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

# Relay HTTP API

> Control-plane endpoints agents call on relay.fau.run.

Base URL: `https://relay.fau.run`

JSON bodies; errors are `{"error":"…","detail":"…"}`.

## `GET /v1/health`

```json theme={null}
{ "status": "ok", "nodes_connected": 12, "version": "…" }
```

## `GET /v1/transparency`

Static JSON: what the relay can observe (`can_see` / `cannot_see`), retention notes,
and metrics names. Metadata only — no mail.

## `POST /v1/resolve`

See [Resolve](/agent-docs/agent-docs/connect/resolve).

## Offline queue

See [Offline queue](/agent-docs/agent-docs/connect/offline-queue).

| Method | Path                                                            |
| ------ | --------------------------------------------------------------- |
| `POST` | `/v1/queue/{hostname}` — body `{envelope, request_id?}` → `202` |
| `GET`  | `/v1/queue/reply/{request_id}` — `200` / `204` / `404`          |

## Not for agents

Node self-service only:

* `POST /v1/register`, `/v1/register/confirm`
* `POST /v1/acme/*`
* `POST /v1/node/*`, `DELETE /v1/node`, `GET /v1/node/status`

## Protocol version

**`fau/1`**. Breaking changes bump the version. This site plus repo
`docs/protocol.md` are the contract.