feature

Routes feature development through plan, spec, and implement stages driven by a deterministic CLI oracle.

1|Updated Jul 9, 2026
One-click install
npx skills add https://github.com/matthewalton/speccle --skill feature-matthewalton
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: feature
Source: https://github.com/matthewalton/speccle/tree/main/packages/plugin/skills/feature
Command: npx skills add https://github.com/matthewalton/speccle --skill feature-matthewalton

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Building features with an AI agent often loses track of where work stands between sessions, leading to half-finished slices, stale progress files, and unreviewed specs. This Skill turns the feature folder itself into the source of truth, so every session resumes exactly where the work actually is. ## Core Features & Use Cases - Stage routing via a deterministic oracle: Runs speccle next to derive the current stage (plan, spec, implement, stale-claims, done) from the feature folder without calling an LLM. - One human gate: Plan and spec share a single session with one approval point, after which implementation runs unattended and commits on a green checks-gate. - Sibling skill orchestration: Delegates to plan-feature, spec-feature, and implement-feature, and hands off to carve-feature or review at loop boundaries. - Use Case: You hand over a ticket describing a new checkout behavior. The Skill plans and specs it with you in one session, then subsequent sessions implement one criterion at a time, each committed on green, until the slice is done. ## Quick Start Ask the agent to speccle this feature description into a planned, specced slice and start implementing it one criterion at a time.

Frequently Asked Questions about feature

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I build a feature with Claude Code one session at a time?▼

Invoke the feature skill, which runs the speccle oracle's next command to detect the current stage from the feature folder. It then plans and specs with you in one gated session, or implements exactly one criterion and commits it on a green checks-gate.

How does the skill know which stage a feature is at?▼

It runs `speccle next <project-root> --json`, a deterministic CLI that derives the stage from the feature folder's actual files. It never reads progress files or guesses, so the state cannot go stale between sessions.

What is a vertical slice in spec-driven development?▼

A vertical slice is a feature folder owning everything one behavior needs: SPEC.md acceptance criteria with stable ids, a CONTEXT.md glossary, ADRs, and tests that claim criteria by carrying the criterion id token.

Can the skill run unattended without human approval?▼

Yes, past the single planning gate. If a run is unattended, open decisions default to their recommendations and are flagged in the summary; implementation then proceeds criterion by criterion, committing only on a green checks-gate.

What happens when a test claims a criterion that does not exist?▼

The oracle reports a stale-claims stage. The skill deletes those tests, verifies the defended code is either still promised by a live criterion or removed, commits that cleanup, and stops until the next session.

When should I use carve instead of the feature skill?▼

Use carve when the requested behavior already runs in the codebase and only needs governing, not changing. The feature skill names carve-feature and stops rather than mixing governing and changing in one pass.