Credential types and their security
WhatsApp Business API uses two main credential types: the Meta System User Token (for direct Meta Cloud API access) and the BSP provider API keys (for access via intermediary like Chat API). Do not confuse them: they have different scope and lifecycles.
For maximum security, use tokens with limited scope: create a System User in Meta Business Manager with strictly necessary permissions for send and receive operations, without account administration permissions.
Secure credential management in code
Never embed API credentials directly in source code. Use environment variables: code reads the key from process.env.CHAT_API_KEY instead of having the key hardcoded. This prevents accidental credential exposure in code repositories.
Use a secret manager for production systems. In CI/CD pipelines, use your provider's secrets management features. Never pass credentials as command-line arguments or in build logs.
Credential rotation
Implement a credential rotation policy: rotate API keys at least every 90 days, or immediately if compromise is suspected. Chat API allows generating new API keys and invalidating old ones without downtime if the rotation process is managed correctly.
Webhook signature verification
Webhooks sent by WhatsApp Business API include an HMAC-SHA256 signature in the header. Always verify this signature before processing the payload: if the signature does not match, reject the request with a 401 error.
Signature verification prevents attacks where a malicious actor sends fake requests to your webhook endpoint to trigger unauthorized actions.
