quickstart-debug-api-endpoints

Systematic API testing and debugging workflow for the Tessl quickstart guide.

⚠️ Quickstart Example Only

This tile is a demonstration example for the Quick Start: Skills, Docs, and Rules guide. It is not intended for production use.

For production, create your own skill with your team's specific testing workflows. See Creating skills for guidance.

Overview

This tile provides a skill that guides your coding agent through a systematic workflow for testing and debugging Express.js API endpoints. The skill activates when you ask your agent to test or debug APIs.

Type: Skill Name: tessl-labs/quickstart-debug-api-endpoints Version: 1.0.0

What's Included

Skill: debug-api-endpoints

Located in skills/debug-api-endpoints/SKILL.md, this skill provides a 4-step systematic testing workflow:

1. Verify Infrastructure

   • Server starts successfully
   • Health check responds
   • Database connection works
   • Environment variables loaded

2. Verify Security

   • Authentication (no token → 401, invalid token → 401, valid token → success)
   • Authorization (wrong role → 403, correct role → success)

3. Verify Validation

   • Required fields
   • Data formats and types
   • Boundary conditions
   • Sanitization (XSS, SQL injection prevention)

4. Verify Functionality

   • Happy paths (valid requests succeed)
   • Edge cases (duplicates, not found, empty lists)
   • Error scenarios (database errors, timeouts, race conditions)

Installation

From Tessl Registry

tessl install tessl-labs/quickstart-debug-api-endpoints

From Local Path

tessl install file:./tiles/tessl-demo/quickstart-debug-api-endpoints

How It Works

Skills are lazy push - they load when relevant:

1. Install the tile
2. Skill becomes available to your agent
3. When you ask to test/debug an API, the skill activates
4. Your agent follows the systematic workflow

Example Usage

After installing this tile, ask your agent:

"Test the /api/posts endpoint"

Your agent will:

• Follow the 4-step workflow systematically
• Check infrastructure before testing endpoints
• Verify security before validation
• Test validation before functionality
• Provide organized, comprehensive test coverage

Instead of random test patterns, you get:

✓ Infrastructure: Server running, health check OK
✓ Security: Auth token required, 401 without token
✓ Validation: Required fields checked, formats validated
✓ Functionality: Happy path works, errors handled correctly

When to Use

Use this skill when you need to:

• Write tests for a new API endpoint
• Debug issues with an existing endpoint
• Verify changes didn't break anything
• Ensure coverage of security and validation

Troubleshooting Order

The skill teaches your agent to debug in this order:

1. Infrastructure problem? → Check logs, database, environment
2. Security problem? → Verify tokens, permissions
3. Validation problem? → Review payload, required fields
4. Functionality problem? → Debug business logic, queries

Used In

This tile is referenced in:

• Quick Start: Skills, Docs, and Rules

Related Tiles

• quickstart-express-api-standards - API coding standards (rules)