Authentication
Who is calling the tool?
Reference notes by Min · Reviewed October 11, 2026
Definition
Authentication establishes confidence in the identity claimed by a person, process or device. For an agent, it verifies the actor presenting a credential.
Separate a claim from its verification. A caller can present a workload name in a request, but the receiving service needs trusted evidence before accepting that identity. Authentication establishes the actor for the next control; resource permission still needs its own evaluation.
What it covers
- Claim
- The identity the actor presents.
- Evidence
- A credential and the trusted issuer or verifier.
- Lifecycle
- How evidence expires, rotates and is invalidated.
Document the trust boundary: who issues evidence, which services accept it and how expiry or compromise is handled. Human sign-in and unattended workload authentication have different lifecycle needs and should not be assumed interchangeable.
In practice
Practical design patterns by Min.
- Validate issuer, audience and expiry at the receiving service.
- Use distinct agent credentials rather than a shared human session.
- Pass verified identity into the authorization check.
Validate credentials with the intended verifier and reject malformed or unexpected evidence. Establish a clear response to issuer outages and expired credentials.
Record the verified actor and verification outcome. Keep credential contents out of general logs and make rotation a routine operating procedure.
Working example
An agent connects to a records service
A support agent requests a customer record.
- Verify its credential and intended audience.
- Resolve the authenticated workload identity.
- Evaluate resource access separately.
Why the controls matter
A records service should identify the support workload before considering whether its assigned task can read a customer record. Failure to verify identity ends the request before resource authorization.
Common pitfalls
- Accepting a display name as proof.
- Treating successful sign-in as unrestricted permission.
Adding authentication at the front end leaves direct downstream endpoints exposed if they accept unauthenticated calls. Review each entry point rather than assuming one login screen covers the full workflow.
Questions for operational review
Use these questions to decide what evidence your team needs. They are editorial prompts, not a compliance checklist.
- Where is the actor verified?
- Which issuer is trusted?
- How is compromised evidence invalidated?
Articles linking here
References
Primary documents reviewed for this entry. Examples and implementation patterns are editorial synthesis.
- NIST CSRC: Authentication ↗Accessed October 11, 2026