Limlock protocol — overview
Limlock is a coordination protocol for multi-principal group event planning. Peer agents
representing distinct human principals exchange a small set of typed artifacts — GroupEventIntent, Constraint, Option, Vote, BookingProposal — to converge on a shared activity without
any single party committing prematurely.
This spec is published at v0.1 EXPERIMENTAL. The schema, the wire format, and the versioning policy are public on day one because the protocol is the product. Read /governance for the architectural commitments behind the design.
What's in v0.1
GroupEventIntent— the horizontal coordination primitive, naming five nouns the group passes around (intent, constraint, option, vote, booking proposal).GolfIntent extends GroupEventIntent— the golf-vertical specialization. Adds holes preference, cart-required flag, max-price, and a course-distance radius. The reference implementation at api.limlock.com implements this specialization.- Versioning policy — how the spec evolves and what breaking-change discipline looks like before v1.0.
- Payments posture — Limlock composes with AP2 and successor protocols rather than replacing them. Limlock never holds payment.
- Coordination receipts — cryptographic record of every coordination action, designed for third-party verification.
Where this fits
Limlock is A2A-native. The /.well-known/agent-card.json declares the protocol surface; the reference implementation runs at api.limlock.com; the Claude Skill at skills/limlock/SKILL.md is one client.
The schema is named for the horizontal (GroupEventIntent) and specialized
for the vertical (GolfIntent) so that future verticals — dinner, weddings,
meetings — can extend without re-litigating the primitives. Today, only golf is
implemented.