Execute

Execute

Execute a complete unit of work: plan it, build it, verify the actual outcomes, commit it.

Invocation Position

This is a primary pipeline skill used after /prd-to-issues has produced a concrete slice, or when the user already has a clearly scoped implementation task.

Use /execute when the work is ready to build, verify, and commit.

Use HITL /execute when the slice still needs active user judgment, supervision, or acceptance decisions during implementation. Use AFK /execute only when the next slice is already durable in GitHub, unblocked, and legible from its issue, boundary map, and any linked research artifact (archive file or spike issue) or docs/solutions/ context.

See Step 0: Prerequisites below for the mandatory Ralph auto-detection and TDD marker gates.

Do not use it to replace /shape, /research, or /write-a-prd when the problem or shape is still unresolved. Do not use it as a substitute for /pre-merge once implementation is complete and ready for review.

Workflow

0. Prerequisites

Branch isolation gate. Before any implementation work, ensure you are working on a clean branch created for this specific task — not a leftover feature branch from previous work.

Isolation already provided — stand down (check this first, before the numbered rules). Some environments hand the session a dedicated, isolated worktree+branch before /execute runs — Conductor workspaces, GitHub Codespaces, devcontainers, and similar hosts each provision "one workspace = one branch, auto-forked from the base," with setup scripts already run. When that is the case the pipeline does not own provisioning: creating a worktree here would nest one inside the host's, and the host's branch (named for the workspace, not the task) is not "stale." Read the environment's signal and cede the worktree to whoever already owns it (Norman — read the world's signifier instead of carrying an in-head assumption that the pipeline always provisions; Meadows — one actor per stock, so the pipeline defers rather than adding a competing manager).

Resolve the provisioning mode from .claude/settings.json worktree.provisioning — "host" | "pipeline" | "auto", default "auto" when the key is absent (mirroring the existing research.storage precedent):

• host — isolation is host-owned. Stand down unconditionally.
• pipeline — the pipeline provisions. Skip this stand-down and run the numbered gate below.
• auto (default) — stand down if either signal fires:
• a host environment variable is present — [ -n "$CONDUCTOR_WORKSPACE_PATH" ], [ -n "$CODESPACES" ], or [ -n "$REMOTE_CONTAINERS" ]. This is the cheapest, primary discriminator: the pipeline's only detection mechanism is Bash, and these vars are visible in the agent's shell. (Do not detect via a .conductor directory in the cwd — Conductor keeps it under $CONDUCTOR_ROOT_PATH, not the workspace.)
• the current working tree is not the repo's primary working tree — git rev-parse --show-toplevel differs from the first path in git worktree list --porcelain.

When standing down: skip worktree creation and EnterWorktree, and work in place on the current branch. The numbered rules below are already satisfied — in particular rule 3 does not apply (a host-provisioned branch is neither base nor task-named, but it is not stale; do not nest a worktree and do not stop). The host has already seeded git-ignored config and dependencies, so the "Worktree setup checklist" is informational only — spot-check .env.local/deps if a command fails, but do not re-provision. Continue to the issue-shape gate.

This stand-down is deliberately asymmetric with /closeout's teardown check. Inflow only needs to answer "am I already isolated?" — generic detection (toplevel ≠ primary) and the env-var hint each settle that. The outflow question — "who owns teardown?" — is stricter and cannot rely on the generic heuristic alone, because a pipeline-made worktree also satisfies toplevel ≠ primary; /closeout keys off the explicit setting or host env var only.

1. Check the current branch: git branch --show-current
2. If the current branch is the base branch (e.g., main, prod, master), create a new feature branch for this task.
3. If the current branch is a different feature branch (not the base branch and not a branch named for this task), you are on a stale branch from previous work. Do not commit new work here. Exception: if the current branch is a sibling slice branch named in this task's Consumes from #N declaration, you are intentionally about to fork from it for a stacked-PR slice — proceed. Exception (host-provisioned): if the stand-down check above fired, this branch is the host's isolated workspace branch — it is not stale; work in place.

To create an isolated branch, use one of these approaches (in order of preference):

• Worktrunk (if wt is available): wt switch --create — creates a new worktree + branch from the appropriate base and switches to it, giving full filesystem isolation. Use the /worktrunk skill for guidance.
• Plain git: git checkout && git checkout -b — creates a new branch from the appropriate base in the current working directory.

The appropriate base is the repo's own base branch by default — whatever the repo declares (git symbolic-ref refs/remotes/origin/HEAD). Do not assume main. For a slice with an unmerged Consumes from #N dependency that produces symbols this slice imports, branch from that sibling slice's branch instead so the stacked PR can target the sibling's PR (Hammant Trunk-Based Development Ch. 13: multiple PRs per story; the sibling's PR must still merge to the repo's base branch within 2 days).

Derive the branch name from the task: e.g., issue-5-landing-page, landing-page, or the issue slug. Do not reuse branch names from previous work.

Enter the worktree as a session (when you created a worktree). Creating the worktree is not the same as the session running inside it — wt switch --create resets the shell cwd back to the project root after each command, so without a further step the session stays anchored at the original checkout and the reported cwd lies about where work is happening. After creating the worktree, enter it with the harness EnterWorktree tool so the session's working directory genuinely is the worktree:

• Call EnterWorktree { path: }. The path must already appear in git worktree list for this repo (it will, because you just created it). This persistently switches the session into the worktree.
• Keep the creation step exactly as above — wt switch --create / git worktree add runs the worktrunk pre-start hooks that seed .env.local and dependencies. EnterWorktree only switches the cwd; it does not run those hooks. Create first (to seed env/deps), then enter.
• This puts the knowledge in the world, not the head: the cwd tells the truth about where edits and commits land (a watching operator can see it), and there is no per-command cd prefix to forget — eliminating the slip class where one un-prefixed command writes to the wrong tree.
• The Plain git option (git checkout -b, no worktree) creates the branch in the current checkout — there is no worktree to enter, so skip EnterWorktree and work in place.

AFK / headless fallback. If EnterWorktree is unavailable (headless runs, AFK Ralph, cron), fall back to cwd-prefix discipline: the shell cwd resets to the project root after every Bash command, so prefix every Bash call in this session with cd &&. Use this only when the harness tool is genuinely unavailable — it is the old workaround, retained for environments without the native mechanism.

This worktree's teardown is owned by /closeout at the pipeline tail — after the PR merges, /closeout re-anchors the shell to the base checkout, removes the worktree, and prunes the merged branch. /execute is the inflow side of the worktree lifecycle; /closeout is the outflow. Step 6 cleanup below removes only the .tdd-* markers — it deliberately does not remove the worktree.

After creating the worktree, set it up. A new worktree inherits tracked files but not git-ignored ones (.env.local, per-worktree deps, build caches). Two paths:

Preferred — configure once via worktrunk hooks (.config/wt.toml in the project):

[pre-start]
copy = "wt step copy-ignored"
install = "pnpm install"

pre-start hooks are blocking — the worktree is not reported ready until they finish. Use pre-start (not post-start) for both, because post-start runs in the background and subsequent commands that need .env.local or node_modules will race the hook. See /worktrunk for the full recipe. One-time per project.

Fallback — manual setup for plain git worktree add (no worktrunk):

• cp /.env.local /.env.local (and any other git-ignored config the project uses).
• Run the project's install command (pnpm install, npm ci, pip install -r requirements.txt, etc.) from the worktree.

Worktree setup checklist (DO-CONFIRM — perform each step, then verify before proceeding). Applies regardless of how the worktree was created:

• [ ] Git-ignored config copied — .env.local (and any other .env.*, *.local, or project-specific ignored config) exists in the worktree
• [ ] Dependencies installed — install command (pnpm install, npm ci, etc.) ran without error in the worktree
• [ ] Session is inside the worktree — pwd reports the worktree path because you entered it via EnterWorktree { path } (not the project root). In the AFK/headless fallback only, this item instead means the cd && prefix is being applied to every Bash call
• [ ] $CLAUDE_PROJECT_DIR scoping correct — if the project references this env var in scripts, verify it resolves to the worktree path, not the primary repo
• [ ] TDD marker absent — .claude/.tdd-active and .claude/.tdd-skipped do not exist in the worktree (fresh slate; Step 3 creates them)

Issue-shape detection gate. If the task is a GitHub issue, verify it is a slice (implementation-ready), not an undecomposed PRD. Run gh issue view --comments and check for a comment matching ^Decomposed into: #\d+.

• If such a comment exists: proceed. The PRD has been decomposed; the operator is presumably working on one of its child slices (and should have supplied that slice's number, not the PRD's).
• If no such comment exists AND the issue body contains shaped-pitch markers (sections named Appetite, Rabbit Holes, No-gos, User Stories, or Implementation Decisions): halt. This is an undecomposed PRD. Invoke /prd-to-issues to produce implementation-ready slices, then restart /execute against one of the child slice issues.
• If multiple Decomposed into: comments exist, read the most recent; /prd-to-issues is responsible for ensuring only one is authoritative.

Skip this gate for one-off tasks not tied to a GitHub issue.

Ralph auto-detection gate. Evaluate all three conditions:

• [ ] The task comes from a GitHub issue (not a one-off verbal request)
• [ ] The issue has multi-slice scope (PRD, big-batch appetite, or multiple user stories)
• [ ] No ralph-once.sh or ralph.sh exists in the repo root

If all three are true, invoke /setup-ralph-loop now. Do not proceed to Step 1 until Ralph setup is complete or the conditions are not met.

Pipeline hooks gate. If .claude/hooks/enforce-classification.sh does not exist in this project, invoke /init-pipeline now to scaffold enforcement hooks.

TDD classification gate. Step 3 requires classifying the work before writing any code. /tdd automatically creates .claude/.tdd-active via harness preprocessing when loaded (not LLM-dependent); visual frontend creates .claude/.tdd-skipped. A PreToolUse hook blocks all .ts file writes unless one of these markers exists. Step 6 removes both markers after commit.

Trivial-task exception. For single-commit cleanups unrelated to active feature work — typo fixes, dead code removal, comment-only changes, formatting-only changes, dependency version bumps without API surface changes — you may skip classification by creating .claude/.tdd-skipped directly. This exception applies only when all of the following are true:

• The task is not tied to an open GitHub issue, PRD, slice issue, or QA bug
• The task is not part of an active feature branch created for multi-slice work
• The change is expected to be a single commit (not a sequence of logical units)
• The change does not touch behavior — no new conditionals, no new state, no new exported symbols, no schema or migration changes

If any of these is false, go through the normal classification gate. When in doubt, use the gate — the cost of one extra /tdd invocation is lower than the cost of an unverified behavior change slipping through as "trivial."

Assumptions validation gate. If the task is a GitHub issue with an "Assumptions from Parent PRD" section, spend 60 seconds checking each listed assumption against current reality before proceeding. For each:

• Is the external service still available at the expected API and pricing tier?
• Does the parent PRD's approach still hold given what you now know?
• Are the packages this slice depends on still at compatible versions and entrypoints? A subpath swap (e.g. pkg → pkg/http, or any pkg/ → pkg/) for a multi-runtime package is a runtime-affecting change disguised as a type-only diff — treat it as an assumption shift, not a free-pass type-equivalent edit.

If all assumptions still hold, proceed to Step 1. If any assumption has changed, stop and flag it to the user — this slice needs a targeted /research + mini-PRD cycle before execution, not a patch during implementation. Do not proceed with stale assumptions and attempt to work around them mid-execution.

Skip this gate entirely for one-off tasks without an "Assumptions from Parent PRD" section.

Un-discharged feasibility check (advisory). If the task's research artifact (archive file or spike issue) still carries Uncertain or Speculative assumptions whose verdicts are cheaply settled by 10 lines of throwaway code — does the library actually expose this, does the streaming path emit partial tags, does this format render where we need it — surface them now and suggest /prototype FEASIBILITY before main implementation. This is advisory, not blocking (per XP's slack principle); the user may have a reason to proceed and discover the answer mid-implementation. But the cost asymmetry is real (XP's Defect Cost Increase): a spike at this moment costs minutes, while the same assumption discovered mid-implementation costs hours of pivot. State the un-discharged assumptions explicitly and let the user decide. Skip this check for one-off tasks without a research artifact or when every assumption is already tagged Verified / Refuted.

Consumes verification gate. Only for issue-based slice work. If the task comes from a GitHub issue created by /prd-to-issues, and its ## Boundary Map / ### Consumes section references an already-closed upstream slice, spend 60 seconds verifying each listed symbol exists at the declared path in the current tree. This catches upstream boundary-map drift before implementation starts.

For each Consumes entry:

1. If it names a file path — check the file exists.
2. If it names a function, type, or exported symbol — grep for the export.
3. If it names a shape (e.g. "Effect Layer", "Zod schema", "React component", "Context provider") — confirm the shape matches, not just the name. A pure helper function does not satisfy a claim of "Effect Layer." A plain object does not satisfy a claim of "Zod schema."
4. If the Consumes entry names a typed symbol from a sibling slice (per /prd-to-issues Boundary Map guidance), confirm the consumer code derives its input

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Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: chrislacey89
• Source: chrislacey89/skills
• License: MIT
• Homepage: https://skills.sh/chrislacey89/skills

Install and usage instructions live in the source repository linked above.