write-openspec-docs

A writing mode for creating or editing OpenSpec user documentation. It follows a house style focused on direct answers, clear structure, and exact command and file names.

In plain words
What is it for?
Drafting or revising OpenSpec guides and reference pages in the documentation tree.
Why use it?
It helps documentation stay concise, scannable, and consistent across pages.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/fission-ai/openspec/write-openspec-docs
Any agent
npx skills add Fission-AI/OpenSpec --skill write-openspec-docs
Clone the repo
git clone --depth 1 https://github.com/Fission-AI/OpenSpec

Made for: Claude Code, Codex.

Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 826 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00055 $0.00826
Opus 5 $0.00028 $0.00413
Sonnet 5 $0.00011 $0.00165
Haiku 4.5 $0.00006 $0.00083

Measured 2d ago against content hash 581e121b2c98, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

write-openspec-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 2d 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.

.agents/skills/write-openspec-docs/SKILL.md · 35 lines

How it starts

The opening of the file, as written. The whole thing — 35 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write OpenSpec docs

You are now writing OpenSpec's user docs. Read writing.md; it is the style authority for everything drafted here. The short version, in effect immediately:

  • A page is a retrieval surface, not an essay. Structure decides whether the reader finds the answer; prose only decides how it reads. Open every section with the answer, never a running story.
  • Choose the page type before the outline. Guides follow the reader's task; reference mirrors the product's structure and uses exact field, command, and file names as scan anchors. Reference needs complete coverage without compressing several facts into one sentence, cell, or paragraph.
  • Draft the shortest version that answers; expanding a spare page is cheap, cutting a bloated one is a rewrite. Plain words, the fewest of them: an idea that fits in one line takes one line. Depth most readers skip goes behind a link, and the payload (commands, real output, failures and fixes) stays whole.
  • Dumb sentences, smart structure. Write the obvious sentence (actor, verb, object, stating the literal event); never compress extra facts in or take an angle. No hype adjectives, no preamble, no em dashes.
  • One job per slot: one fact per sentence, list intros only announce the list, one reader question or lookup target per section. A related fact gets its own slot, never a ride in someone else's.
  • Ground items in what the reader can verify: path or folder first, concept as the gloss, real output shown honestly.
  • No house template. Inventories open with a list naming every item, then expand each in its own unit after the list, never inline. Sequences take numbered steps (numbers mean order; inventories take bullets). Single ideas and reasoning stay in short prose.
  • Every load-bearing fact sits on a scan anchor: code fence, numbered bold lead-in, **Term**: fact bullet, table, file tree. Never only mid-paragraph.
  • Before finishing, run two backstop tests. Retrievability: can each question or exact product name be found by scanning alone? The glance: inspect the rendered page as shapes; does it look finishable, or like work? Check table-heavy changes at desktop and narrow widths. A failure means a slot got written without being earned; fix it now, don't leave it for review.

Read the full file on GitHub · 35 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

  1. 2d ago First seen · 35 lines · 55 tokens per session scan A 581e121b2c98

Subscribe to this mod's changes

write-openspec-docs is a skill published in the GitHub repository Fission-AI/OpenSpec (66,714 stars, last pushed 4d ago), licensed MIT. It adds 55 tokens to every session and 826 once invoked, about $0.0003 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.