GSD Pi is a command-line coding agent and project workflow system that plans, implements, verifies, and tracks software work through milestones, tasks, Git worktrees, and stored project notes. It is for developers who want structured, longer-running agent sessions using different model providers. The catalogue entries extend GSD Pi with skills and agents.
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-pi --skill write-docsgit clone --depth 1 https://github.com/open-gsd/gsd-piWrote 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-pi/write-docs)<a href="https://agentmods.dev/skills/open-gsd/gsd-pi/write-docs"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-pi/write-docs/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-pi/write-docs"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-pi/write-docs.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 | $0.00094 | $0.01278 |
| Opus 5 | $0.00047 | $0.00639 |
| Sonnet 5 | $0.00019 | $0.00256 |
| Haiku 4.5 | $0.00009 | $0.00128 |
Grade A, and why
write-docs 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Invocation points:
- User asks to write or rewrite a piece of documentation
- Before shipping a feature that adds user-facing behavior — docs need updates
- After
write-milestone-briefwhen the brief needs a public-facing summary for non-GSD consumers - PR description for a meaningful change
<core_principle> WRITE FOR THE FRESH READER. The test is not "does the maintainer understand it" — you are the maintainer. The test is "can someone who has never seen this code act correctly after reading this?"
ITERATE STRUCTURE BEFORE PROSE. An outline that's wrong will not be saved by good sentences. Agree on the sections, what each is for, and in what order before drafting the body.
NO FILE PATHS IN TRUNK DOCS. Paths rot. Describe modules, behaviors, and invariants. A README that cites src/foo.ts:42 is a future broken link.
</core_principle>
Stage 1: Context gathering
- Who is the reader? Internal engineer, open-source contributor, end user, future you at 3am. The answer changes everything.
- What should they be able to do after reading? Name the single post-read action. "Understand the auth flow" is not an action — "implement a new auth provider using the documented extension points" is.
- What do they already know? Assume they have docs for the language and framework, not for your codebase. Don't re-explain React; do explain your project's conventions.
- What context from this conversation/codebase belongs in the doc? Ask the user to dump any missing material. Do not invent examples.
One round of clarifying questions. Then proceed.
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.
- 5d ago First seen · 83 lines · 94 tokens per session scan A 819628ac9708
write-docs is a skill published in the GitHub repository open-gsd/gsd-pi (1,210 stars, last pushed today), licensed MIT. It adds 94 tokens to every session and 1,278 once invoked, about $0.0005 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
gsd-graphify
Build, query, and inspect the project knowledge graph in .planning/graphs/.
gsd-mempalace-capture
File a phase artifact into MemPalace; mirror decision facts into its temporal KG.
gsd-quick
Execute a quick task with GSD guarantees (atomic commits, state tracking) but skip optional agents.
gsd-surface
Toggle which skills are surfaced — apply a profile, list, or disable a cluster without reinstall.
gsd-complete-milestone
Archive completed milestone and prepare for next version.
gsd-import
Ingest external plans with conflict detection against project decisions before writing anything.