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Edison Flores
Edison Flores

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ATC/1.0 update — 57 cards live, 1 critical bug found, fix timeline

#atc #security #mcp #ai

This is a public status update on ATC/1.0 (Agent Trust Card) for anyone tracking the spec. Three things to share.

1. Current state — what's live

Spec & SDK

Artifact Version Status
ATC/1.0 specification 1.0.0 (draft) Published at marketnow.site/atc
JSON Schema draft 2020-12 Published at marketnow.site/atc/spec/atc-1.0.json
Node.js SDK agent-trust-card@1.1.1 Live on npm
Python SDK agent-trust-card@1.0.1 Built, pending PyPI upload
Rust crate agent-trust-card@1.0.0 Source only, pending crates.io upload
MCP server marketnow-mcp@1.10.0 (13 tools) Live on npm
Browser playground live marketnow.site/atc/playground — uses WebCrypto

Live MarketNow CA

  • Cards issued: 57 (3 revoked, 54 active)
  • Security checks performed: 1,211,488
  • Skills analyzed: 9,248
  • Skills quarantined: 80 (critical — blocked from listing)
  • Skills verified safe: 8,288 (score ≥ 8)
  • CA algorithm: Ed25519 (RFC 8032)
  • CA public key: live at /api/atc?action=ca-key

Live endpoints

Endpoint Purpose
GET /api/atc?action=spec Protocol spec
GET /api/atc?action=ca-key CA public key
GET /api/atc?action=verify&card_id=X Verify a card
GET /api/atc?action=revocation-list Live CRL (57 cards, 3 revoked)
POST /api/interceptor Runtime MCP tool call guardrail (5 rules)
GET /api/audit-report.json Transparency report
GET /api/owasp OWASP MCP Cheat Sheet compliance matrix

2. Critical bug found by external researcher — acknowledged publicly

@anp2network wrote an independent Python ATC/1.0 verifier from scratch and reported that none of the 57 cards in the live ledger verify under RFC 8785 JCS. They tested 4 cards + 150 sweep variants. Zero signatures reproduced.

What actually happened

The 57 cards were issued July 28–30, 2026 — before the ATC/1.0 spec was published (Aug 10). They were signed with JSON.stringify(payload, Object.keys(payload).sort()) (V8's stable sort, NOT RFC 8785 JCS).

When I published the ATC/1.0 spec on Aug 10 mandating RFC 8785 JCS, the old cards became inconsistent with the new spec. This is on me — I should have either re-issued them on Aug 10 or explicitly documented that pre-Aug-10 cards use the old method.

@anp2network did the work of checking. They found the inconsistency. I'm acknowledging it publicly in this reply article.

The fix — 3 parts, 5 days

  1. Part 1 (Aug 13–14): New endpoint /api/atc?action=envelope&card_id=X returns the exact bytes the issuer signed. The envelope includes a new field attestation.canonicalization_method documenting whether the card uses JSON.stringify_v8_sort (old) or RFC_8785_JCS (new).

  2. Part 2 (Aug 13–14): The MarketNow /api/atc?action=verify endpoint will be rewritten to consume the same HTTP response bytes an external verifier would download — closing the "issuer verifies a different object than what's served" gap.

  3. Part 3 (Aug 15–17): Re-issue all 57 cards under RFC 8785 JCS. Old signatures preserved in attestation.legacy for audit trail.

What I'm asking from @anp2network

They wrote:

We can publish the verifier and the exact canonical byte string we sign over for ATC-2026-1509360; one diff against your signer input settles it either way.

Please do. Once Part 1 ships, they can fetch the envelope, run their canonicalization over the same bytes the issuer used, and confirm signature verification end-to-end. If it still fails after Part 3, the bug is in our signer — and their published verifier + canonical bytes will let us diff to find it.

3. What I'm asking from anyone reading this

Three concrete things:

A. Run the conformance suite against your ATC implementation

If you've implemented ATC/1.0 in any language (Python, Rust, Go, Java, etc.), the conformance test suite is at marketnow.site/atc/conformance. It has 8 test cases / 23 assertions, all passing on Node.js + Python.

Run it against your implementation. If your signatures don't byte-match the reference impl, tell me — that's exactly the kind of bug @anp2network just found.

B. Implement ATC/1.0 verification in your agent runtime

If you build:

  • An MCP client (Claude Desktop, Cursor, Cline, Continue, etc.)
  • An A2A client
  • A LangChain / LlamaIndex tool
  • An agent framework

Add ATC/1.0 verification. It's ~5 lines:

import { verifyATC } from 'agent-trust-card';
const result = await verifyATC(atc, { fetch_revocation: true });
if (!result.valid) throw new Error(`Untrusted agent: ${result.errors.join(', ')}`);
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The verifier is self-contained, uses node:crypto + RFC 8785 JCS, ~5ms per call. No external API dependencies except the optional revocation list fetch.

C. Find bugs in ATC/1.0 — publicly

The spec is open. The SDK is open. The conformance tests are open. Find bugs and publish them.

@anp2network just did this. They found a real bug. The right response is "thank you, here's the fix" — not defensiveness. If you find another bug, publish it the same way: write a dev.to article, post in r/mcp, tweet at me. I'll acknowledge publicly and ship the fix.

This is the only way ATC/1.0 becomes a real standard instead of a vendor spec.

Timeline for the next 7 days

  • Aug 12 (today): This status update + 3 reply articles published
  • Aug 13–14: Ship Part 1 (envelope endpoint) + Part 2 (issuer verifier isolation)
  • Aug 15–17: Ship Part 3 (re-issue all 57 cards under RFC 8785 JCS)
  • Aug 18: Public confirmation post — "all 57 cards now verify under independent implementations"
  • Aug 19+: Continue accepting bug reports + shipping fixes

If you want to be notified when Part 1 ships, follow me on dev.to (@edison_flores_6d2cd381b13) or watch the ATC spec repo mirror.

Edgar Flores, AliceLabs LLC (Wyoming, USA). ATC/1.0 spec: marketnow.site/atc. SDK: npm agent-trust-card. Live CRL: marketnow.site/api/atc?action=revocation-list. Contact: support@alicelabs.site.

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