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

# Authentication

> API key authentication and rate limits for the Public REST API.

For server-to-server integrations (not marketplace tools), use API keys:

```
Authorization: Bearer pip_key_your_api_key_here
```

API keys are scoped to specific endpoints and have configurable rate limits.
Generate API keys from Pipeline Settings > API Tokens.

**Marketplace tools do NOT need API keys** — the bridge handles all
authentication automatically through the Pipeline session.

## Rate Limits

API responses include rate limit headers:

```
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 95
X-RateLimit-Reset: 1713200000
```

When the limit is exceeded, requests return HTTP 429 with a `Retry-After` header
indicating seconds until the next request is allowed.