cypher_receive_npub_proof

Tool of cypher-mcp

Receive npub ownership confirmation from a patron. Completes the npub-OWNERSHIP-PROOF flow (the credential-delivery counterpart is ``receive_credentials``). **Call this only after the user confirms they have replied.** Deterministic, one-shot retrieval: name the response with ``(patron_npub, dpop_token)`` — the ``dpop_token`` being the value returned by ``request_npub_proof``. The tool drains ONLY the pinned rendezvous relay that challenge was published on, stopping at the DM whose phrase matches. Mismatched DMs are deleted and NACK'd (without revealing the expected phrase). If called before the user replies, their message will never be found. Do NOT poll, loop, or retry. The signed DM itself proves npub ownership (the patron's nsec signed it). On success, returns the ``dpop_token`` — the same token. The calling application MUST remember it and pass it as the ``dpop_token`` parameter on every subsequent paid tool call. The proof (a hash of the token) is stored in the vault keyed by that hash — the MCP never stores the raw token itself. Free.