Indexed parameters

The Proxmox VE API has parameters that exist once per device: net0, net1, scsi0, scsi1, ipconfig0. The value of each is the configuration string that Proxmox VE expects.

In the generated methods each family is one argument, named with an N at the end: an object with the index as key and the string as value, { 0: "...", 1: "..." }. These arguments belong to the methods with about a hundred parameters (createVm, updateVm), so in practice they are sent with a raw call, where the names are those of the API:

const result = await client.set("/nodes/pve01/qemu/100/config", {
  net0: "model=virtio,bridge=vmbr0,firewall=1",
  net1: "model=virtio,bridge=vmbr1,tag=100",
});

With the devices already in an object by index, client.addIndexedParameter adds them to the parameters under those names:

const networks = {
  0: "model=virtio,bridge=vmbr0,firewall=1",   // net0
  1: "model=virtio,bridge=vmbr1,tag=100",      // net1
};

const parameters = {};
client.addIndexedParameter(parameters, "net", networks);

const result = await client.set("/nodes/pve01/qemu/100/config", parameters);

Only the indexes you send change: the calls above leave net2 as it is. The value of an index replaces the whole device: when you change an existing network device keep its macaddr, or Proxmox VE generates a new one. The most used families:

Family	Sent as	For
`netN`	`net0`, `net1`, …	Network devices of VMs and containers
`scsiN`, `virtioN`, `sataN`, `ideN`	`scsi0`, `virtio0`, …	Disks and CD-ROM drives of VMs
`ipconfigN`	`ipconfig0`, …	Cloud-init IP configuration of VMs
`hostpciN`, `usbN`	`hostpci0`, `usb0`, …	Passthrough of host devices
`mpN`	`mp0`, `mp1`, …	Mount points of containers

The format of each value is in the description of the parameter in the API viewer, and in the pages of the Proxmox VE administration guide linked below. The client does not check the string: Proxmox VE does, and a wrong one gives status 400 with the reason in error.

Network of a VM

model=<model>,bridge=<bridge> followed by options, as described in Network Device.

Option	Meaning	Example
`model`	Emulated card	`virtio`, `e1000`, `vmxnet3`
`bridge`	Bridge of the node to attach to	`vmbr0`
`tag`	VLAN tag	`tag=100`
`firewall`	Apply the Proxmox VE firewall	`firewall=1`
`macaddr`	MAC address, generated when left out	`macaddr=BC:24:11:00:00:01`
`rate`	Rate limit in MB/s	`rate=100`
`mtu`	MTU, `virtio` only	`mtu=9000`
`queues`	Multiqueue, `virtio` only	`queues=4`
`link_down`	Create the device disconnected	`link_down=1`

Disks of a VM

To create a new disk give the storage and the size in GiB: <storage>:<size>. To attach an existing volume give its id: <storage>:<volume>. Options follow, as described in Hard Disk.

// POST: allocating a disk runs as a task
const result = await client.create("/nodes/pve01/qemu/100/config", {
  scsi0: "local-lvm:32,discard=on,iothread=1",      // new 32 GiB disk
  scsi1: "local-lvm:100,backup=0",                  // new 100 GiB disk, left out of backups
  ide2: "local:iso/debian-13.1.0-amd64-netinst.iso,media=cdrom",
});

The configuration of a VM has two endpoints: PUT (client.set) applies the change and returns nothing, POST (client.create) returns a task, which is what you need when the change allocates a disk.

Bus	Indexes	Notes
`scsiN`	0 to 30	The usual choice, with `scsihw` set to `virtio-scsi-single`
`virtioN`	0 to 15	VirtIO block
`sataN`	0 to 5
`ideN`	0 to 3	Mostly CD-ROM drives

Option	Meaning	Values
`cache`	Cache mode	`none`, `writethrough`, `writeback`, `directsync`, `unsafe`
`discard`	Pass TRIM to the storage	`on`, `ignore`
`iothread`	Dedicated I/O thread	`0`, `1`
`ssd`	Present the disk as SSD	`0`, `1`
`backup`	Include the disk in backups	`0`, `1`
`media`	Kind of drive	`disk`, `cdrom`

The EFI disk and the TPM state exist only once, so they are plain parameters, efidisk0 and tpmstate0:

const result = await client.create("/nodes/pve01/qemu/100/config", {
  bios: "ovmf",
  efidisk0: "local-lvm:1,efitype=4m,pre-enrolled-keys=1",
});

Cloud-init

ipconfigN configures the network device with the same index: ipconfig0 is for net0. See Cloud-Init Support.

const result = await client.set("/nodes/pve01/qemu/100/config", {
  ciuser: "admin",
  sshkeys: encodeURIComponent(publicKey),
  ipconfig0: "ip=192.168.1.100/24,gw=192.168.1.1",   // static
  ipconfig1: "ip=dhcp",                              // DHCP
});

The API wants sshkeys URL-encoded, with spaces as %20: encode it yourself, as above.

Containers

Containers use the same pattern with their own formats: netN carries name, bridge and addresses, mpN a volume and its path in the container.

const result = await client.set("/nodes/pve01/lxc/200/config", {
  net0: "name=eth0,bridge=vmbr0,ip=dhcp",
  mp0: "local-lvm:8,mp=/var/lib/data",   // new 8 GiB volume mounted at /var/lib/data
});

A complete VM, from nothing to started, is in Create a VM.