c++

A set of project rules for modern C++ development, covering C++17 and C++20, the standard library, and system-level programming. The supplied details do not list the individual rules.

In plain words
What is it for?
Use it while writing or reviewing C++17 or C++20 code, including code that uses the standard library or interacts closely with the operating system.
Why use it?
It gives an agent project-specific expectations for C++ code instead of relying on generic assumptions. The available information is too limited to name particular checks.

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/wulnut/lark_agent/c
Clone the repo
git clone --depth 1 https://github.com/Wulnut/lark_agent

Made for: Cursor.

Per session 888 This file is loaded in full into every session.
When invoked 888 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00888 $0.00888
Opus 5 $0.00444 $0.00444
Sonnet 5 $0.00178 $0.00178
Haiku 4.5 $0.00089 $0.00089

Measured yesterday against content hash 0c5348770e17, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

c++ 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.

.cursor/rules/languages/c++.mdc · 73 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. yesterday First seen · 73 lines · 888 tokens per session scan A 0c5348770e17

Subscribe to this mod's changes

c++ is a cursor rule published in the GitHub repository Wulnut/lark_agent (2 stars, last pushed 5mo ago), licensed GPL-3.0. It adds 888 tokens to every session, about $0.0044 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 2026-08-31.