# Curbi v33 — agents verify proof bundles over MCP

New read-only MCP tool **`verify_bundle`**: the open Curbi Proof verifier, unchanged, available to any agent. It runs on a bundle with keys the caller chooses and checks signatures, key windows, RFC 9162 inclusion, attestation binding and history.

- **Keys:** required; they are the only trust anchor. Keys inside a bundle are never trusted.
- **Test keys:** verify only with `allowTest`.
- **Isolation:** no network, nothing stored.
- **What a verified bundle means:** a key you chose signed and logged these receipts. It does not show that the provider action happened.

This is the free-verification side of PROOF-001 (Founder decision 2). It needs no production key or ledger.

## Evidence
- **`v33/site.test.mjs`:** 5 tests.
  - All 16 conformance vectors through MCP, each with its own clock, identical to the standalone verifier.
  - Bundle keys are ignored and test keys are refused by default.
  - Input validation, read-only and closed-world annotations, and no I/O.
  - The official SDK verifies the valid vector and rejects the tampered one through the canonically built Worker.
  - The tool is listed on /mcp/, in ai.json, in the site index and in the start block.
- **Full canonical build:** `python3 v17/build.py`, plus every layer, v27 MCP and review review suite.