# Simplify APIs and trusted services communication

Bridge the gap between devices and services through secure, automated exchanges. Whether it's IoT or background processes, ensure the integrity of data.

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- [Read our docs](/content/docs/customize/actions/flows-and-triggers/machine-to-machine-flow/index.html)

## Forge trustworthy bridges for both internal and external APIs

Empower your APIs to communicate securely with non-interactive third-party applications. Keep it simple:

• Applications authenticate themselves to Auth0 via their Client Id and Client Secret.  
• Auth0 verifies the information and responds with an Access Token.  
• Armed with the Access Token, applications can confidently call the API.

## Go beyond human identities with IoT

When machines talk, make sure it's secure. Leverage the unique Identity of each IoT device for a streamlined, impenetrable communication setup.

## Seamless API onboarding for non-interactive apps

Integrate non-interactive applications like servers, CLIs, daemons, and more into your ecosystem. They might operate in the background, but their security takes the front seat.

## Scopes and granular permissions

Chart the course for every client's journey in your API landscape. Grant or restrict access based on granular permissions:

• Application Backends  
• Command line interfaces  
• Miscellaneous processes

## Security backed by standards

Sleep better knowing every byte of data exchanged adheres to globally accepted standards. Dive into the OAuth2 Client Credentials Grant flow, and witness security in motion.

## Frequently asked questions

### Can I limit the scope of M2M tokens in Auth0?

Yes, Auth0 allows you to define [coarse-grained scopes](/content/docs/get-started/apis/scopes/index.html) for every M2M client. Following the principle of least privilege, you can ensure a service only has access to the specific API endpoints it needs (e.g., 'read:reports'). This minimizes the potential impact of a compromised machine identity by limiting what it can do within your ecosystem.

### Does Auth0 support M2M for IoT devices?

Yes, Auth0 [M2M authentication](/content/docs/get-started/onboarding/self-service-m2m#use-cases/index.html) is ideal for securing IoT devices and sensors that need to communicate with back-end APIs. By treating each device as a secure client, Auth0 ensures that data transmitted from the field is authenticated at the source, preventing unauthorized data injection and protecting the integrity of your IoT network and data analytics.

### How does Auth0 manage M2M client secrets?

Auth0 manages M2M security by allowing developers to easily [rotate client secrets](/content/docs/get-started/applications/rotate-client-secret/index.html) and support asymmetric keys for [authentication](/content/platform/authentication/index.html). This allows security teams to maintain a high security posture without disrupting automated workflows. Auth0 also provides detailed audit logs for every M2M token request, ensuring full visibility into machine-level access and activity.

### What is Auth0 Machine-to-Machine (M2M) authentication?

Auth0 [Machine-to-Machine (M2M)](/content/docs/get-started/onboarding/self-service-m2m/index.html) authentication enables secure communication between non-human identities, such as back-end services, APIs, and CLI tools. By using the OAuth 2.0 Client Credentials flow, Auth0 issues secure, time-bound JWT tokens that allow automated systems to authorize with each other securely, eliminating the need for hard-coded passwords or long-lived secrets.

### Why is M2M security critical for microservices?

In a [microservices architecture](/content/docs/get-started/architecture-scenarios/server-application-api/index.html), M2M security ensures that service-to-service communication is verified and follows least-privilege principles. Auth0 prevents unauthorized lateral movement within your cloud infrastructure by requiring every internal request to present a valid, scoped token, ensuring that even if one service is compromised, the rest of your system remains protected.

### How else can a confidential M2M client authenticate?

[Client Secrets](/content/docs/secure/application-credentials#client-secret-authentication/index.html) are the default way, supported as a symmetrical authentication method. Two additional asymmetric authentication methods include: [Private Key JWT](/content/docs/get-started/authentication-and-authorization-flow/authenticate-with-private-key-jwt/index.html), use of a pair of public and private keys as credentials, and [mTLS for OAuth](/content/docs/get-started/authentication-and-authorization-flow/authenticate-with-mtls/index.html), leveraging a standard X.509 client certificate that is registered with Auth0 that is also paired with a corresponding private key.

## Ready to dive in?

Unlock the potential of seamless machine-to-machine communications.

- [Get started](/content/signup?place=header&type=button&text=sign%20up/index.html)

## Resources

- [Docs: Register Machine-to-Machine Applications](/content/docs/get-started/auth0-overview/create-applications/machine-to-machine-apps/index.html)
- [Developers: Developer Center](https://developer.auth0.com)
- [Community: Community Support](https://community.auth0.com)