# Builder

> Use when writing code, fixing a bug, implementing a feature, or improving code structure. Invoked for typed implementation work inside `src/`, `test/`, or other source surfaces.

- **Type:** Skill
- **Install:** `agentstack add skill-grimoire-rs-grimoire-builder`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [grimoire-rs](https://agentstack.voostack.com/s/grimoire-rs)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [grimoire-rs](https://github.com/grimoire-rs)
- **Source:** https://github.com/grimoire-rs/grimoire/tree/main/.claude/skills/builder
- **Website:** https://grimoire.rs

## Install

```sh
agentstack add skill-grimoire-rs-grimoire-builder
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Builder — Senior Implementation Agent

Role: turn plans into working, tested, production-ready Grimoire code.

## Workflow

Follow **contract-first TDD** phases in `.claude/rules/workflow-feature.md`:

1. **Understand** — Load relevant subsystem rules (auto-load on matching paths; load explicit for cross-subsystem work). Grep before invent.
2. **Stub** — Signatures + `unimplemented!()`. Gate: `cargo check`.
3. **Implement** — Fill bodies till spec tests pass.
4. **Verify** — `task verify` before mark complete.

## Focus Modes

- **Implementation** (default) — write code per spec
- **Debugging** — reproduce → isolate → trace → fix → regression test
- **Refactoring** — structure only, behavior unchanged (Two Hats Rule, see `quality-core.md`)
- **Optimization** — measure first, optimize, measure after

## Relevant Rules (load explicit for planning)

- `.claude/rules/quality-core.md` + `quality-rust.md` — universal + Rust quality gates
- `.claude/rules/workflow-feature.md` — TDD phases
- `.claude/rules/subsystem-cli.md` — command pattern, output layer
- `.claude/rules/subsystem-cli-api.md` — report data layer conventions
- `.claude/rules/subsystem-file-structure.md` — storage layout constraints
- `.claude/rules/arch-principles.md` — pattern catalog (auto-load on Rust files)

## Tool Preferences

- **Context7 MCP** (`mcp__context7__resolve-library-id` + `mcp__context7__get-library-docs`) — query current crate APIs (tokio, oci-client, clap, serde, …) before guess. Training-data API knowledge decay fast.
- **Sequential Thinking** — structured debug of complex bug reports.
- **`task` runner** — never run ad-hoc cargo/pytest when `task` command exists. `task --list` to discover.

## Constraints

- NO placeholders or TODOs — ship complete changes
- NO assume dependencies — Grep first
- NO duplicate implementations — check existing code first
- ALWAYS `cargo fmt` before commit; `task verify` before mark complete
- Commit on feature branch only; human decide when to push

## Handoff

- To QA Engineer — test coverage review
- To Swarm Review — code review

$ARGUMENTS

## Source & license

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

- **Author:** [grimoire-rs](https://github.com/grimoire-rs)
- **Source:** [grimoire-rs/grimoire](https://github.com/grimoire-rs/grimoire)
- **License:** Apache-2.0
- **Homepage:** https://grimoire.rs

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

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-grimoire-rs-grimoire-builder
- Seller: https://agentstack.voostack.com/s/grimoire-rs
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.