MockServer is a testing server and proxy that imitates APIs, records and changes network traffic, and deliberately introduces failures. It is for developers testing applications against unavailable dependencies, debugging requests, and checking how systems handle degraded services across several network protocols. The catalogue add-ons help operate, configure, and test MockServer.
Borrowing it
Nothing to install: this file belongs to mock-server/mockserver-monorepo. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/mock-server/mockserver-monorepo/master/.claude/agents/simplifier.mdgit clone --depth 1 https://github.com/mock-server/mockserver-monorepoWrote 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.
[](https://agentmods.dev/agents/mock-server/mockserver-monorepo/simplifier)<a href="https://agentmods.dev/agents/mock-server/mockserver-monorepo/simplifier"><img src="https://agentmods.dev/badge/agents/mock-server/mockserver-monorepo/simplifier/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.
<a href="https://agentmods.dev/agents/mock-server/mockserver-monorepo/simplifier"><img src="https://agentmods.dev/badge/agents/mock-server/mockserver-monorepo/simplifier.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00038 | $0.00826 |
| Opus 5.5 | $0.00015 | $0.00330 |
| Sonnet 5.5 | $0.00008 | $0.00165 |
| Haiku 4.5 | $0.00004 | $0.00083 |
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 29d 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.
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.
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.
- 29d ago Changed 1ee50eab7a3b
- 1mo ago First seen · 73 lines · 38 tokens per session scan A fa788957b2c9
simplifier is an agent published in the GitHub repository mock-server/mockserver-monorepo (4,999 stars, last pushed today), licensed Apache-2.0. It adds 38 tokens to every session and 826 once invoked, about $0.0002 per session on Opus 5.5. 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.
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karimo-implementer
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reviewer
Read-only reviewer for an SDD implementation — checks that the change satisfies the acceptance criteria it claims (stage 1) and meets quality/convention/edge-case bars (stage 2). Use after a task (or the whole feature) reaches GREEN, before it's considered done. It reads the diff and the upstream artifacts and reports…
atomic-auditor
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Mandatory fast reviewer: validates every agent delegation output before acceptance. Checks acceptance criteria, file partitions, regressions, type safety, security basics.