OpenSpec is a specification-driven development framework that records software requirements and implementation plans as readable Markdown artifacts. It helps developers and AI coding assistants agree on what should be built before code is written, including work spanning multiple repositories. The catalogue add-ons provide workflow skills and instructions for using OpenSpec.
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 Fission-AI/OpenSpec --skill openspec-proposegit clone --depth 1 https://github.com/Fission-AI/OpenSpecWrote 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/fission-ai/openspec/openspec-propose)<a href="https://agentmods.dev/skills/fission-ai/openspec/openspec-propose"><img src="https://agentmods.dev/badge/skills/fission-ai/openspec/openspec-propose/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/fission-ai/openspec/openspec-propose"><img src="https://agentmods.dev/badge/skills/fission-ai/openspec/openspec-propose.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
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 →
- high Memory Poisoning · line 118 Skill manipulates agent memory, state, or stored context. Memory corruption can alter personality, override safety rules, or cause unpredictable behavior.Fix: Protect agent memory and state from modification by untrusted content. Use read-only memory for critical instructions and validate all state changes.
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 | $0.00066 | $0.03497 |
| Opus 5.5 | $0.00026 | $0.01399 |
| Sonnet 5.5 | $0.00013 | $0.00699 |
| Haiku 4.5 | $0.00007 | $0.00350 |
Grade A, and why
openspec-propose 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 29d 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.
This is a copy
84% identical to openspec-ff-change — 76 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 174 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Propose a new change - create the change and generate all artifacts in one step.
Planning boundary: This workflow creates planning artifacts only. The user request that selected or triggered this workflow authorizes planning only, even if it asks to build or fix something. Do not edit project code. After the planning artifacts are complete, stop. Do not start implementation in the same response, even if the initial request asks for it. Wait for a new user request after the artifacts are presented; then start the apply workflow.
I'll create a change with the artifacts your schema defines. With the default spec-driven schema that is:
- proposal.md (what & why)
specs/<capability-path>/spec.md(what the system must do - a delta, not the main spec)- design.md (how)
- tasks.md (implementation steps)
<capability-path> is the spec directory relative to specs/ (for example, user-auth or identity/user-auth). Preserve an existing capability's full path and follow the project's established organization for new capabilities.
When the user is ready to implement, they must start the apply workflow explicitly.
Store selection: If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run openspec store list --json to discover registered store ids, then pass --store <id> on the commands that read or write specs and changes (new change, status, instructions, list, show, validate, archive, doctor, context, schemas, view). Once selected, treat --store <id> as sticky for the rest of the workflow. Every unscoped example of those commands below is shorthand: before running it, append the flag. For example, run openspec status --change "<name>" --json --store "<id>", not the unscoped form shown below. Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local openspec/ root.
Project check: These steps expect a project that already uses OpenSpec. Before the first step that writes anything (new change, archive, sync specs, or authoring an artifact file), confirm the project has a root: run openspec list --json (with --store <id> when a store is selected, since the store is then the root) and read root. A root object means the project is set up. "root": null means it is not - there is no openspec/ directory here, and a write such as openspec new change would create one as a side effect. The command also exits non-zero, which is that answer rather than a broken CLI, so read the JSON instead of retrying or working around it.
One "root": null is not about setup: when a status error message starts with Declared in or Invalid store declaration in and names this project's openspec/config.yaml (or config.yml), the project does use OpenSpec through a store it declares, which this machine cannot resolve (the store is not registered, or the store: line is malformed). Do not treat it as uninitialized and skip the branches below: stop before writing and show the user that error's message and fix.
Otherwise, with no root, what happens next depends on how this workflow was reached:
- Auto-selected: you chose this workflow yourself, without the user naming OpenSpec, naming this skill, or running its slash command. Stop using OpenSpec and answer the request normally, as you would with no OpenSpec installed. Do not ask them to set anything up and do not mention OpenSpec setup.
- Explicit OpenSpec request: the user named OpenSpec, named this skill, or ran its slash command. Stop before writing and ask how to proceed: set this project up (
openspec init), target a store they already have (--store <id>), or continue without OpenSpec for this request. Wait for their answer.
In both branches, never create the root as a side effect: do not run openspec init until the user asks for it, do not hand-create openspec/ files, and do not let a command create it.
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.
- 29d ago Changed · +11 lines · +19 tokens per session 7848351e7c51
- 1mo ago Changed · +10 lines af5f5e5ebd0c
- 1mo ago Changed · +4 lines f4ef2689aa61
- 1mo ago First seen · 149 lines · 47 tokens per session scan A c0537ce31111
openspec-propose is a skill published in the GitHub repository Fission-AI/OpenSpec (72,052 stars, last pushed today), licensed MIT. It adds 66 tokens to every session and 3,497 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 84% identical to openspec-ff-change, differing in 76 lines, and is treated as a copy.
Other skills, from other repositories
add-community-extension
Add a community extension to the Spec Kit catalog from a GitHub issue submission. USE FOR: processing extension submission issues, validating catalog entries, updating catalog.community.json and docs/community/extensions.md, creating PRs. DO NOT USE FOR: creating new extensions from scratch, or first-party extension…
code-review
Reviews Spec Kit code changes for consistency with applicable design documents, positive and negative test coverage, regression evidence for bug fixes, and consistent repository terminology. Use when reviewing a diff or pull request. Do not use for implementing changes or posting GitHub review actions.
openprd-harness
A workflow guide for OpenPrd, a workspace for turning unclear product ideas into clarified requirements and a handoff for implementation. It helps choose and run each stage, from questions through final handoff.
openprd-shared
A shared set of rules for working with OpenPrd, a workspace for turning product ideas into documented requirements and plans.
openprd-frontend-design
A design guide for OpenPrd interface and frontend work. It helps define the page's purpose, visual direction, assets, layout, and quality checks before implementation.
openprd-requirement-intake
A requirement-intake skill for sorting product requests, feature changes, bug fixes, and process changes before planning the work.