Contribute

Contributing to the specification

The WCP specification lives in WCP_SPEC.md in the workerclassprotocol/wcp repository. Contributions to the spec happen through GitHub.

Process

1. Open an issue at github.com/workerclassprotocol/wcp/issues to describe the change you want to make
2. Discuss the change in the issue thread. This is where scope and rationale are established.
3. Submit a pull request with your edits to WCP_SPEC.md
4. Review and merge — changes must not break existing conformant implementations

What belongs in the spec

• Normative definitions of RouteInput, RouteDecision, and registry record fields
• Capability namespace rules and taxonomy governance
• Policy profile definitions and risk tier semantics
• Attestation and evidence requirements
• Compliance level definitions (WCP-Basic, WCP-Standard, WCP-Full)

What doesn't belong in the spec

• Transport-level concerns (that's MCP/A2A)
• Implementation-specific behavior (that goes in SDK docs)
• UI/UX decisions (that's up to each implementation)
• Vendor-specific extensions (use the x.* or org.* namespaces)

Building a conformant implementation

A WCP-conformant implementation at the WCP-Basic level must:

• Accept RouteInput with all required fields (§4.1)
• Produce RouteDecision with one of the three outcomes: DISPATCH, DENY, STEWARD_HOLD (§4.2)
• Implement fail-closed behavior: unknown capabilities are always denied (§5.1)
• Produce deterministic routing decisions given identical inputs (§5.2)

WCP-Full additionally requires:

• Controls enforcement and declaration verification (§5.3)
• Mandatory telemetry — three events per dispatch (§5.4)
• Dry-run mode (§5.5)
• Discovery API endpoints (§5.6)
• Evidence receipts with SHA-256 payload hash (§5.7)
• Human-in-loop routing with supervisor levels (§5.8)
• Signatory tenant validation in production (§5.9)
• Worker code attestation in production (§5.10)

Extending the capability catalog

The WCP catalog (capability IDs, worker species, controls, policies, profiles) is maintained in the workerclassprotocol/wcp repository. Community additions are welcome via pull request.

Requirements for a new catalog entry:

• Capability ID follows the format rules in §3.2 (lowercase, dot-separated, 2–4 segments, max 64 chars)
• A corresponding worker species ID in wrk.*
• A working implementation in at least one language
• Clear description of what the capability does and what it doesn't do

Use x.* for experimental capabilities. Once a capability is stable and has a working implementation, open a PR to promote it to the reserved cap.* namespace.