The security of an API Verifactu also depends on how your application uses it. The integration connects invoicing information, credentials and internal processes. Define from the outset who can configure the service, what data is retained and how to respond to accidental exposure.
Set boundaries for credential use
OWASP recommends HTTPS and keeping secrets out of URLs. Keep authenticated calls on the server and verify TLS certificates. User screens only need to display operation status; they do not need the API Key or client secret. Also review what information remains in diagnostic tools and shared test collections.
Design permissions for specific tasks
Viewing an invoice result and changing integration settings are different activities. Define which roles can perform each one and record significant changes. If your software manages several businesses, check authorisation on every operation using server context rather than trusting only an identifier supplied by the browser.
Keep useful, limited logs
For investigating a failure, an operation reference, timestamp and result code are often more useful than indiscriminate copies of all data. Design technical logs that help correlate events and avoid including secrets. Decide who can access these logs and how long they are needed, based on their purpose and applicable obligations.
- Review deployment variables and configuration files.
- Check that responses do not reveal credentials.
- Restrict access to backups and logs.
- Test permissions across different users and businesses.
Prepare your incident response
Document who should contact the provider and how to replace credentials using the available procedure. After a change, check operations and notifications that depend on them. This operational work complements code review and avoids improvisation when a key has been shared accidentally or authorised personnel change.