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-compilegit 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-compile)<a href="https://agentmods.dev/commands/gregorbiswanger/featherspec/sdd-compile"><img src="https://agentmods.dev/badge/commands/gregorbiswanger/featherspec/sdd-compile.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 | $0.00016 | $0.01825 |
| Opus 5 | $0.00008 | $0.00912 |
| Sonnet 5 | $0.00003 | $0.00365 |
| Haiku 4.5 | $0.00002 | $0.00183 |
Grade A, and why
sdd-compile 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 — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.
/sdd-compile — Execution Brief
The user may name a spec path and whether to run tests after the command. If the spec is not
given, ask which one. Run the tests unless the user explicitly declines — the project has a
test command if its manifest declares a test script or .memory-bank/techContext.md documents
one.
Gather context first
Run git status --short and git log --oneline -10 (if this is a git repository) and use the
results. Read the referenced spec, its plan — the .plan.md sibling, or for a completed
iteration the archive entry its **Plan:** line names — AGENTS.md, and
.memory-bank/activeContext.md. The scope and docs-sync checks operate on
git diff <baseline>, where <baseline> is the plan's Baseline: line; if none is recorded,
use the commit before the plan's first step commit (step IDs in commit messages) and say so.
Re-derive every verdict from the repository, not from the plan's checkboxes. Read the code and the tests before the plan's claims about them, and treat a ticked box as a claim to check. Delegate this brief to a subagent that receives only the file paths (no conversation history) whenever your tool supports it — mandatory if this session implemented the work: the context that produced a gap is the worst placed to find it. If delegation is impossible, say so in one line at the top of the brief and re-run every check yourself, trusting no note from your own session.
Expected state and verdict rubric
This check normally runs before the done/ move: the state it certifies is the spec
In Progress in active/ with its plan Done beside it. That state is correct, never a
finding — and the done/ move is never a readiness fix: the move follows READY
(/sdd-lifecycle demands this brief first), so naming it under next steps as a way to
become ready is circular. A spec already in done/ makes this a post-hoc audit — say so
and read the plan from the archive.
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 · 114 lines · 16 tokens per session scan A 8f04fec76222
sdd-compile is a command published in the GitHub repository GregorBiswanger/featherspec (45 stars, last pushed 5d ago), licensed MIT. It adds 16 tokens to every session and 1,825 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.