SettlementWitness

nutstrut/default-settlement-verifier

Connects Claude to DefaultVerifier's SAR (Settlement Attestation Receipt) infrastructure for cryptographic verification of agent task completion. Exposes endpoints to submit task specs and outputs, receive signed receipts with verdict and confidence scores, retrieve receipts by ID or wallet address, and access public verification keys. Useful when you need provable attestation that an AI agent actually fulfilled its specification, especially in multi-party scenarios where settlement or payment depends on verified execution. Receipts are Ed25519-signed, publicly retrievable, and include counterparty binding for bilateral agreements. Ships with verification examples in Node and Python for local signature checking against the published JWKS.

tool: 1
transport: HTTP
last updated: Jul 5, 2026

View on GitHub

Install

From registry metadata

$ npx add-mcp https://defaultverifier.com/mcp --name settlement-witness

Run in your terminal. add-mcp asks which agents to add it to (Claude Code, Codex, Cursor and more). Add -g to install it for every project.

Review the command, arguments and environment values before installing. MCP servers run with your local permissions.

Other ways

Claude Code

$ claude mcp add --transport http settlement-witness https://defaultverifier.com/mcp

Run in your terminal. Add --scope user to make it available in every project.

Tools

Verified live · 1 tools

Verified live against the running server on Nov 6, 2026.

settlement_witnessThin MCP adapter that forwards to SettlementWitness and returns the exact receipt JSON.3 params

Thin MCP adapter that forwards to SettlementWitness and returns the exact receipt JSON.

Parameters* required

output*object

spec*object

task_id*string

Readme

DefaultVerifier — SAR Verification Infrastructure

SAR (Settlement Attestation Receipt) is a verification protocol that produces cryptographically signed receipts proving whether an AI agent completed a task according to its specification.

DefaultVerifier is a live SAR verifier implementation with a public receipt registry, metrics API, and explorer.

If it matters—Verify it.

Architecture

Understand the SAR stack and verification model:

👉 SAR Architecture

Example Response

{ "witness": "SettlementWitness", "witness_version": "v0", "task_id": "example", "verifier_endpoint": "https://defaultverifier.com/verify", "witness_timestamp": "2026-01-01T00:00:00Z", "receipt_id": "...", "receipt": { "profile": "settlement-witness-verified-v0.2", "task_id_hash": "sha256:...", "verdict": "PASS", "reason_code": "CONDITION_SATISFIED", "ts": "...", "verifier_kid": "...", "counterparty": "0xABC...", "receipt_id": "sha256:...", "sig": "base64url:..." },

"_ext": { "agent_id": "0x123:demo" } }

Notes

View the full README on GitHub

Details

Repository: github.com/nutstrut/default-settlement-verifier
Transport: HTTP
Registry: MCP registry, active
Tools verified: Nov 6, 2026