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 rules/stblake/mathilda/cursorrulesgit 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 | $0.00422 | $0.00422 |
| Opus 5 | $0.00211 | $0.00211 |
| Sonnet 5 | $0.00084 | $0.00084 |
| Haiku 4.5 | $0.00042 | $0.00042 |
Grade A, and why
cursorrules 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 yesterday.
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.
- yesterday First seen · 39 lines · 422 tokens per session scan A a506e967214a
cursorrules is a cursor rule published in the GitHub repository stblake/mathilda (11 stars, last pushed 2d ago), licensed GPL-3.0. It adds 422 tokens to every session, about $0.0021 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 cursor rules, from other repositories
part-3-autonomous-research-mode
Autonomous research tiers, brainstorm-to-paper workflow, Tier 3, proof checks, and persistence.
hosted-web-contract
Hybrid deployment contract — genericmode, hosted sandbox, proxy auth, web-team boundary, updater policy.
part-2-compiler-tool-design-specification
Compiler architecture, paper construction phases, validation, RAG, and Lean rigor flow.
latex-renderer
LaTeX renderer security, KaTeX parsing, and large-document rendering requirements.
program-directory-and-file-definitions
Project directory map, runtime roots, and purpose summaries for major source files.
api-key-controls
Cloud provider keys, Boost routing, Supercharge, free-model fallback, and workflow metrics.