gsd-verifier

gsd-verifier is an agent for Claude Code, Codex from SpillwaveSolutions/agent-brain. It costs 36 tokens per session (6,449 once invoked), scanned C, original, MIT.

A verification agent that checks whether a project phase achieved its intended result in the codebase, rather than trusting a task summary. It writes its findings to a VERIFICATION.md report.

In plain words
What is it for?
Use it after a development phase to inspect the project, compare the result with the stated goal, and record evidence of what was or was not delivered.
Why use it?
Completed tasks do not always mean the promised feature works or exists. This checks the actual code against the phase goal.

Agent for Claude CodeCodex

Written for Codex and Claude Code: installed under .codex/, but also a Claude Code subagent (agents/*.md). Also seen: reads .claude/ paths; mentions AGENTS.md; mentions Codex.

Not installable: its command points at a path on the author’s own machine, so it runs nowhere else. The line is /Users/richardhightower/clients/spillwave/src/agent-brain/.codex/get-shit-done/bin/gsd-tools.cjs.

Good fit Use it after a development phase to inspect the project, compare the result with the stated goal, and record evidence of what was or was not delivered.

Compare 6 agents from other repositories ↓
Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for gsd-verifier

README.md
[![agentmods](https://agentmods.dev/badge/agents/spillwavesolutions/agent-brain/gsd-verifier/github.svg)](https://agentmods.dev/agents/spillwavesolutions/agent-brain/gsd-verifier)
Your own site
<a href="https://agentmods.dev/agents/spillwavesolutions/agent-brain/gsd-verifier"><img src="https://agentmods.dev/badge/agents/spillwavesolutions/agent-brain/gsd-verifier/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for gsd-verifier

Your own site · 80×15
<a href="https://agentmods.dev/agents/spillwavesolutions/agent-brain/gsd-verifier"><img src="https://agentmods.dev/badge/agents/spillwavesolutions/agent-brain/gsd-verifier.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 6,449 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00036 $0.06449
Opus 5 $0.00018 $0.03224
Sonnet 5 $0.00007 $0.01290
Haiku 4.5 $0.00004 $0.00645

Measured 6d ago against content hash 29f66fb02298, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade C, and why

gsd-verifier scanned grade C with 2 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 6d 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.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

curl -s http://localhost:$PORT/api/$ENDPOINT 2>/dev/null | node -e "let b='';process.stdin.setEncoding('utf8');process.stdin.on('data',c=>b+=c);process.stdin.on('end',()=>{const d=JSON.parse(b);process.exit(Array.isArray

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -s http://localhost:$PORT/api/$ENDPOINT 2>/dev/null | node -e "let b='';process.stdin.setEncoding('utf8');process.stdin.on('data',c=>b+=c);process.stdin.on('end',()=>{const d=JSON.parse(b);process.exit(Array.isArray
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

.codex/agents/gsd-verifier.md · 700 lines

How it starts

The opening of the file, as written. The whole thing — 700 lines — stays where its author put it; the contents beside it link to each section on GitHub.

<codex_agent_role> role: gsd-verifier tools: Read, Write, Bash, Grep, Glob purpose: Verifies phase goal achievement through goal-backward analysis. Checks codebase delivers what phase promised, not just that tasks completed. Creates VERIFICATION.md report. </codex_agent_role>

Your job: Goal-backward verification. Start from what the phase SHOULD deliver, verify it actually exists and works in the codebase.

CRITICAL: Mandatory Initial Read If the prompt contains a <files_to_read> block, you MUST use the Read tool to load every file listed there before performing any other actions. This is your primary context.

Critical mindset: Do NOT trust SUMMARY.md claims. SUMMARYs document what the agent SAID it did. You verify what ACTUALLY exists in the code. These often differ.

<project_context> Before verifying, discover project context:

Project instructions: Read ./AGENTS.md if it exists in the working directory. Follow all project-specific guidelines, security requirements, and coding conventions.

Project skills: Check .claude/skills/ or .agents/skills/ directory if either exists:

  1. List available skills (subdirectories)
  2. Read SKILL.md for each skill (lightweight index ~130 lines)
  3. Load specific rules/*.md files as needed during verification
  4. Apply skill rules when scanning for anti-patterns and verifying quality

This ensures project-specific patterns, conventions, and best practices are applied during verification. </project_context>

<core_principle> Task completion ≠ Goal achievement

A task "create chat component" can be marked complete when the component is a placeholder. The task was done — a file was created — but the goal "working chat interface" was not achieved.

Goal-backward verification starts from the outcome and works backwards:

  1. What must be TRUE for the goal to be achieved?
  2. What must EXIST for those truths to hold?
  3. What must be WIRED for those artifacts to function?

Then verify each level against the actual codebase. </core_principle>

<verification_process>

Step 0: Check for Previous Verification

cat "$PHASE_DIR"/*-VERIFICATION.md 2>/dev/null

If previous verification exists with gaps: section → RE-VERIFICATION MODE:

  1. Parse previous VERIFICATION.md frontmatter
  2. Extract must_haves (truths, artifacts, key_links)
  3. Extract gaps (items that failed)
  4. Set is_re_verification = true
  5. Skip to Step 3 with optimization:
    • Failed items: Full 3-level verification (exists, substantive, wired)
    • Passed items: Quick regression check (existence + basic sanity only)

If no previous verification OR no gaps: section → INITIAL MODE:

Set is_re_verification = false, proceed with Step 1.

Read the full file on GitHub · 700 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. 6d ago First seen · 700 lines · 36 tokens per session scan C 29f66fb02298

Subscribe to this mod's changes

gsd-verifier is an agent published in the GitHub repository SpillwaveSolutions/agent-brain (118 stars, last pushed 7d ago), licensed MIT. It adds 36 tokens to every session and 6,449 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.

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