modernize-brief

modernize-brief is a command for Claude Code from ronmkr/PromptBook. It costs 16 tokens per session (581 once invoked), scanned A, original, Apache-2.0.

A command that turns an existing legacy-system assessment into a phased modernization plan. Modernization means replacing or improving older software, and the brief is the document a steering group approves before engineers execute the work.

In plain words
What is it for?
Use it to recommend or document a target technology stack, map old components to new ones, sequence 3–6 modernization phases, define entry and exit criteria, and estimate effort.
Why use it?
It brings code findings, system structure, and business rules into one plan with a target architecture, dependencies, phases, and completion checks.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: positional $N argument.

Good fit Use it to recommend or document a target technology stack, map old components to new ones, sequence 3–6 modernization phases, define entry and exit criteria, and estimate effort.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/ronmkr/promptbook/modernize-brief
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/ronmkr/PromptBook

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 modernize-brief

README.md
[![agentmods](https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-brief/github.svg)](https://agentmods.dev/commands/ronmkr/promptbook/modernize-brief)
Your own site
<a href="https://agentmods.dev/commands/ronmkr/promptbook/modernize-brief"><img src="https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-brief/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 modernize-brief

Your own site · 80×15
<a href="https://agentmods.dev/commands/ronmkr/promptbook/modernize-brief"><img src="https://agentmods.dev/badge/commands/ronmkr/promptbook/modernize-brief.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 581 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 $0.00016 $0.00581
Opus 5 $0.00008 $0.00291
Sonnet 5 $0.00003 $0.00116
Haiku 4.5 $0.00002 $0.00058

Measured 8d ago against content hash fb1c98ed0a21, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

modernize-brief 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 8d 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.

plugins/standard/code-modernization/commands/modernize-brief.md · 66 lines

How it starts

The opening of the file, as written. The whole thing — 66 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Synthesize everything in analysis/$1/ into a Modernization Brief — the single document a steering committee approves and engineering executes.

Target stack: $2 (if blank, recommend one based on the assessment findings).

Read analysis/$1/ASSESSMENT.md, analysis/$1/TOPOLOGY.html (and the .mmd files alongside it), and analysis/$1/BUSINESS_RULES.md first. If any are missing, say so and stop — they come from /modernize-assess, /modernize-map, and /modernize-extract-rules respectively. Run those first.

The Brief

Write analysis/$1/MODERNIZATION_BRIEF.md:

1. Objective

One paragraph: from what, to what, why now.

2. Target Architecture

Mermaid C4 Container diagram of the end state. Name every service, data store, and integration. Below it, a table mapping legacy component → target component(s).

3. Phased Sequence

Break the work into 3-6 phases using strangler-fig ordering — lowest-risk, fewest-dependencies first. For each phase:

  • Scope (which legacy modules, which target services)
  • Entry criteria (what must be true to start)
  • Exit criteria (what tests/metrics prove it's done)
  • Estimated effort (person-weeks, derived from COCOMO + complexity data)
  • Risk level + top 2 risks + mitigation

Render the phases as a Mermaid gantt chart.

4. Behavior Contract

List the P0 rules from BUSINESS_RULES.md (the ones tagged Priority: P0 — money, regulatory, data integrity) that MUST be proven equivalent before any phase ships. These become the regression suite. Flag any P0 rule with Confidence < High as a blocker requiring SME confirmation before its phase starts.

5. Validation Strategy

State which combination applies: characterization tests, contract tests, parallel-run / dual-execution diff, property-based tests, manual UAT. Justify per phase.

6. Open Questions

Anything requiring human/SME decision before Phase 1 starts. Each as a checkbox the approver must tick.

7. Approval Block

Approved by: ________________  Date: __________
Approval covers: Phase 1 only | Full plan

Read the full file on GitHub · 66 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. 8d ago First seen · 66 lines · 16 tokens per session scan A fb1c98ed0a21

Subscribe to this mod's changes

modernize-brief is a command published in the GitHub repository ronmkr/PromptBook (2 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 16 tokens to every session and 581 once invoked, about $0.0001 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.