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.
npx agentmods add rules/nedcodes-ok/cursorrules-collection/cppgit clone --depth 1 https://github.com/nedcodes-ok/cursorrules-collectionWhat 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 | $0.00496 | $0.00496 |
| Opus 5 | $0.00248 | $0.00248 |
| Sonnet 5 | $0.00099 | $0.00099 |
| Haiku 4.5 | $0.00050 | $0.00050 |
Grade A, and why
cpp 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 yesterday.
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 — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C++ Cursor Rules
You are an expert modern C++ developer (C++17/20/23). Follow these rules:
Memory & Resources
- RAII everywhere: resources tied to object lifetimes
- Smart pointers: unique_ptr by default, shared_ptr when genuinely shared
- Never raw new/delete in application code — use make_unique/make_shared
- Move semantics for transferring ownership. Pass unique_ptr by value to transfer
- std::span for non-owning views of contiguous data
Modern C++ Style
- auto for type deduction when the type is obvious from context
- Structured bindings: auto [key, value] = pair
- constexpr for compile-time computation where possible
- std::optional over sentinel values, std::variant over unions
- Range-based for loops. std::ranges algorithms over raw iterators
- Use [[nodiscard]] on functions where ignoring return value is a bug
Error Handling
- std::expected (C++23) or tl::expected for functions that can fail
- Exceptions for truly exceptional situations — not control flow
- noexcept on move constructors, destructors, swap
- Use error codes at API boundaries (C interop, embedded)
- Never catch (...) silently — log or rethrow
Classes & Design
- Rule of 0: prefer defaulted special members via RAII members
- Rule of 5 only when managing resources directly
- final on classes not designed for inheritance
- Override keyword on all virtual function overrides
- Prefer composition and templates over deep inheritance hierarchies
Concurrency
- std::jthread over std::thread — automatic joining
- std::scoped_lock for multiple mutexes. std::unique_lock for condition variables
- Prefer lock-free with std::atomic when possible
- std::async with std::launch::async for fire-and-forget tasks
- Avoid mutable shared state — message passing where possible
Build & Safety
- Enable -Wall -Wextra -Wpedantic -Werror in CI
- Address/Thread/UB sanitizers in debug builds
- Use clang-tidy with modernize and performance checks
- Prefer std::array over C arrays, std::string_view over const char*
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.
- yesterday First seen · 52 lines · 496 tokens per session scan A 720db74fcaea
cpp is a cursor rule published in the GitHub repository nedcodes-ok/cursorrules-collection (37 stars, last pushed 6mo ago), licensed MIT. It adds 496 tokens to every session, about $0.0025 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.