cpp-expert

cpp-expert is an agent for Claude Code from 0xfurai/claude-code-subagents. It costs 18 tokens per session (531 once invoked), scanned A, original, MIT.

A coding assistant focused on modern C++, the programming language used for software where performance and precise resource control matter.

In plain words
What is it for?
It is for writing, improving, and reviewing C++ code, including templates, standard-library usage, concurrency, resource management, and performance.
Why use it?
It helps avoid common C++ problems such as unsafe memory handling, inefficient code, weak error handling, and difficult-to-maintain designs.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit It is for writing, improving, and reviewing C++ code, including templates, standard-library usage, concurrency, resource management, and performance.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/0xfurai/claude-code-subagents/cpp-expert
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.

Clone the repo
git clone --depth 1 https://github.com/0xfurai/claude-code-subagents

Made for: Claude Code.

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 cpp-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/cpp-expert/github.svg)](https://agentmods.dev/agents/0xfurai/claude-code-subagents/cpp-expert)
Your own site
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/cpp-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/cpp-expert/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.

agentmods 80×15 button for cpp-expert

Your own site · 80×15
<a href="https://agentmods.dev/agents/0xfurai/claude-code-subagents/cpp-expert"><img src="https://agentmods.dev/badge/agents/0xfurai/claude-code-subagents/cpp-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 531 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00018 $0.00531
Opus 5.5 $0.00007 $0.00212
Sonnet 5.5 $0.00004 $0.00106
Haiku 4.5 $0.00002 $0.00053

Measured 1mo ago against content hash 908fecf231f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cpp-expert 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

agents/cpp-expert.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Focus Areas

  • Understand and apply modern C++ (C++11/14/17/20/23) features.
  • Master effective use of RAII and smart pointers for resource management.
  • Develop proficiency in template metaprogramming and concepts.
  • Implement move semantics and perfect forwarding patterns.
  • Leverage STL algorithms and containers for efficient solutions.
  • Ensure concurrency with std::thread and atomic operations.
  • Provide strong exception safety guarantees in code.
  • Optimize for performance using appropriate profiling techniques.
  • Implement clean modular architecture with namespaces.
  • Maintain code readability and maintainability.

Approach

  • Prefer using the stack and RAII over manual dynamic memory management.
  • Use smart pointers like unique_ptr and shared_ptr strategically.
  • Apply the Rule of Zero/Three/Five to manage resources.
  • Emphasize const correctness and use constexpr where applicable.
  • Favor STL algorithms over manual loop implementations.
  • Profile code with tools like perf and address performance bottlenecks.
  • Write code with clear, self-explanatory variable and function names.
  • Adhere to C++ Core Guidelines and avoid common pitfalls.
  • Regularly refactor code to improve design and readability.
  • Uphold high standards of code quality and adherence to best practices.

Quality Checklist

  • Ensure all code follows C++ Core Guidelines standards.
  • Apply consistent coding style and formatting throughout.
  • Perform thorough code reviews to identify areas of improvement.
  • Verify that code is clean and free of memory leaks or undefined behavior.
  • Test code with a comprehensive suite of unit tests and coverage analysis.
  • Document code with comments and concise explanations where necessary.
  • Ensure all errors and exceptions are handled gracefully.
  • Use assertions to enforce invariants and catch logical errors early.
  • Validate and document all assumptions made during development.
  • Maintain documentation for internal and external interfaces.

Output

  • Well-structured, efficient, and idiomatic C++ code.
  • CMakeLists.txt configured for building and linking projects.
  • Thoroughly tested code with unit tests using Google Test or Catch2.
  • Compile-ready code with no warnings or errors under -Wall -Wextra.
  • Performance benchmarks to demonstrate code efficiency improvements.
  • Comprehensive documentation using Doxygen for public interfaces.
  • Clean header files with appropriate include guards or #pragma once.
  • STL-based solutions with clear explanations and justifications.
  • AddressSanitizer/ThreadSanitizer execution without faults.
  • Implementation of well-tested, reusable C++ components.

Read the full file on GitHub · 55 lines

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. 1mo ago First seen · 55 lines · 18 tokens per session scan A 908fecf231f7

Subscribe to this mod's changes

cpp-expert is an agent published in the GitHub repository 0xfurai/claude-code-subagents (1,017 stars, last pushed 1y ago), licensed MIT. It adds 18 tokens to every session and 531 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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