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

# Relations

> Relation concepts for future public API documentation.

<Warning>
  **Early access** — Prefer MCP `relations` or CLI helpers. [**Join the Product Brain Community**](https://community.productbrain.io).
</Warning>

Relations connect Chain entries.

Current public access is through CLI and MCP surfaces. Stable external HTTP API contracts should be documented here when they are intentionally exposed.