Adapters: spec tools

A spec tool stores the plan artifact. The only adapter is plain Markdown. To add a spec tool, map it to the contract in contract.md (D18).

Plain (default)

Concept	Target
Plan artifact	docs/plans/<id>.md with the six sections
Decision log	docs/plans/<id>.decisions.md
Progress file	docs/plans/<id>.progress.json
Spec delta	docs/plans/<id>.spec.md
Spec	docs/specs/<capability>.md, written by stone spec apply
G2 approval	A human approves the PR that adds the plan, or adds the plan-approved label
Validate	A script checks that the six sections exist and are not empty

Progress file format:

{
  "id": "issue-123-export-csv",
  "tasks": [
    {
      "id": "t1",
      "description": "Add the export button to the report page.",
      "test_steps": ["Open a report.", "Select Export.", "A CSV file downloads."],
      "passes": false
    }
  ]
}

Frameworks we do not adopt (D40)

Cornerstone is its own framework (D40). We read these spec-driven tools and borrow ideas from them. We do not adopt them.

Tool	Reason
Spec Kit	No single tool joins a neutral core, harness adapters, gates by profile, and an eval plan.
BMAD	Same reason.
Agentic Code	Same reason.