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/tyrchen/cursor-rust-rulesWrote 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/tyrchen/cursor-rust-rules/concurrency)<a href="https://agentmods.dev/rules/tyrchen/cursor-rust-rules/concurrency"><img src="https://agentmods.dev/badge/rules/tyrchen/cursor-rust-rules/concurrency/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/tyrchen/cursor-rust-rules/concurrency"><img src="https://agentmods.dev/badge/rules/tyrchen/cursor-rust-rules/concurrency.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 | $0.03699 |
| Opus 5.5 | $0.00000 | $0.01480 |
| Sonnet 5.5 | $0.00000 | $0.00740 |
| Haiku 4.5 | $0.00000 | $0.00370 |
Grade A, and why
concurrency 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 1mo 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 — 570 lines — stays where its author put it; the contents beside it link to each section on GitHub.
⚡ RUST CONCURRENCY BEST PRACTICES
TL;DR: Modern async/await patterns and thread-safe data structures for high-performance Rust applications.
🔍 CONCURRENCY ARCHITECTURE STRATEGY
graph TD
Start["Concurrency Requirements"] --> ConcurrencyType{"Concurrency<br>Pattern?"}
ConcurrencyType -->|Async I/O| AsyncPattern["Async/Await Pattern"]
ConcurrencyType -->|CPU Intensive| ParallelPattern["Parallel Processing"]
ConcurrencyType -->|Shared State| SharedStatePattern["Shared State Management"]
ConcurrencyType -->|Message Passing| MessagePattern["Message Passing"]
AsyncPattern --> TokioRuntime["Tokio Runtime"]
ParallelPattern --> Rayon["Rayon Parallel Iterators"]
SharedStatePattern --> DashMap["DashMap Collections"]
MessagePattern --> Channels["Channel Communication"]
TokioRuntime --> AsyncPrimitives["Async Sync Primitives"]
Rayon --> ThreadPool["Thread Pool Management"]
DashMap --> LockFree["Lock-Free Data Structures"]
Channels --> ChannelTypes["Channel Type Selection"]
AsyncPrimitives --> ErrorHandling["Error Handling"]
ThreadPool --> ErrorHandling
LockFree --> ErrorHandling
ChannelTypes --> ErrorHandling
ErrorHandling --> Testing["Concurrency Testing"]
Testing --> Performance["Performance Monitoring"]
Performance --> Production["Production Concurrency"]
style Start fill:#4da6ff,stroke:#0066cc,color:white
style AsyncPattern fill:#4dbb5f,stroke:#36873f,color:white
style SharedStatePattern fill:#ffa64d,stroke:#cc7a30,color:white
style MessagePattern fill:#d94dbb,stroke:#a3378a,color:white
🎯 ASYNC RUNTIME SELECTION
Tokio as the Standard
- Always use Tokio for async runtime
- Use tokio::sync primitives instead of std::sync for async code
- Leverage async/await patterns throughout the application
- Avoid blocking operations in async contexts
# Cargo.toml - Tokio configuration
[dependencies]
tokio = { version = "1.45", features = [
"macros",
"rt-multi-thread",
"signal",
"sync"
] }
dashmap = { version = "6", features = ["serde"] }
async-trait = "0.1"
futures = "0.3"
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.
- 1mo ago First seen · 570 lines · 0 tokens per session scan A 2b281c701894
concurrency is a cursor rule published in the GitHub repository tyrchen/cursor-rust-rules (27 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 3,699 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 2026-08-30.
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table-of-contents-standard
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arc-deref-pattern
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wrap-vs-specify
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core
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