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 skills add open-gsd/gsd-core --skill gsd-ns-reviewgit 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/skills/open-gsd/gsd-core/gsd-ns-review)<a href="https://agentmods.dev/skills/open-gsd/gsd-core/gsd-ns-review"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-core/gsd-ns-review/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.
<a href="https://agentmods.dev/skills/open-gsd/gsd-core/gsd-ns-review"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-core/gsd-ns-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00016 | $0.00253 |
| Opus 5 | $0.00008 | $0.00127 |
| Sonnet 5 | $0.00003 | $0.00051 |
| Haiku 4.5 | $0.00002 | $0.00025 |
Grade A, and why
gsd-ns-review 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 9d 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.
What it actually says
Route to the appropriate quality / review skill based on the user's intent.
gsd-code-review-fix was absorbed by gsd-code-review --fix in #2790.
| User wants | Invoke |
|---|---|
| Review code for quality and correctness | gsd-code-review |
| Auto-fix code review findings | gsd-code-review --fix |
| Audit UAT / acceptance testing | gsd-audit-uat |
| Security review of a phase | gsd-secure-phase |
| Evaluate AI response quality | gsd-eval-review |
| Review UI for design and accessibility | gsd-ui-review |
| Validate phase outputs | gsd-validate-phase |
| Debug a failing feature or error | gsd-debug |
| Forensic investigation of a broken system | gsd-forensics |
| Autonomous audit-to-fix pipeline | gsd-audit-fix |
| Cross-AI peer review of plans | gsd-review |
| Generate a UI design contract | gsd-ui-phase |
Invoke the matched skill directly using the Skill tool.
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.
- 9d ago First seen · 29 lines · 16 tokens per session scan A 4111ea56e820
gsd-ns-review is a skill published in the GitHub repository open-gsd/gsd-core (9,368 stars, last pushed today), licensed MIT. It adds 16 tokens to every session and 253 once invoked, about $0.0001 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 2026-09-03.
Other skills, from other repositories
best-practices
Apply modern web development best practices for security, compatibility, and code quality. Use when asked to "apply best practices", "security audit", "modernize code", "code quality review", or "check for vulnerabilities".
code-optimizer
Deep code optimization audit using parallel specialist agents that hunt performance anti-patterns via pattern-based detection, avoiding anchoring bias. Covers DB queries, memory leaks, algorithmic complexity, concurrency, bundle size, dead code, I/O/network, rendering, caching, and build config. Use when asked to…
forensics
Post-mortem a failed GSD auto-mode run. Traces symptom to root cause via .gsd/ activity, journal, metrics, and lock artifacts, producing a filing-ready bug report with file:line refs and a fix suggestion. Use when asked to "forensics", "post-mortem", "why did auto-mode fail", "trace the stuck loop", "debug the crash"…
observability
Add agent-first observability — structured logs, health endpoints, failure-state persistence, explicit failure modes — so the next agent can diagnose problems unattended. Use when asked to "add logging", "add observability", "add metrics", "make this observable", or when building/refactoring a subsystem that runs…
review
Review code changes for security, performance, bugs, and quality. Reviews staged changes, unstaged changes, specific commits, or PR-ready diffs.
lint
Lint and format code. Auto-detects ESLint, Biome, Prettier, or language-native formatters and runs them with auto-fix. Reports remaining issues with actionable suggestions.