Creates durable technical specs for new features by analyzing existing codebase and issue requirements.
Install
mkdir -p .claude/skills/spec-matteocervelli && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/9519" && unzip -o skill.zip -d .claude/skills/spec-matteocervelli && rm skill.zipInstalls to .claude/skills/spec-matteocervelli
Activation
This is the description your AI agent reads to decide when to run this skill — the better it matches your request, the more reliably it fires.
Write a durable feature spec before touching code. Reads the codebase map, reads related models/migrations to ask technical questions (not generic ones), then produces a structured spec doc in docs/specs/. Designed to pipeline with /implementation --issue N. Use before any feature implementation.Key capabilities
- →Load codebase maps and architecture documentation
- →Read GitHub issues for requirements
- →Generate structured feature specifications
- →Perform adversarial reviews of specifications
How it works
The tool reads codebase indices and issue details to generate a structured specification document before any implementation begins.
Inputs & outputs
When to use spec
- →Drafting a feature specification from a GitHub issue
- →Analyzing database models and migrations for a new feature
- →Performing an adversarial review of a proposed feature spec
- →Preparing documentation for implementation phase
About this skill
/spec — Feature Specification
Trigger
/spec --issue N [--fast]
--issue N— required. Reads GitHub issue #N.--fast— skip questions, apply defaults fromreference/defaults.md, still requires user approval of the spec (hard gate).
Output
docs/specs/YYYY-MM-DD-{slug}-issue-{N}.md
YAML frontmatter includes issue: N so /implementation --issue N finds
this file automatically.
Workflow
Step 1 — Load codebase map
ls docs/codebase/INDEX.md 2>/dev/null || echo "missing"
If exists and < 7 days old: read architecture.md + conventions.md.
If missing or stale: run /map-codebase first, then proceed.
Step 2 — Read issue
gh issue view N --json title,body,labels,state
Step 3 — Brainstorm (9 stages)
See workflows/brainstorm.md.
Key principle: Stage 1 reads actual related code (models, migrations, FK patterns) before formulating questions. Questions must demonstrate codebase understanding — reference specific tables, patterns, or files found in Stage 1.
Step 4 — Write spec
Use templates/spec.md. Every column, every endpoint, every file in manifest.
No placeholders. No TBD. If unknown → make it a deferred decision, explicitly.
Step 5 — Adversarial review (optional)
Ask explicitly:
"Do you want an adversarial review of this spec before committing? This spawns a Codex/Gemini reviewer that looks for: missing constraints, wrong FK assumptions, scope creep, contradictions, and security gaps."
- Yes → run
/review solve "adversarial spec review: find flaws in docs/specs/{filename}", present findings, offer to fix before commit - No → proceed to Step 6
Step 6 — Commit spec
git add docs/specs/{filename}
git commit -m "docs(spec): {feature slug} spec — issue #{N}"
Step 7 — Hand off
Print this block verbatim so the user can copy-paste it:
Spec committed: docs/specs/{filename} (on main)
── Option A: implement in current session ──────────────────
/implementation --issue {N}
── Option B: implement in a parallel worktree ──────────────
git worktree add -b feature/{N}-{slug} ../{project}-{N} main
# open new Claude Code session in ../{project}-{N}
/implementation --issue {N}
── Fast mode (no questions, Codex review at end) ───────────
/implementation --issue {N} --fast
Spec stays on main. The branch is created by worktree add or by /implementation at start. Multiple specs can be committed to main in parallel — they are docs only, no code conflicts.
Do not start implementing. Do not write any code.
References
workflows/brainstorm.md— 9-stage spec generation with technical question guidelinesreference/defaults.md— fast mode assumptions tabletemplates/spec.md— required spec document format
When not to use it
- →When implementing features without a specification
- →When the codebase map is missing or stale
Prerequisites
Limitations
- →Requires an existing codebase index
- →Does not allow code implementation during the specification phase
How it compares
It mandates the creation of a durable specification document linked to a GitHub issue, preventing ad-hoc implementation.
Compared to similar skills
spec side by side with the closest alternatives in the catalog.
| Skill | Installs | Updated | Safety | Difficulty |
|---|---|---|---|---|
| spec (this skill) | 0 | 2mo | Review | Intermediate |
| repo-research-analyst | 1 | 6mo | Review | Intermediate |
| business-knowledge-workflow | 1 | 3mo | No flags | Intermediate |
| gathering-requirements | 3 | 8mo | No flags | Intermediate |
Try saying
Example prompts that trigger this skill in your AI assistant.
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