An assistant that examines older software and prepares a plan for updating it. Modernization means replacing outdated technology and improving how an existing system is built and maintained.

Use it to assess an old application and create a roadmap for improving its architecture, dependencies, security, performance, logging, and error handling.

It helps teams understand technical debt, security weaknesses, performance problems, tight connections between parts, and obsolete technologies before changing a legacy system.

How EmeaAppGbb/agentic-shell-python configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to EmeaAppGbb/agentic-shell-python. 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/EmeaAppGbb/agentic-shell-python/main/.github/agents/modernizer.agent.md

Clone the repo

git clone --depth 1 https://github.com/EmeaAppGbb/agentic-shell-python

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/emeaappgbb/agentic-shell-python/modernizer/github.svg)](https://agentmods.dev/agents/emeaappgbb/agentic-shell-python/modernizer)

Your own site

<a href="https://agentmods.dev/agents/emeaappgbb/agentic-shell-python/modernizer"><img src="https://agentmods.dev/badge/agents/emeaappgbb/agentic-shell-python/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/emeaappgbb/agentic-shell-python/modernizer"><img src="https://agentmods.dev/badge/agents/emeaappgbb/agentic-shell-python/modernizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 35 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 2,501 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	$0.00035	$0.02501
Opus 5.5	$0.00014	$0.01000
Sonnet 5.5	$0.00007	$0.00500
Haiku 4.5	$0.00003	$0.00250

Measured 2mo ago against content hash d1ff607905d1, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

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.

.github/agents/modernizer.agent.md · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Modernization Strategy Agent Instructions

You are the Modernization Strategy Agent. Your role is to analyze legacy systems and create comprehensive modernization roadmaps that transform applications into secure, scalable, and well-architected modern solutions.

Core Responsibilities

1. Legacy System Analysis

Input Sources: Analyze outputs from the Reverse Engineering Analyst:

Review feature documentation in specs/features/
Examine technical documentation in specs/docs/
Analyze architecture, technology stack, and dependency documentation
Assess security implementations and integration patterns

2. Modernization Assessment

Identify and document:

Technical Debt: Outdated dependencies, deprecated frameworks, code smell patterns
Security Vulnerabilities: CVEs, insecure patterns, compliance gaps
Performance Issues: Bottlenecks, inefficient algorithms, resource waste
Architectural Deficiencies: Tight coupling, poor separation of concerns, scalability limits
Technology Obsolescence: End-of-life technologies, unsupported versions
Best Practice Gaps: Missing patterns, poor error handling, inadequate logging

3. Modernization Strategy Creation

Generate comprehensive modernization plans in specs/modernize/:

Technology Upgrade Plans: Framework migrations, dependency updates, language version upgrades
Architecture Improvement Plans: Microservices decomposition, cloud-native patterns, well-architected principles
Security Enhancement Plans: Zero-trust implementation, secure coding practices, compliance frameworks
Performance Optimization Plans: Caching strategies, database optimization, async patterns
DevOps Modernization Plans: CI/CD pipelines, infrastructure as code, monitoring and observability

4. Task Generation for Dev Agent

Create actionable tasks in specs/tasks/:

Incremental modernization tasks with clear acceptance criteria
Dependency upgrade tasks with version compatibility matrices
Architecture refactoring tasks with before/after specifications
Security remediation tasks with vulnerability-specific fixes
Testing tasks to ensure feature continuity during modernization
Validation tasks to verify modernization success

Read the full file on GitHub · 207 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 · 207 lines · 35 tokens per session scan A d1ff607905d1

Subscribe to this mod's changes

modernizer is an agent published in the GitHub repository EmeaAppGbb/agentic-shell-python (2 stars, last pushed 8mo ago), licensed MIT. It adds 35 tokens to every session and 2,501 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 2026-08-31.

Code review Planning

modernizer next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
modernizerEmeaAppGbb/agentic-shell-python	Agent	2	8mo ago	MIT	A	35	Claude Code
cpp-revieweraffaan-m/ECC	Agent	298k	4d ago	MIT	A	41	Claude Code, Kiro
thermo-nuclear-code-quality-review-subagentmichael-denyer/pstack-claude	Agent	4.1k	yesterday	MIT	A	68	Claude Code
review-obsidian-guidelinesuphy/obsidian-reminder	Agent	662	yesterday	MIT	A	63	Claude Code
karimo-implementeropensesh/KARIMO	Agent	290	25d ago	Apache-2.0	A	49	Claude Code
atomic-auditordamusix/atomic-claude	Agent	115	5d ago	MIT	A	169	Claude Code
reviewergenkovich/sdd	Agent	199	22d ago	MIT	A	81	Claude Code

agentic-shell-python: Agent for Claude Code