Skill
Development
Skill
/implement
Implement through pattern learning
Install
$ npx -y skills add bitcraft-apps/spec-first --skill implement --agent claude-codeHow it fires
How this skill gets triggered: by you, by Claude, or both.
- Fires itselfAuto-invocation. Claude auto-loads it when your prompt matches the work.Auto-invocation is when the right skill fires by itself at the right moment, driven by a FLOW.md router and a hook, instead of you invoking it by name. It is the difference between a skill being installed and a skill actually getting used.Read the full definition →
- You can call itInvoke it directly when you want it.
- Slash command
/implement
Context preview
The summary Claude sees to decide when to auto-load this skill.
Implement through pattern learning
SKILL.md
implement.SKILL.mdname: implement
description: Implement through pattern learning
disable-model-invocation: true
argument-hint: "[--isolate] [SPECIFICATION_OR_PATH]"
Implement Command
Creates a minimal implementation that follows the existing patterns. One agent does the steps in order.
Usage
/sf:implement [--isolate] [SPECIFICATION_OR_PATH]
Context
Read the current branch. Check whether `.sf/spec.md` exists.
Input Resolution
1. If the skill has arguments: use them as a specification path or as inline requirements 2. Else if `.sf/spec.md` exists: use it 3. Else: ask the user where the specification is. Wait for the answer.
Execution
**Step 1 — Learn**
- Search the codebase for the closest existing pattern for this specification. Stop when you
have one good example. Do not survey the whole repository.
- Write the example to `.sf/research/pattern-example.md`.
**Step 2 — Implement**
- Follow the pattern you found. No creativity.
- Write the simplest change that works. No abstractions for later. One feature at a time.
- Test that it works.
- Write `.sf/implementation-summary.md`.
**Gate — Post-Implementation:** run `scripts/validate-implementation.sh`, in this skill directory. **If validate-implementation.sh fails (non-zero exit), check every criterion the spec meets, or finish the work it names. Do not report the implementation as done.**
Output: Implementation + `.sf/implementation-summary.md`
If Step 1 finds no pattern: create the basic file structure the language expects, implement only the core requirement, and note in the summary: "No existing patterns found - used minimal approach".
Philosophy
This command enforces:
- Pattern consistency over creativity
- Working code over perfect code
- Minimal solution over extensible solution
On Claude Code
Claude Code has subagents. Use them for both steps.
Context arrives for free:
- Branch: !`git branch --show-current 2>/dev/null`
- Spec exists: !`test -f .sf/spec.md && echo "yes" || echo "no"`
- Parse $ARGUMENTS. `--isolate` is a Claude-only flag: strip it and set ISOLATE=true.
- Use the **AskUserQuestion** tool to ask for the specification location.
- Step 1: use the Agent tool with subagent_type="Explore" to find the pattern for $SPECIFICATION
(request "medium" thoroughness in the prompt).
- Step 2: Task: implement-minimal with spec: $SPECIFICATION. If ISOLATE is true, add
isolation: "worktree".
- Gate: `bash ${CLAUDE_PLUGIN_ROOT}/scripts/validate-implementation.sh ${CLAUDE_PROJECT_DIR:+$CLAUDE_PROJECT_DIR/.sf}`
Read more
name: implement description: Implement through pattern learning disable-model-invocation: true argument-hint: "[--isolate] [SPECIFICATION_OR_PATH]"
Implement Command
Creates a minimal implementation that follows the existing patterns. One agent does the steps in order.
Usage
/sf:implement [--isolate] [SPECIFICATION_OR_PATH]
Context
Read the current branch. Check whether `.sf/spec.md` exists.
Input Resolution
1. If the skill has arguments: use them as a specification path or as inline requirements 2. Else if `.sf/spec.md` exists: use it 3. Else: ask the user where the specification is. Wait for the answer.
Execution
**Step 1 — Learn**
- Search the codebase for the closest existing pattern for this specification. Stop when you
have one good example. Do not survey the whole repository.
- Write the example to `.sf/research/pattern-example.md`.
**Step 2 — Implement**
- Follow the pattern you found. No creativity.
- Write the simplest change that works. No abstractions for later. One feature at a time.
- Test that it works.
- Write `.sf/implementation-summary.md`.
**Gate — Post-Implementation:** run `scripts/validate-implementation.sh`, in this skill directory. **If validate-implementation.sh fails (non-zero exit), check every criterion the spec meets, or finish the work it names. Do not report the implementation as done.**
Output: Implementation + `.sf/implementation-summary.md`
If Step 1 finds no pattern: create the basic file structure the language expects, implement only the core requirement, and note in the summary: "No existing patterns found - used minimal approach".
Philosophy
This command enforces:
- Pattern consistency over creativity
- Working code over perfect code
- Minimal solution over extensible solution
On Claude Code
Claude Code has subagents. Use them for both steps.
Context arrives for free:
- Branch: !`git branch --show-current 2>/dev/null`
- Spec exists: !`test -f .sf/spec.md && echo "yes" || echo "no"`
- Parse $ARGUMENTS. `--isolate` is a Claude-only flag: strip it and set ISOLATE=true.
- Use the **AskUserQuestion** tool to ask for the specification location.
- Step 1: use the Agent tool with subagent_type="Explore" to find the pattern for $SPECIFICATION
(request "medium" thoroughness in the prompt).
- Step 2: Task: implement-minimal with spec: $SPECIFICATION. If ISOLATE is true, add
isolation: "worktree".
- Gate: `bash ${CLAUDE_PLUGIN_ROOT}/scripts/validate-implementation.sh ${CLAUDE_PROJECT_DIR:+$CLAUDE_PROJECT_DIR/.sf}`
Ships withsf
Write the requirements before you write the code. Spec First gives you a workflow with three steps. First, define what to build. Then implement it from the spec. Last, generate the documentation. All steps run in your terminal.
Get the whole plugin