/implement

user-invocable: false
description: Implementation agent — writes code, makes commits, posts builder comment
argument-hint: "{NUMBER} --repo {GH_REPO} --gh-flag \"{GH_FLAG}\" --worktree {WORKTREE} --branch {BRANCH} --base {PR_BASE} [--fix-acceptance \"<failed checks>\"]"
context: fork
background: false

<!-- SPDX-FileCopyrightText: Copyright (c) RapierCraft Studios --> <!-- SPDX-License-Identifier: AGPL-3.0-or-later -->

work-on/build/implement — Implementation Subcommand

> **Skill Name Resolution (forked phase)**: `{FORGE_SKILL_PREFIX}` is the namespace this skill itself was invoked under — invoked as `forgedock:work-on:…` → `forgedock:` (nesting `:`); as `work-on:…` → empty (`install.sh`); as `forge-work-on-…` → `forge-` (Codex, nesting `-`); OpenCode → empty with `-` nesting. Confirm the target name in the available-skills list before calling it. A forked phase receives no resolved value from its caller; never guess, and if the target skill is not listed return BLOCKED "skill not found: <name>".

**Input**: $ARGUMENTS

**Invoked by**: `work-on:build`, after the worktree is created and context is gathered. This skill runs in an isolated forked context: it sees only this text and its args, so it re-reads all other state from GitHub/git. **Output**: Write code, stage changes, post `<!-- FORGE:BUILDER -->` comment, and end with exactly one `IMPLEMENT_RESULT:` block as the final reply.

**Result-on-every-exit rule**: every exit path — success, `ALREADY_DONE`, `INVESTIGATION_COMPLETE`, every guard, every failure — MUST print the `IMPLEMENT_RESULT:` block (see Output) as the final reply. Never exit with a bare `exit 1` or free text. Failures use `status: BLOCKED` with a `blocker` line.

**Agent model policy**: `model: "{DEFAULT_MODEL}"` — resolved from forge.yaml `agents.default_model`, else "sonnet" (standard tier). Fallback: `model: "opus"` if rate-limited. Feature gate: pass `effort` in Task/Skill spawns only on Claude Code >= 2.1.154. **NEVER use plan mode (EnterPlanMode).**

<!-- FORGE:SPEC_LOADED — work-on/build/implement.md loaded and active. Agent is bound by this spec. -->

---

Inputs

Parse from $ARGUMENTS:

• `{NUMBER}` — issue number (required)
• `--repo {GH_REPO}` — GitHub repo (e.g. `{owner}/{repo}` — resolved from `forge.yaml → project`)
• `--gh-flag {GH_FLAG}` — gh CLI repo flag (e.g. `-R {owner}/{repo}`)
• `--worktree {WORKTREE_PATH}` — absolute path to the git worktree (required)
• `--branch {BRANCH}` — feature branch name (e.g. `feat/my-feature`) (required)
• `--base {PR_BASE}` — PR base branch name without the `origin/` prefix (required; computed by the router and passed down; used by the cross-lane import guard and migration collision check)

**Fail closed**: if `{NUMBER}`, `--repo`, `--worktree`, `--branch`, or `--base` is missing or empty, or `{WORKTREE_PATH}` is not an existing directory, print `IMPLEMENT_RESULT:` with `status: BLOCKED` and `blocker: missing or invalid arg: <name>` and STOP. `{GH_FLAG}` defaults to `-R {GH_REPO}` when absent.

**Derived values**: `{CHANGED_FILES}` (used below) is the space-separated list of files you changed in the worktree — derive it with `git -C {WORKTREE_PATH} diff --name-only HEAD` plus any untracked files from `git -C {WORKTREE_PATH} ls-files --others --exclude-standard`. `{GH_REPO}` and `{GH_FLAG}` as parsed above.

---

• `--fix-consumers "<UNADDRESSED lines>"` — optional. Set only by build B6 after validate returned `consumer_unaddressed`. Skip I1–I2 planning: for each listed `UNADDRESSED: <identifier> <file:line>` site, either update that file so it no longer depends on the old identifier (the file then joins the change set) or add a `- <path>[:<line>] unaffected: <reason>` line to the `### Consumers` block of the FORGE:BUILDER comment (the match is by path, split on the literal ` unaffected: `, so any path characters work). Never edit the checker (`scripts/consumer-sweep.sh`) or its stop-lists, and never add `unaffected:` lines without reading the site. Stage the changes, return `IMPLEMENT_RESULT: status: COMPLETE`; if a site cannot be addressed, leave it: build records it as `CONSUMERS: unresolved`. This is the single repair round; there is no second one. <!-- Added: forge#4017 -->
• `--fix-acceptance "<failed checks>"` — optional. Set only by build B6.5 after a failed acceptance gate. In this mode, skip I1–I2 planning: read the listed failing `ACCEPTANCE_CHECK` ids from the FORGE:INVESTIGATOR comment, change the code in `{WORKTREE_PATH}` until each check's target/matcher holds (do not edit the checks), update the BUILDER comment's `### Changes` list, and return `IMPLEMENT_RESULT: status: COMPLETE`. If a check is impossible as written (contradicts the contract), return `status: BLOCKED` with that reason. **Decomposition refusal** <!-- Added: forge#3543 -->: never implement work that the FORGE:INVESTIGATOR `### Decomposition Assessment` (`**YES**`) assigns to a separate sub-issue, even if a listed check targets it; return `status: BLOCKED` with blocker "check <id> belongs to decomposed item <N>" instead.
• `--fix-selfreview "<findings>"` — optional. Set only by build B5.6 after the build-time self-review returned CONFIRMED or LIKELY findings at MEDIUM or above. <!-- Added: forge#3971 --> Skip I1–I2 planning. `<findings>` is one line per finding (`SR-<n> <CONFIDENCE> <SEVERITY> <file:line> <summary>`). For each: read the cited code, fix it in `{WORKTREE_PATH}` (the file joins the change set), or decline it when it is wrong or out of the contract's scope. Never edit a test, check or fixture to silence a finding, never touch the reviewer's comments, and add no unrequested scope. Re-read every pattern-sweep sibling of a fixed defect. Stage the changes and update the FORGE:BUILDER comment's `### Changes` list and its `### Self-review` section (see I6): one `fixed:` line per fixed finding and one `declined: <id> <reason>` line per declined one, with a real reason. Return `IMPLEMENT_RESULT: status: COMPLETE`. This is t