Small Business API Security Checklist

APIs connect websites, CRMs, inventory, payments, scheduling, analytics, and internal tools. Security depends on the identity, permission, data, and failure rules around each connection.

Inventory endpoints and owners

List APIs, accounts, environments, data types, providers, consumers, scopes, owners, and expiration or review dates. Remove unused connections instead of letting them remain invisible.

Protect authentication and secrets

Use appropriate credentials, secure storage, rotation, revocation, environment separation, and limited scopes. Do not place secrets in source code, client-side bundles, URLs, or ordinary logs.

Check authorization separately

Confirm that an authenticated user can access only the records and actions allowed by their role, organization, location, or customer relationship. Test object identifiers for cross-record access.

Validate inputs and failures

Handle malformed values, duplicate requests, unexpected fields, large payloads, timeouts, rate limits, provider errors, retries, and partial success. Return useful errors without exposing internal details.

The API integration checklist and internal security checklist cover implementation and operations.

Monitor and review

Log security-relevant events, failures, latency, unusual access, and integration health without storing unnecessary sensitive data. Set alerts, retain evidence appropriately, and review vendors and scopes regularly.