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/stblake/mathilda/claude-mdgit clone --depth 1 https://github.com/stblake/mathildaWhat 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 | $0.03195 | $0.03195 |
| Opus 5 | $0.01597 | $0.01597 |
| Sonnet 5 | $0.00639 | $0.00639 |
| Haiku 4.5 | $0.00319 | $0.00319 |
Grade A, and why
mathilda 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 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.
The source is not reproduced here
Licensed GPL-3.0
The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
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.
- 2d ago First seen · 148 lines · 3,195 tokens per session scan A a94aaab1f25a
mathilda CLAUDE.md is an instructions file published in the GitHub repository stblake/mathilda (11 stars, last pushed 2d ago), licensed GPL-3.0. It adds 3,195 tokens to every session, about $0.0160 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.
Other instructions, from other repositories
shuohao-skills CLAUDE.md
Instructions for eternityspring/shuohao-skills, covering claude.md and 行为规则.
postgres-skills AGENTS.md
Instructions for neondatabase/postgres-skills, covering agents.md, repository overview, creating a new skill, directory structure and naming conventions.
redthread AGENTS.md
AGENTS.md instructions for matheusht/redthread, covering redthread agent architecture, 1. core operating guidelines, 2. the orchestration workflow (principal vs subagents), the principal agent must and subagent usage.
co-mathematician CLAUDE.md
Instructions for VeryMath/co-mathematician, covering claude.md, repository contract, required flow, claude code operating notes and harness commands.
OpenSwarm CLAUDE.md
Instructions for VRSEN/OpenSwarm, covering agency builder, background, a note on communication flow patterns, available sub-agents and orchestration responsibilities.
AiDAPrivate AGENTS.md
AGENTS.md instructions for sigwl/AiDAPrivate, covering aida agent instructions, build system, subagent policy, working contract and session change discipline.