codemod-generator

A command that generates a codemod, meaning a script that automatically changes source code across many files, together with tests and a rollback plan.

In plain words
What is it for?
Use it for large-scale code migrations, including a jscodeshift transform, test cases, a migration runner, and MIGRATION.md and ROLLBACK.md documents.
Why use it?
It packages the transformation and its safety checks so a code migration can be tested, run, documented, and reversed if needed.

Command

Part of the design-system-ops plugin — 40 skills, 14 commands shipped together

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.

agentmods
npx agentmods add commands/murphytrueman/design-system-ops/codemod-generator
Clone the repo
git clone --depth 1 https://github.com/murphytrueman/design-system-ops

Or install design-system-ops, the plugin that ships this one along with the rest of its 40 skills, 14 commands.

Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 188 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00011 $0.00188
Opus 5 $0.00005 $0.00094
Sonnet 5 $0.00002 $0.00038
Haiku 4.5 $0.00001 $0.00019

Measured 3d ago against content hash 722fd694d260, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codemod-generator 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 3d 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.

commands/codemod-generator.md · 15 lines

What it actually says

Run the codemod-generator skill to produce a migration codemod.

Load the codemod-generator skill from ${CLAUDE_PLUGIN_ROOT}/skills/codemod-generator/SKILL.md and follow its complete workflow.

The user should provide the migration context as an argument: $ARGUMENTS

Before starting, read the knowledge notes declared in the skill's frontmatter references: field, located in ${CLAUDE_PLUGIN_ROOT}/knowledge-notes/.

Produce the full codemod package including: jscodeshift transform, test cases, migration runner script, MIGRATION.md, and ROLLBACK.md.

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. 3d ago First seen · 15 lines · 11 tokens per session scan A 722fd694d260

Subscribe to this mod's changes

codemod-generator is a command published in the GitHub repository murphytrueman/design-system-ops (174 stars, last pushed 11d ago), licensed MIT. It adds 11 tokens to every session and 188 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 2026-08-30.