# Core Reference

- Canonical URL: https://docs.fairvisor.com/docs/reference/core-reference/
- Section: docs
- Last updated: n/a
> Canonical API contracts, lifecycle, headers, reasons, and metrics.


## API contracts

- [Decision API](/docs/reference/api/)
- [Request Lifecycle](/docs/reference/request-lifecycle/)
- [Response Headers](/docs/reference/headers/)
- [Rejection Reasons](/docs/reference/reasons/)
- [Debug Session](/docs/reference/debug-session/)

## Telemetry

- [Metrics](/docs/reference/metrics/)
- [Streaming Enforcement](/docs/reference/streaming/)