> ## 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.

# Networking and connectivity

> Configure URLs, rate limits, load balancer settings, and network access paths for a self-hosted Braintrust data plane.

Use these settings to change where SDKs connect, tune incoming request behavior, and control which external and private services the data plane can reach.

## Client routing

### Customize the webapp URL

The SDKs guide users to `https://www.braintrust.dev` (or the `BRAINTRUST_APP_URL` variable) to view their experiments. In some
advanced configurations, you can reverse proxy traffic to the `BRAINTRUST_APP_URL` from the SDKs while pointing users to a different URL.

To do this, you can set the `BRAINTRUST_APP_PUBLIC_URL` environment variable to the URL of your webapp. By default, this variable is set to the value of `BRAINTRUST_APP_URL`, but you can customize it as you wish. This variable is *only* used to display information, so even its destination does not need to be accessible from the SDK.

<Tabs>
  <Tab title="AWS">
    Set it through the `braintrust_api_extra_env_vars` passthrough map (Terraform module v6.0.0 or later):

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      BRAINTRUST_APP_PUBLIC_URL = "https://braintrust.example.com"
    }
    ```

    Deployments still served by the API Lambda (before module v6.0.0, or v6 with `enable_ecs_api = false`) set the same variable through `service_extra_env_vars.APIHandler` instead.
  </Tab>

  <Tab title="GCP / Azure">
    Add it to `api.extraEnvVars` in your `values.yaml`:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: BRAINTRUST_APP_PUBLIC_URL
          value: "https://braintrust.example.com"
    ```
  </Tab>
</Tabs>

### Constrain SDKs to the data plane

If you're self-hosting the data plane, you can also constrain the SDKs to only communicate with your data plane. Normally, they
communicate with the control plane to:

* Get your data plane's URL
* Register and retrieve metadata (e.g. about experiments)
* Print URLs to the webapp

The data plane can proxy the endpoints that the SDKs use to communicate with the control plane, allowing your SDKs to only communicate with the data plane directly. Set the `BRAINTRUST_APP_URL` environment variable to the URL of your data plane and `BRAINTRUST_APP_PUBLIC_URL` to `https://www.braintrust.dev` (or the URL of your webapp).

<Tabs>
  <Tab title="AWS">
    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      BRAINTRUST_APP_URL        = "https://dataplane.example.com"
      BRAINTRUST_APP_PUBLIC_URL = "https://www.braintrust.dev"
    }
    ```
  </Tab>

  <Tab title="GCP / Azure">
    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: BRAINTRUST_APP_URL
          value: "https://dataplane.example.com"
        - name: BRAINTRUST_APP_PUBLIC_URL
          value: "https://www.braintrust.dev"
    ```
  </Tab>
</Tabs>

## Inbound traffic

### Set HTTPS on the API load balancer

On AWS with the ECS API, an internal Application Load Balancer (ALB) fronts the API services. By default, the ALB serves plain HTTP on port 80 using its AWS-assigned DNS name. To serve HTTPS on a custom domain instead, set both `braintrust_api_alb_certificate_arn` and `braintrust_api_alb_custom_domain` (available in Terraform module v6.0.0 or later):

```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
braintrust_api_alb_certificate_arn = "arn:aws:acm:us-east-1:123456789012:certificate/abc123"
braintrust_api_alb_custom_domain   = "braintrust.internal.example.com"
```

When both are set, the ALB serves HTTPS on port 443, plain HTTP is disabled, and all API URLs use `https://<braintrust_api_alb_custom_domain>`. The certificate must cover the custom domain, and the domain must resolve to the ALB.

<Note>
  These two variables must both be set or both be null. Setting only one fails at plan time.
</Note>

### Set the HTTP keep-alive timeout

When the API server runs behind a load balancer, you may need to configure the HTTP keep-alive timeout to prevent connection resets. Load balancers typically have an idle timeout for connections, and if the API server's keep-alive timeout is shorter than the load balancer's timeout, the API server closes the connection while the load balancer still considers it open. When the load balancer tries to reuse that backend connection, it encounters a closed socket, resulting in connection reset errors and 502 responses.

The API server exposes the following environment variable to configure the keep-alive timeout:

* `TS_API_KEEP_ALIVE_TIMEOUT_SECONDS`: The HTTP keep-alive timeout in seconds. Default: `65`

The default value of 65 seconds is designed to work with most load balancers, including AWS Application Load Balancer (which has a default idle timeout of 60 seconds). However, if your load balancer has a longer idle timeout, you should set this value to match or exceed your load balancer's timeout.

For example, to match an AWS ALB configured with a 300-second idle timeout:

<Tabs>
  <Tab title="AWS">
    Set it through the `braintrust_api_extra_env_vars` passthrough map (Terraform module v6.0.0 or later). This applies to the ECS API services:

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      TS_API_KEEP_ALIVE_TIMEOUT_SECONDS = "300"
    }
    ```
  </Tab>

  <Tab title="GCP / Azure">
    Add it to `api.extraEnvVars` in your `values.yaml`:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: TS_API_KEEP_ALIVE_TIMEOUT_SECONDS
          value: "300"
    ```
  </Tab>
</Tabs>

### Set the CloudFront origin timeout

On AWS, requests are served through CloudFront, which closes a connection and returns `504 Gateway Timeout` if the origin takes too long to respond. Long-running scorers or tools invoked through `/function/invoke` can exceed the default 60-second origin read timeout. Raise it with the `cloudfront_origin_read_timeout` Terraform variable (available in Terraform module v5.3.0 or later):

```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
cloudfront_origin_read_timeout = 120
```

The value must be between 1 and 180 seconds. CloudFront caps the origin read timeout at 180 seconds, and values above 60 seconds can require an AWS Support request to raise the account quota.

### Set inbound request rate limits

The API server can rate-limit log ingestion, SQL queries, and function invocation. Configure each surface separately with its own environment variables for limits, window length, and enforcement.

All three surfaces behave the same way in these respects:

* **Windows**: Each limit uses a fixed window that starts when the first matching request is counted, not on a clock boundary. The counter resets after the configured number of seconds, and the next matching request starts a new window. Rejected requests still count toward the limit.
* **Enforcement**: With enforcement disabled, requests over a limit are allowed and the API server logs a warning. With enforcement enabled, they fail with HTTP 429 and a `Retry-After` header, and the response body reports the configured limit, the window length, and the requests consumed. A limit of `0` is a real zero-request limit, so with enforcement enabled every matching request is rejected.
* **Replicas**: Each limit applies across all API server replicas combined.
* **Restarts**: Rate limit configuration is read once at process start. Restart or redeploy the API services after changing any of these variables.

<Note>
  None of these variables has a dedicated Terraform variable or Helm value, so pass them through your deployment's environment variable map, as shown in the examples below. Variables that take `<id>=<max_requests>` pairs accept a comma-separated list of pairs.
</Note>

#### Limit log ingestion

Log ingestion limits apply per organization and per project, and both are disabled by default. A project limit replaces the organization limit rather than adding to it, so a project with its own entry ignores the organization limit entirely. With no limit configured, ingestion is uncapped.

**Window and enforcement**

* `RATELIMIT_API_LOGS_ORG_WINDOW_SECS`: Window length in seconds. Default `60`. Despite the name, this also sets the window for project-based limits.
* `RATELIMIT_API_LOGS_ORG_ENFORCE`: Return HTTP 429 when a limit is exceeded. Default `false` (log a warning and allow the request). Despite the name, this also governs the enforcement of project-based limits.

**Organization limits**

* `RATELIMIT_API_LOGS_ORG`: Per-organization limits, as `<org_id>=<max_requests>` pairs. Find an organization's ID in the [organization switcher](/docs/admin/organizations#find-your-organization-id).

**Project limits**

<Note>
  Project-scoped limits require data plane v2.2.1 or later.
</Note>

* `RATELIMIT_API_LOGS_PROJECT`: Per-project limits, as `<project_id>=<max_requests>` pairs. Find a project's ID under **<Icon icon="settings-2" /> Settings** > [**<Icon icon="wrench" /> General**](https://www.braintrust.dev/app/~/configuration/general).
* `RATELIMIT_API_LOGS_PROJECT_DEFAULT`: Limit for every project without an entry in `RATELIMIT_API_LOGS_PROJECT`. Set it only if you want every project capped.

<Tabs>
  <Tab title="AWS">
    Set these variables through the `braintrust_api_extra_env_vars` passthrough map (Terraform module v6.0.0 or later). For example:

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      RATELIMIT_API_LOGS_ORG             = "<org_id>=1000"
      RATELIMIT_API_LOGS_PROJECT         = "<project_id>=500"
      RATELIMIT_API_LOGS_ORG_WINDOW_SECS = "60"
      RATELIMIT_API_LOGS_ORG_ENFORCE     = "true"
    }
    ```

    Deployments still served by the API Lambda (before module v6.0.0, or v6 with `enable_ecs_api = false`) set the same variables through `service_extra_env_vars.APIHandler` instead.
  </Tab>

  <Tab title="GCP / Azure">
    Add these variables to `api.extraEnvVars` in the `values.yaml` you pass to the Helm chart. For example:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: RATELIMIT_API_LOGS_ORG
          value: "<org_id>=1000"
        - name: RATELIMIT_API_LOGS_PROJECT
          value: "<project_id>=500"
        - name: RATELIMIT_API_LOGS_ORG_WINDOW_SECS
          value: "60"
        - name: RATELIMIT_API_LOGS_ORG_ENFORCE
          value: "true"
    ```
  </Tab>
</Tabs>

<Warning>
  Setting a log ingestion limit to `0` with enforcement on rejects every matching logging request and stores nothing. Any spans the client does not retry are lost.
</Warning>

A request counts as one unit against whichever limit applies, regardless of how many spans it carries. If any organization or project referenced in the request exceeds its limit, the entire payload is rejected.

#### Limit SQL queries

SQL query limits apply per organization and per project, and both are disabled by default. A project limit adds to the organization limit rather than replacing it, so it can only tighten the effective limit. Organizations without their own entry fall back to `RATELIMIT_BTQL_DEFAULT`, and with no default configured, queries are uncapped.

**Window and enforcement**

* `RATELIMIT_BTQL_WINDOW_SECS`: Window length in seconds. Default `60`.
* `RATELIMIT_BTQL_ENFORCE`: Return HTTP 429 when a limit is exceeded. Default `false` (log a warning and allow the query).

**Organization limits**

* `RATELIMIT_BTQL_ORG`: Per-organization limits, as `<org_id>=<max_queries>` pairs. Find an organization's ID in the [organization switcher](/docs/admin/organizations#find-your-organization-id).
* `RATELIMIT_BTQL_DEFAULT`: Limit for every organization without an entry in `RATELIMIT_BTQL_ORG`.
* `RATELIMIT_BTQL_DEFAULT_FUNCTIONS`: Separate default for queries against prompts and functions. Defaults to 20 times `RATELIMIT_BTQL_DEFAULT`, including when set to `-1`.

**Project limits**

<Note>
  Project-scoped limits require data plane v2.2.1 or later.
</Note>

* `RATELIMIT_BTQL_PROJECT`: Per-project limits, as `<project_id>=<max_queries>` pairs. Setting one above the organization limit has no effect. With no organization limit configured, the project limit is the only one that applies. Find a project's ID under **<Icon icon="settings-2" /> Settings** > [**<Icon icon="wrench" /> General**](https://www.braintrust.dev/app/~/configuration/general).

<Tabs>
  <Tab title="AWS">
    Set these variables through the `braintrust_api_extra_env_vars` passthrough map (Terraform module v6.0.0 or later). For example:

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      RATELIMIT_BTQL_ORG         = "<org_id>=1000"
      RATELIMIT_BTQL_PROJECT     = "<project_id>=100"
      RATELIMIT_BTQL_WINDOW_SECS = "60"
      RATELIMIT_BTQL_ENFORCE     = "true"
    }
    ```

    Deployments still served by the API Lambda (before module v6.0.0, or v6 with `enable_ecs_api = false`) set the same variables through `service_extra_env_vars.APIHandler` instead.
  </Tab>

  <Tab title="GCP / Azure">
    Add these variables to `api.extraEnvVars` in the `values.yaml` you pass to the Helm chart. For example:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: RATELIMIT_BTQL_ORG
          value: "<org_id>=1000"
        - name: RATELIMIT_BTQL_PROJECT
          value: "<project_id>=100"
        - name: RATELIMIT_BTQL_WINDOW_SECS
          value: "60"
        - name: RATELIMIT_BTQL_ENFORCE
          value: "true"
    ```
  </Tab>
</Tabs>

A query counts once against the organization limit and once against each project it reads, so a query spanning several projects must stay under every limit it touches.

<Note>
  These limits apply to queries from the API, the SDKs, and the MCP server. Queries issued from the Braintrust UI are exempt.
</Note>

#### Limit function invocation

Invocation limits cover a project's prompts, scorers, tools, and other custom code functions. They are project-scoped, and there is no organization-scoped limit. Two independent limits apply: a per-project limit that is disabled by default, and a per-function cap that is on by default with a fixed 10-second window and always returns HTTP 429.

**Window and enforcement**

* `RATELIMIT_INVOKE_WINDOW_SECS`: Window length in seconds for the project limits. Default `10`. It does not affect the per-function cap.
* `RATELIMIT_INVOKE_ENFORCE`: Return HTTP 429 when a project limit is exceeded. Default `false` (log a warning and allow the invocation). It does not affect the per-function cap.

**Project limits**

<Note>
  Project-scoped limits require data plane v2.2.1 or later.
</Note>

* `RATELIMIT_INVOKE_PROJECT`: Per-project limits, as `<project_id>=<max_invocations>` pairs. The count covers every function in the project, across all API keys. Find a project's ID under **<Icon icon="settings-2" /> Settings** > [**<Icon icon="wrench" /> General**](https://www.braintrust.dev/app/~/configuration/general).
* `RATELIMIT_INVOKE_PROJECT_DEFAULT`: Limit for every project without an entry in `RATELIMIT_INVOKE_PROJECT`. Set it only if you want every project capped.

**Per-function limit**

* `INVOKE_RATE_LIMIT_PER_10S`: Maximum invocations per function, per API key, in a 10-second window. Default `10000`. The count is per function, not per project.
* `ENABLE_INVOKE_RATE_LIMIT`: Whether invocation rate limiting runs at all. Default `true`. Setting it to `false` turns off the per-function cap and the project limits.

<Tabs>
  <Tab title="AWS">
    Set these variables through the `braintrust_api_extra_env_vars` passthrough map (Terraform module v6.0.0 or later). For example:

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    braintrust_api_extra_env_vars = {
      RATELIMIT_INVOKE_PROJECT     = "<project_id>=100"
      RATELIMIT_INVOKE_WINDOW_SECS = "10"
      RATELIMIT_INVOKE_ENFORCE     = "true"
      INVOKE_RATE_LIMIT_PER_10S    = "5000"
    }
    ```

    Deployments still served by the API Lambda (before module v6.0.0, or v6 with `enable_ecs_api = false`) set the same variables through `service_extra_env_vars.APIHandler` instead.
  </Tab>

  <Tab title="GCP / Azure">
    Add these variables to `api.extraEnvVars` in the `values.yaml` you pass to the Helm chart. For example:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: RATELIMIT_INVOKE_PROJECT
          value: "<project_id>=100"
        - name: RATELIMIT_INVOKE_WINDOW_SECS
          value: "10"
        - name: RATELIMIT_INVOKE_ENFORCE
          value: "true"
        - name: INVOKE_RATE_LIMIT_PER_10S
          value: "5000"
    ```
  </Tab>
</Tabs>

<Note>
  Preprocessors are exempt from invocation rate limits.
</Note>

## Outbound traffic

### Secure outbound requests

The data plane makes outbound requests both to Braintrust and to URLs you or your users supply, such as webhooks, remote scorers, and integrations.

**Allow traffic to Braintrust through your firewall**

If you restrict outbound network traffic, allow the data plane to reach Braintrust at:

```
www.braintrust.dev
braintrust.dev
gateway.braintrust.dev
```

`gateway.braintrust.dev` is the Braintrust-hosted Gateway. Allow traffic to it only if your deployment uses the Braintrust-hosted Gateway. Note that AWS deployments using Terraform module v6.5.0 or later by default route quarantine LLM calls (from user-authored code such as custom scorers and tools) through the self-hosted AI Proxy Lambda.

This is firewall guidance. The data plane does not enforce a destination allowlist itself.

**Block requests to internal addresses**

To stop user-supplied URLs from reaching private or reserved IP addresses (server-side request forgery), configure URL validation. See [Configure URL security](/docs/admin/self-hosting/configure/security#configure-url-security).

**Trust a private certificate authority**

If the internal services your custom scorers and tools call present certificates signed by a private or enterprise certificate authority, supply the CA bundle so those requests validate. See [Configure a custom CA bundle](/docs/admin/self-hosting/configure/security#configure-a-custom-ca-bundle).

### Set outbound request rate limits

The Braintrust API server can rate-limit the outbound requests it makes to external domains, such as `BRAINTRUST_APP_URL`. Rate limiting prevents unintentionally overloading an external domain, which might otherwise block the API server's IP in response. It is disabled by default. When enabled, requests are counted per API auth token per destination domain within a rolling window.

* `OUTBOUND_RATE_LIMIT_MAX_REQUESTS`: The maximum number of requests per window. Default `0`, which disables rate limiting. Set a value greater than `0` to enable it.
* `OUTBOUND_RATE_LIMIT_WINDOW_MINUTES`: The window length in minutes before the count resets. Default `1`.

<Tabs>
  <Tab title="AWS">
    Use the dedicated variables (Terraform module v1.0.0 or later):

    ```hcl theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    outbound_rate_limit_max_requests   = 100
    outbound_rate_limit_window_minutes = 1
    ```
  </Tab>

  <Tab title="GCP / Azure">
    Set the environment variables through `api.extraEnvVars`:

    ```yaml theme={"theme":{"light":"github-light","dark":"github-dark-dimmed"}}
    api:
      extraEnvVars:
        - name: OUTBOUND_RATE_LIMIT_MAX_REQUESTS
          value: "100"
        - name: OUTBOUND_RATE_LIMIT_WINDOW_MINUTES
          value: "1"
    ```
  </Tab>
</Tabs>

### Connect to internal resources over VPC

On AWS, to connect Braintrust's VPC to other internal resources (like an LLM Gateway), use one of the following approaches:

* Create a VPC Endpoint Service for your internal resource, then create a VPC Interface Endpoint inside the Braintrust "Quarantine" VPC.
* Set up VPC peering with the Braintrust "Quarantine" VPC.