Req Dev Lite

Requirements Development Agent — Lite (req-dev-lite)

Your job: interrogate the requirements provider like a trial lawyer until falsifiable, real requirements surface — then synthesize a local PRD markdown file.

The goal is not "collect as many requirements as possible"; it is "collect as many real requirements as possible". Most PRDs fail not because too few questions were asked, but because answers with no falsification mechanism were accepted.

| Aspect | req-dev (full, not in this repo) | req-dev-lite (this skill) | |---|---|---| | PRD output | issue tracker (gh CLI) | local file docs/prd/YYYY-MM-DD-{slug}.md | | Bucket C (open items) | one issue each | ## Open Items table at the end of the PRD | | Prerequisites | issue tracker + triage labels configured | none | | Snapshot | docs/req/open-items-snapshot-*.md | docs/prd/{slug}-snapshot.md | | Retro path | skills/req-dev/sessions/ | skills/req-dev-lite/sessions/ |

Use lite for early idea validation, solo projects, throwaway exploration, or whenever you want a PRD file without an issue tracker.

North-star rules (apply throughout)

1. One question at a time. Never stack A/B/C questions.
2. If the code can answer it, don't ask. Check the code first.
3. **Every question leads with a recommended answer + the condition that would

falsify it**, so the user verifies instead of imagining. Question shape must follow the three-part pattern in references/question-bank.md (Recommended answer / Why ask / Push-back if).

1. Three-bucket rule — every requirement must fit one of three buckets or be discarded:

• Bucket A: a Gherkin Given-When-Then example with real values (not "a

reasonable amount" — "$1,000")

• Bucket B: a measurable outcome metric (baseline + target + deadline)
• Bucket C: an open item (owner + deadline), written into the PRD's Open Items table

Inputs

Required: project root writable (to create docs/prd/). Recommended: existing CONTEXT.md / docs/adr/; at least one real-scenario anecdote from the user (past tense, not "in the future we will...").

When missing: docs/prd/ → lazy-create. CONTEXT.md → follow grill-with-docs lazy-creation. No anecdote → stage 2 digs one out with Mom-Test phrasing ("When was the last time..."); future-tense hypotheticals are not accepted.

Stage 0 — preflight

• [ ] Probe CONTEXT.md / docs/adr/ (missing is fine — lazy creation).
• [ ] Probe docs/prd/ for historical PRDs/snapshots (resume detection, see "User-initiated Stop").
• [ ] If the full req-dev is also installed and the user didn't specify which — ask once.

The 8-stage flow

Stage 1 — Opening four (Impact Mapping)

Ask in order. Discussing What is forbidden until Why and Who are nailed down.

1. Why — what business goal does this serve, and how is it quantified?

(Recommended: a concrete sub-item of an existing OKR / north-star metric.)

1. Who — whose behavior must change for this to count as success? (Down to job title.)
2. How — how must their behavior change? (From behavior X to behavior Y, concretely.)
3. What — what can we build to drive that change?

> ⚠️ Users routinely skip ahead to What. Pull them back one level every time.

Stage 2 — Grilling loop (grill-with-docs + Mom Test)

Apply the grilling discipline from [../../third_party/grill-with-docs/SKILL.md](../../third_party/grill-with-docs/SKILL.md): one question per turn, recommended answers, code-first verification, terminology calibration, scenario stress-tests, inline CONTEXT.md updates.

Layer the Mom Test on top (full bank in references/question-bank.md):

Banned questions (never ask): "Would you use X?" / "Do you think X is useful?" / "Imagine X..." / "In the future would you...?" / "Would you pay for X?" / "What do you think of this feature?" — they harvest compliments, not facts.

Mandatory shapes:

• "When was the last time you did X? Walk me through it."
• "How do you solve this today?" (the workaround reveals the real cost)
• "Why hasn't this been fixed yet?" (reveals true priority and blockers)
• "What did the last failure cost you (time / money / churn)?"
• "Walk me through the steps, from the start." (instead of "describe it")

Stage 2.5 — Solution interceptor (5 Whys)

Trigger: the user proposes a concrete technology/tool/implementation ("use Redis", "add a toggle", "build a dashboard", "use MongoDB").

Interrupt immediately and run the chain: Why this solution? → Why does it matter now? → Why can't the current way do it? → Who is affected and how much? → What is the underlying outcome? (Ulwick shape: "minimize/maximize [verb][object][constraint]")

No solution enters the PRD before the root cause is found. Record the root cause as an outcome metric (Bucket B); demote the original proposal to "one implementation candidate".

Stage 3 — Domain calibration (grill-with-docs home turf)

Follow grill-with-docs exactly: halt on terminology conflicts with CONTEXT.md; force vague words ("account", "cancel", "order") down to concrete entities; stress-test fuzzy relationships with invented extreme scenarios; force a choice when code and narration disagree; land decisions inline in CONTEXT.md, open an ADR for the significant ones (formats: ../../third_party/grill-with-docs/CONTEXT-FORMAT.md, ADR-FORMAT.md).

Stage 4 — Structure into User Stories (INVEST + SBE)

Every story must pass the 30-second INVEST check (Independent / Negotiable / Valuable / Estimable / Small / Testable) and carry ≥1 Gherkin example with real values. Template: templates/user-story.md.

Stage 4.5 — Unhappy-path enumeration (Cockburn Extensions)

For every main-flow story, enumerate failure branches step by step. A missing branch sends you back to stage 2.

Stage 5 — Final gate (Volere Quality Gateway + 7-label review)

Every story + AC passes two review layers — full criteria and examples in references/quality-gateway.md (Chinese; it is also the scoring anchor for prd-gate).

Tri-state verdict (allowed failures = floor(N × 0.2)):

• PASS — all stories pass Volere 4 + 7 labels
• PASS-WITH-OPEN-ITEMS — ≥80% pass; every failure fits Bucket C without blocking the PRD
• FAIL — failures exceed the threshold, or the core Why/Who is not nailed down. Rework.

> ⚠️ Core Why/Who veto: if stage 1's Why or Who fails Volere traceability, > the verdict is FAIL regardless of the pass ratio.

> 💡 Stage 5 is the author-model's in-conversation self-review — a cheap > pre-filter, systematically biased toward PASS. The authoritative verdict comes > from the independent prd-gate in stage 7.

Stage 6 — Three-bucket triage (hard constraint)

Bucket A → PRD User Stories. Bucket B → Problem Statement § Outcome Metrics. Bucket C → the PRD's trailing ## Open Items table (owner + deadline + trigger context + best assumption, all mandatory). Anything that fits no bucket is discarded into ## 6. Out of Scope with the reason.

Stage 7 — Landing (local file, no GitHub)

1. Generate the PRD from templates/prd-local.en.md (English) or

templates/prd-local.md (Chinese) — same section contract either way.

1. Write /docs/prd/YYYY-MM-DD-{slug}.md (suffix -2/-3 on same-day collisions).
2. Bucket C → the trailing ## Open Items table.
3. Independent gate (prd-gate — mandatory when available): probe for the

prd_gate package (python -c "import prd_gate" or src/prd_gate/ in the repo).

• Available → run python -m prd_gate score --prd ; answer the

emitted judge-tasks in a fresh-context subagent (give it ONLY the PRD + references/quality-gateway.md — never this conversation); run merge. Write gate_mode: prd-gate plus the report's final_gate_verdict / gate_aggregate / gate_confidence into the frontmatter (copy, never hand-edit). Verdict FAIL → do not land; rework per the report's Evidence (back to stage 2/5, max 3 rounds).

• Unavailable → use the stage-5 self-review verdict and must write

gate_mode: self-reported — downstream consumers treat that verdict with capped trust.

1. Write the session snapshot docs/prd/{slug}-snapshot.md (templates/open-items-snapshot.md).
2. Report to the user: PRD path + gate verdict (with gate_mode) + snapshot path +

bucket tally (A:B:C counts + discards).

Stage 8 — Auto-retrospective (do not bother the user)

After landing, before the closing summary, write a structured retro to skills/req-dev-lite/sessions/YYYY-MM-DD-HHMM-{slug}.md using sessions/_template.md. Hard rules: never modify SKILL.md/templates here; no raw transcript (structured data only); redact PII from quoted user words. Interrupted sessions also get a retro with status: aborted|paused.

Anti-pattern self-checks

• Compliment trap: "sounds great" / "should be fine" → demand a concrete example.
• Future-tense trap: "later" / "users will" → pull back to the past: "when did this last happen?"
• Solution-as-requirement: "add a toggle" / "build a dashboard" → 5 Whys interceptor.
• Abstract-AC trap: "handle errors properly" → demand a Gherkin example.
• Happy-path trap: only success flows described → stage 4.5.

User-initiated Stop (resumable state)

| Type | Trigger | Meaning | |---|---|---| | user_initiated | "park it", "I'm tired", "good enough", "just generate the PRD", "GRILL ENOUGH" | user's call; resume later | | agent_failed | ≥3 consecutive turns stuck on the same question / grilling loop / evasive answers | agent failure → retro signal |

On stop (either type): unanswered items → Bucket C rows tagged [resumable] with "stuck at stage N"; jump to stage 6 and land a PRD from the answered portion with frontmatter status: partial; write resume fields into the snapshot (pending_stage, pending_items, stop_reason, resumable_slug); retro gets status: paused.

Resume ("continue req-dev-lite "): find {slug}-snapshot.md in docs/prd/, read pending_stage/pending_items, continue from there (ask the pending items first, never restart), new retro with resumed_from, then flip [resumable] rows to resolved or still-open.

When to stop

Not "all questions asked" — all three buckets settled and the final gate passed. A user-initiated Stop is also a legitimate stop; agent_failed is not — it is a failure for the retro loop to digest.

Verification checklist (before the closing summary)

• [ ] Required inputs satisfied (project root writable)
• [ ] Stage 0 preflight ran (CONTEXT / PRD history / full-vs-lite disambiguation)
• [ ] Stage 1 Why and Who nailed down before What (core veto not bypassed)
• [ ] 5 Whys interceptor fired whenever solution language appeared
• [ ] Every story has ≥1 Gherkin example with real values
• [ ] Cockburn Extensions enumerated for every happy path
• [ ] Stage 5 tri-state verdict explicit; stage 7 gate ran (or gate_mode: self-reported set)
• [ ] Five anti-patterns audited; hits counted in the retro
• [ ] Buckets A+B+C account for 100% of candidate requirements — nothing silently dropped
• [ ] PRD file + snapshot + stage-8 retro all written
• [ ] If stopped: stop_reason classified, snapshot has full resume info

Files

Self-contained (no dependency on anything outside this repo). Every document is bilingual: English canonical + a .zh.md Chinese sibling.

• references/methods.md — the 12 methods annotated (5 core + 2 checks + 5 optional)
• references/question-bank.md — Mom Test banned/mandatory questions + Impact

Mapping openers + 5 Whys triggers + Cockburn/7-label/domain-calibration questions

• references/quality-gateway.md — Volere 4 + 7-label criteria with examples

(the prd-gate scoring anchor)

• references/attribution.md — verified sources, licenses + safety-review log
• templates/prd-local.en.md / templates/prd-local.md — the PRD contract (EN / 中文 — these two ARE the bilingual pair)
• templates/user-story.md, templates/open-items-snapshot.md
• sessions/_template.md, sessions/README.md

Downstream consumer contract (interface to auto-dev-lite)

The PRD this skill produces is the input contract for auto-dev-lite step 0.5: section numbering, US-NNN heading shape, the 7-field story body order, and the 9-column Open Items table are parsed mechanically. Do not restructure them. Frontmatter consumed downstream: status, final_gate_verdict, gate_mode (absent = self-reported), gate_confidence, session_id, snapshot. Full contract: ../auto-dev-lite/references/prd-import-rules.md. Template changes require the sync protocol described there (update both sides + regression on a historical PRD).

Current alignment: templates/prd-local(.en).md @ 2026-06-10 ↔ prd-import-rules contract @ 2026-06-10.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: samgao2000
• Source: samgao2000/prd-grill
• License: MIT

Install and usage instructions live in the source repository linked above.