cursorrules

A set of project rules and pinned documentation references for a Rust command-line and library project.

In plain words
What is it for?
Use it when changing the project's Rust code, especially its core logic, command-line interface, asynchronous runtime, routing, or data-serialization code.
Why use it?
It keeps changes consistent with the project's code layout, formatting, naming, testing, and compatibility requirements. Rust is a programming language; a command-line tool runs from a terminal.

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/nrl-ai/chub/cursorrules
Clone the repo
git clone --depth 1 https://github.com/nrl-ai/chub

Made for: Cursor.

Per session 468 This file is loaded in full into every session.
When invoked 468 The same file — it is already loaded in full.
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 $0.00468 $0.00468
Opus 5 $0.00234 $0.00234
Sonnet 5 $0.00094 $0.00094
Haiku 4.5 $0.00047 $0.00047

Measured 2d ago against content hash d71666e14362, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 2d 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.

.cursorrules · 38 lines

What it actually says

Project Rules

  • This is a Rust CLI + library project (workspace with chub-core and chub-cli crates)
  • Run cargo fmt --all and cargo clippy --all -- -D warnings before committing
  • All business logic goes in chub-core; CLI/output/MCP concerns go in chub-cli
  • Maintain byte-for-byte format compatibility with the original JS Context Hub
  • Use serde(rename) attributes to keep camelCase JSON field names
  • Tests are inline #[cfg(test)] blocks, not separate test files (except integration tests)
  • Do not add Co-Authored-By trailers to commits

Pinned Documentation

Use chub get <id> to fetch these docs when working with these libraries:

  • serde/derive (rust) — Core serialization framework — used everywhere for JSON/YAML
  • clap/derive (rust) — CLI argument parsing with derive macros
  • tokio/runtime (rust) — Async runtime for MCP server and HTTP serving
  • axum/routing (rust) — HTTP framework for chub serve

Project Context

Use chub get project/<name> or ask Chub for these:

  • project/architecture — Crate layout, data flow, and key design decisions
  • project/conventions — Rust coding standards and patterns used in this project
  • project/team-features — How team features work and how to extend them

Module: cli (crates/chub-cli/**)

  • Each command in its own file under src/commands/
  • Use owo-colors for terminal output, support --json flag on all commands
  • MCP tools use schemars::JsonSchema for parameter schema generation

Module: core (crates/chub-core/**)

  • No CLI concerns (no stdout/stderr, no clap, no owo-colors)
  • All public functions return Result using crate::error::Error
  • Search pipeline: tokenizer -> BM25 -> inverted index -> lexical boost

Module: team (crates/chub-core/src/team/**)

  • Team features live in .chub/ directory (git-tracked)
  • Three-tier config: ~/.chub/ -> .chub/ -> .chub/profiles/
  • All team modules must work gracefully when .chub/ doesn't exist
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. 2d ago First seen · 38 lines · 468 tokens per session scan A d71666e14362

Subscribe to this mod's changes

cursorrules is a cursor rule published in the GitHub repository nrl-ai/chub (11 stars, last pushed 5mo ago), licensed MIT. It adds 468 tokens to every session, about $0.0023 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.