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.
git clone --depth 1 https://github.com/beel-collab/presets.devWrote 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/rules/beel-collab/presets.dev/rust-rules)<a href="https://agentmods.dev/rules/beel-collab/presets.dev/rust-rules"><img src="https://agentmods.dev/badge/rules/beel-collab/presets.dev/rust-rules/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/rules/beel-collab/presets.dev/rust-rules"><img src="https://agentmods.dev/badge/rules/beel-collab/presets.dev/rust-rules.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00000 | $0.01112 |
| Opus 5.5 | $0.00000 | $0.00445 |
| Sonnet 5.5 | $0.00000 | $0.00222 |
| Haiku 4.5 | $0.00000 | $0.00111 |
Grade A, and why
rust-rules 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 today.
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 — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rust Rules for Cursor: Ownership, Errors and Async
Install
Install the native export at .cursor/rules/rust-rules.mdc.
Copy that export, not this catalog file. Catalog fields such as tools and author are for presets.dev.
Install one skill file per name. Cursor, GitHub Copilot, Codex, Antigravity CLI, and Devin can all read .agents/skills, so a second copy with the same name collides.
Rust Rules for Cursor: Ownership, Errors and Async
File-scoped Cursor rule for Rust. It attaches when a matching file is in context.
Updated for Rust 1.100.0, Nov 2026
Do not upgrade dependencies or the framework version unless the task asks.
Stay on the rust-toolchain and the MSRV in Cargo.toml. Rust 1.100.0 stabilizes the never type and custom allocators. The 1.99 C-ABI variadics and raw-pointer layout APIs are already stable. Those FFI and layout APIs are not a reason to rewrite safe Rust. Do not raise the MSRV just because 1.100 exists. Read Cargo.toml before you add a crate.
Project shape
A library crate returns Result. A binary's main decides how to exit. Modules follow the existing tree. unsafe lives in the smallest block that needs it, with a comment that states the invariant. Do not use unsafe to avoid the borrow checker.
Prefer borrowing. Clone when the ownership story is actually a copy, and say why if the clone is on a hot path.
Errors
Library code does not unwrap or expect on a path a caller can trigger. expect is for a bug in the program, with a message that explains the broken invariant. Use the project's error type. ? propagates. A match that drops the error and returns a default hides a failure.
Async
An async function is cancel-safe at its await points, or it documents that it is not. Cancel safety is what happens if the future is dropped at an .await. It is separate from which mutex you hold.
Do not hold a std::sync::Mutex or a parking_lot guard across an .await. Those guards are !Send, so the future cannot be spawned on a multi-thread runtime. Holding one also blocks a worker thread and can deadlock. tokio::sync::Mutex is the lock you may hold across .await. A spawned task has a join handle or a structured scope. Blocking work does not run on the async runtime. Use the project's spawn_blocking helper.
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.
- today First seen · 101 lines · 0 tokens per session scan A aadaab99fef6
rust-rules is a cursor rule published in the GitHub repository beel-collab/presets.dev (3 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,112 tokens. 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 2026-11-13.
rust-rules compared with cursor rules from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| rust-rulesbeel-collab/presets.dev | Cursor rule | 3 | yesterday | MIT | A | 0 | Cursor |
| ponytailDietrichGebert/ponytail | Cursor rule | 190k | 15d ago | MIT | A | 604 | Cursor |
| angular-20angular/angular | Cursor rule | 101k | today | MIT | A | 0 | Cursor |
| dev-standardapache/superset | Cursor rule | 76k | today | Apache-2.0 | A | 1,147 | Cursor |
| prefer-direct-imports-over-module-mocksprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |
| config-validation-and-normalizationprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |
| control-plane-descriptorsprisma/orm | Cursor rule | 48k | today | Apache-2.0 | A | 0 | Cursor |