BATON

Hand off AI work — with a receipt.

An AI did the work. How does the next person — or the next AI — know it actually works, not just that the build passed? BATON seals a unit of AI work into a portable capsule, and an independent verifier replays it and issues a server-signed Verification Receipt. The receiver trusts observed evidence, not a claim.

Never trust an agent handoff without a receipt.

BATON is a standard MCP (Model Context Protocol) server — any MCP-capable tool (Claude Code, Codex CLI, Gemini CLI, Cursor …) connects with one URL. The producer and the verifier can be different models, machines, and people.

Why this, and not the dozen orchestration tools?

Running Claude + Codex + Gemini together (swarms, rooms, agent messaging) is a crowded space. BATON isn't that. The one thing almost nobody does: bind the handoff artifact to independent execution evidence as a single, forgeable-proof trust unit. That's the receipt.

Claude did the work
   ↓  baton_pass  → sealed capsule (BTN-H-…)
Codex / a teammate receives it
   ↓  baton_verify → replay in a clean env, observe the real flow
   ↓
🕸️ VERIFIED — signed receipt: who verified · what was observed · in what env · with what artifacts
   ↓
trust  (or reject)

The real buyer isn't "me switching Claude→Codex" (just re-read the repo). It's outsourcer→in-house, leaver→joiner, KO team→US team — where "an AI made this, does it really work?" is a question worth paying to answer.

The receipt (the differentiator)

baton_verify doesn't return a ✅ sticker. It returns a signed record:

{
  "kind": "baton.verification-receipt/v1",
  "capsule": "BTN-H-…",              // the handoff this verifies
  "verifier": "receiver-spider",    // WHO verified — independent of the producer
  "environment": { "os": "ubuntu-24.04", "node": "24.2" },
  "observed": [{ "claim": "payment succeeds", "observed": true,
                 "detail": "POST /pay 200 + order row +1" }],
  "artifacts": ["playwright.trace.zip", "network.har"],
  "verdict": "verified",
  "signature": "…hmac-sha256…"       // server-signed → tamper the verdict, break the sig
}

Flip verdict to "verified" without re-signing and the badge is refused. A passing build never earns verified on its own — only observed E2E does (this is what catches a silent upsert that returns 200 but writes nothing).

Tools

Group	Tools	What it does
Handoff	baton_pass baton_receive baton_diff baton_revoke	Seal a work capsule into a code (BTN-H-…), hand it over, diff versions. Body encrypted with a code-derived key — the server never sees plaintext
Verify	baton_verify baton_verify_plan baton_consolidate + spider_* ×6	Independent verifier replays and issues the signed receipt (no observation, no 🕸️); consolidate gathers many handoffs into one result board by trust tier
Team rooms (supporting)	baton_create_room baton_new_invite baton_join baton_send baton_inbox baton_who baton_leave baton_kick baton_approve baton_close_room	A persistent room the owner manages; people enter via rotating invite codes (BTN-R-…, 72h, re-issuable). Owner can kick, approve (optional gate), close. After join, activity is keyed by member_id
Operations	baton_task_* baton_git_* baton_cost_*	Cycle-safe private task DAG, Git commit/diff/test evidence binding, and idempotent provider/model/task cost ledger

Operations dashboard: /ops.html. It stores only task metadata, Git evidence, and cost facts; BATON never asks for repository credentials.

Network dashboard: /network.html. Shared Memory encrypts bodies under the account key and searches metadata only. MCP Hub rejects credential-bearing URLs. Marketplace reputation accepts only independent, server-signed VERIFIED receipts.

모든 공개 화면은 한국어를 기본으로 제공하며 /dash.html(협업방), /board.html(검증 결과), /ops.html(작업·Git·비용), /network.html(기억·MCP·에이전트)을 상호 연결한다.

Design principles (from the security review)

• Code-derived encryption. The server stores only ciphertext + code_hash. Without the code, even the operator can't read the plaintext — the proof of "we can't lock you in."
• Signed receipts. Verdicts are HMAC-signed server-side (BATON_RECEIPT_SECRET); no client can forge verified.
• Prompt-injection containment. Inbound capsules/messages are returned fenced as untrusted data; secrets are auto-masked before storage.
• Codes are ≥128-bit secrets, one-time codes redeem atomically, alias-spoofing blocked.
• A passing build ≠ working behavior. verified requires observed side effects, never static analysis alone.

Run

npm install
npm test                                      # 15/15 E2E groups pass
node src/server.js                            # stdio (local / any CLI)
BATON_HTTP=1 PORT=8080 node src/server.js      # remote Streamable HTTP

Register (remote)

claude mcp add --transport http baton https://baton-mcp-production.up.railway.app/mcp

Billing/gating is off by default (dogfooding phase). Set BATON_BILLING=on to re-enable quotas. See USAGE.md for the full guide.

Storage

MVP uses SQLite (better-sqlite3) — self-host single binary. The hosted service drops a Postgres adapter into the narrow interface in src/store.js.

License

MIT