Ubios-udapi-server
Because it is central to the device's operation, it often appears in system logs ( /var/log/messages ) when issues arise.
To put it simply, is a local microservice running on your UniFi OS console. It acts as a middleware layer that translates high-level API calls into actionable commands for the underlying UniFi Network Application.
For advanced users using SSH access, the state of the server can be inspected in /config/ubios-udapi-server/ubios-udapi-server.state . While manually stopping or modifying this service is generally discouraged—as it can "break" the router's ability to process traffic—it is a primary point of investigation for the Ubiquiti Community and support teams when diagnosing persistent connectivity "ghosts".
: It offers a single, standardized API layer across diverse hardware formats. ubios-udapi-server
| Feature | Cloud API | Local ubios-udapi-server | | :--- | :--- | :--- | | | High (150-300ms) | Very Low (<10ms) | | Internet Dependency | Required | Not required (works offline) | | Rate Limits | Strict (120 req/min) | Configurable / None (hardware limited) | | Data Granularity | Aggregated | Raw, per-packet telemetry | | Use Case | Remote monitoring | Real-time automation & local integration |
Most users never SSH into their UDM-Pro. That’s fine. But if any of the following describe you, learning the ubios-udapi-server will change your workflow:
Whenever you alter a setting in the UniFi Site Manager —such as adding a VLAN, mapping an IP address, or toggling threat management—the UI does not talk directly to Linux configuration files. Instead, it pushes a JSON configuration state to ubios-udapi-server . The daemon processes this input and configures underlying system programs like udhcpc (DHCP client), nftables (firewall), and dnsmasq (DNS). Core System Responsibilities Because it is central to the device's operation,
Look for active (running) .
Exposes REST-like APIs over HTTP/HTTPS (usually port 443) for:
Many community tools (e.g., unifi-os scripts, custom dashboards) rely on ubios-udapi-server because it’s consistent across firmware versions. For advanced users using SSH access, the state
Because the ubios-udapi-server.state file represents the entire system configuration, it can be monitored for changes. In a GitHub issue discussion, a user mentioned thinking of monitoring this file to trigger scripts when a configuration change was detected. This could allow administrators to build automation that reacts to any network or device setting change in real-time.
This central role makes it indispensable for understanding how your UDM works. When you change a setting in the UI, you can be sure the ubios-udapi-server is the process translating that change into reality.
Click . Give it a name (e.g., Home_Assistant ). Copy the key immediately—you will not see it again. Treat this like a password.
When you click "Apply Changes" in the UniFi Network Controller dashboard, the application does not write directly to Linux configuration files. Instead, it sends structured JSON or Protocol Buffer payloads to ubios-udapi-server . The daemon processes these requests and configures the OS kernel in real-time. Core Responsibilities and Functions
Users attempting to rotate their external WAN public IP address sometimes find that the server continuously appends a -r flag to udhcpc commands. This forces the router to request its previously assigned IP address from the ISP.