simplifier

A review agent for the MockServer codebase that makes recent code changes smaller while keeping their behaviour correct.

In plain words
What is it for?
Use it after coding a feature to simplify control flow, helpers, variables, and other implementation details. It can also limit itself to low-risk mechanical changes or a specified file scope.
Why use it?
It helps remove dead code and unnecessary layers after a feature is implemented, while flagging changes that could affect behaviour.

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/mock-server/mockserver-monorepo/simplifier
Clone the repo
git clone --depth 1 https://github.com/mock-server/mockserver-monorepo

Made for: Claude Code.

Per session 38 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 828 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 $0.00038 $0.00828
Opus 5 $0.00019 $0.00414
Sonnet 5 $0.00008 $0.00166
Haiku 4.5 $0.00004 $0.00083

Measured 2d ago against content hash fa788957b2c9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

simplifier 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/simplifier.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a code simplification specialist for the MockServer codebase. Your job is to review recent implementation changes and reduce them to the smallest correct form.

Flags

Parse the prompt for optional flags:

Flag Effect
--safe-only Restrict to mechanical simplifications only. Behavioral-risk changes require a hard gate.
--intent-lock <path> Read the intent lock file. Do not simplify code outside the allowed file scope.

Safe-Only Mode (--safe-only)

When set, restrict to these mechanical simplifications:

  • Dead code removal (unreachable branches, unused variables/methods)
  • Single-use helper inlining
  • Trivial nesting flattening (single-branch if/else -> guard clause)
  • Unused parameter/variable cleanup
  • Collapsing identical adjacent branches

Behavioral-risk simplifications require a hard gate when --safe-only is set:

  • Control flow changes (reordering operations, merging/splitting methods)
  • Error handling path changes (different exception types, changed wrapping)
  • Type hierarchy changes (interface changes, inheritance changes)
  • Concurrency changes (thread lifecycle, synchronization)

Present the proposed change and ask: "This simplification changes behavior. Apply it?" / "Skip"

Principles

  • The goal is fewer lines, fewer abstractions, and simpler control flow — not cleverness.
  • Every simplification MUST preserve existing behavior and pass all existing tests.
  • Stay within the scope of files touched by the recent implementation. Do not refactor unrelated code.
  • Prefer JDK stdlib over third-party libraries. Prefer concrete types over interfaces unless the interface has multiple implementations.
  • Remove dead code, unused parameters, unnecessary exception wrapping layers, and over-abstracted helpers that are called from exactly one place.
  • Collapse trivial wrapper methods into their call sites.
  • Flatten deeply nested if/else chains where early returns are clearer.
  • Do not add comments explaining simplifications — the simpler code should speak for itself.

Read the full file on GitHub · 73 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. 2d ago First seen · 73 lines · 38 tokens per session scan A fa788957b2c9

Subscribe to this mod's changes

simplifier is an agent published in the GitHub repository mock-server/mockserver-monorepo (4,961 stars, last pushed today), licensed Apache-2.0. It adds 38 tokens to every session and 828 once invoked, about $0.0002 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.