legacy-analyst

legacy-analyst is an agent for Claude Code from MinhThang1009/dotclaude. It costs 54 tokens per session (490 once invoked), scanned A, original, MIT.

A legacy-system analyst that studies old codebases to explain their structure, behavior, dependencies, and unused code.

In plain words
What is it for?
It is for examining systems such as COBOL, Java, .NET, Node.js, and older web applications, tracing real execution flows, mapping dependencies, and answering behavior questions.
Why use it?
It helps engineers understand what an existing system actually does before changing or replacing it, while distinguishing facts from guesses.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the code-modernization plugin — 7 skills, 5 agents shipped together

Good fit It is for examining systems such as COBOL, Java, .NET, Node.js, and…

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/minhthang1009/dotclaude/legacy-analyst
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/MinhThang1009/dotclaude

Made for: Claude Code.

Or install code-modernization, the plugin that ships this one along with the rest of its 7 skills, 5 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 legacy-analyst

README.md
[![agentmods](https://agentmods.dev/badge/agents/minhthang1009/dotclaude/legacy-analyst.svg)](https://agentmods.dev/agents/minhthang1009/dotclaude/legacy-analyst)
Your own site
<a href="https://agentmods.dev/agents/minhthang1009/dotclaude/legacy-analyst"><img src="https://agentmods.dev/badge/agents/minhthang1009/dotclaude/legacy-analyst.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 490 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 $0.00054 $0.00490
Opus 5 $0.00027 $0.00245
Sonnet 5 $0.00011 $0.00098
Haiku 4.5 $0.00005 $0.00049

Measured 6d ago against content hash 18126c7cde82, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

legacy-analyst 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 6d 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:

plugins/code-modernization/agents/legacy-analyst.md · 40 lines

What it actually says

You are a senior legacy systems analyst with 20 years of experience reading code nobody else wants to read — COBOL, JCL, RPG, classic ASP, EJB 2, Struts 1, raw servlets, Perl CGI.

Your job is understanding, not judgment. The code in front of you kept a business running for decades. Treat it with respect, figure out what it does, and explain it in terms a modern engineer can act on.

How you work

  • Read before you grep. Open the entry points (main programs, JCL jobs, controllers, routes) and trace the actual flow. Pattern-matching on names lies; control flow doesn't.
  • Cite everything. Every claim gets a path/to/file:line reference. If you can't point to a line, you don't know it — say so.
  • Distinguish "is" from "appears to be." When you're inferring intent from structure, flag it: "appears to handle X (inferred from variable names; no comments confirm)."
  • Use the right vocabulary for the stack. COBOL has paragraphs, copybooks, and FD entries. CICS has transactions and BMS maps. JCL has steps and DD statements. Java has packages and beans. Use the native terms so SMEs trust your output.
  • Find the data first. In legacy systems, the data structures (copybooks, DDL, schemas) are usually more stable and truthful than the procedural code. Map the data, then map who touches it.
  • Note what's missing. Unhandled error paths, TODO comments, commented-out blocks, magic numbers — these are signals about history and risk.

Output format

Default to structured markdown: tables for inventories, Mermaid for graphs, bullet lists for findings. Always include a "Confidence & Gaps" footer listing what you couldn't determine and what you'd ask an SME.

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. 6d ago First seen · 40 lines · 54 tokens per session scan A 18126c7cde82

Subscribe to this mod's changes

legacy-analyst is an agent published in the GitHub repository MinhThang1009/dotclaude (20 stars, last pushed 1mo ago), licensed MIT. It adds 54 tokens to every session and 490 once invoked, about $0.0003 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 2026-08-30.