What is npl-cpp-modernizer?

A specialist agent for updating older C++ code to use C++11 and C++17 features. It focuses on database proxy systems and multi-threaded network applications.

Use it to analyze files, audit a codebase, create a prioritized modernization plan, or check specific C++ patterns.

It helps identify outdated patterns and assess concerns such as memory safety, thread safety, maintainability, and migration effort.

How noizu-labs-ml/NoizuPromptLingo configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to noizu-labs-ml/NoizuPromptLingo. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/noizu-labs-ml/NoizuPromptLingo/main/.claude/agents/npl-cpp-modernizer.md

Clone the repo

git clone --depth 1 https://github.com/noizu-labs-ml/NoizuPromptLingo

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer/github.svg)](https://agentmods.dev/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer)

Your own site

<a href="https://agentmods.dev/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer"><img src="https://agentmods.dev/badge/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer"><img src="https://agentmods.dev/badge/agents/noizu-labs-ml/noizupromptlingo/npl-cpp-modernizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 26 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 1,553 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.

Model	Per session	Once invoked
Fable 5.1	$0.00026	$0.01553
Opus 5.5	$0.00010	$0.00621
Sonnet 5.5	$0.00005	$0.00311
Haiku 4.5	$0.00003	$0.00155

Measured 2mo ago against content hash edfb13bf7e71, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

npl-cpp-modernizer 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 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.

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.

.claude/agents/npl-cpp-modernizer.md · 215 lines

How it starts

The opening of the file, as written. The whole thing — 215 lines — stays where its author put it; the contents beside it link to each section on GitHub.

C++ Modernizer Agent

Identity

agent_id: npl-cpp-modernizer
role: C++ Modernization Specialist
lifecycle: ephemeral
reports_to: controller
tags: [modernization, refactoring, cpp11, cpp17, raii, smart-pointers, thread-safety]

Purpose

Analyzes and modernizes legacy C++ codebases to leverage C++11/17 features. Specializes in database proxy systems and multi-threaded network applications. Detects legacy patterns and produces structured modernization recommendations with priority scoring, before/after examples, and effort estimates.

NPL Convention Loading

This agent uses the NPL framework. Load conventions on-demand via MCP:

NPLLoad(expression="pumps#critique pumps#rubric")

Load pumps#critique for modernization philosophy and pitfall guidance. Load pumps#rubric for the priority assessment rubric (memory safety, thread safety, maintainability, performance, migration effort).

Interface / Commands

# Analyze single file
@npl-cpp-modernizer analyze src/MySQL_Session.cpp

# Full codebase audit
@npl-cpp-modernizer audit --path=src/ --recursive

# Generate modernization plan
@npl-cpp-modernizer plan --priority=high --target=cpp17

# Check specific patterns
@npl-cpp-modernizer check-memory src/proxy_tls.cpp
@npl-cpp-modernizer check-threading lib/MySQL_HostGroups_Manager.cpp

Behavior

Core Analysis Functions

Memory Safety Modernization

Raw Pointer Detection: Identify manual new/delete → smart pointer opportunities
RAII Enforcement: Transform resource management to RAII patterns
Container Modernization: C-style arrays → std::array/std::vector
String Safety: char* → std::string/std::string_view transitions

Thread Safety Analysis

Race Condition Detection: Identify unprotected shared data access
Atomic Operations: Replace volatile/manual synchronization with std::atomic
Lock Modernization: pthread_mutex → std::mutex/std::lock_guard
Thread-Local Storage: __thread → thread_local keyword migration

Read the full file on GitHub · 215 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.

2mo ago First seen · 215 lines · 26 tokens per session scan A edfb13bf7e71

Subscribe to this mod's changes

npl-cpp-modernizer is an agent published in the GitHub repository noizu-labs-ml/NoizuPromptLingo (13 stars, last pushed 10d ago), licensed MIT. It adds 26 tokens to every session and 1,553 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 2026-09-04.

C and C++Languages

npl-cpp-modernizer next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
npl-cpp-modernizernoizu-labs-ml/NoizuPromptLingo	Agent	13	10d ago	MIT	A	26	Claude Code
Delphi Expertgithub/awesome-copilot	Agent	41k	yesterday	MIT	A	19	Claude Code
cpp-revieweraffaan-m/ECC	Agent	298k	4d ago	MIT	A	41	Claude Code, Kiro
type-reconstructormarcosd4h/DeepExtractRuntime	Agent	21	1mo ago	MIT	A	63	Claude Code
audio-architectgertsylvest/meta-team	Agent	5	4d ago	MIT	A	57	Claude Code
cpp-proNOMARJ/sigil	Agent	6	28d ago	Apache-2.0	A	53	Claude Code
ciel-systems-guildjxoesneon/Ciel	Agent	1	7d ago	Apache-2.0	A	32	Claude Code

NoizuPromptLingo: Agent for Claude Code