atn-prototype

Reference prototype for Agent Trust Negotiation (ATN). Peer-to-peer trust handshake protocol for AI agents with capability negotiation, delegation, provenance, and SCITT-anchored receipts. Companion to IETF draft-somoza-atn-agent-trust-negotiation.

ATN Reference Implementation (Prototype)

This is a reference prototype for the Agent Trust Negotiation protocol described in draft-somoza-atn-agent-trust-negotiation-00. It is not production code. It exists to demonstrate that the specification is implementable and that the capability intersection algebra and handshake state machine behave as specified.

What this demonstrates

1. The four ATN artifacts as TypeScript types: Capability Manifest, Delegation Chain, Provenance Attestation, Session Receipt.
2. The capability intersection algorithm specified in the draft.
3. The four-message handshake: ATH_HELLO, ATH_OFFER, ATH_ACCEPT, ATH_RECEIPT.
4. Ed25519 signing and verification of artifacts and messages.
5. Digest binding between artifact references and document content.
6. Refusal override semantics.

What this does NOT demonstrate

1. Real DNS resolution (stubbed).
2. Real HTTPS fetches of artifacts (stubbed; artifacts passed in-memory).
3. SCITT log submission (stubbed; logged to stdout).
4. Full RATS integration (only the artifact structure).
5. Production error handling, retries, rate limits.

How to run

Requires Node.js 20 or later.

npm install
npm start

Output shows a complete handshake between two synthetic agents with mismatched capability requests, demonstrates that the intersection algorithm narrows the scope correctly, and prints a signed Session Receipt.

Files

• src/types.ts: type definitions for all ATN artifacts and messages.
• src/crypto.ts: Ed25519 key generation, JWS signing, JWS verification, SHA-256 digest.
• src/intersection.ts: the capability intersection algebra from Section 9 of the draft.
• src/handshake.ts: the Initiator and Responder state machines.
• src/index.ts: end-to-end demo.

Mapping to the specification

Draft section	File
Capability Manifest (§ Capability Manifest)	types.ts, intersection.ts
Delegation Chain (§ Delegation Chain)	types.ts
Provenance Attestation (§ Provenance Attestation)	types.ts
Session Receipt (§ ATH_RECEIPT)	types.ts, handshake.ts
Capability Intersection Algebra	intersection.ts
ATH state machine	handshake.ts
Algorithm: Ed25519 default	crypto.ts

License

CC0 1.0 Universal. Public domain. Use freely.