RCO-A2A - Record of Cleared Orders

RCO-A2A — Record of Cleared Orders

RCO is the Record of Cleared Orders. A receipt is written when a gate clears an agentic order:

{decision_id, gtin, market, actor_class, rule_version, cleared_at, writer, prev_hash, hash, sig, kid}

Each receipt is hash-chained to the one before it and signed by the office key. Two tools, nothing else:

• write_receipt — authenticated (Authorization: Bearer <writer token>, one token per writer), returns decision_id. Idempotent on decision_id.
• verify_receipt(decision_id) — public, returns the receipt, its chain position, its signature and the key to check it.

Door: https://mcp.rco-a2a.ai/mcp (Model Context Protocol, streamable HTTP, stateless, JSON-RPC 2.0). Page and kit: https://rco-a2a.ai/. Verify URL: https://rco-a2a.ai/receipts/{decision_id}. Ledger held by the Agentic Private Office.

The chain

• hash = sha256: + hex of SHA-256 over the canonical JSON of {actor_class, cleared_at, decision_id, gtin, market, prev_hash, rule_version, writer} — keys sorted, no whitespace, nulls kept.
• The first receipt's prev_hash is sha256: + 64 zeros.
• sig = Ed25519 (EdDSA) over the UTF-8 bytes of the hash string, base64url. kid names the key on https://rco-a2a.ai/.well-known/jwks.json (rco-office-2026-10).
• Receipts loaded from the ledger era (2026-10-15 → 2026-10-27) carry kid gsc-rco-2026-08, sig null, and the Azure Confidential Ledger transaction that holds their original hash. Fields the ledger never held are null.

Connect

MCP client configuration (any client that speaks streamable HTTP):

{ "mcpServers": { "rco-a2a": { "type": "streamable-http", "url": "https://mcp.rco-a2a.ai/mcp" } } }

Verify one receipt from a shell:

curl -s https://mcp.rco-a2a.ai/mcp -H 'content-type: application/json' -H 'accept: application/json' \  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"verify_receipt","arguments":{"decision_id":"dec_b73fe75bff87ef889d8ca304"}}}'

or GET https://rco-a2a.ai/receipts/dec_b73fe75bff87ef889d8ca304.

Check a signature (Python):

import json, base64, requestsfrom cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PublicKeyr = requests.get("https://rco-a2a.ai/receipts/" + DECISION_ID).json()k = next(k for k in requests.get("https://rco-a2a.ai/.well-known/jwks.json").json()["keys"] if k["kid"] == r["receipt"]["kid"])pad = lambda s: s + "=" * (-len(s) % 4)Ed25519PublicKey.from_public_bytes(base64.urlsafe_b64decode(pad(k["x"]))).verify(base64.urlsafe_b64decode(pad(r["receipt"]["sig"])), r["receipt"]["hash"].encode())

Errors

Typed, inside the tool result (isError: true): not_authorised · invalid_receipt · invalid_decision_id · not_found · store_unavailable · store_error · chain_contention.

Source

worker/ — the Cloudflare Worker (index.js routes and kit, mcp.js the two tools, chain.js the record and its chain, export.js the nightly copy to the office's S3 bucket). schema.sql — the D1 table, append-only (triggers refuse UPDATE and DELETE). public/ — the office page and the five record pages. rails/ — the history loader and the D1 rail. No secret is in this repository.

MIT. © 2026 Agentic KG Holdings.