rust-conventions

rust-conventions is a cursor rule for Cursor from c9r-io/orchestrator. It costs 0 tokens per session (234 once invoked), scanned A, original, MIT.

A set of Rust coding rules for service backends, covering project structure, error handling, asynchronous code, and testing.

In plain words
What is it for?
Use it when building Rust HTTP or gRPC services, defining business logic, handling network calls, and writing unit or integration tests.
Why use it?
It helps keep Rust services organized and makes failures easier to propagate, understand, and test.

Cursor rule for Cursor

Install

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.

agentmods
npx agentmods add rules/c9r-io/orchestrator/rust-conventions
Clone the repo
git clone --depth 1 https://github.com/c9r-io/orchestrator

Made for: Cursor.

Wrote 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.

agentmods badge for rust-conventions

README.md
[![agentmods](https://agentmods.dev/badge/rules/c9r-io/orchestrator/rust-conventions.svg)](https://agentmods.dev/rules/c9r-io/orchestrator/rust-conventions)
Your own site
<a href="https://agentmods.dev/rules/c9r-io/orchestrator/rust-conventions"><img src="https://agentmods.dev/badge/rules/c9r-io/orchestrator/rust-conventions.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 234 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00234
Opus 5 $0.00000 $0.00117
Sonnet 5 $0.00000 $0.00047
Haiku 4.5 $0.00000 $0.00023

Measured 3d ago against content hash e71aa652855b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rust-conventions 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 3d 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.

.cursor/rules/rust-conventions.mdc · 35 lines

What it actually says

Rust Conventions (Service Development)

Apply these rules if the backend is Rust under core/.

Structure

  • Keep HTTP/gRPC handlers thin.
  • Put business logic in service/ with dependency injection via traits.
  • Keep domain models in domain/ with validation and invariants.
  • Repositories provide persistence behind mockable traits.

Error Handling

  • Use typed errors for business logic (thiserror), and attach context at boundaries (anyhow or eyre).
  • Do not swallow errors (ok()/unwrap() in production paths).
  • Prefer returning Result<T, E> from functions instead of side effects.

Async

  • Avoid tokio::spawn unless you can explain lifecycle and error handling.
  • Prefer explicit timeouts at network boundaries.

Testing

  • Unit tests should not require Docker.
  • Mock repositories with mockall and mock HTTP dependencies with wiremock.
  • Integration/E2E tests can use docker-compose, but keep them separate from unit tests.
Changes

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.

  1. 3d ago First seen · 35 lines · 0 tokens per session scan A e71aa652855b

Subscribe to this mod's changes

rust-conventions is a cursor rule published in the GitHub repository c9r-io/orchestrator (21 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 234 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.