cpp-fundamentals-agent

cpp-fundamentals-agent is an agent for Claude Code from pluginagentmarketplace/custom-plugin-cpp. It costs 50 tokens per session (3,371 once invoked), scanned B, original, no licence file.

A teaching agent for C++ basics, including variables, data types, operators, control flow, functions, and program structure.

In plain words
What is it for?
Use it to learn or explain core C++ concepts and practise writing small programs.
Why use it?
It helps beginners understand the building blocks of C++ through clear explanations and examples.

Agent for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: model in frontmatter.

Part of the custom-plugin-cpp plugin — 12 skills, 6 commands, 9 agents shipped together

Good fit Use it to learn or explain core C++ concepts and practise writing small programs.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent
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/pluginagentmarketplace/custom-plugin-cpp

Made for: Claude Code.

Or install custom-plugin-cpp, the plugin that ships this one along with the rest of its 12 skills, 6 commands, 9 agents.

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-fundamentals-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent/github.svg)](https://agentmods.dev/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent)
Your own site
<a href="https://agentmods.dev/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent"><img src="https://agentmods.dev/badge/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent/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-fundamentals-agent

Your own site · 80×15
<a href="https://agentmods.dev/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent"><img src="https://agentmods.dev/badge/agents/pluginagentmarketplace/custom-plugin-cpp/cpp-fundamentals-agent.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,371 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00050 $0.03371
Opus 5.5 $0.00020 $0.01348
Sonnet 5.5 $0.00010 $0.00674
Haiku 4.5 $0.00005 $0.00337

Measured 2mo ago against content hash 4309107be1a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

cpp-fundamentals-agent scanned grade B with 1 finding 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 2mo 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.

Strips warnings and disclaimersmediumAnti-refusal

Omitting safety caveats hides risk from the user and is a common jailbreak preamble.

- [ ] Code compiles without warnings (-Wall)
agents/cpp-fundamentals-agent.md · 509 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

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. 2mo ago First seen · 509 lines · 50 tokens per session scan B 4309107be1a2

Subscribe to this mod's changes

cpp-fundamentals-agent is an agent published in the GitHub repository pluginagentmarketplace/custom-plugin-cpp (7 stars, last pushed 9mo ago), with no licence file. It adds 50 tokens to every session and 3,371 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it B with 1 finding (strips warnings and disclaimers). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.