DEX Architecture

  • Release version: Zurich
  • Updated August 10, 2026
  • 4 minutes to read
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    Summary of DEX Architecture

    Digital End-User Experience (DEX) architecture in the Zurich release provides a seamless, integrated digital experience for end users by leveraging multi-tenant, cloud-native ServiceNow shared services. This architecture removes the need for a MID Server by enabling direct, secure bi-directional communication between DEX endpoint agents and your ServiceNow instance. It supports authentication, message buffering, stateful stream processing, policy updates, and on-demand execution of checks on DEX agents.

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    Key Components and Functionality

    • Agent Client Collector (ACC): Installed on end-user devices (laptops, VDIs), ACC collects device and application performance metrics, supports configurable policy frequencies for data collection, and can perform remedial actions such as clearing cache or restarting apps.
    • Browser Extension: Tracks application performance and network metrics like page load times and network jitter, communicating securely with ACC and routing data through ServiceNow shared services.
    • DEX Desktop Assistant: Integrates ServiceNow functionalities into users’ workflows, allowing access to local application monitoring, requests, push notifications, and network tests.

    Agent Registration and Communication

    After installation, ACC registers with your ServiceNow instance, downloads necessary certificates, and establishes a secure, encrypted gRPC connection (using mutual TLS) with the ServiceNow shared services. This channel enables secure transmission of performance metrics to your instance and receipt of policies and commands from the instance. Data isolation is maintained using the Hermes Messaging Service and Stream Connect, ensuring organizational data is segregated within shared service clusters.

    Security and Data Management

    • Data Security: Includes an allow list to restrict executable commands, certificate signing of plugins for integrity, role-based access control for actions, and comprehensive auditing of remedial actions.
    • Data Isolation: Uses client certificates tied to your ServiceNow instance to isolate data securely within shared services, with strong encryption via elliptic curve cryptography.
    • Data Access: Collected DEX data is visible only to users with appropriate DEX roles, aligning with standard ServiceNow data governance practices.
    • Data Retention: Raw device metrics are stored for up to seven days, while aggregated metrics used for trend analysis are retained longer. Hermes Messaging Service retains data for 36 hours; other shared services do not persist metric data in transit.

    Practical Benefits for ServiceNow Customers

    This architecture enables customers to efficiently monitor and remediate end-user device and application performance without additional infrastructure like MID Servers. It ensures secure, reliable data flow and strict data isolation, supporting compliance and operational visibility. Customers can expect streamlined policy management, real-time metric collection, and integration of digital experience monitoring into daily workflows while maintaining control over data access and retention.

    Digital End-User Experience (DEX) architecture provides a seamless and integrated digital experience for end users.

    DEX uses a set of new multi-tenant, cloud-native services called ServiceNow shared services. In this architecture, DEX endpoint agents are able to communicate with the ServiceNow shared services without a MID Server. ServiceNow shared services provide authentication to DEX agents and enable message buffering and stateful stream processing of data sent to your ServiceNow instance and a time series datastore. ServiceNow shared services also enable a secure way to send policy updates and on-demand execution of checks on the DEX agents. Thus, ServiceNow shared services enable secure bi-directional communication between your ServiceNow instance and the DEX endpoint agents.

    Figure 1. DEX architectural diagram
    High-level architectural diagram of Digital End-User Experience.

    Binaries installed on endpoints

    • Agent Client Collector (ACC): Deployed onto the end-user device endpoints such as a laptop or Virtual Desktop infrastructure (VDI) to collect various device level performance and operational metrics. ACC enables you to do the following:
      • Configure a policy frequency to control what metrics are collected and the frequency of collection. To learn more about the metrics collected by DEX, see View collected metrics with Metrics analyzer.
      • Get the agent run remedial actions on the endpoint, such as clearing cache, restarting an application, and many more.
    • Browser extension: Helps track application performance and network metrics like page load time and network jitter. The communication between the browser extension and ACC, as well as the device and application metrics, are routed via the ServiceNow shared services. For more information, see Enable DEX browser extension.
    • DEX Desktop Assistant: Enables employees to incorporate ServiceNow functionalities into their daily workflow, providing access to monitoring local applications, requests, and push notifications and to performing network tests.

    Agent registration highlights

    • After the installation, ACC is registered on your organization's ServiceNow instance and the required certificates are downloaded from the instance. All the communication between ACC and your instance happens over secured HTTPS.
    • After the ACC registration, a connection with the ServiceNow shared services is established. The agent is authenticated with the shared services via the downloaded certificates.
    • ACC opens a bi-directional communication with the ServiceNow shared services using gRPC Remote Procedure Calls (gRPC) connection. gRPC connection is a secure and encrypted channel to send and receive data from the endpoints. The channel is secured via mutual Transport Layer Security (mTLS).
    • ACC sends various devices and application performance metrics to the shared services.
    • The instance also pushes data, such as DEX policies, to the agent via this bi-directional channel.
    • The ServiceNow shared services use the ServiceNow Hermes Messaging Service and Stream Connect to isolate your organization’s data.

      For more information, see Hermes and Stream Connect.

    • Raw metrics collected from endpoints are processed further using the shared services and eventually pushed to your ServiceNow instance.
    • In addition, some of the configuration device metrics and agent heartbeats are directly pushed to the ServiceNow instance. The operation is performed over a secured HTTPS channel via a REST endpoint.

    Data security

    There are various security measures to promote that the scripts are run securely.

    • Allow list: File shipped along with the agent verifying that no command other than the ones in the allow lists can be executed.

      For more information on the list, see Generate an Agent Client Collector allow list.

    • Plugins certificate signing: The scripts are packaged in plugins which are deployed to the endpoint. To promote data integrity, the plugins can be signed by a certificate so that there are no malicious plugins deployed.

      For more information on certificate signing, see Secure a custom plugin with a certificate.

    • Role-based access: All actions are available to only specific roles and user criteria within ServiceNow. For example, advanced actions can be assigned to the DEX engineer role and basic actions to the Service Desk.

      For more information, see Configure the Remedial Actions Framework.

    • Audit: All action runs are audited in the Remedial Action Executions table (ssn_reacf_remedial_action_execution).

      For information about emergency plans (such as notification and restore the service), see DEX subscription.

    Data isolation

    Your data is stored in a separate topic when the Hermes Messaging Service and Stream Connect persist in the file system while data is sent and received.

    The agent client certificate issued by your ServiceNow instance holds the instance name for your organization. After the agent is authenticated, the instance name from the agent certificate is used to keep data isolated within a shared services cluster.

    mTLS is used for a secure communication between the agent and server components. The agent authenticates itself using a client certificate with the following parameters:
    • Public Key Algorithm: id-ecPublicKey (ECDSA)
    • Key Size: 256-bit
    • Elliptic Curve: NIST Curve P-256

    The setup promotes strong encryption and efficient key exchange using elliptic curve cryptography.

    Agent assets and plugins (like DEX) that are downloaded from your ServiceNow instance through the shared services are signed by ServiceNow or the asset owners during their release. Signing promotes the authentication and integrity of the agent's asset or plugin to the agent.

    Data access

    All collected data is transformed and presented on your ServiceNow instance.

    Any data collected in the context of DEX is visible to users only with appropriate DEX roles. For more information about the DEX roles, see Installed with DEX.

    When following the standard ServiceNow practices on data governance, no special handling is required for DEX.

    Data retention

    All the raw metrics collected from devices are stored in the ServiceNow instance for a maximum of seven days. Aggregated metrics are stored for a longer duration based on the type of aggregation. Aggregation metrics are used to show trend lines for various metrics. Hermes Messaging Service stores data for 36 hours by default. No other ServiceNow shared services store any metric data in transit.