> NOTICE — Pre-launch build. Every record here is a dated observation of a real MCP endpoint operated by a third party, rendered from the published archive. Coverage is partial — the figures cover the snapshots in the export this build was made from, not the whole chain and not the whole ecosystem. Claims and badges are not open.

# sendletter.eu/api/mcp

Last observed: 2026-08-30T09:02:31.458Z
Recorded as: AUTH_REQUIRED (http_401)
Transport: streamable-http
Observations held: 22
Published: yes

## Observations

| Observed | Snapshot | Recorded as | Detail | Latency ms | Tools | Tool schema fingerprint |
|---|---|---|---|---|---|---|
| 2026-08-09T09:16:10.687Z | REL-SNAP-005 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-10T09:15:41.920Z | REL-SNAP-006 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-11T09:18:05.601Z | REL-SNAP-007 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-12T09:16:35.418Z | REL-SNAP-008 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-13T09:09:38.314Z | REL-SNAP-009 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-14T09:23:06.322Z | REL-SNAP-010 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-15T09:13:06.881Z | REL-SNAP-011 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-16T09:14:24.364Z | REL-SNAP-012 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-17T11:44:07.987Z | REL-SNAP-013 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-18T09:12:19.520Z | REL-SNAP-014 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-19T08:57:05.998Z | REL-SNAP-015 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-20T09:05:32.902Z | REL-SNAP-016 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-21T09:21:02.864Z | REL-SNAP-017 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-22T08:57:39.931Z | REL-SNAP-018 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-23T09:58:24.209Z | REL-SNAP-019 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-24T09:01:06.617Z | REL-SNAP-020 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-25T09:03:25.811Z | REL-SNAP-021 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-26T08:59:38.364Z | REL-SNAP-022 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-27T09:13:05.288Z | REL-SNAP-023 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-28T09:11:02.833Z | REL-SNAP-024 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-29T09:00:40.881Z | REL-SNAP-025 | AUTH_REQUIRED | http_401 | - | - | - |
| 2026-08-30T09:02:31.458Z | REL-SNAP-026 | AUTH_REQUIRED | http_401 | - | - | - |

## Identity

Record key: sendletter.eu/api/mcp (the normalised endpoint observed)
Registry names (not anchored — no inclusion proof reaches this field): eu.sendletter/sendletter (what the registry said when we swept it, as observed by us — not evidence that the registry was correct, that the name belongs to whoever registered it, or that it still resolves)
Name reported by the server: not reported (self-reported, unverified, never used as identity)

Each observation carries a merkle leaf in the snapshot it belongs to. The chain
establishes that a root existed by a given time; it does not establish that any
measurement is true.