Implement Task with Verification

SkillProductivity

Implement a task step by step with automated LLM-as-Judge verification at the end of each phase

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the Implement Task with Verification skill

What this skill tells your AI

The instructions your AI receives, as published by neolabhq/context-engineering-kit in skills/implement-task/SKILL.md and read by ahel’s review.

Your job is to implement solution in best quality using task specification and sub-agents. You MUST NOT stop until it is critically necessary or you are done! Avoid asking questions until it is critically necessary! Dispatch one implementation agent per step, then — when every step of an implementation phase is done — launch ONE sdd:code-reviewer for that phase, iterate till issues are fixed, then move to the next phase!

Execute task implementation steps with automated quality verification using a single sdd:code-reviewer agent per implementation phase.

User Input

$ARGUMENTS

Vocabulary (read this first — two different things are called "phase")

TermMeaning
Workflow Phase 0-5The stages of THIS skill (select task, load, execute, DoD, move, report).
Implementation phase / Phase NA milestone in the TASK file's ### Phase Overview. It groups steps, names a Reviewer model, and lists the acceptance criteria due at that milestone. This is the unit of code review.
StepOne sub-task file at .specs/sub-tasks/<task-name>/<NN>-<step-slug>.md. This is the unit of implementation dispatch. The step name is that file's basename without .md.

Command Arguments

Parse the following arguments from $ARGUMENTS:

Argument Definitions

ArgumentFormatDefaultDescription
task-filePath or filenameAuto-detectTask file name or path (e.g., add-validation.feature.md)
--continue--continueNoneContinue implementation from the last completed step: resolves the implementation phase in progress, completes its outstanding steps, then reviews that phase — see Context Resolution for --continue.
--refine--refinefalseIncremental refinement mode - detect changes against git, map them to steps, and re-verify from the implementation phase that owns the earliest affected step.
--human-in-the-loop--human-in-the-loop [Phase 1,Phase 3,...]NoneImplementation phases after whose review to pause for human verification. If no phases specified, pauses after every implementation phase.
--target-quality--target-quality X.X4.0Single target threshold value (out of 5.0) applied to every implementation phase review.
--max-iterations--max-iterations N3Maximum fix→re-review cycles per implementation phase. Default is 3 iterations. Set to unlimited for no limit.
--skip-reviews--skip-reviewsfalseSkip all phase reviews - steps proceed without quality gates.
--modelopus|sonnet|haikuUnsetModel for all sub-agents (implementation agents AND sdd:code-reviewer) that overrides every model in the task file; when omitted, step models come from the Parallelization Overview and reviewer models from the Phase Overview.
--strict--strictfalseDisable the Iteration Discretion Rule - a phase is marked PASS ONLY when combined_score >= THRESHOLD, otherwise iterate until MAX_ITERATIONS is reached.

Configuration Resolution

Parse $ARGUMENTS and resolve configuration as follows:

# Extract task file (first positional argument, optional - auto-detect if not provided)
TASK_FILE = first argument that is a file path or filename

# Single quality threshold — there is exactly one, and it is NEVER read from the task file
THRESHOLD = --target-quality value || 4.0

# Initialize other defaults
MODEL_OVERRIDE = --model value (opus|sonnet|haiku) || none  # none = no override; models come from the task file
MAX_ITERATIONS = --max-iterations || 3  # default is 3 iterations
HUMAN_IN_THE_LOOP_PHASES = --human-in-the-loop || [] (empty = none, "*" = all implementation phases)
SKIP_REVIEWS = --skip-reviews || false
REFINE_MODE = --refine || false
CONTINUE_MODE = --continue || false
STRICT_MODE = --strict || false

# Special handling for --human-in-the-loop without a phase list
if --human-in-the-loop present without phase identifiers:
    HUMAN_IN_THE_LOOP_PHASES = "*" (all implementation phases)

THRESHOLD is the ONLY quality threshold in this workflow. There is no separate standard/critical/lenient value, no comma-separated form, and no threshold anywhere in the task file — the planning agents are forbidden from writing one.

Context Resolution for --continue

When --continue is used, state is resolved by implementation phase, then step:

  1. Phase and Step Resolution:
    • Read the task file's ### Parallelization Overview step table and ### Phase Overview.
    • A step is complete when its row in the step table is marked [DONE].
    • An implementation phase is complete when its #### Phase N heading carries either marker: [REVIEWED] (its review ran and passed) or [REVIEWED-SKIPPED] (its steps finished and its review was deliberately suppressed by an earlier --skip-reviews run).
    • RESUME_PHASE = the first implementation phase marked neither [REVIEWED] nor [REVIEWED-SKIPPED]. Treating [REVIEWED-SKIPPED] as unfinished would re-run exactly the review the user suppressed.
    • RESUME_STEPS = the steps of RESUME_PHASE that are not [DONE], in dependency order.
  2. Verify the resumed phase's existing work:
    • If RESUME_PHASE already has some [DONE] steps but neither marker, and RESUME_STEPS is empty (all steps done, review never ran):
      • If SKIP_REVIEWS is true: launch nothing. Mark the phase [REVIEWED-SKIPPED] and resume at the next implementation phase.
      • Otherwise: launch the sdd:code-reviewer for RESUME_PHASE (passing the 4 inputs documented in Workflow Phase 2) — Model: MODEL_OVERRIDE if set — otherwise that phase's Reviewer model.
        • If the phase PASSES per the Iteration Discretion Rule: mark it [REVIEWED] and resume at the next implementation phase.
        • Otherwise: enter the Failure Handling flow for that phase.
    • If RESUME_STEPS is non-empty: dispatch those steps first, then review the phase as normal — and SKIP_REVIEWS still suppresses that review, marking the phase [REVIEWED-SKIPPED] instead.
  3. State Recovery:
    • Check task file location (in-progress/, todo/, done/)
    • If in todo/, move to in-progress/ before continuing
    • Pre-populate captured values from existing artifacts

Refine Mode Behavior (--refine)

When --refine is used, it detects changes to project files (not the task file) and maps them to steps, then re-verifies from the implementation phase that owns the earliest affected step.

  1. Detect Changed Project Files:

    First, determine what to compare against based on git state:

    # Check for staged changes
    STAGED=$(git diff --cached --name-only)
    
    # Check for unstaged changes
    UNSTAGED=$(git diff --name-only)
    

    Comparison logic:

    StagedUnstagedCompare AgainstCommand
    YesYesStaged (unstaged only)git diff --name-only
    YesNoLast commitgit diff HEAD --name-only
    NoYesLast commitgit diff HEAD --name-only
    NoNoNo changesExit with message
    • If both staged AND unstaged: Compare working directory vs staging area (unstaged changes only)
    • If only staged OR only unstaged: Compare against last commit
    • This ensures refine operates on the most recent work in progress
  2. Map Changes to Steps:

    • Read the task file's ### Parallelization Overview to get every step name, its implementation phase, and its Sub-Task File path.
    • Refine mode is the ONE case where you may read sub-task files: they are specification artifacts (like the task file), not implementation outputs, and their #### Expected Output sections are the only place file paths per step are recorded. Read ONLY the #### Expected Output and #### Subtasks sections you need.
    • Build a mapping: {changed_file → step name → implementation phase}
  3. Determine Affected Scope:

    • Find all steps that have associated changed files
    • REFINE_FROM_PHASE = the earliest implementation phase containing an affected step
    • All implementation phases from that point onwards need re-verification
    • Earlier phases (unaffected) are preserved as-is
  4. Refine Execution:

    • For each affected implementation phase (in order):
      • Launch ONE sdd:code-reviewer agent to verify the phase (including the user's changes), passing the 4 standard inputs — Model: MODEL_OVERRIDE if set — otherwise that phase's Reviewer model
      • If the phase PASSES per the Iteration Discretion Rule: mark it [REVIEWED], proceed to the next phase
      • Otherwise: enter the Failure Handling flow, then re-review
    • User's manual fixes are preserved - implementation agents should build upon them, not overwrite
  5. Example:

    # User manually fixed src/validation/validation.service.ts
    # (This file is the Expected Output of step `02-validation-service`, in Phase 1)
    
    /implement my-task.feature.md --refine
    
    # Detects: src/validation/validation.service.ts modified
    # Maps to: step `02-validation-service` → Phase 1
    # Action: Launch ONE sdd:code-reviewer for Phase 1
    #   - If PASS: User's fix is good, proceed to Phase 2
    #   - If FAIL: reason about blast radius, dispatch fixes for the affected
    #     steps only, without overwriting the user's changes, then re-review
    # Continues: Phase 2, Phase 3... (re-verify all subsequent phases)
    
  6. Multiple Files Changed:

    # User edited an output of a Phase 1 step AND an output of a Phase 3 step
    
    /implement my-task.feature.md --refine
    
    # Earliest affected phase: Phase 1
    # Re-verifies: Phase 1, Phase 2, Phase 3...
    # (Phase 2 re-verified even though no direct changes, because it builds on Phase 1)
    
  7. Staged vs Unstaged Changes:

    # Scenario: User staged some changes, then made more edits
    # Staged: src/validation/validation.service.ts (git add done)
    # Unstaged: src/validation/validators/email.validator.ts (still editing)
    
    /implement my-task.feature.md --refine
    
    # Detects: Both staged AND unstaged changes exist
    # Mode: Compares unstaged only (working dir vs staging)
    # Only email.validator.ts is considered for refine
    
    # --
    
    # Scenario: User only has staged changes (ready to commit)
    # Staged: src/validation/validation.service.ts
    # Unstaged: none
    
    /implement my-task.feature.md --refine
    
    # Detects: Only staged changes
    # Mode: Compares against last commit
    

Human-in-the-Loop Behavior

Human verification checkpoints are keyed on implementation phases, never on individual steps.

  1. Trigger Conditions:

    • After an orchestrator-level PASS on the review of an implementation phase in HUMAN_IN_THE_LOOP_PHASES
    • After a fix iteration completes for such a phase (before the next re-review)
    • If HUMAN_IN_THE_LOOP_PHASES is "*", triggers after every implementation phase
  2. At Checkpoint:

    • Display the phase's step results summary
    • Display generated artifacts with paths
    • Display the reviewer's combined_score and consolidated issues
    • Ask user: "Review phase output. Continue? [Y/n/feedback]"
    • If user provides feedback, incorporate into the next iteration or phase
    • If user says "n", pause workflow
  3. Checkpoint Message Format:

    ---
    ## 🔍 Human Review Checkpoint - Phase N
    
    **Phase:** {phase heading}
    **Steps:** {step names}
    **Reviewer model:** {model used}
    **Combined Score:** {combined_score}/5.0 (threshold: {THRESHOLD})
    **Status:** ✅ PASS / ☑️ ACCEPTED / 🔄 ITERATING (attempt {n})
    
    **Artifacts Created/Modified:**
    - {artifact_path_1}
    - {artifact_path_2}
    
    **Reviewer Feedback (top issues):**
    {feedback summary — High/Medium issues from reviewer.issues, with the step each belongs to}
    
    **Action Required:** Review the above artifacts and provide feedback or continue.
    
    > Continue? [Y/n/feedback]:
    ---
    

Task Selection and Status Management

Task Status Folders

Task status is managed by folder location:

  • .specs/tasks/todo/ - Tasks waiting to be implemented
  • .specs/tasks/in-progress/ - Tasks currently being worked on
  • .specs/tasks/done/ - Completed tasks

The task's sub-task folder .specs/sub-tasks/<task-name>/ never moves while the task file travels between these folders, so the Sub-Task File paths recorded in the task file stay valid.

Status Transitions

WhenAction
Start implementationMove task from todo/ to in-progress/
Final verification PASSMove task from in-progress/ to done/
Implementation failure (user aborts)Keep in in-progress/

CRITICAL: You Are an ORCHESTRATOR ONLY

Your role is DISPATCH and AGGREGATE. You do NOT do the work.

Properly build context of sub agents!

CRITICAL: For each sub-agent you dispatch, you MUST provide:

For an implementation agent (one per step):

  • Task file path
  • That step's sub-task file path — exactly one, taken from the Sub-Task File column of the Parallelization Overview
  • Value of ${CLAUDE_PLUGIN_ROOT} so agents can resolve paths like @${CLAUDE_PLUGIN_ROOT}/scripts/create-scratchpad.sh

For the sdd:code-reviewer (one per implementation phase):

  • Task file path
  • Phase identifier
  • Artifact path(s) reported by that phase's implementation agents
  • CLAUDE_PLUGIN_ROOT

What You DO

  • Read the task file ONCE (Workflow Phase 1 only)
  • Launch sub-agents via Task tool
  • Receive reports from sub-agents
  • Mark steps and implementation phases complete after the orchestrator-level PASS rule on reviewer output as [DONE]
  • Reason about blast radius when a phase review fails, and choose fix / re-review models accordingly
  • Aggregate results and report to user

What You NEVER Do

Prohibited ActionWhyWhat To Do Instead
Read implementation outputsContext bloat → command lossSub-agent reports what it created
Read sub-task files (except --refine mapping)The implementation agent reads its own sub-task filePass the path from the Parallelization Overview
Read reference filesSub-agent's job to understand patternsInclude path in sub-agent prompt
Read artifacts to "check" themContext bloat → forget verificationsLaunch sdd:code-reviewer agent
Evaluate code quality yourselfNot your job, causes forgettingLaunch sdd:code-reviewer agent
Review a step individuallyReview is a PHASE-level gateReview once, at the end of the phase
Skip a phase review "because simple"Every phase review is mandatory unless --skip-reviewsLaunch sdd:code-reviewer anyway
Never add comments/marks/notes about results of review, scratchpads, iterations, etc. to the task file.The task file is a specification artifact, not a log. If task not done, it should be visible from code only!You can write only [DONE] mark ever, or nothing at all!

Anti-Rationalization Rules

If you think: "I should read this file to understand what was created" → STOP. The sub-agent's report tells you what was created. Use that information.

If you think: "I'll quickly verify this looks correct" → STOP. Launch a sdd:code-reviewer agent. That's not your job.

If you think: "This phase is too simple to need verification" → STOP. Unless SKIP_REVIEWS is true, every implementation phase gets exactly one review. No exceptions.

If you think: "This step looks risky, I'll review it before the phase ends" → STOP. Reviewing per step is exactly what this workflow removed. Wait for the phase to complete.

If you think: "I need to read the sub-task file to write a good prompt" → STOP. Put the sub-task file PATH in the sub-agent prompt. The sub-agent reads it.

Why This Matters

Orchestrators who read files themselves = context overflow = command loss = forgotten steps. Every time.

Orchestrators who "quickly verify" = skip sdd:code-reviewer agents = quality collapse = failed artifacts.

Your context window is precious. Protect it. Delegate everything.


CRITICAL

Configuration Rules

  • Model precedence (MODEL_OVERRIDE): if --model was given, that model WINS over the task file and over every default in this skill — dispatch EVERY sub-agent with it (implementation agents of any type AND sdd:code-reviewer), ignoring the Parallelization Overview's Model column and the Phase Overview's Reviewer model. It is an override, NOT a fallback. If --model was NOT given (MODEL_OVERRIDE = none), model selection is unchanged: each step uses the Model its Parallelization Overview row names, and each phase review uses that phase's Reviewer model, falling back to the default named in each dispatch block.
  • Use the single THRESHOLD (default 4.0) for every implementation phase review. There is no per-component, per-criticality or lenient variant.
  • Never read a threshold from the task file. The planning agents write none; if one somehow appears, ignore it.
  • The threshold is applied at THIS orchestrator layer against combined_score returned by code-reviewer. NEVER pass any threshold to the code-reviewer agent — or he will try to reach target score and as result become subjective.
  • A phase PASSES if combined_score >= THRESHOLD. If 3.0 <= combined_score < THRESHOLD, the phase passes ONLY when the Iteration Discretion Rule says so — never below the fixed floor of 3.0. If combined_score < 3.0, the phase FAILS unconditionally.
  • Default is 3 iterations - stop after 3 fix→re-review cycles for an implementation phase and proceed to the next phase (with warning)!
  • If MAX_ITERATIONS is set to unlimited: Iterate until the quality threshold is met (no limit)
  • Trigger human-in-the-loop checkpoints ONLY after implementation phases in HUMAN_IN_THE_LOOP_PHASES (or all phases if "*")!
  • If SKIP_REVIEWS is true: Skip ALL code-reviewer dispatches - proceed directly to the next implementation phase after its steps complete!
  • If CONTINUE_MODE is true: Skip to RESUME_PHASE / RESUME_STEPS - do not re-implement already completed steps!
  • If REFINE_MODE is true: Detect changed project files, map to steps, re-verify from REFINE_FROM_PHASE - preserve user's fixes!
  • If STRICT_MODE is true: The Iteration Discretion Rule is DISABLED - a phase passes ONLY on combined_score >= THRESHOLD, otherwise iterate until MAX_ITERATIONS!

Execution & Evaluation Rules

  • Use foreground agents only: Do not use background agents. Launch parallel agents when possible. Background agents constantly run in permissions issues and other errors.
  • Parallelism comes from the task file: steps whose Parallel with: column names each other MUST be dispatched simultaneously in one message. Never serialize what the plan says is parallel.
  • Never cross a phase boundary in parallel: a step of Phase N+1 may only start after Phase N has been reviewed and marked [REVIEWED] (or marked [REVIEWED-SKIPPED] when SKIP_REVIEWS is true).

Relaunch the code-reviewer till you get valid results, if following happens:

  • Reject Long Reports: If the code-reviewer returns a very long report instead of using the scratchpad as requested, reject the result. This indicates the agent failed to follow the "use scratchpad" instruction.
  • Combined Score 5.0 is a Hallucination: If the code-reviewer returns a combined_score of exactly 5.0/5.0, treat it as a hallucination or lazy evaluation. Reject it and re-run the agent. This applies to the weighted aggregate only — an individual criterion may legitimately score 5 and no score is rationed, but every criterion across spec compliance, code quality and Muda waste analysis landing strictly past its score_4 anchor at once is not a plausible review outcome. Never use it as a reason to question a single high criterion score.
  • Reject Missing Scores: If the code-reviewer's report is missing the combined_score (or any sub-score: spec_compliance_score, builtin_score), reject it. This indicates the agent failed to follow the rubric instructions.
  • Reject PASS/FAIL Verdicts in Report: If the code-reviewer's output contains a PASS/FAIL verdict or references a threshold, reject it. The orchestrator owns that decision; the agent must remain threshold-blind.
  • Reject Out-of-Scope Findings: If the reviewer penalizes acceptance criteria that the phase's #### Phase N block does NOT list — reporting work a LATER phase delivers as "missing" or "incomplete" — reject the report and re-run the agent, restating that a phase is a checkpoint, not the finish line.
Iteration Discretion Rule

Your main task is to COMPLETE the task within target quality. Two failure modes are equally real:

  • Burning iterations and context on nitpicks so the overall task never completes → the task is failed.
  • Accepting a result whose quality is genuinely too poor to be considered complete → an even worse failure.

Apply to every implementation phase's combined_score:

  • combined_score < 3.0 → FAIL, unconditionally. No discretion. Iterate with reviewer feedback until the phase passes or MAX_ITERATIONS is reached.
  • 3.0 <= combined_score < THRESHOLD → discretion band. ONLY inside this band MAY you decide that a phase below the target is acceptable. The fixed floor is 3.0 and the band ceiling is THRESHOLD. If --target-quality set THRESHOLD <= 3.0 the band is empty: every score is either an unconditional FAIL (< 3.0) or a PASS, and there is no discretion to exercise.
  • Inside the band, when the outstanding issues are ONLY Low/Medium priority (any High or Critical finding removes discretion entirely) AND none of them breaks an acceptance criterion the phase is responsible for or causes a meaningful defect (i.e. they are nitpicks), you MUST reason FIRST — before dispatching another iteration — about whether iterating (or marking the phase failed) is worth the time and context cost.
  • At most ONE nitpick-driven iteration, and it counts against MAX_ITERATIONS. If it again surfaces only nitpicks, you MUST mark the phase PASS (☑️ ACCEPTED in the summary table), report the outstanding issues in the final report, and continue with the next phase. If it returns a combined_score below 3.0, the FAIL path applies instead.
  • A phase that does not build, lint or test green is NEVER inside the discretion band, whatever the score says. Each phase must leave a working, committable, CI-green state.
  • You MUST be critical, NOT lenient. Stopping short of target MUST be an intentional decision grounded in the absence of real, requirement-breaking issues. A genuine blocking issue that prevents completing the phase within MAX_ITERATIONS MUST be reported as a failure, never papered over.
  • If STRICT_MODE is true, this whole rule is DISABLED: stop only when combined_score >= THRESHOLD or MAX_ITERATIONS is reached. --strict changes nothing else — THRESHOLD, MAX_ITERATIONS, the < 3.0 unconditional FAIL, human-in-the-loop checkpoints, code-reviewer dispatch and --skip-reviews are unaffected. With --skip-reviews no combined_score is produced at all, so both this rule and --strict are inert.

Overview

This command orchestrates multi-step task implementation with:

Shortened here. Read the whole file on GitHub.

Signals

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Aug 2026
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Source
github.com/neolabhq/context-engineering-kit