dev-pipeline

Calvinball-driven development pipeline as Claude Code subagents. Part of the claude-workbench marketplace.

What this is

Three specialized subagents that move work through a GitHub project board:

• Miss Wormwood (Haiku) — triage. Polls Calvinball for unrefined items, generates acceptance criteria, scores WSJF, moves to Backlog.
• Moe (Opus) — development. Picks up Ready/In Progress items, clones repos, writes code + tests, creates PRs, moves to In Review.
• Tracer Bullet (Sonnet) — code review. Reviews PRs in In Review, approves or requests changes, escalates after 3 rounds.

How it works

n8n polls Calvinball every 15 minutes via HTTP (zero Claude tokens on idle). When work exists, n8n dispatches the appropriate agent via claude -p --agent dev-pipeline:{name}.

GitHub webhook → Calvinball (filter + queue)
                      ↓
n8n polls every 15 min (HTTP, zero tokens)
                      ↓ work found
      ┌───────────────┼───────────────┐
      ↓               ↓               ↓
  Wormwood          Tracer           Moe
  (Haiku)           (Sonnet)         (Opus)

Each agent uses the right-sized model for its task. Token overhead per dispatch: ~5-8K (lean agent definition + minimal tools) vs ~25-30K for a full Claude Code session.

Token efficiency

Scenario	Cost
Idle poll (no work)	0 tokens — n8n handles HTTP
Wormwood triage	~5-8K input + output (Haiku)
Tracer review	~5-8K input + output (Sonnet)
Moe development	Full session (Opus, variable)

Prerequisites

• n8n — workflow automation (npm install -g n8n)
• Claude Code — claude CLI on PATH (provides agent dispatch + OAuth auth)
• gh CLI — authenticated for GitHub operations
• jq — JSON processing
• macOS Keychain entries:
  • Service calvinball-mcp, account client-id — Calvinball OAuth client ID
  • Service calvinball-mcp, account client-secret — Calvinball OAuth client secret

Setup

# From the plugin directory:
bash n8n/setup.sh

The setup script:

1. Installs n8n if missing
2. Verifies Keychain credentials
3. Creates a launchd service (auto-starts n8n at login on port 5679)
4. Imports the three workflow templates
5. Tests Keychain access from launchd context

After setup, activate the workflows in the n8n UI at http://localhost:5679, or they'll start on their next scheduled trigger.

Re-running after a plugin update

When the plugin version bumps, re-run bash n8n/setup.sh to re-import updated workflow templates. The launchd plist is preserved unless --force is passed.

Dispatch paths

Two ways to invoke the same agent definitions:

1. Unattended (default) — n8n polls Calvinball on cron, dispatches via claude -p --agent.
2. Interactive — Hobbes or any parent agent dispatches a subagent via the Agent tool.

Same agents/*.md definitions drive both paths.

Risks and limitations

• Mac must be on. n8n and Claude Code both run locally. No server-side autonomy yet.
• Moe concurrency. A lock file at /tmp/moe.lock prevents concurrent Moe runs. If Moe hangs, the lock file must be manually deleted.
• Moe budget cap. --max-budget-usd 5.00 limits per-run spend. Complex implementations may hit this ceiling.
• launchd Keychain access. The plist sets SessionCreate: true for Keychain access. If auth fails in n8n, verify with launchctl print gui/$(id -u)/com.mikebronner.n8n.
• Calvinball must be running. The OAuth token endpoint and project-items API must be reachable at https://calvinball.mikebronner.dev.

Monitoring

• n8n UI: http://localhost:5679 — execution history, per-node data flow, failed runs with errors.
• Agent logs: ~/.n8n/logs/wormwood-*.log, tracer-*.log, moe-*.log — full agent output per dispatch.
• n8n process logs: ~/.n8n/logs/n8n-stdout.log, n8n-stderr.log.

Troubleshooting

Problem	Fix
n8n not starting	Check ~/.n8n/logs/n8n-stderr.log. Common: wrong Node.js version (needs >=22.16).
Auth fails in workflow	Verify Keychain: security find-generic-password -s calvinball-mcp -a client-id -w
Moe stuck (lock file)	rm /tmp/moe.lock
Agent not found	Verify plugin installed: claude agents should list dev-pipeline:miss-wormwood etc.
Calvinball unreachable	Check Herd/Valet: curl https://calvinball.mikebronner.dev/api/project-items

Installation

/plugin marketplace add mike-bronner/claude-workbench
/plugin install dev-pipeline@claude-workbench