credits) model slug such as `moonshotai/kimi-k3`. The model ID determines the upstream route. When the selected provider uses a different native format, the gateway translates the request and response.

For base URLs, examples, translation behavior, and regional endpoints, see [API formats](/langsmith/llm-gateway-api-formats).

## Choose how credentials are managed

| Option                                            | Upstream credential                                                                                                                  | Setup and billing                                                                 |
| ------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------- |
| Bring your own provider account                   | An administrator stores the provider key in workspace [Provider Secrets](/langsmith/llm-gateway-admin-setup#1-add-provider-secrets). | The provider bills usage to your provider account.                                |
| [Gateway Credits](/langsmith/llm-gateway-credits) | LangChain owns the upstream credential.                                                                                              | No provider secret is required. Invocations are billed to your LangSmith account. |

## Go further

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/langsmith/llm-gateway-quickstart" arrow="true">
    Make a request with cURL, Python, or TypeScript, then view its trace.
  </Card>

  <Card title="Administrator setup" icon="settings" href="/langsmith/llm-gateway-admin-setup" arrow="true">
    Enable the gateway, add provider credentials, and grant developer access.
  </Card>
</CardGroup>

Need provider-native request and response behavior? Use [Direct model access](/langsmith/llm-gateway-direct-model-access) to bypass the standardization layer. This is an advanced alternative to the standard API.

For further questions, contact [LangChain support](https://support.langchain.com).

***

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