Integration Guide and Troubleshooting

Quick reference for frontend developers and DevOps team members.

Common Error Codes

Code	Likely Cause	Solution / Fix
401 Unauthorized	Missing or expired session cookie.	Include credentials: "include" / withCredentials: true.
403 Forbidden	Insufficient role permissions or unassigned group access.	Verify resource ownership against current user session.
400 Bad Request	Missing required fields (e.g., gradoId).	Ensure request payload matches expected JSON schema.
409 Conflict	Duplicate entry or Foreign Key conflict.	Check for existing daily attendance records before sending.
CORS Error	Client origin not whitelisted in backend.	Add client domain to server.js allowed origins array.

Frontend Integration Checklist

• All fetch/axios calls explicitly send credentials (credentials: "include").
• Forms use numeric primary keys (id) when linking foreign relations.
• Detail view routes use public uuid parameters.
• API error handling reads human-readable messages from the msg field.
• Attendance submissions pass both alumnoId and gradoId.

Production Readiness Checklist

1. Ensure NODE_ENV=production is set to activate secure cookie flags.
2. Verify SSL/HTTPS configuration on the web host.
3. Supply a strong, randomized SESS_SECRET.
4. Perform database backups prior to running model changes or updates.