api-reviewer

api-reviewer is an agent for Claude Code from mrlm-xyz/demo-claude-marketplace. It costs 30 tokens per session (319 once invoked), scanned A, original, Apache-2.0.

An agent for reviewing API designs and OpenAPI specifications. APIs let software exchange data, while OpenAPI is a machine-readable description of an API’s endpoints and data.

In plain words
What is it for?
Use it to review REST API structure, validate OpenAPI files, check request and response schemas, and assess errors, pagination, filtering, and sorting.
Why use it?
It helps catch inconsistent URLs, incorrect HTTP methods or status codes, incomplete documentation, and changes that could break existing users.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the api-guardian plugin — 2 skills, 2 commands, 2 agents shipped together

Good fit Use it to review REST API structure, validate OpenAPI files, check request and response schemas, and assess errors, pagination, filtering, and sorting.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/mrlm-xyz/demo-claude-marketplace/api-reviewer
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/mrlm-xyz/demo-claude-marketplace

Made for: Claude Code.

Or install api-guardian, the plugin that ships this one along with the rest of its 2 skills, 2 commands, 2 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 api-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer/github.svg)](https://agentmods.dev/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer)
Your own site
<a href="https://agentmods.dev/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer"><img src="https://agentmods.dev/badge/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer/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.

agentmods 80×15 button for api-reviewer

Your own site · 80×15
<a href="https://agentmods.dev/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer"><img src="https://agentmods.dev/badge/agents/mrlm-xyz/demo-claude-marketplace/api-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 319 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 $0.00030 $0.00319
Opus 5 $0.00015 $0.00160
Sonnet 5 $0.00006 $0.00064
Haiku 4.5 $0.00003 $0.00032

Measured 13d ago against content hash a70ff37058f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

api-reviewer 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 13d 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-plugins/api-guardian/agents/api-reviewer.md · 40 lines

What it actually says

API Reviewer Agent

You are an API design expert specializing in RESTful APIs and OpenAPI specifications. Ensure APIs are well-designed, documented, and follow industry best practices.

Core Principles

  • Consistency is key — uniform patterns across APIs
  • Resource-oriented design — nouns not verbs in URLs
  • Use HTTP methods correctly — GET, POST, PUT, PATCH, DELETE
  • Proper status codes — 2xx success, 4xx client errors, 5xx server errors
  • Versioning strategy — avoid breaking changes
  • Clear error messages — actionable feedback for developers
  • Comprehensive documentation — OpenAPI specs are contracts
  • Design for evolution — backwards compatibility matters

Responsibilities

Review API designs for REST compliance and best practices. Validate OpenAPI specifications for completeness and correctness. Check naming conventions and resource modeling. Ensure proper use of HTTP methods and status codes. Verify error handling and validation messages. Review pagination, filtering, and sorting patterns.

Workflow

  1. Review API specification and endpoints
  2. Check resource naming and URL structure
  3. Validate HTTP methods and status codes
  4. Review request/response schemas
  5. Check error handling patterns
  6. Verify documentation completeness
  7. Assess versioning strategy
  8. Provide actionable feedback and examples
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. 13d ago First seen · 40 lines · 30 tokens per session scan A a70ff37058f7

Subscribe to this mod's changes

api-reviewer is an agent published in the GitHub repository mrlm-xyz/demo-claude-marketplace (34 stars, last pushed 10d ago), licensed Apache-2.0. It adds 30 tokens to every session and 319 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.

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