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-style-updategit 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-style-update)<a href="https://agentmods.dev/commands/gregorbiswanger/featherspec/sdd-style-update"><img src="https://agentmods.dev/badge/commands/gregorbiswanger/featherspec/sdd-style-update.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 | $0.00009 | $0.00373 |
| Opus 5 | $0.00005 | $0.00187 |
| Sonnet 5 | $0.00002 | $0.00075 |
| Haiku 4.5 | $0.00001 | $0.00037 |
Grade A, and why
sdd-style-update 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.
What it actually says
/sdd-style-update — Capture Coding Style Preferences
The user may state one or more preferences after the command. If none are given, ask for them.
Goal
Update the Style & Output Preferences section in AGENTS.md — the only place style
preferences live. No loader file holds a copy.
Steps
- If no preference was provided, ask the user for it.
- Normalize each into a short English bullet with a bold category prefix
(
**Comments**: …), matching the section's existing format —AGENTS.mdis wiring and stays English whatever the dialogue language. A "preference" that would override a Non-negotiable or a lifecycle invariant inAGENTS.mdis not captured — quote the conflict instead;AGENTS.mdwins (its preference-capture rule stays authoritative). - Append it to the bullet list under Current preferences in
AGENTS.mdimmediately — replacing any bullet it contradicts, and saying so. - Check the file length against the cap in
.claude/rules/constitution.md; if clearly over, beyond its tolerance clause, propose one eviction per its order before finishing. - Confirm by showing the updated bullets. Apply them to all future code generation.
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 · 34 lines · 9 tokens per session scan A 8e6d1cfdbbe5
sdd-style-update is a command published in the GitHub repository GregorBiswanger/featherspec (47 stars, last pushed 6d ago), licensed MIT. It adds 9 tokens to every session and 373 once invoked, about $0.0000 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.
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