MCP surface

The rcf MCP server is registered by rcf init into your project-root .mcp.json, and served over stdio by the rcf mcp verb. A harness that reads .mcp.json at session start picks it up automatically; others can point at rcf mcp directly, and Wire your agent covers what to check when the wiring does not take. Where a tool mirrors a CLI verb, the verb is named; all of them are in the CLI reference.

Reading the tree

rcf_validate

Reports whether the tree is structurally sound: schema violations, broken references and stale Code Node pointers across every document. Issues come back as data, not as a tool error; the issues are the answer. The pack instructs the agent to run it first in any session and again after every tree edit. CLI: rcf define validate.

rcf_coverage

Reports which requirements have at least one complete chain down to a test case. A test case counts only when its pointer resolves to a real test in the working tree; a row whose pointer leads nowhere is reported as covered-unresolved, its own class, never as coverage. Strict mode demands per-criterion coverage; a scope id narrows the read to one requirement or story. CLI: rcf audit coverage.

rcf_trace

Answers "what hangs off this document" (forward), "what does it hang off" (back), or both, from any document id. Given a source path instead of an id, it resolves through the matching Code Nodes and traces back up to the root, so "why does this file exist" is answerable from the code side too. CLI: rcf audit trace.

rcf_impact

The before-you-change-it query: fans out from one document to every ancestor and descendant a change would touch, each labelled with the action it needs (re-run, re-verify, review-scope and friends). The pack instructs the agent to run it before changing anything with dependents. CLI: rcf audit impact.

rcf_read

Returns one document's body, or a single field of it, by id, including inline acceptance criteria and test cases. The method note it carries: read the real document before editing it; updates patch what exists, never a remembered body. CLI: rcf define read.

Writing the tree

rcf_create

Creates a document of a given kind. Inline kinds (acceptance criteria, test cases) mutate their parent document; every other kind writes one new file. The description itself restates the method's first rule: chain content is elicited with the stakeholder, never fabricated in one shot. CLI: rcf define create.

rcf_update

Patches fields on an existing document, by dot-path or deep merge, and refuses to touch identity fields. CLI: rcf define update.

rcf_delete

Deletes a document. Refuses by default when anything depends on it; cascading and dry-run variants exist, and the tool's own advice is to run rcf_impact first when unsure what hangs off the target. CLI: rcf define delete.

rcf_link

Appends architecture component links to a user story, idempotently, returning the post-state. This is how the tech layer of the chain stays attached to the stories that depend on it. CLI: rcf define link.

rcf_unlink

The reverse of rcf_link, with the matching honesty note: unlink only what the stakeholder agreed no longer applies. CLI: rcf define unlink.

Driving the build

rcf_build

Assembles the complete spec bundle for one work item: the work itself, queue and dependency context, acceptance criteria with their ancestry, architectural context, the existing test surface and the completion contract. Bundle assembly is mechanical; it projects what the tree says and leaves judging the item's quality to the review gates. CLI: rcf build bundle.

The two prompts

rcf_execute_build_cycle

Serves the build-cycle playbook: per-stage guidance, referee commands, failure modes and escalation rules for the five-stage loop. The shipped guidance tells the agent to fetch it once per session, then drive the queue.

rcf_elicit_requirements

Serves the elicitation playbook: the question frames for every layer of the chain, the quality bar for a testable acceptance criterion, and when to stop asking and start writing.

Both prompts serve the same bytes as the matching pages in this section; MCP and the public URLs are two routes to one shipped pack.

Pinned against: rcf-lite@0.15.0. Tool names, prompt names and every behaviour above are taken from that installed package's MCP server source and guidance manifest.