Spec Driven Workflow

Spec-Driven Workflow

The spec is the shared source of truth for what to build and how to know it is done.

Quick size guide

Read references/problem-size-guide.md when size is unclear.

Gated procedure

Do not advance phases until the current artifact is good enough (user review for medium+; self-check for small).

SIZE → SPECIFY → ANALYZE (medium+) → PLAN (medium+) → CLEAR → IMPLEMENT → REVIEW
                    ↑______________ living spec + plan sync ______________|

1. Size — Match depth to problem size (table above).
2. Specify — Surface assumptions first, then write testable requirements (REQ-XXX preferred). Default Requirements-First. Read references/spec-writing-guide.md.
   • Bugfix (non-obvious / high-risk defects): use Current / Expected / Unchanged — read references/bugfix-workflow.md.
   • Design-First (strict NFRs, existing architecture, feasibility before scope): draft TECH/approach first, then derive REQs — see references/spec-writing-guide.md.
3. Analyze (medium+) — Cross-requirement check for conflicts, ambiguity, and gaps before planning. Read references/analyze-requirements.md.
4. Plan (medium+) — Break work into concrete, verifiable tasks. Prefer a written plan before multi-file changes.
   • Architecture packet (Large, and Medium when architecture/integration is ambiguous): require system context + container views (or “N/A — architecture proven”) and link ADRs for irreversible choices via solution-architecture / /design-architecture before multi-phase implement. See references/problem-size-guide.md.
   • Tracer bullet (Large, and Medium when architecture/integration is ambiguous): include a thin vertical slice + one verify before multi-phase implement, or an explicit “N/A — architecture proven” justification. See references/problem-size-guide.md.
   • Prefer splitting build tasks from verify/review tasks so QA can proceed in parallel with the next REQ slice (optional for Small).
5. Clear (Medium+) — Persist exploration into the living spec/plan; start implement lean. Do not carry the full exploration transcript as working context. Bounded explore (subagent or dedicated chat) is fine; durable findings must already be in artifacts. For multi-session work, read references/session-handoff.md (start checklist: living spec + plan + progress before coding).
6. Implement — Follow the spec/plan; map each requirement to tests unless non-behavioral with explicit justification. On Medium+ session end (or incomplete work), write the handoff/progress section per session-handoff.md — not an AFK product.
7. Review — Separate evaluate pass (generator ≠ evaluator): refute-minded check of spec compliance, regression fence, security-sensitive paths, tests, and docs/README drift on user-facing surface changes (hand off to /update-readme / readme-authoring; do not full-sync inside review unless asked). Do not treat implement-session self-grade as done. Read references/review-evaluator.md.
8. Brownfield — Document existing behavior with extract-spec before large changes. Read references/brownfield-workflow.md.

Before writing a spec

Surface assumptions immediately. List what you are assuming and invite correction before drafting:

ASSUMPTIONS:
1. …
2. …
→ Correct me now or I'll proceed with these.

Reframe vague goals as success criteria (measurable / testable), then confirm:

REQUIREMENT: "Make the dashboard faster"
SUCCESS CRITERIA:
- LCP < 2.5s on 4G
- Initial data load < 500ms
→ Are these the right targets?

Sketch test seams (medium+). Prefer the highest useful existing boundary (API, module, port) over inventing new ones; confirm with the user before locking them into the spec. Details: references/spec-writing-guide.md.

Do not silently fill ambiguous requirements — that is the failure mode SDD exists to prevent.

Living spec + plan sync

Update the spec when decisions or scope change; prefer updating the spec before implementing the change. Link PRs back to the spec section or REQ-XXX they satisfy.

After material REQ/design edits: re-run /plan-impl (or refresh Cursor Plan YAML todos) so tasks match the living spec. Do not implement against a stale plan.

Artifact homes

Before writing a spec or plan, resolve the output home (do not assume .cursor/):

1. Explicit path from the user (--out, @file, concrete path)
2. Existing project convention (docs/specs|plans or .cursor/docs/specs / .cursor/plans)
3. Client default — Cursor / or Cursor wiring → .cursor/...; otherwise → docs/specs + docs/plans

Read references/artifact-homes.md whenever creating or locating specs/plans.
Read references/cursor-adapter.md when the home is Cursor (Plan YAML todos required).

Slash commands are optional thin wrappers; details in references/commands-reference.md.

Progressive disclosure

Load references only when needed:

Quality gates

• Assumptions surfaced before drafting when requirements are ambiguous.
• Requirements are specific and testable.
• Medium+ specs get a cross-requirement analyze pass (or explicit “N/A — tiny REQ set already reviewed”) before plan.
• Medium+ specs name preferred test seams (highest useful existing boundary) when behavior is non-trivial.
• Bugfix specs (when used) document Unchanged behavior and tests cover the fence.
• After material living-spec edits, the plan/todos are resynced before implement.
• Large / ambiguous Medium plans include an architecture packet gate (or “N/A — architecture proven”) via solution-architecture when integration boundaries are unclear.
• Implemented requirements have automated tests (or a short justification when truly non-behavioral).
• Fail-closed verify: Before claiming done, run project-cmds (or documented project verify). If verify is not configured, do not claim done — instruct /quick-start or set project-cmds / portable equivalent. “Looks good” without verify is forbidden.
• Multi-session handoff (Medium+): Session start reads living spec + plan + progress; session end updates handoff (next REQ/T#, git expectation) per session-handoff.md. Not an AFK/Ralph product.
• Generator ≠ evaluator (Medium+): Do not claim done from implement self-grade alone; run a separate refute-minded /review per review-evaluator.md (bugfixes: Unchanged fence required).