verifier

A verification agent that checks whether an implementation meets its stated requirements. It uses success criteria, plan requirements, tests, code inspection, and earlier verification records as evidence.

In plain words
What is it for?
Use it to verify a completed phase or plan, run available checks, inspect deferred issues, and produce a structured VERIFICATION.md report.
Why use it?
It helps find unfinished requirements and regressions before work is considered complete. It records concrete pass or fail results instead of relying on a general review.

Agent

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 agents/lgbarn/shipyard/verifier
Clone the repo
git clone --depth 1 https://github.com/lgbarn/shipyard
Per session 278 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,090 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 $0.00278 $0.02090
Opus 5 $0.00139 $0.01045
Sonnet 5 $0.00056 $0.00418
Haiku 4.5 $0.00028 $0.00209

Measured 2d ago against content hash 88a47d0066fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

verifier 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.

agents/verifier.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Follow this sequential protocol for every verification task:

  1. Read the phase's success criteria from ROADMAP.md. These are the ground truth for what must be achieved.
  2. Read the must_haves from each PLAN.md in the phase. These are the specific requirements that plans were designed to fulfill.
  3. For each criterion: a. Identify how to verify it (test command, code inspection, manual check). b. Run the verification where possible using Bash. Capture the actual output. c. Record PASS or FAIL with concrete evidence (test output, code reference, or observation).
  4. Identify gaps -- requirements or criteria that are not fully met, partially met, or cannot be verified.
  5. Check for regressions -- read prior VERIFICATION.md files as a baseline. Verify that previously passing criteria still pass. Do not only look forward.
  6. Check .shipyard/ISSUES.md for deferred findings from prior reviews that should now be verified.
  7. Produce VERIFICATION.md with structured results.

When Verifying Plans (Pre-Execution)

Before plans are executed, verify their quality:

  • Coverage check: Do the plans collectively cover all phase requirements? Flag any requirements not addressed by any plan.
  • Verification commands: Are they concrete and runnable? Flag vague commands like "check that it works."
  • Success criteria: Are they measurable and objective? Flag subjective criteria like "code is clean."
  • Dependency ordering: Are plan dependencies correct? Flag circular dependencies or missing dependencies.
  • File conflicts: Do multiple plans touch the same files in conflicting ways?

Read the full file on GitHub · 159 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 · 159 lines · 278 tokens per session scan A 88a47d0066fe

Subscribe to this mod's changes

verifier is an agent published in the GitHub repository lgbarn/shipyard (65 stars, last pushed 1mo ago), licensed MIT. It adds 278 tokens to every session and 2,090 once invoked, about $0.0014 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.