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 instructions/axiomantic/spellbook/claude-mdgit clone --depth 1 https://github.com/axiomantic/spellbookWrote 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/instructions/axiomantic/spellbook/claude-md)<a href="https://agentmods.dev/instructions/axiomantic/spellbook/claude-md"><img src="https://agentmods.dev/badge/instructions/axiomantic/spellbook/claude-md.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 | $0.00058 | $0.00058 |
| Opus 5 | $0.00029 | $0.00029 |
| Sonnet 5 | $0.00012 | $0.00012 |
| Haiku 4.5 | $0.00006 | $0.00006 |
Grade A, and why
spellbook CLAUDE.md 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
Spellbook Development
Read and follow the instructions in AGENTS.md.
PR Review Bot
- Bot username: axiomantic-momus[bot]
- Re-review comment: /ai-review
- Auto-reviews on PR creation: no
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 · 9 lines · 58 tokens per session scan A 3980cdd5c565
spellbook CLAUDE.md is an instructions file published in the GitHub repository axiomantic/spellbook (10 stars, last pushed yesterday), licensed MIT. It adds 58 tokens to every session, 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 2026-08-31.
Other instructions, from other repositories
claude-code-ultimate-guide AGENTS.md
AGENTS.md instructions for FlorianBruniaux/claude-code-ultimate-guide, covering claude code ultimate guide - project context, purpose, repository structure, published at: https://cc.bruniaux.com/whitepapers/ and key files.
claude-code-ultimate-guide CLAUDE.md
Claude Code instructions for FlorianBruniaux/claude-code-ultimate-guide, covering claude code ultimate guide - project context, purpose, repository structure, published at: https://cc.bruniaux.com/whitepapers/ and key files.
claudekit AGENTS.md
Instructions for duthaho/claudekit, covering agents.md, what this is, build, test, run, architecture and conventions & gotchas.
claude-plugins CLAUDE.md
Claude Code instructions for aiocean/claude-plugins, covering claude.md, what this is, plugin structure, marketplace registry and plugin categories.
aicontext copilot-instructions.md
Copilot instructions for zahardev/aicontext, covering project rules and prompts.
nextjs-skills CLAUDE.md
Instructions for mohamed-hossam1/nextjs-skills: All contribution rules — style, naming, file layout, verification — live in AGENTS.md. Read that first.