Web API (Pi)

The Pi’s web page is a client of a small HTTP API on port 80. The same API is open to your own tools. There is no authentication: use it on a direct cable or a trusted network. At most 4 connections are served at once; more get 503 busy with Retry-After: 1 and are counted.

GET /status

JSON with the engine’s state: host name, IP, uptime, the link, the USB-C gadget mode, computer audio, the Overbridge stream, whether the Rytm’s USB MIDI is attached, temperature, out, notes, the FIFO target, underruns, the display (screensaver, brightness, display, blank), Wi-Fi (mode, connected, networks, …), the recorder (rec: state, take, channels, frames, drops, card speed, free space, peaks), the page’s own cost (web.maxus, web.refused), the voices’ machines (machines), the send FX (fx: type, post, the 12 sends), the version (version, commit, dirty, build), the display’s touch test (touchtest), the drone, the IN L/R source (fxin), the LFOs (lfo: every LFO’s settings and phase) and core 0’s load.

The page polls it once a second and keeps one request open at a time. Do the same.

GET /log?since=N

The console log from byte N of a 64 KB ring. The first line is START END, then the bytes; poll again with since=END.

POST /cmd

c=<command> in a form body (or as a URL parameter, except wifi= commands, which are taken only from a POST body): any console command, exactly as on the serial console (without the leading :). A request whose Origin or Referer is another site is refused (400). The answer is the text ok. Examples:

Command
notes=1, out=main	MIDI notes, output mode
notemach=0:plaits	voice 0’s machine for MIDI notes
sendfx, sendfx=1:chorus, killfx	show or override the send FX; fade the tails
rec=start, rec=stop, rec=arm, rec=ch:in,voices, rec=bits:16, rec=name:PREFIX	the recorder
um, um=rescan, um=assign:1:sc.acid, um=clear:1, um=empty, um=save:<slot>:<name>, um=presets	user machines (save a preset of what the slot plays now; rescan the preset lists)
lfo, lfo=N:KEY:VALUE	the LFOs
fxin=1|0|?	the IN L/R source
screensaver=60, brightness=80	the display
wifi, wifi=scan	Wi-Fi

The watchdog test is refused from the web.

Wi-Fi: /wifi/*

Request
GET /wifi/status	mode, chip, on, the network in use (ethernet / wifi), the address, the stored network’s name (the only answer with a network name), the last scan’s networks, the join’s state and reason
GET /wifi/scan	start a scan (refused while Wi-Fi is off or a join is tried)
POST /wifi/join	ssid=, psk=, open=1 in the form body (never the URL): store it and restart the Pi to try it; the previous setting comes back after 90 s without a connection
POST /wifi/forget, POST /wifi/power (on=0|1)	forget the stored network; Wi-Fi on or off

The POST requests are accepted only from the page itself (same origin) and answer JSON: {"ok":true} or {"ok":false,"code":N,"error":"..."}.

GET /lists

The project’s sample pool and its JUNO and FM lists as JSON (the Pool & presets tab).

Files: /fs/*

Request
GET /fs/ls?path=	a folder listing; boot files are marked "ro":1, the kept folders "ro":2
GET /fs/get?path=&off=&len=	a file, in ranges (the page uses 64 KB)
POST /fs/put?path=&off=&total=&crc=	one chunk (multipart, one part). The file is written to <path>.part, checked as it goes, and moved into place only when the last chunk’s CRC-32 matches the client’s. 409 expected N means resume from offset N
POST /fs/del?path=	delete a file or an empty folder
POST /fs/mkdir?path=[&p=1]	make a folder (p=1: every missing folder on the way)
POST /fs/mv?path=&to=	rename

Every /fs/* POST answers HTTP 200 with the text <code> <message>. Boot files are never written, deleted or renamed; /.rytm, /Samples and /Plugins are never deleted or renamed. A package uploaded into /Plugins is checked (header, size, CRC, API version, target) before it goes in place.

GET /um

The user machines as an array of JSON objects, shared in shape with the Teensy console:

{"t":"plugin","id","ver","size","api","image","bss","state","cpu","ns","blocks","name","slots":[..],"fit","why","file","target","fp","status"}
{"t":"slot","slot":1..5,"id","ver","state","name","fp","ns","blocks","src","updated","collision","unknown","want_fp","want_name","mixed","want_n","want_id","want_ver","presets","pre_ok","pre_ext",...}
{"t":"plugins","n","project","arena":[size,used],"state_limit","block_ns","gen","scanning","prints","resolves","fresh","listed","dir"}
{"t":"mem","k":"code|data|state","size","used"} ... {"t":"mem_end"}, then on the Pi {"t":"mem","k":"sd",...}

ns / block_ns is the share of one render core a voice of that machine uses.

The slot list file

Export and import use {"format":"sidecar-slots","version":1,"project":"NAME","slots":[{"slot":1,"id","ver","name","fp"}, {"slot":5,"empty":true}]}. Slots the file does not name are left alone.