Common Issues

Solutions to problems you might encounter.

Server Won't Start

Port Already in Use

Symptom: Error message "Port 3001 is already in use"

Solution: 1. Choose a different port in project settings 2. Or stop whatever is using that port: - On Windows: netstat -ano | findstr :3001 then taskkill /PID <pid> /F - On macOS/Linux: lsof -i :3001 then kill <pid>

Server Starts but Requests Fail

Symptom: Server shows as running but requests return connection refused

Solution: 1. Check you're using the correct port 2. Try http://127.0.0.1:PORT instead of http://localhost:PORT 3. Check your firewall isn't blocking the port

Endpoints Not Working

404 Not Found

Symptom: Endpoint exists but returns 404

Causes & Solutions: 1. Endpoint is disabled - Check the enabled toggle 2. Path mismatch - Verify the path matches exactly (case-sensitive) 3. Method mismatch - Verify you're using the correct HTTP method 4. Server not restarted - Some changes require server restart

Wrong Response Returned

Symptom: Getting unexpected response data

Check: 1. Response variations - You may have multiple variations configured 2. Conditional logic - Check if conditions are matching differently than expected 3. Caching - Try a fresh request with curl or disable browser cache

Template Variables

Variables Not Replaced

Symptom: Response shows {{name}} literally instead of generated value

Causes: 1. Typo in helper name - Check spelling exactly 2. Missing closing braces - Must be {{name}} not {{name} or {name} 3. Wrong response type - Body must be text, not binary

Request Data Not Available

Symptom: {{params.id}} returns empty

Check: 1. Path parameter name matches - /users/{id} -> {{params.id}} 2. For query params, use {{query.paramName}} 3. For body fields, use {{body.fieldName}}

Proxy Issues

Proxy Returns Errors

Symptom: Proxy endpoint returns 500 or 502 errors

Check: 1. Target URL is correct and accessible 2. Target API is running 3. Network connectivity (try curl to target directly) 4. SSL certificate issues - some APIs require valid certificates

Recordings Not Appearing

Symptom: Requests go through but nothing in Recordings tab

Check: 1. Recording toggle is enabled on the endpoint 2. You're making requests to the proxy endpoint, not the target directly

Data & Storage

Lost Endpoints After Update

Symptom: Endpoints disappeared after app update

Solution: Endpoints are stored in your project folder. Check: - Windows: %APPDATA%\api-dev-studio\projects\ - macOS: ~/Library/Application Support/api-dev-studio/projects/ - Linux: ~/.config/api-dev-studio/projects/

Database Corruption

Symptom: App won't start or shows database errors

Solution: 1. Close the app completely 2. Delete project.db and local.db from the app data directory 3. Restart the app (databases will be recreated) 4. Re-import your projects from backups

Note: This loses request history. Export important data regularly.

Performance

App Running Slowly

Try: 1. Clear old requests from Request Inspector 2. Delete old recordings you don't need 3. Reduce number of response variations 4. Restart the app

Getting More Help

If your issue isn't listed here:

1. Check the full documentation at apidevstudio.com/docs
2. Search existing issues on GitHub
3. Open a new issue with:
4. Your OS and app version
5. Steps to reproduce
6. Expected vs actual behavior
7. Any error messages