# Contributing to JCP

JCP is one of the [Transaction Science open standards](../README.md). The wire
format and the right to fork are public; Transaction Science is the steward, not
the proprietor.

## Ground rules

- **Reference code** (`jcp-rs/`) is Apache-2.0. **Specification text** (`SPEC.md`)
  is CC-BY-4.0.
- Rust toolchain is pinned by the repo `rust-toolchain.toml`. `cargo test
  --workspace` MUST pass and `cargo clippy --workspace --all-targets` MUST be
  warning-free.
- Any change to a wire structure (the Grant, the Frame, the `jcp/1` receipt core,
  the canonical encoding) requires regenerating and committing `conformance/v1/`
  (`cargo run -p jcp-conformance --bin gen-vectors -- conformance/v1`).
- Two invariants are correctness, not style, and a PR that weakens either will be
  declined: **enforcement happens outside the model**, and a `data` frame can
  **never** exercise a capability.

## The smallest valuable contributions

- **Transport bindings:** map Frames onto a concrete ordered, authenticated
  channel (e.g. an MCP/A2A bridge that wraps existing tool/agent calls in Grants
  and Frames) without moving the decision into the model.
- **Measured energy:** a `HwShunt` cost backend (RAPL/NVML) so a runtime debits
  hardware-measured joules instead of a model estimate.
- **Conformance:** adversarial negatives (a chain that amplifies mid-delegation, a
  receipt whose budget disagrees with the grant, a frame that replays a spent
  nonce) and independent implementations certifying against `conformance/v1/`.
- **Revocation & chains:** grant revocation lists and multi-hop attenuation-chain
  verification (validate the whole chain narrows monotonically to its root).
- **Capability discovery:** a signed, content-addressed catalog of a server's
  resources and actions, so a grant's `resource`/`actions` bind to real content.

Issues and PRs scope by the `jcp` subdirectory tag.