fast-onboard

name	fast-onboard
description	Analyzes repository structure and generates CLAUDE.md documentation. Use when user mentions "onboard", "analyze project", "understand codebase", "project structure", or when working with new/unfamiliar repositories.
allowed-tools	["Bash","Read","Write","Task","Glob"]
model	haiku

Fast Onboard

Rapidly analyzes new projects and generates comprehensive CLAUDE.md documentation.

Prerequisites

Required: jq (Fatal if missing) Recommended: scc, fd, tree Subagent: .claude/agents/repo-analyzer.md

Workflow

Step 1: Parallel Data Collection

Execute these Bash commands in parallel (single message with multiple Bash tool calls):

#	Command	Output
1	command -v jq && echo ok	jq check (abort if missing)
2	scc --format json --by-file --no-cocomo --no-size --exclude-dir node_modules,dist,build,target,.git,vendor,venv,__pycache__,.next,coverage,.claude . 2>/dev/null || echo null	Code stats
3	git rev-parse --git-dir >/dev/null 2>&1 && jq -n --arg r "$(git remote get-url origin 2>/dev/null || echo none)" --arg b "$(git branch --show-current)" --arg c "$(git log -1 --format='%h - %s' 2>/dev/null)" '{remote:$r,branch:$b,lastCommit:$c}' || echo null	Git info
4	fd -t f -E node_modules -E dist -E build -E target -E .git -E vendor -E venv -E __pycache__ -E .next -E coverage -E .claude . 2>/dev/null | wc -l | tr -d ' '	Total files
5	fd -e js -e jsx -e ts -e tsx -t f -E node_modules -E dist -E build -E .git -E .next -E coverage -E .claude 2>/dev/null | wc -l | tr -d ' '	JS/TS files
6	fd -e py -t f -E node_modules -E .git -E venv -E __pycache__ -E .claude 2>/dev/null | wc -l | tr -d ' '	Python files
7	fd -e go -t f -E node_modules -E .git -E vendor -E .claude 2>/dev/null | wc -l | tr -d ' '	Go files
8	fd -e rs -t f -E node_modules -E target -E .git -E .claude 2>/dev/null | wc -l | tr -d ' '	Rust files
9	fd -d 3 -t f -E node_modules -E .git -E .claude 'package\.json$|requirements\.txt$|go\.mod$|Cargo\.toml$|pyproject\.toml$' . 2>/dev/null | jq -R . | jq -sc .	Deps
10	fd -d 2 -t f -i -E node_modules -E .git -E .claude 'readme|changelog|license' . 2>/dev/null | jq -R . | jq -sc .	Docs
11	{ fd -d 3 -t f -E node_modules -E .git 'Dockerfile|docker-compose|Makefile' .; fd -d 4 -t f -g '.github/workflows/*.yml' .; } 2>/dev/null | sort -u | jq -R . | jq -sc .	Infra
12	tree -L 2 -d -J -I 'node_modules|dist|build|target|.git|vendor|venv|__pycache__|.next|coverage|.claude' . 2>/dev/null || echo '[]'	Structure

Step 2: Assemble JSON

Combine results into .claude/.onboard-cache.json:

mkdir -p .claude && jq -n \
  --arg name "$(basename "$PWD")" \
  --arg path "$PWD" \
  --argjson git '<result_3>' \
  --argjson codeStats '<result_2>' \
  --argjson total <result_4> \
  --argjson js <result_5> \
  --argjson py <result_6> \
  --argjson go <result_7> \
  --argjson rust <result_8> \
  --argjson deps '<result_9>' \
  --argjson docs '<result_10>' \
  --argjson infra '<result_11>' \
  --argjson structure '<result_12>' \
  '{
    meta: {generatedAt: (now | strftime("%Y-%m-%dT%H:%M:%SZ"))},
    project: {name: $name, path: $path},
    git: $git,
    codeStats: $codeStats,
    files: {total: $total, javascript: $js, python: $py, go: $go, rust: $rust},
    dependencyFiles: $deps,
    docs: $docs,
    infrastructure: $infra,
    structure: $structure
  }' > .claude/.onboard-cache.json

Step 3: Launch repo-analyzer

Task(
  subagent_type: "repo-analyzer",
  prompt: "Analyze .claude/.onboard-cache.json and generate CLAUDE.md"
)

Error Handling

Condition	Behavior
jq missing	Fatal - Abort workflow
scc/fd/tree missing	Use null/0/[], continue
repo-analyzer missing	Report error

References

• reference.md - JSON schema, prompt template