test-api

A command that checks REST API endpoints, which are web addresses that software uses to exchange data. It validates responses, error handling, security details, performance, and whether the endpoint follows its documented contract.

In plain words
What is it for?
Use it to test individual endpoints or generate broader checks for valid requests, invalid data, authentication failures, edge cases, security, and load.
Why use it?
It can expose incorrect responses, missing security headers, slow requests, and differences between an API and its specification.

Command

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 commands/cyperx84/claude-code-plugin-examples/test-api
Clone the repo
git clone --depth 1 https://github.com/cyperx84/claude-code-plugin-examples
Per session 7 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 395 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00007 $0.00395
Opus 5 $0.00003 $0.00198
Sonnet 5 $0.00001 $0.00079
Haiku 4.5 $0.00001 $0.00040

Measured yesterday against content hash 760dc0145449, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-api scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

allowed-tools: Bash(curl:*, node:*)
examples/04-real-world/api-testing-plugin/commands/test-api.md · 75 lines

What it actually says

API Endpoint Testing

Test API: $ARGUMENTS (URL or specification)

Comprehensive Testing

1. Quick Test

/test-api https://api.example.com/users

# Tests:
✅ GET /users (200 OK, 45ms)
✅ Response is valid JSON
✅ Returns array of users
⚠️  No rate limiting detected
⚠️  Missing CORS headers

2. Full Test Suite

Automatically generates tests for:

  • Happy Path - Valid requests
  • Error Cases - Invalid data, auth failures
  • Edge Cases - Empty, null, large data
  • Security - Auth, injection, headers
  • Performance - Response time, load

3. Contract Testing

API Contract Validation:
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

GET /users
✅ Status: 200 OK
✅ Content-Type: application/json
✅ Response Schema: Valid
⚠️  Missing: pagination metadata
❌ Response Time: 1.2s (expected < 500ms)

POST /users
✅ Status: 201 Created
✅ Validates required fields
✅ Returns created resource
✅ Sets Location header

DELETE /users/:id
✅ Status: 204 No Content
✅ Requires authentication
⚠️  No confirmation step (security risk)

Example Usage

# Test single endpoint
/test-api GET https://api.example.com/users

# Test with authentication
/test-api https://api.example.com/users --auth "Bearer token"

# Load test
/test-api https://api.example.com/users --load 100

# Generate test suite
/test-api https://api.example.com/openapi.json --generate-tests

Pattern Demonstrated: API Testing & Validation Automation

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 · 75 lines · 7 tokens per session scan A 760dc0145449

Subscribe to this mod's changes

test-api is a command published in the GitHub repository cyperx84/claude-code-plugin-examples (2 stars, last pushed 10mo ago), licensed MIT. It adds 7 tokens to every session and 395 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.