Decision Catalog Protocol

Decision Catalog Protocol (DCP) is a small interoperability contract for publishing the finite decisions a system can legally make right now. Providers derive catalogs from live state, decision systems such as RLCD select bounded actions, and providers retain authority over validation and execution.

This repository contains the normative DCP specification, machine-readable schemas, conformance suite, public reference site, wire examples, implementation directory, and listing policy. The intended public homes are decisions.directory and dcp.fpl.dev.

Protocol surface

• GET /v1/decisions publishes a state-derived, revision-bound catalog.
• POST /v1/decisions/plan optionally performs provider-local selection.
• POST /v1/decisions/execute validates and applies an exact bounded action.
• /.well-known/dcp advertises provider identity, versions, and endpoints.

The current draft is DCP 0.1. Its JSON Schema 2020-12 contracts live under public/schemas/v0.1 with stable $id values at https://decisions.directory/schemas/v0.1/. Version 0.1 defines exact version negotiation; discovery and authorization metadata; catalog, action, execute, receipt, error, and directory-entry contracts; and a transport-neutral streaming event model with a WebSocket binding.

DCP also defines speculative, per-word operation as an append-only decision chain. Evidence revisions accumulate state; safe actions may be prepared early; explicit finality commits one valid selection; superseded preparations are cancelled. Confidence alone never grants execution authority.

Implementations and directory listings

The parameter rounds profile standardizes read-only follow-up questions after action/target selection: validated datums, named parameters, prompt literals, or bounded numeric estimates. Its schemas and Rust types preserve revisions and leave joint validation with the provider.

The site lists DCP providers and clients with links to their source. To request a listing, publish /.well-known/dcp, provide a deterministic catalog fixture, declare each action's execution semantics, and open a listing issue or pull request in this repository.

Local development

Requires Node.js 22.13 or newer.

npm install
npm test
npm run start

The production preview is available at http://localhost:3000 by default. npm run test:conformance runs only the protocol schema and semantic fixture suite.

Status

DCP is currently a draft protocol. Implementations may experiment with it, but must advertise their supported protocol version and reject stale catalog revisions.

License

No license has been selected yet. All rights reserved until one is added.