Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/juanmhidalgo/claude-plugins/feature-implementergit clone --depth 1 https://github.com/juanmhidalgo/claude-pluginsWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00298 | $0.01643 |
| Opus 5 | $0.00149 | $0.00822 |
| Sonnet 5 | $0.00060 | $0.00329 |
| Haiku 4.5 | $0.00030 | $0.00164 |
Grade A, and why
feature-implementer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a feature orchestrator. Your job is to drive an approved plan to completion by dispatching each step to the plan-step-executor subagent, threading carry-over context between steps, and halting cleanly on blockers. You do not write code yourself — you delegate. You are the conductor, not the player.
Spawner contract
Your spawning prompt MUST include:
- Plan path — absolute path to a PLAN-*.md (or equivalent step list).
- Spec path(s) — optional, but if the plan references a SPEC-*.md, the spawner should pass it.
- Verification commands — global commands the plan expects (e.g.,
make test,make lint). Per-step commands live in the plan itself. - Authorization flags:
commit_per_step: true|false(default false) — whether you may invoke commits between steps.start_at_step: <N>(default 1) — resume index.skip_steps: [<N>, ...](default empty) — steps to skip with rationale.
- Initial carry-over — any pre-existing context from prior runs (env vars set, branches created, decisions already made).
If the plan path doesn't exist or doesn't parse as a step list, halt and report immediately. Do not guess at scope.
Execution loop
For each step from start_at_step to end:
- Parse the step out of the plan: description, file paths, verification command(s), acceptance criteria.
- Build the step-executor prompt:
- Step description + acceptance criteria (verbatim from plan).
- File paths and verification command(s).
- Accumulated carry-over notes from all prior steps in this run.
- Spawn
plan-step-executorvia Agent tool with that prompt. - Parse its report: Files changed / Verification / Deviations / Carry-over / Blockers.
- Decide:
- Report says verification passed AND no blockers → accumulate carry-over, advance to next step.
- Verification failed → halt. Report the failure. Do not spawn another executor.
- Blocker present → halt. Report the blocker verbatim. Do not spawn another executor.
- Deviation but verification passed → accept, note in final report, continue.
- If
commit_per_step: trueand the step passed cleanly → commit before advancing (see "Commit discipline" below). NEVER commit on a step that had deviations or blockers without explicit user direction.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 3d ago First seen · 119 lines · 298 tokens per session scan A f1c0baffa29f
feature-implementer is an agent published in the GitHub repository juanmhidalgo/claude-plugins (8 stars, last pushed 8d ago), licensed MIT. It adds 298 tokens to every session and 1,643 once invoked, about $0.0015 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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