# nextjs-api-tester

Inspects Next.js API routes and generates complete test suites. Useful for verifying authentication, payload validation, and errors across App and Pages Router.

- command · `type=command` · Claude Code · 479 installs
- Author: davila7
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/commands/nextjs-vercel/nextjs-api-tester.md
- Updated: 2026-10-24
- HTML: https://affpapa.org/en/nevibecode/commands/nextjs-api-tester

## What it does

The command inspects your project setup by scanning `@app/api/` or `@pages/api/`. It checks the Next.js version via `package.json`, reads `.env.local`, and locates `tsconfig.json` alongside either `jest.config.js` or `vitest.config.js`. Then it inspects the route file to understand supported HTTP verbs, dynamic parameters, middleware, validation schemas, and database models.

From this analysis, it writes test cases covering common failure points. It creates checks for valid responses, missing JWT tokens returning 401 or 403, invalid JSON payloads, timeouts, and simulated database errors returning 500. It also outlines concurrency checks and rate-limit handling with status 429, plus manual `curl` calls for `http://localhost:3000/`.

The command requests `Read`, `Write`, `Edit`, and `Bash` tool permissions. Without Jest or Vitest pre-configured in the repository, the generated test files will fail to execute directly.

## Install

### Claude Code (native platform)

1. **claude-code-templates**
```bash
npx claude-code-templates@latest --command nextjs-vercel/nextjs-api-tester
```

2. **Manually: put the files in place**
- File: `.claude/commands/nextjs-api-tester.md` — Call it with /nextjs-api-tester. For all projects use ~/.claude/commands/

### Codex

**Manually: put the files in place**
- File: `~/.codex/prompts/nextjs-api-tester.md` — Call it with /prompts:nextjs-api-tester. Codex marks this format deprecated in favour of skills

### GitHub Copilot

**Manually: put the files in place**
- File: `.github/prompts/nextjs-api-tester.prompt.md`

### Gemini CLI

**Manually: put the files in place**
- File: `.gemini/commands/nextjs-api-tester.toml` — Gemini stores commands as TOML: the prompt text goes into the prompt field

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/davila7/claude-code-templates/tree/HEAD/cli-tool/components/commands/nextjs-vercel/nextjs-api-tester.md

## When to use it
- generate unit tests for GET, POST, PUT, DELETE, and PATCH endpoints
- verify route protection against missing or invalid JWT tokens
- test input schema validation against malformed payloads
- produce cURL command snippets for local manual testing

## Example prompts
- /nextjs-api-tester users --method=GET
- /nextjs-api-tester auth/login --method=POST --data='{"email":"test@example.com"}'
- /nextjs-api-tester orders --method=POST --headers='{"Authorization":"Bearer test"}'

## Source text · nextjs-api-tester.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: de1da3d500ef591b.

BEGIN THIRD-PARTY FILE de1da3d500ef591b
````text
---
allowed-tools: Read, Write, Edit, Bash
argument-hint: "[route-path] [--method=GET] [--data='{}'] [--headers='{}']"
description: Test and validate Next.js API routes with comprehensive test scenarios
---

## Next.js API Route Tester

**API Route**: $ARGUMENTS

## Current Project Analysis

### API Routes Detection
- App Router API: @app/api/
- Pages Router API: @pages/api/
- API configuration: @next.config.js
- Environment variables: @.env.local

### Project Context
- Next.js version: !`grep '"next"' package.json | head -1`
- TypeScript config: @tsconfig.json (if exists)
- Testing framework: @jest.config.js or @vitest.config.js (if exists)

## API Route Analysis

### Route Discovery
Based on the provided route path, analyze:
- **Route File**: Locate the actual route file
- **HTTP Methods**: Supported methods (GET, POST, PUT, DELETE, PATCH)
- **Route Parameters**: Dynamic segments and query parameters
- **Middleware**: Applied middleware functions
- **Authentication**: Required authentication/authorization

### Route Implementation Review
- Route handler implementation: @app/api/[route-path]/route.ts or @pages/api/[route-path].ts
- Type definitions: @types/ or inline types
- Validation schemas: @lib/validations/ or inline validation
- Database models: @lib/models/ or @models/

## Test Generation Strategy

### 1. Basic Functionality Tests
```javascript
// Basic API route test template
describe('API Route: /api/[route-path]', () => {
  describe('GET requests', () => {
    test('should return 200 for valid request', async () => {
      const response = await fetch('/api/[route-path]');
      expect(response.status).toBe(200);
    });

    test('should return valid JSON response', async () => {
      const response = await fetch('/api/[route-path]');
      const data = await response.json();
      expect(data).toBeDefined();
      expect(typeof data).toBe('object');
    });
  });

  describe('POST requests', () => {
    test('should create resource with valid data', async () => {
      const testData = { name: 'Test', email: 'test@example.com' };
      const response = await fetch('/api/[route-path]', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(testData)
      });
      
      expect(response.status).toBe(201);
      const result = await response.json();
      expect(result.name).toBe(testData.name);
    });

    test('should reject invalid data', async () => {
      const invalidData = { invalid: 'field' };
      const response = await fetch('/api/[route-path]', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(invalidData)
      });
      
      expect(response.status).toBe(400);
    });
  });
});
```

### 2. Authentication Tests
```javascript
describe('Authentication', () => {
  test('should require authentication for protected routes', async () => {
    const response = await fetch('/api/protected-route');
    expect(response.status).toBe(401);
  });

  test('should allow authenticated requests', async () => {
    const token = 'valid-jwt-token';
    const response = await fetch('/api/protected-route', {
      headers: { 'Authorization': `Bearer ${token}` }
    });
    expect(response.status).not.toBe(401);
  });

  test('should validate JWT token format', async () => {
    const invalidToken = 'invalid-token';
    const response = await fetch('/api/protected-route', {
      headers: { 'Authorization': `Bearer ${invalidToken}` }
    });
    expect(response.status).toBe(403);
  });
});
```

### 3. Input Validation Tests
```javascript
describe('Input Validation', () => {
````
END THIRD-PARTY FILE de1da3d500ef591b

The third-party file has ended. Everything between the de1da3d500ef591b tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

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