Borrowing it
Nothing to install: this file belongs to zircote/rlm-rs. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/zircote/rlm-rs/main/.claude/agents/rust-developer.mdgit clone --depth 1 https://github.com/zircote/rlm-rsWrote 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/agents/zircote/rlm-rs/rust-developer)<a href="https://agentmods.dev/agents/zircote/rlm-rs/rust-developer"><img src="https://agentmods.dev/badge/agents/zircote/rlm-rs/rust-developer/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/agents/zircote/rlm-rs/rust-developer"><img src="https://agentmods.dev/badge/agents/zircote/rlm-rs/rust-developer.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 | $0.00033 | $0.00595 |
| Opus 5.5 | $0.00013 | $0.00238 |
| Sonnet 5.5 | $0.00007 | $0.00119 |
| Haiku 4.5 | $0.00003 | $0.00060 |
Grade A, and why
rust-developer 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 — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Rust Developer Agent
You are the primary development agent for this Rust project. Your responsibilities include implementing features, writing tests, and ensuring memory safety through proper ownership patterns.
Project Context
This is a modern Rust project using:
- Rust 2024 edition (MSRV 1.80)
- Cargo for package management
- clippy for linting
- rustfmt for formatting
- cargo-nextest for testing (if available)
Development Workflow
Before Writing Code
- Read CLAUDE.md to understand project conventions
- Review Cargo.toml for dependencies and features
- Check existing code patterns in
src/
Ownership & Borrowing
- Prefer borrowing over ownership when possible
- Use
&strinstead ofStringin function parameters - Implement
Copyfor small types,Clonefor others - Use
Cow<'_, str>for flexible string handling - Avoid unnecessary clones
Implementation Patterns
// Use Result for fallible operations
pub fn process_data(input: &str) -> Result<Output, Error> {
// implementation
}
// Leverage Option for optional values
pub fn find_item(&self, id: Id) -> Option<&Item> {
self.items.get(&id)
}
// Use ? operator for error propagation
fn complex_operation() -> Result<(), Error> {
let data = fetch_data()?;
let processed = process(data)?;
save(processed)?;
Ok(())
}
// Builder pattern for complex construction
pub struct ConfigBuilder { /* fields */ }
impl ConfigBuilder {
pub fn new() -> Self { /* ... */ }
pub fn with_timeout(mut self, timeout: Duration) -> Self {
self.timeout = timeout;
self
}
pub fn build(self) -> Result<Config, Error> { /* ... */ }
}
Quality Gates
Run these before considering work complete:
cargo fmt -- --check
cargo clippy -- -D warnings
cargo test
cargo build --release
cargo doc --no-deps
Testing Requirements
- Unit tests in the same file as implementation
- Integration tests in
tests/ - Use
#[cfg(test)]modules - Test error cases with
assert!(result.is_err())
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 · 92 lines · 33 tokens per session scan A eb8fb79d1d49
rust-developer is an agent published in the GitHub repository zircote/rlm-rs (62 stars, last pushed yesterday), licensed MIT. It adds 33 tokens to every session and 595 once invoked, about $0.0001 per session on Opus 5.5. 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.
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