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

# Project keys

> Configure server-side authentication and verify which project receives your data.

Use a project service key for SDK requests and OpenTelemetry exports. Create it in **Settings → Integrations & API keys** within the project you want to use.

## Configure the application

Store the key as `HUE_API_KEY` in your server environment or secret manager. Pass it to the SDK constructor, as shown in the [quickstart](/quickstart). Hue constructors do not automatically load environment files.

For direct HTTP requests, authentication uses `Authorization: Bearer <project-service-key>`. The key determines the destination project. Resource attributes, observed user IDs and session IDs cannot select a different project.

## Understand access

Current service keys have the `project_write` capability. They authorize telemetry ingestion and project evaluation API operations; telemetry-only and read-only service keys are not currently available. Treat the key as a project credential and keep it out of browser bundles, logs, source control and prompts.

A service key does not represent a signed-in Hue user. Human review and general trace browsing use the application's authenticated user session. The SDKs do not currently expose a general trace-search API.

## Verify and rotate

Call `hue.checkConnection()` in TypeScript or `hue.validate_project()` in Python. These send a project lookup without a trace and return the project identity. Confirm it matches the project you intend to use before exporting data.

When replacing a key, configure the replacement in the server's secret store, verify the connection, then revoke the old key in project settings. Never include either credential in a support report. A successful connection check validates project access; the first-trace check separately verifies instrumentation and delivery.

## Connection settings

Both SDKs default to `https://app.hue.run`. Omit `baseUrl` in TypeScript and `base_url` in Python for Hue Cloud. You do not need to choose or discover a different endpoint for a normal Hue Cloud integration.

For local development or another configured Hue deployment, pass a different origin through `baseUrl` in TypeScript or `base_url` in Python. If your application uses `HUE_BASE_URL`, read it explicitly and pass it to the constructor. SDKs do not load environment files automatically.

Supply an origin without credentials, an API path, query parameters or a fragment. HTTPS is required except for loopback HTTP. SDKs append their own paths; a standard OTLP exporter instead needs the full [signal endpoint](/integrations/opentelemetry).