Long-Lived Agent Credential

Long-lived agent credential occurs when a synthetic subject uses a token, secret, key, certificate, or service credential that remains valid for an extended period. This may include static Application Programming Interface (API) keys, persistent OAuth tokens, stored connector secrets, or credentials without automatic expiry.

This configuration creates an elevated exposure condition because leaked, copied, or misused credentials may remain usable long after the original deployment, workflow, or tool action. A long-lived credential can allow continued access even where the synthetic subject’s purpose has changed or the responsible owner is no longer monitoring it.

The primary risk is persistent unauthorized access. If a long-lived agent credential is exposed through logs, repositories, configuration files, browser storage, vendor tooling, or Model Context Protocol (MCP) server settings, an unauthorized party may act with the synthetic subject’s permissions until the credential is discovered and revoked.

Investigators should review token age, expiry settings, credential rotation history, vault records, access logs, connector configuration, repository exposure, and recent authentication activity. Particular attention should be given to credentials with no expiry, stale tokens, and credentials used after a deployment or integration was retired.

Investigative Relevance

Long-lived agent credentials are relevant because they extend the window in which a synthetic subject’s access can be misused. This sub-section is especially relevant where credentials grant access to customer data, production systems, mailboxes, cloud resources, or external tools.