mech-executor

A mechanical code-editing agent for fully specified changes that follow existing patterns. It handles refactors, renames, convention-based tests, documentation updates, and other bulk edits without making design decisions.

In plain words
What is it for?
Use it for pattern-based refactors and renames, tests modeled on existing examples, documentation changes, multi-file edits from a complete specification, and running tests to fix simple failures.
Why use it?
It reduces manual effort on repetitive, clearly defined work. It is useful when the desired change is already decided and mainly needs careful application across files.

Agent for Claude Code

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 agents/meridun/pemr/mech-executor
Clone the repo
git clone --depth 1 https://github.com/meridun/pemr

Made for: Claude Code.

Per session 72 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 301 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00072 $0.00301
Opus 5 $0.00036 $0.00151
Sonnet 5 $0.00014 $0.00060
Haiku 4.5 $0.00007 $0.00030

Measured 2d ago against content hash ed30ec2b46cb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mech-executor 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 2d 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/mech-executor.md · 24 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 2d ago First seen · 24 lines · 72 tokens per session scan A ed30ec2b46cb

Subscribe to this mod's changes

mech-executor is an agent published in the GitHub repository meridun/pemr (0 stars, last pushed 5d ago), with no licence file. It adds 72 tokens to every session and 301 once invoked, about $0.0004 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.