Marketing API Key Rotation and Vendor Credential Handover

Executive summary

Core workflow

Inventory credentials

List API keys, OAuth applications, webhook secrets, SMTP credentials, and service identities. Record system, purpose, owner, permissions, creation date, last-use evidence, dependencies, storage location, and recovery contact—but never the secret value itself. Use an approved vault, not a shared document or chat history.

Separate personal accounts from managed service identities. Classify credentials by impact: read-only analytics access differs from a token that can export customer data or send messages. Review high-impact credentials first when exposure or staff changes create urgency.

Reduce permissions

Compare scopes and roles with the integration's current purpose. Remove unused permissions, split read/write duties when supported, and replace shared credentials with named accounts or service identities. Check support for short-lived tokens, OAuth, IP restrictions, and environment-specific credentials.

Separate development, staging, and production secrets. Do not embed secrets in source code, browser JavaScript, public repositories, build logs, or analytics events. If exposure is suspected, revoke or rotate promptly and follow the incident process; routine schedules are not enough.

Stage the rotation

Where overlapping credentials are supported, create the replacement, store it securely, update the integration, validate expected behaviour, then revoke the old key. If overlap is unavailable, schedule a controlled cutover and prepare recovery steps that do not require restoring a compromised secret. Inventory jobs, webhooks, exports, and vendor automations that use the credential.

Test business outcomes, not just authentication. Run a low-risk operation, inspect logs, and confirm that secret values are not exposed in errors. Watch queue backlog and failed jobs after cutover. Keep an owner available and document the exact revocation step.

Coordinate vendor handover

Include credentials in vendor onboarding, agency transitions, and employee offboarding. Ask vendors to identify credentials they created, but verify revocation directly with the provider. Remove access from workspaces, password managers, deployment tools, and integration consoles. Deleting a vendor's local note does not revoke the key.

Use a handover record naming the new owner, affected workflows, rotation date, validation evidence, and exceptions. Grant access through the approved vault with an expiry or review date. If a transition period is required, document its scope and end date.

Monitor and rehearse

Monitor authentication failures, unusual API volume, unexpected exports, and permission changes where logs permit. Alert on meaningful signals rather than every routine refresh. If provider audit history is limited, record that gap and use integration logs that do not store secret values.

Rehearse rotation for critical integrations. Confirm that staff can find the owner, update the secret, validate dependent jobs, and revoke the old credential. Remove obsolete copies and update the inventory after each rotation. Rotation alone does not prove secure storage or appropriate access.

Worked example

Worked example: An outgoing agency owns a token that syncs lead forms to the CRM. The team creates a replacement under an internal service identity, tests a controlled submission, revokes the old token at the provider, removes agency access, and documents the handover.

Implementation checklist

• Inventory excludes secret values
• Each credential has an owner and purpose
• Permissions match actual need
• Secrets kept out of code and shared documents
• Replacement validated before revocation where possible
• Vendor access revoked at provider
• Rotation steps rehearsed

Key takeaways

• Inventory excludes secret values.
• Each credential has an owner and purpose.
• Permissions match actual need.
• Secrets kept out of code and shared documents.
• Replacement validated before revocation where possible.
• Vendor access revoked at provider.
• Rotation steps rehearsed.

References and further reading

• OWASP Secrets Management Cheat Sheet — Starting point; confirm current applicability before publication.
• OWASP REST Security Cheat Sheet — Starting point; confirm current applicability before publication.
• NIST Cybersecurity Framework — Starting point; confirm current applicability before publication.