build

A command for carrying out a software plan with temporary helper agents and review checkpoints.

In plain words
What is it for?
Use it to execute selected plans or phases, apply project settings, and run the configured review and validation stages.
Why use it?
It organizes implementation into phases and checks the work as it progresses, reducing missed steps.

Command

Install

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.

agentmods
npx agentmods add commands/lgbarn/shipyard/build
Clone the repo
git clone --depth 1 https://github.com/lgbarn/shipyard
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,393 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What 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.

ModelPer sessionOnce invoked
Fable 5 $0.00009 $0.04393
Opus 5 $0.00005 $0.02197
Sonnet 5 $0.00002 $0.00879
Haiku 4.5 $0.00001 $0.00439

Measured 2d ago against content hash 22aada1ed0d3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

build 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 2d 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.

commands/build.md · 378 lines

How it starts

The opening of the file, as written. The whole thing — 378 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/shipyard:build - Plan Execution

You are executing the Shipyard build workflow. Follow these steps precisely.

Step 1: Parse Arguments

  • If a phase number is provided, use it.
  • If --plan N is provided, execute only that specific plan (format: W.P).
  • If --light is provided, skip post-phase auditor and simplifier (Steps 5a and 5b). Use this during early iteration — the full pipeline runs at ship time regardless.
  • If no phase number, read .shipyard/STATE.json for the current phase.
  • Read .shipyard/config.json for gate preferences (security_audit, simplification_review, iac_validation, documentation_generation).
  • Follow Worktree Protocol (detect if running in a git worktree; if so, use worktree root for paths and record the branch name; see docs/PROTOCOLS.md) -- detect worktree, record working directory and branch.
  • Follow Model Routing Protocol (select the correct model for each agent role using model_routing from config; see docs/PROTOCOLS.md) -- read model_routing from config for agent model selection.

Step 2: Validate State

  1. Verify .shipyard/ exists. If not, tell the user to run /shipyard:init first.
  2. Read .shipyard/ROADMAP.md and locate the target phase.
  3. Read .shipyard/STATE.json for current context.
  4. Load all plan files from .shipyard/phases/{N}/plans/.
  5. Check which plans have already been completed (have SUMMARY.md files in .shipyard/phases/{N}/results/).
  6. If all plans are complete, inform the user and suggest /shipyard:ship or next phase.

Step 2b: Team or Agent Dispatch

Detection: Check the SHIPYARD_TEAMS_ENABLED environment variable (exported by scripts/team-detect.sh). This variable is set to true when CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1.

Prompt (conditional): If SHIPYARD_TEAMS_ENABLED=true, use AskUserQuestion with exactly two options:

  • "Team mode (parallel teammates)" -- uses TeamCreate/TaskCreate/SendMessage/TeamDelete lifecycle
  • "Agent mode (subagents)" -- uses standard Task dispatch (current behavior)

Read the full file on GitHub · 378 lines

Changes

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.

  1. 2d ago First seen · 378 lines · 9 tokens per session scan A 22aada1ed0d3

Subscribe to this mod's changes

build is a command published in the GitHub repository lgbarn/shipyard (65 stars, last pushed 1mo ago), licensed MIT. It adds 9 tokens to every session and 4,393 once invoked, about $0.0000 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 2026-08-30.