This document describes the Pi-KVM API. Since the system consists of microservices, here is a common API with a common entry point provided by Nginx. The examples above use `curl` and [`websocat`](https://github.com/vi/websocat) with the `-k` parameter to disable SSL certificate verification, since the self-signed certificateis used in the default installation.
Most of the data during the user's work with pikvm is transmitted over a web socket. This includes mouse events, keyboard input, change the state of the various subsystems (such as ATX and Mass Storage Drive). Each event type will be described in the corresponding paragraph for its component. When connecting via a web socket, the client receives current states as separate events. Then, as the states change, it will receive new events.
In a normal situation, opening a socket session triggers the video streamer to start. The streamer works as long as there is at least one client connected via a web socket. After the last connection is closed and the client timeout expires, the streamer will also be terminated.
It is possible create a session that will not start the streamer and will not be counted when counting clients to stop the streamer. To do this, use the URL parameter `stream=0`:
After connecting the client receives a bundle of states of all KVMD subsystems. After the batch is completed, it sends a `loop` event, which means that the websocket has entered event loop mode. Now it will send new states and respond to client's requests.
Another type of event is `ping`, which can be sent by the client: `{"event_type": "ping", "event": {}}`. If the server is running, it will respond with pong: `{"event_type": "pong", "event": {}}`.
## System info: `/api/info`
On `GET` this handle will return general information about the Pi-KVM device. If you specify the `fields` query parameter, only the requested category will be selected, like `fields=system,hw`. By default all categories will be displayed:
"extras": { // Installed applications; null on internal error
"ipmi": {
"daemon": "kvmd-ipmi",
"description": "Show IPMI information",
"enabled": true,
"icon": "share/svg/ipmi.svg",
"keyboard_cap": false,
"name": "IPMI",
"path": "ipmi",
"place": 21,
"port": 623
},
"vnc": {
"daemon": "kvmd-vnc",
"description": "Show VNC information",
"enabled": true,
"icon": "share/svg/vnc.svg",
"keyboard_cap": false,
"name": "VNC",
"path": "vnc",
"place": 20,
"port": 5900
}
},
"hw": { // Hardware info
"health": {
"temp": {
"cpu": 36.511, // /sys/class/thermal/thermal_zone0/temp / 1000; null on error
"gpu": 35.0 // vcgencmd measure_temp; null on error
},
"throttling": { // vcgencmd get_throttled; null on error
"parsed_flags": {
"freq_capped": {
"now": false,
"past": false
},
"throttled": {
"now": false,
"past": false
},
"undervoltage": {
"now": false,
"past": false
}
},
"raw_flags": 0
}
},
"platform": {
"base": "Raspberry Pi 4 Model B Rev 1.1", // /proc/device-tree/model; null on error
"type": "rpi"
}
},
"meta": { // /etc/kvmd/meta.yaml; null on error
"kvm": {},
"server": {
"host": "localhost.localdomain"
}
},
"system": {
"kernel": {
"machine": "x86_64",
"release": "5.8.14-arch1-1",
"system": "Linux",
"version": "#1 SMP PREEMPT Wed, 07 Oct 2020 23:59:46 +0000"
},
"kvmd": {
"version": "2.1"
},
"streamer": {
"app": "ustreamer",
"features": { // {} on error
"HAS_PDEATHSIG": true,
"WITH_GPIO": false,
"WITH_OMX": false,
"WITH_PTHREAD_NP": true,
"WITH_SETPROCTITLE": true
},
"version": "2.1" // "" on error
}
}
}
}
```
</details>
Each category is represented by its own event in the websocket (`info_hw_state`, `info_system_state`, etc). The event content has the same format as the category content in API.
## System log: `/api/log`
On `GET` this handle will display messages from all KVMD services as plain text. The `follow=1` request parameter turns the request into an infinite one and you will receive new log messages in real time. The seek parameter runs the log for the specified time in seconds. For example, `seek=3600` will show the log for the last hour. Both the `seek` and `follow` parameters can be used together.
