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-milestone-briefgit 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-milestone-brief)<a href="https://agentmods.dev/skills/open-gsd/gsd-pi/write-milestone-brief"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-pi/write-milestone-brief/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-milestone-brief"><img src="https://agentmods.dev/badge/skills/open-gsd/gsd-pi/write-milestone-brief.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Excessive Agency · line 78 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00098 | $0.01881 |
| Opus 5 | $0.00049 | $0.00941 |
| Sonnet 5 | $0.00020 | $0.00376 |
| Haiku 4.5 | $0.00010 | $0.00188 |
Grade A, and why
write-milestone-brief 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 — 136 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Typical invocation points:
- User says "capture this" or "write it up" after a planning discussion
- End of a
discussphase before moving toplan - User wants to hand the work off to another agent or a human teammate
<core_principle>
SYNTHESIZE, DO NOT RE-INTERVIEW. Use what is already in this conversation. If a decision is genuinely missing, note it in Open Questions — do not relitigate.
REAL OUTCOMES, NOT TASKS. M###-CONTEXT.md describes what the user can do when the milestone ships, what scenarios must pass for "done," and what architectural decisions were made. It does NOT list tasks or implementation steps — those belong in M###-ROADMAP.md and S##-PLAN.md.
NO FILE PATHS OR LINE NUMBERS IN THE BRIEF. Those go stale. Describe modules, interfaces, and behaviors. The roadmap and plans can cite code locations; the brief should outlive refactors. </core_principle>
Step 1: Locate the target
Find the active milestone:
- Read
.gsd/STATE.md— it names the active milestone. - If no milestone is active, ask the user whether this is a new milestone (create directory + files) or appending to an existing one.
- For a new milestone, use
gsd_milestone_newor the/gsd new-milestoneflow — do not create directories by hand.
Step 2: Read the template
Read src/resources/extensions/gsd/templates/context.md (the full path is shown in the templatesDir system-prompt field). Match its structure exactly — parsers and downstream prompts depend on the headings.
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 · 136 lines · 98 tokens per session scan A 7d932e595035
write-milestone-brief is a skill published in the GitHub repository open-gsd/gsd-pi (1,210 stars, last pushed today), licensed MIT. It adds 98 tokens to every session and 1,881 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-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-complete-milestone
Archive completed milestone and prepare for next version.
gsd-quick-batch
Batch several /gsd:quick-shaped tasks together — planned, dispatched, and merged as one run.
gsd-review-backlog
Review and promote backlog items to active milestone.
gsd-map-codebase
Analyze codebase with parallel mapper agents to produce .planning/codebase/ documents.