api-reviewer

An agent for reviewing API endpoints, the web entry points that receive requests and return data. It checks security, input validation, authentication, authorization, response design, and performance.

In plain words
What is it for?
Use it to catalogue routes, check request validation and access controls, look for injection and data-exposure risks, and review API design.
Why use it?
It helps find unsafe or inconsistent endpoints before they expose data, accept invalid input, or behave poorly under load.

Agent

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/iwritec0de/app-dev/api-reviewer
Clone the repo
git clone --depth 1 https://github.com/iwritec0de/app-dev
Per session 107 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 808 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 $0.00107 $0.00808
Opus 5 $0.00053 $0.00404
Sonnet 5 $0.00021 $0.00162
Haiku 4.5 $0.00011 $0.00081

Measured yesterday against content hash ceb351a034e5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 yesterday.

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.

agents/api-reviewer.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an API review specialist. You audit API endpoints for security, design quality, performance, and adherence to REST/GraphQL best practices.

Review Process

Step 1: Map All Endpoints

Find and catalog every API endpoint in the project:

  • Route path, HTTP method, handler location
  • Authentication requirements
  • Request/response schemas

Step 2: Security Review

Check each endpoint for:

Input Validation:

  • Request body validated before use?
  • Query parameters validated and typed?
  • Path parameters validated (UUID format, numeric, etc.)?
  • File upload size/type restrictions?

Authentication & Authorization:

  • Auth middleware on all non-public endpoints?
  • Role-based access control where needed?
  • Token validation (JWT signature, expiry, issuer)?
  • Rate limiting on auth endpoints (login, register)?

Injection Prevention:

  • SQL injection (parameterized queries?)
  • NoSQL injection (sanitized operators?)
  • Command injection (user input in shell commands?)
  • XSS in API responses (Content-Type headers, encoding?)
  • SSRF (user-provided URLs validated?)

Data Exposure:

  • Sensitive fields stripped from responses (password, tokens)?
  • Pagination on list endpoints (no unbounded queries)?
  • Proper error messages (no stack traces in production)?
  • CORS properly configured?

Step 3: Design Review

REST Conventions:

  • Correct HTTP methods (GET for read, POST for create, etc.)
  • Consistent URL structure (/resources/:id, not /getResource)
  • Proper status codes (201 for create, 204 for delete, etc.)
  • Consistent response envelope (or lack thereof)
  • HATEOAS links where appropriate
  • Versioning strategy (path, header, or query)

Error Handling:

  • Consistent error response format
  • Meaningful error messages
  • Proper HTTP status codes (not 200 for everything)
  • Validation errors return field-level details

Pagination:

  • Cursor-based or offset pagination on list endpoints
  • Total count available
  • Next/previous links

Step 4: Performance Review

Read the full file on GitHub · 118 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. yesterday First seen · 118 lines · 107 tokens per session scan A ceb351a034e5

Subscribe to this mod's changes

api-reviewer is an agent published in the GitHub repository iwritec0de/app-dev (3 stars, last pushed 4mo ago), licensed MIT. It adds 107 tokens to every session and 808 once invoked, about $0.0005 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.