build-feature

name	build-feature
description	Use for end-to-end feature delivery from idea to verified code. Orchestrates brainstorming, plan-writing, and plan-execution with validated handoffs and 11 gates. No shortcuts, no skipped gates, no unverified claims. Triggers: "build feature", "build this", "implement end-to-end", "full pipeline".

Build Feature

Overview

Meta-orchestrator that chains three complete workflows — brainstorming, plan-writing, and plan-execution — into a single design-to-delivery pipeline. Each macro-phase runs its full sub-workflow with all phases and gates preserved. Pipeline state transfers between macro-phases via file paths on disk, making the pipeline resumable across sessions.

Core principle: From idea to verified code in one pipeline. No shortcuts. No skipped gates. No unverified claims. No deprecated code. No legacy patterns.

Announce: "I'm using the build-feature skill to run the full design-to-delivery pipeline."

The Iron Law

FROM IDEA TO VERIFIED CODE IN ONE PIPELINE.
NO SHORTCUTS. NO SKIPPED GATES. NO UNVERIFIED CLAIMS.

Pipeline

graph TD
    M1["Macro-Phase 1: Design\n(brainstorming)\n6 phases, 4 gates"] --> T1["docs/specs/YYYY-MM-DD-topic-design.md"]
    T1 --> V1{"Handoff\nValidator\n(Mode A)"}
    V1 -->|validated| M2["Macro-Phase 2: Plan\n(plan-writing)\n6 phases, 4 gates"]
    M2 --> T2[".plan/plan-YYYYMMDD-slug.md"]
    T2 --> V2{"Handoff\nValidator\n(Mode B)"}
    V2 -->|validated| M3["Macro-Phase 3: Execute\n(plan-execution)\n7 phases, 3 gates"]
    M3 --> Done(("Completion Report\n+ Fidelity Score"))

    T1 -.->|"user may exit"| E1(("Design complete"))
    T2 -.->|"user may exit"| E2(("Plan complete"))

    classDef macro fill:#2563eb,stroke:#1d4ed8,color:#fff,font-weight:bold
    classDef artifact fill:#16a34a,stroke:#15803d,color:#fff
    classDef validator fill:#d97706,stroke:#b45309,color:#fff,font-weight:bold
    classDef done fill:#7c3aed,stroke:#6d28d9,color:#fff
    classDef exit fill:#6b7280,stroke:#4b5563,color:#fff

    class M1,M2,M3 macro
    class T1,T2 artifact
    class V1,V2 validator
    class Done done
    class E1,E2 exit

Pipeline State

State transfers between macro-phases via files — no in-memory coupling:

Transition	Artifact	Location
Design to Plan	Design spec	docs/specs/YYYY-MM-DD-<topic>-design.md
Plan to Execute	Implementation plan	.plan/plan-{YYYYMMDD}-{slug}.md

This makes every macro-phase independently resumable. If a session ends after Design, start a new session at Plan by pointing to the spec file.

Session Continuity

At the start of every session, read .claude/stn-skills-pipeline-state.json if it exists.

• State found: Report "Found active pipeline '{pipeline_id}' — {active_skill} at Phase {current_phase}/{total_phases}. Gates passed: {gates_passed}." Use AskUserQuestion: "Resume from {active_skill} Phase {current_phase}, or start a fresh pipeline?" Options: ["Resume", "Start fresh"]
  • On "Resume": Invoke the active_skill via the Skill tool. The skill's Session Resumption Protocol reads the state file and continues from the correct phase.
  • On "Start fresh": Delete the state file. Begin from Macro-Phase 1.
• No state found: Initialize the state file with pipeline_id: "{YYYYMMDD}-{slug}", active_skill: "brainstorming", current_phase: 1, total_phases: 6, gates_passed: [], gates_total: 4, artifact_path: null, handoff_validated: false. Begin from Macro-Phase 1.

This ensures build-feature survives session boundaries without losing progress or restarting completed work.

---

Macro-Phase 1: Design (Brainstorming)

How to execute: Read skills/brainstorming/SKILL.md and follow its complete 6-phase workflow from Phase 1 through Phase 6, including all 4 gates. Dispatch agents from skills/brainstorming/agents/ and load references from skills/brainstorming/references/ exactly as that SKILL.md specifies.

• Agents: skills/brainstorming/agents/ (problem-decomposer, assumptions-surfacer, multi-lens-explorer, approach-evaluator, adversarial-reviewer)
• References: skills/brainstorming/references/ (cognitive-lenses, decision-matrix-template, design-spec-template, reasoning-flaw-catalog)
• Gates: Problem Confirmation, Exploration Review, Approach Selection, Final Spec Approval
• Output: Design spec saved to docs/specs/YYYY-MM-DD-<topic>-design.md

Error handling: If adversarial review finds Blockers (Phase 4), resolve them within brainstorming — do NOT escalate to build-feature level. The brainstorming SKILL.md defines its own blocker resolution loop.

MANDATORY: After GATE 4, invoke the next skill via the Skill tool. Do NOT start planning without it.

After GATE 4 (Final Spec Approval), use AskUserQuestion:

• Question: "Design spec saved to {path}. Continue to plan-writing, or stop here?"
• Options: ["Continue to plan-writing", "Stop here"]

On "Continue to plan-writing": Immediately invoke the Skill tool: Skill(skill: "stn-skills:plan-writing", args: "{spec_file_path}") On "Stop here": The pipeline ends. The design spec is on disk and can be used independently with /stn-skills:plan-writing in a future session.

Handoff Validation: Design → Plan

Before starting Macro-Phase 2, run skills/pipeline-handoff-validator/SKILL.md Mode A on the design spec file. Present the Handoff Compliance Table. If gaps are found, offer to return to brainstorming or proceed with acknowledged gaps.

---

Macro-Phase 2: Plan (Plan-Writing)

How to execute: Read the design spec file from Macro-Phase 1. Then read skills/plan-writing/SKILL.md and follow its complete 6-phase workflow. In Phase 1, pass the design spec file path as input. Dispatch agents from skills/plan-writing/agents/ and load references from skills/plan-writing/references/ exactly as that SKILL.md specifies.

• Agents: skills/plan-writing/agents/ (codebase-cartographer, task-decomposer, step-author, plan-verifier)
• References: skills/plan-writing/references/ (plan-document-template, task-anatomy, placeholder-detector-rules)
• Gates: Scope Confirmation, DAG Review, Verification Results, Final Plan Approval
• Output: Plan saved to .plan/plan-{YYYYMMDD}-{slug}.md

Error handling: If Plan Quality Score < 90 after 2 rework cycles (Phase 5), present remaining defects to user at GATE 3. User decides: accept with known gaps, or stop pipeline.

MANDATORY: After GATE 4, invoke the next skill via the Skill tool. Do NOT start executing without it.

After GATE 4 (Final Plan Approval), use AskUserQuestion:

• Question: "Plan saved to {path}. Continue to execution, or stop here?"
• Options: ["Continue to execution", "Stop here"]

On "Continue to execution": Immediately invoke the Skill tool: Skill(skill: "stn-skills:plan-execution", args: "{plan_file_path}") On "Stop here": The pipeline ends. Both spec and plan are on disk. Resume execution later with /stn-skills:plan-execution pointing to the plan file.

Handoff Validation: Plan → Execution

Before starting Macro-Phase 3, run skills/pipeline-handoff-validator/SKILL.md Mode B on the plan file. Present the Handoff Compliance Table. If gaps are found, offer to return to plan-writing or proceed with acknowledged gaps.

---

Macro-Phase 3: Execute (Plan-Execution)

How to execute: Read the plan file from Macro-Phase 2. Then read skills/plan-execution/SKILL.md and follow its complete 7-phase workflow. In Phase 1, pass the plan file path as input. Dispatch agents from skills/plan-execution/agents/ and load references from skills/plan-execution/references/ exactly as that SKILL.md specifies.

• Agents: skills/plan-execution/agents/ (task-implementer, spec-compliance-reviewer, code-quality-reviewer, integration-reviewer, completion-verifier)
• References: skills/plan-execution/references/ (checkpoint-protocol, circuit-breaker-thresholds, completion-report-template, drift-detection-rules, reflect-retry-escalate, status-codes, task-handoff-template)
• Gates: Plan Confirmation, Completion Review, Acceptance
• Output: Completion report with Execution Fidelity Score

Error handling: Circuit breakers (YELLOW/RED) and adaptive replanning are handled within plan-execution's Phase 3. If execution halts (RED circuit breaker), the .claude/plan-execution-state.json state file preserves progress for resumption.

---

Rules

1. Follow sub-skill SKILL.md files — Each macro-phase means reading and executing the referenced SKILL.md in full. This SKILL.md tells you WHICH sub-skill to run and WHEN. The sub-skill SKILL.md tells you HOW.
2. All gates preserved — The pipeline has 11 total gates (4 + 4 + 3). User confirms at each one. Present exactly what the sub-skill's gate specifies.
3. Exit at any gate — User can stop the pipeline at any gate boundary. Work is saved to disk. Inform the user which command resumes from here.
4. File-based handoff — Macro-Phase 1 output file → Macro-Phase 2 input. Macro-Phase 2 output file → Macro-Phase 3 input. Read the file path from the previous macro-phase's final output.
5. Error containment — Errors within a sub-skill are handled by that sub-skill's own mechanisms (blocker loops, rework cycles, circuit breakers). Only escalate to user when the sub-skill's error handling is exhausted.
6. Resumable — If a session ends mid-pipeline, resume by invoking the appropriate individual skill with the last artifact path. After Design: /stn-skills:plan-writing with spec path. After Plan: /stn-skills:plan-execution with plan path.

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Red Flags — STOP and Correct

If you catch yourself:

• Skipping the handoff validator between macro-phases
• Combining brainstorming and plan-writing into a single step
• Starting plan-execution without a plan file on disk
• Proceeding past a sub-skill gate without user confirmation
• Passing in-memory context instead of reading the artifact file
• Skipping macro-phases ("the user knows what they want, skip to execution")

ALL of these mean: STOP. The pipeline exists because shortcuts produce failures.

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Common Rationalizations

Excuse	Reality
"The user already has a clear idea, skip brainstorming"	Clear ideas still have unexplored alternatives and hidden assumptions. Use Focused complexity.
"The spec is simple, skip handoff validation"	Simple specs with missing acceptance criteria produce the most rework during execution.
"I can plan and execute simultaneously"	Simultaneous planning and execution eliminates the verification gate that catches plan defects.
"Handoff validation is redundant after GATE 4 approval"	User approval validates direction. Contract validation checks completeness. Different concerns.
"This is a small feature, the full pipeline is overkill"	Small features through the full pipeline take 30 minutes. Small features debugged after skipping gates take hours.
"I'll remember the spec details, no need to read the file"	Memory drifts. The file is the contract. Read it.