← Back to glossaryGlossary

Machine-to-Machine (M2M) Authentication

Reviewed 19 July 2026Canonical definitionPart of: Agent Identity & Access Terms →

Machine-to-machine authentication is how one service or agent proves its identity to another without a human login. Common methods include client credentials, mutual TLS, and signed tokens.

§01 / QUESTIONSterm: Machine-to-Machine (M2M) Authentication
Questions

Common questions.

What is Machine-to-Machine (M2M) Authentication?

Machine-to-machine authentication is how one service or agent proves its identity to another without a human login.

How is Machine-to-Machine (M2M) Authentication used in production?

Common methods include client credentials, mutual TLS, and signed tokens.

Which terms are related to Machine-to-Machine (M2M) Authentication?

Closely related concepts include Machine Identity, Workload Identity, Non-Human Identity (NHI), SPIFFE (Secure Production Identity Framework for Everyone). Each is defined in the Prefactor glossary.

§02 / RELATEDnext: where this fits
Keep reading

Where this fits.

See how every agent performs, and make it better

Prefactor helps teams observe, evaluate, and improve their AI agents in production, across every framework and provider.