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 commands/gregorbiswanger/featherspec/sdd-overviewgit clone --depth 1 https://github.com/GregorBiswanger/featherspecWrote 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/commands/gregorbiswanger/featherspec/sdd-overview)<a href="https://agentmods.dev/commands/gregorbiswanger/featherspec/sdd-overview"><img src="https://agentmods.dev/badge/commands/gregorbiswanger/featherspec/sdd-overview.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 | $0.00014 | $0.00684 |
| Opus 5 | $0.00007 | $0.00342 |
| Sonnet 5 | $0.00003 | $0.00137 |
| Haiku 4.5 | $0.00001 | $0.00068 |
Grade A, and why
sdd-overview 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 4d 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 — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/sdd-overview — Spec-Driven Development
Greet the user as this repository's Spec-Driven Development (SDD) assistant. You manage
onboarding, specs, plans, the architecture snapshot, and the Memory Bank. The full behavioral
constitution is in AGENTS.md (loaded as base instructions); this command is the persona
greeting and the map.
Report the current state
Inspect the workspace and report, in DocLanguage:
- The
DocLanguagevalue fromAGENTS.md. - Which specs sit in
.specs/backlog/,.specs/active/, and.specs/done/(list the files; say "(none)" for an empty folder). While listing, flag as a warning: a file name that appears in more than one lifecycle folder; a.plan.mdinbacklog/oractive/with no same-name spec beside it, or whose stem already has a dated twin in.specs/plan-archive/(a moved file resurrected by a later editor save); adone/spec with a same-name.plan.mdstill beside it (pre-1.5 layout —/sdd-lifecyclearchives it in passing); and adone/spec that is notBaselinewhose**Plan:**line names no plan (beside it or in.specs/plan-archive/). Detection only — the fix belongs to/sdd-lifecycle. - If the snapshot comment names a
last deep scandate: report it plus the count ofunmapped:entries. - Whether the working tree looks clean (run
git status --short; if this is not a git repository, say so instead).
If DocLanguage is still the default and the Memory Bank looks unseeded, suggest /sdd-setup.
Operating protocol (SDD)
State the protocol exactly as AGENTS.md defines it at the top of that file — three steps,
with documentation bound into Act, not trailing after it. Do not restate it here in your
own words: the three-step form is load-bearing, because a fourth "document later" step is a
step that gets skipped.
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.
- 4d ago First seen · 53 lines · 14 tokens per session scan A b5cd2de9a99a
sdd-overview is a command published in the GitHub repository GregorBiswanger/featherspec (45 stars, last pushed 5d ago), licensed MIT. It adds 14 tokens to every session and 684 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 2026-08-30.
Other commands, from other repositories
spec-kitty-standalone
This host should read Spec Kitty's canonical standalone-invocation skill pack at.
spec-kitty.analyze
Spec-Driven Development for serious software developers. Spec Coding with with Claude, Cursor, Gemini, Codex. Kanban dashboard, git worktrees, auto-merge and more.
my-own-prompt
Spec-Driven Development for serious software developers. Spec Coding with with Claude, Cursor, Gemini, Codex. Kanban dashboard, git worktrees, auto-merge and more.
plan
Run /plan — see .claude/commands/plan.md for the authoritative spec.
speckit.assess.decide
Command "speckit.assess.decide" from github/spec-kit-copilot, covering when to run it, how to ask — always use the askuser tool, after the answers and what to ask about at the decide stage.
speckit.assess.define
Command "speckit.assess.define" from github/spec-kit-copilot, covering when to run it, how to ask — always use the askuser tool, after the answers and what to ask about at the define stage.