implement-feature

name	implement-feature
description	Implements a feature from the issue tracker -- spec, design, fix, review, test, publish
allowed-tools	mcp__*, Bash, Read, Write, Edit, Glob, Grep, Task
disable-model-invocation	true
argument-hint	<ISSUE-ID> | --description "<text>" [--decompose] [--no-decompose] [--decompose-only] [--dry-run] [--profile <name>] [--yolo] [--step-mode] [--clarification "<text>"]

/implement-feature

Read and apply the mandatory execution guard defined in skills/implement-feature/data/guard-block.md BEFORE any other instruction in this file.

<stage_allowlist> required: code_analysis, fixer_reviewer, test, publisher optional: smoke_check, acceptance_gate </stage_allowlist>

You are a THIN CONTROLLER. Implement feature $ARGUMENTS from the issue tracker by dispatching specialist subagents via the Task tool. NEVER inline agent logic. Read ## Automation Config from CLAUDE.md.

Mode flag parsing

GOT_YOLO=false ; GOT_STEP_MODE=false
[[ "$ARGUMENTS" == *"--yolo"* ]]      && GOT_YOLO=true
[[ "$ARGUMENTS" == *"--step-mode"* ]] && GOT_STEP_MODE=true
$GOT_YOLO && $GOT_STEP_MODE && { echo "[ERROR] Flags --yolo and --step-mode are mutually exclusive" >&2; exit 1; }

Additional flags parsed from $ARGUMENTS:

• --decompose → decompose_mode = FORCE ; --no-decompose → DISABLED ; neither → AUTO
• --decompose-only → decompose_only_mode = true (implies FORCE; mutually exclusive with --no-decompose)
• --description "<text>" → description_mode = true; mutually exclusive with Issue ID
• --dry-run → execute steps 01-02 only, display report, no side effects
• --clarification "<text>" → CLARIFICATION_TEXT = "<text>"; passed to ../../core/resume-detection.md

Mode semantics: default = supervised autopilot (pauses only on NEEDS_CLARIFICATION); --yolo = zero gates to PR; --step-mode = pause after each step (c continue / s skip / a abort).

Configuration

Follow ../../core/config-reader.md. Required sections: Issue Tracker (Type, State transitions, On start set), Feature Workflow (Feature query, On start set), Source Control (Remote, Base branch, Branch naming), PR Rules (Labels), PR Description Template, Build & Test (Build, Test, Verify commands), Retry Limits, Module Docs, Hooks, Custom Agents, Notifications, Decomposition, Error Handling, Agent Overrides, Local Deployment, Pipeline Profiles. Full key list in docs/reference/automation-config.md.

MCP pre-flight

Follow ../../core/mcp-preflight.md. In --description + --yolo mode: BLOCK with context-specific error (cannot create tracker card; no interactive fallback). Otherwise STOP with setup guidance.

If the MCP server is unavailable, display: Cannot connect to your issue tracker — MCP server unavailable. Please configure with /agent-flow:setup-mcp before retrying.

Step 0b: Config Validity Gate

Scan Automation Config required sections for <!-- TODO: and <...> placeholders; block if incomplete. Canonical logic mirrored in skills/fix-bugs/SKILL.md Step 0b.

See ../../core/mcp-body-formatting.md for newline-handling in MCP comment bodies.

Issue-ID validation (path-traversal defense)

if [[ ! "${ISSUE_ID}" =~ ^[A-Za-z0-9#._-]+$ || "${ISSUE_ID}" =~ ^\.+$ ]]; then
  echo "[BLOCK] Invalid issue_id: ${ISSUE_ID}" >&2; exit 1
fi

Pipeline profile parsing

Follow ../../core/profile-parser.md. Valid stage names: spec-analyst, analyst-impact, test-engineer, test-engineer-e2e. NEVER skip: fixer, reviewer, publisher.

Resume detection

Follow ../../core/resume-detection.md. Inputs: ISSUE_ID, MODE, GOT_YOLO, GOT_STEP_MODE, Webhook_URL, On_events, CLARIFICATION_TEXT. Outputs: RESUME_POINT, RESTORED_CONTEXT, PIPELINE_TYPE.

If RESUME_POINT == "FRESH", run the dispatch table below from step 01. Otherwise jump to the corresponding step per the FEATURE pipeline mapping in ../../core/resume-detection.md Step 6.

Init (state + run_id + start webhook)

After resume detection (when RESUME_POINT == "FRESH"):

1. Create .agent-flow/{ISSUE_ID}/ and initialize state.json via ../../core/state-manager.md — top-level status = "running", pipeline = "implement-feature", mode = "feature", empty stages = {} map, run_id = <uuid>.
2. Check out the working branch per Branch naming in Source Control config.
3. Fire pipeline-started webhook if configured (see ../../core/agent-states.md).
4. Apply Issue Tracker → On start set transition to the issue (state + implicit self-assign — same protocol as skills/fix-bugs/SKILL.md Step 1).

Step dispatch

Use the Read tool to load each step file below in order. Each step file specifies the subagent to dispatch, the prompt template, the pre-dispatch atomic state.json write (dispatched_at, dispatch_witness, agent_name, stage_name, status="in_progress" per core/lib/stage-invariant.sh), and the post-dispatch state finalization. Step files own ALL dispatch logic; this controller only sequences and merges output.

#	Step file	Stage (state.json)	Subagent	Model
01	skills/implement-feature/steps/01-spec.md	spec_analysis + code_analysis	spec-analyst, then analyst --phase impact	sonnet
02	skills/implement-feature/steps/02-architect.md	code_analysis (architect output)	architect	opus
03	skills/implement-feature/steps/03-decomposition.md	decomposition	(no dispatch — heuristic + tracker subtask creation; may dispatch backlog-creator)	sonnet (if dispatched)
04	skills/implement-feature/steps/04-fixer-reviewer-loop.md	fixer_reviewer	fixer ↔ reviewer loop	opus
05	skills/implement-feature/steps/05-smoke.md	smoke_check	(no dispatch — Build + Test commands)	n/a
06	skills/implement-feature/steps/06-test.md	test (+ optional e2e_test)	test-engineer (and test-engineer --e2e)	sonnet
07	skills/implement-feature/steps/07-acceptance-gate.md	acceptance_gate	acceptance-gate (conditional)	sonnet
08	skills/implement-feature/steps/08-publish.md	publisher	publisher + terminal dispatch-audit surface	haiku

Use the Read tool to load skills/implement-feature/steps/01-spec.md and execute it before step 02; repeat for each row of the table in order. Each step file's pre-dispatch write block consumes the canonical stage name listed in column 3 (binds to core/lib/stage-invariant.sh::compute_dispatch_witness).

Optional and conditional stages (smoke_check step 05, acceptance_gate step 07, e2e_test inside step 06) MUST write an explicit status = "skipped" to state.json when their config-gate evaluates negatively — never leave the stage at pending (alarm-fatigue protection: the terminal report in step 08 distinguishes WITNESS_MISSING on an OPTIONAL stage as EXPECTED_OPTIONAL_NOT_RUN, not an anomaly).

The orchestrator MUST inject EXPECTED_AGENT_NAME and EXPECTED_STAGE_NAME as Tier-1 prompt variables on every dispatch so subagents can cross-verify their ## Step Completion Invariants section against state.json.

Default mode checkpoints

In default mode (no --yolo, no --step-mode):

• Spec Checkpoint after step 01: display spec + AC summary; ask the user to confirm or revise before architect runs.
• Decomposition Approval checkpoint after step 02: show architect task tree + AC coverage; user approves before fixer loop starts.

--yolo skips both checkpoints and runs fully autonomous to PR. --step-mode prompts [step-mode] Step NN/08 completed. Continue? [c/s/a] after every step — see ../../core/resume-detection.md for a (abort) handling.

Decomposition specifics

Full decomposition logic — AC coverage check, task-tree validation, tracker subtask creation, --decompose-only exit — lives in skills/implement-feature/steps/03-decomposition.md. The controller never inlines decomposition heuristics.

--dry-run path

If $ARGUMENTS contains --dry-run: execute steps 01 and 02 only, display the spec summary + architect task tree, then EXIT without dispatching fixer/reviewer/test/publisher. No tracker writes, no git commits, no PR.

Agent overrides + step-mode prompt

Before EVERY Task dispatch, follow ../../core/agent-override-injector.md for TOML override loading and prompt injection (handled inside each step file — the controller never re-implements override loading).

After each step completes, if $GOT_STEP_MODE == true: pause and display step-result summary, prompt [step-mode] Step NN/08 completed. Continue? [c/s/a]. c = continue; s = skip next step (write status = "skipped" to next stage's state.json record before resuming); a = abort (write status = "paused" and last_completed_step to state.json; exit 0; resume by re-invoking /agent-flow:implement-feature <ISSUE-ID>).

Near-miss WARN: if a file exists at customization/steps/implement-feature/{NN}-*.md that does NOT match any of the 8 canonical step filenames, log [WARN] Unrecognized step override file: {filename} and continue.

Block handler

Follow ../../core/block-handler.md. On fixer / reviewer / test-engineer block → dispatch rollback-agent (haiku) to revert git state. Block comment format: [agent-flow] prefix per CLAUDE.md "Block Comment Template". Write to state.json: status = "blocked", outcome = "failed", block = {...} per ../../core/state-manager.md atomic write protocol. Pipeline halts cleanly with exit 0 (graceful block).

Architecture freshness check (advisory)

Advisory pre-architect warning — does not block dispatch:

last_commit=$(git log -1 --format="%H" -- docs/architecture.md 2>/dev/null)
if [ -n "$last_commit" ]; then
  commits_since=$(git rev-list HEAD ^"$last_commit" --count 2>/dev/null || echo 0)
  [ "$commits_since" -ge 25 ] && echo "[WARN] docs/architecture.md has not been updated in ${commits_since} commits (threshold: 25)."
fi

Step detail files

All eight step files live in skills/implement-feature/steps/. Each owns its full dispatch prose, pre-dispatch witness write, post-dispatch state finalization, and webhook firing. This controller is structurally bound by the <stage_allowlist> block above — Area D terminal surfacing in step 08 reads that block to classify audit-log anomalies.