Server.json

Learn about the server.json file that contains critical configuration data for your servers.

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Last updated 12 days ago

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The

server.json

file is a file that has variable data, such as the current allocation ID, for each server. It’s automatically generated and populated for each server based on the configuration variables and the server data. It has all the built-in configuration variables and any custom values from your build configuration variables. The

server.json

file exists within each server’s server ID directory. By default, it has all the built-in configuration variables, such as the allocation ID supplied by your matchmaker, and the connection port. But you can also add any number of configuration variables to track in the build configuration settings. Here’s an example of what a

server.json

file might look like when populated with the configuration variables from a server:


{	"ipv6": "::1",	"port": "9000",	"allocatedUUID": "1a04a1ac-a31a-11ed-a5e3-00155d4f1a62",	"serverID": "12345",	"machineID": "6789",	"fleetID": "c0a3e2a1-6955-415c-b1d4-af9199833e6a",	"regionID": "f15a6c27-de2a-4848-abc3-9579fbfd2259",	"regionName": "North America",	"queryPort": "9010",	"ip": "127.0.0.1",	"queryType": "sqp",	"serverLogDir": "/mnt/unity/logs/"}

allocatedUUID

The

allocatedUUID

variable is a special built-in configuration variable that changes each time a server is allocated or unallocated. When a server is allocated, the

allocatedUUID

field has the server’s allocation ID. When a server is unallocated, the

allocatedUUID

field has an empty string.

Note

Other configuration variables keep their value despite the server allocation status.

Here’s an example of a

server.json

file of an allocated server:


{	"ipv6": "::1",	"port": "9000",	"allocatedUUID": "1a04a1ac-a31a-11ed-a5e3-00155d4f1a62",	"serverID": "12345",	"machineID": "6789",	"fleetID": "c0a3e2a1-6955-415c-b1d4-af9199833e6a",	"regionID": "f15a6c27-de2a-4848-abc3-9579fbfd2259",	"regionName": "North America",	"queryPort": "9010",	"ip": "127.0.0.1",	"queryType": "sqp",	"serverLogDir": "/mnt/unity/logs/"}

Here’s an example of a

server.json

file of an unallocated server:


{	"ipv6": "::1",	"port": "9000",	"allocatedUUID": "",	"serverID": "12345",	"machineID": "6789",	"fleetID": "c0a3e2a1-6955-415c-b1d4-af9199833e6a",	"regionID": "f15a6c27-de2a-4848-abc3-9579fbfd2259",	"regionName": "North America",	"queryPort": "9010",	"ip": "127.0.0.1",	"queryType": "sqp",	"serverLogDir": "/mnt/unity/logs/"}

You can track the allocation ID of a server by monitoring the

server.json

for changes. To detect changes, set up an event trigger that detects file changes or a process to check the file for changes at a regular interval.

Note

The recommended best practice is to use the API to subscribe to game server lifecycle events (Unity Services Web API Docs), rather than monitoring for changes because the interval check causes unnecessary resource usage.

File location

The

server.json

file is available on disk in the following location:

For Linux, it's in the
```
$HOME
```
environment variable. For example
```
$HOME/server.json
```
.

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Server.json

allocatedUUID

File location