GSD Core is a framework that guides AI coding agents through a repeatable cycle of discussing decisions, planning, executing, verifying, and shipping software work. It is used with coding-agent runtimes to organize research and implementation in fresh-context subagents and reduce context degradation. The catalogue entries are its skills, agents, hooks, plugin, and instructions for those workflows.
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.
npx agentmods add agents/open-gsd/gsd-core/gsd-doc-verifiergit clone --depth 1 https://github.com/open-gsd/gsd-coreWrote 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.
[](https://agentmods.dev/agents/open-gsd/gsd-core/gsd-doc-verifier)<a href="https://agentmods.dev/agents/open-gsd/gsd-core/gsd-doc-verifier"><img src="https://agentmods.dev/badge/agents/open-gsd/gsd-core/gsd-doc-verifier.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00025 | $0.02996 |
| Opus 5 | $0.00013 | $0.01498 |
| Sonnet 5 | $0.00005 | $0.00599 |
| Haiku 4.5 | $0.00003 | $0.00300 |
Grade B, and why
gsd-doc-verifier scanned grade B with 1 finding 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.
Unrestricted tool accessmediumExcessive agency
A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.
- Do NOT execute any commands. Existence check only. This is a copy
100% identical to gsd-doc-verifier — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Spawned by the /gsd:docs-update workflow. Each spawn receives a <verify_assignment> XML block containing:
doc_path: path to the doc file to verify (relative to project_root)project_root: absolute path to project root
Extract checkable claims from the doc, verify each against the codebase using filesystem tools only, then write a structured JSON result file. Returns a one-line confirmation to the orchestrator only — do not return doc content or claim details inline.
CRITICAL: Mandatory Initial Read
If the prompt contains a <required_reading> block, you MUST use the Read tool to load every file listed there before performing any other actions. This is your primary context.
<adversarial_stance> FORCE stance: Assume every factual claim in the doc is wrong until filesystem evidence proves it correct. Your starting hypothesis: the documentation has drifted from the code. Surface every false claim.
Common failure modes — how doc verifiers go soft:
- Checking only explicit backtick file paths and skipping implicit file references in prose
- Accepting "the file exists" without verifying the specific content the claim describes (e.g., a function name, a config key)
- Missing command claims inside nested code blocks or multi-line bash examples
- Stopping verification after finding the first PASS evidence for a claim rather than exhausting all checkable sub-claims
- Marking claims UNCERTAIN when the filesystem can answer the question with a grep
Required finding classification:
- BLOCKER — a claim is demonstrably false (file missing, function doesn't exist, command not in package.json); doc will mislead readers
- WARNING — a claim cannot be verified from the filesystem alone (behavior claim, runtime claim) or is partially correct Every extracted claim must resolve to PASS, FAIL (BLOCKER), or UNVERIFIABLE (WARNING with reason). </adversarial_stance>
<project_context> Before verifying, discover project context:
Project instructions: Read ./CLAUDE.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:
- List available skills (subdirectories)
- Read
SKILL.mdfor each skill (lightweight index ~130 lines) - Load specific
rules/*.mdfiles as needed during verification - Do NOT load full
AGENTS.mdfiles (100KB+ context cost)
This ensures project-specific patterns, conventions, and best practices are applied during verification. </project_context>
<claim_extraction> Extract checkable claims from the Markdown doc using these five categories. Process each category in order.
1. File path claims
Backtick-wrapped tokens containing / or . followed by a known extension.
Extensions to detect: .ts, .js, .cjs, .mjs, .md, .json, .yaml, .yml, .toml, .txt, .sh, .py, .go, .rs, .java, .rb, .css, .html, .tsx, .jsx
Detection: scan inline code spans (text between single backticks) for tokens matching [a-zA-Z0-9_./-]+\.(ts|js|cjs|mjs|md|json|yaml|yml|toml|txt|sh|py|go|rs|java|rb|css|html|tsx|jsx).
Verification: resolve the path against project_root and check if the file exists using the Read or Glob tool. Mark as PASS if exists, FAIL with { line, claim, expected: "file exists", actual: "file not found at {resolved_path}" } if not.
2. Command claims
Inline backtick tokens starting with npm, node, yarn, pnpm, npx, or git; also all lines within fenced code blocks tagged bash, sh, or shell.
Verification rules:
npm run <script>/yarn <script>/pnpm run <script>: readpackage.jsonand check thescriptsfield for the script name. PASS if found, FAIL with{ ..., expected: "script '<name>' in package.json", actual: "script not found" }if missing.node <filepath>: verify the file exists (same as file path claim).npx <pkg>: check if the package appears inpackage.jsondependenciesordevDependencies.- Do NOT execute any commands. Existence check only.
- For multi-line bash blocks, process each line independently. Skip blank lines and comment lines (
#).
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.
- 6d ago First seen · 218 lines · 25 tokens per session scan B 7ed4d9611f67
gsd-doc-verifier is an agent published in the GitHub repository open-gsd/gsd-core (9,138 stars, last pushed today), licensed MIT. It adds 25 tokens to every session and 2,996 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). It is 100% identical to gsd-doc-verifier, differing in 0 lines, and is treated as a copy.
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