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 saski/arnesto --skill openspecgit clone --depth 1 https://github.com/saski/arnestoWrote 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/saski/arnesto/openspec)<a href="https://agentmods.dev/skills/saski/arnesto/openspec"><img src="https://agentmods.dev/badge/skills/saski/arnesto/openspec.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 5.1 | $0.00055 | $0.01349 |
| Opus 5 | $0.00028 | $0.00674 |
| Sonnet 5 | $0.00011 | $0.00270 |
| Haiku 4.5 | $0.00006 | $0.00135 |
Grade A, and why
openspec 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 3d 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 — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.
OpenSpec
Use OpenSpec as the planning layer when work needs durable requirements, reviewable intent, or a multi-session implementation trail. Keep the repository's normal engineering rules active: start implementation with tests where applicable, work in small steps, and run the project's canonical checks.
Before You Start
- Check whether the current repository already has an
openspec/directory ordocs/openspec/. - Resolve and verify the CLI with the NVM-aware procedure below.
- If OpenSpec is missing and the user asked to adopt it, initialize it with the shared installer after confirming the target repository.
- If OpenSpec is present, read the relevant
openspec/specs/*/spec.mdand activeopenspec/changes/<change>/artifacts before proposing edits. Ifopenspec/is a symlink todocs/openspec/, keep usingopenspec/...paths for CLI compatibility while recognizing that the physical files live underdocs/openspec/. - Treat OpenSpec artifacts as source files: update them with the same care as code, keep language precise, and include them in validation.
CLI Runtime Resolution
Non-interactive clients such as Codex App may not inherit the shell that loads NVM. On this machine OpenSpec is managed by the NVM default Node installation; the exact Node version is intentionally not hard-coded. Before reporting a missing CLI, use this resolution sequence:
if ! openspec --version >/dev/null 2>&1; then
if [ -s "$HOME/.nvm/nvm.sh" ]; then
. "$HOME/.nvm/nvm.sh"
fi
fi
openspec --version
Do not conclude that OpenSpec is unavailable merely because it is absent from
the initial PATH, or because ~/.agents/bin/openspec reports
env: node: No such file or directory. Load NVM and retry first. Only treat it
as missing when the post-NVM openspec --version still fails.
Shared Installer
This tooling repo exposes a portable installer through the shared ~/.agents symlink:
~/.agents/skills/openspec/scripts/install-openspec
~/.agents/skills/openspec/scripts/install-openspec /path/to/repo
What ships with it
1 file 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.
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.
- 3d ago First seen · 131 lines · 55 tokens per session scan A 025d1213d6e1
openspec is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 55 tokens to every session and 1,349 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 2026-09-03.
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