> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cc-software/configure/interface-options/facility-management-interfaces/event-sync.md). # Event sync Synchronize selected events between Command Centre servers. > 📋 **Prerequisites:** Run [Cardholder Sync](/knowledge-hub/products/cc-software/configure/interface-options/facility-management-interfaces/cardholder-sync.md) first. Event Sync depends on it. The Event Sync utility replicates **Events** from a Source server to a Destination server, so one server sees another's events as well as its own. It is for shared and multi-tenant buildings. * **Dependency:** the Destination server needs a Cardholder to associate each event with, so **Cardholder Sync must run first** to duplicate all Source cardholders on the Destination. Location-change events, such as Door Access Granted, can update the correlated cardholder's location (moved into the mapped Access Zone). * Source and Destination cardholders are linked by a **unique Personal Data Field (PDF)** value, created on both servers during Cardholder Sync configuration. * Event Sync synchronises **only the events specified in `EventSyncConfig.json`**. **Worked example:** "Big Buildings Inc." (the base building) and "Computer Life" (a 2nd-floor office) each run a server. Cardholder Sync from Computer Life to Big Buildings puts Computer Life cardholders on the base-building server, so they can access its doors and raise events there. Event Sync from Big Buildings to Computer Life replicates those access events back to Computer Life for monitoring. Supported on **v8.70+**. *** 🔗 **Related** * [Cardholder Sync](/knowledge-hub/products/cc-software/configure/interface-options/facility-management-interfaces/cardholder-sync.md). The required first step. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://help.security.gallagher.com/knowledge-hub/products/cc-software/configure/interface-options/facility-management-interfaces/event-sync.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.