Hosting VST3 & AudioUnit Plugins (hc_vstpipe)

If you’ve been making music on a Mac, you probably own plugins that homecrate can’t load. VST3 plugins in particular simply don’t run inside an iPad app, or inside the Mac version of that app — that’s a platform limitation, not a missing feature.

hc_vstpipe is the way around it. You run a small free companion app on a Mac; it loads the real plugin, in its own process, exactly the way a desktop DAW would. homecrate sends it that track’s audio, MIDI and transport position, and the processed audio comes back. In the DAW it behaves like any other plugin slot: you pick it, you pick a plugin inside it, its parameters show up, and the binding saves with your project.

It’s not an emulation or a re-implementation. It really is your plugin, running natively, with its own editor available on the Mac.

📖 Full reference: this page covers using hc_vstpipe inside the DAW. For the complete guide — every control, the connection modes, latency, and troubleshooting — see hc_vstpipe.

[SCREENSHOT: hc_vstpipe editor — green CONNECTED dot, endpoint and latency line, bound plugin name, parameter sliders]

Why It Works This Way

Three reasons, all of them structural:

Desktop plugin windows can’t be drawn inside the app. Nearly every VST3 draws its interface using Mac-desktop-only interface code, which the Mac version of homecrate has no way to put on screen.
The plugin-hosting code desktop DAWs rely on doesn’t build for this kind of app at all. It isn’t a matter of switching it on.
Loading unsigned third-party code would break the App Store sandbox. homecrate is a Mac App Store app, and running arbitrary plugin binaries inside it isn’t something a sandboxed app is allowed to do.

Splitting the hosting into a separate app solves all three at once, and it has a real bonus: a plugin that crashes takes down the companion, not your session.

What You Need

Requirement	Detail
A Mac	Apple Silicon only. The companion is built for arm64 and there is no Intel version. macOS 12 or later.
The companion app	homecrate VST Pipe, free, from homecrate.app
Your plugins	VST3 or AudioUnit plugins already installed on that Mac
homecrate	Running on the same Mac, or on an iPad/iPhone that can reach that Mac over the network

The companion is not on the Mac App Store — it can’t be, because loading third-party plugin code is exactly what App Store sandboxing forbids. Download it from homecrate.app. It’s signed with a Developer ID and notarized by Apple, so it opens normally without any security workarounds, and it updates itself.

The companion is currently early software (version 0.1.0). It works, but expect it to change more often than the app does.

Setting Up

On the same Mac — nothing to configure

If homecrate and the companion are running on the same Mac, there is no setup. The plugin looks for the companion locally by default, so:

Launch homecrate VST Pipe.
Let it scan your plugins (first scan takes a while; after that it’s cached).
Load hc_vstpipe on a track in homecrate.

The status dot goes green and reads CONNECTED. No pairing, no addresses, no settings.

iPad or iPhone to a Mac — pair with a QR code

When homecrate is on a different device from the companion, you need to tell it where to look. That’s what pairing is for.

Make sure both devices are on the same network.
Launch homecrate VST Pipe on the Mac and open its pairing QR code.
In homecrate, load hc_vstpipe on a track and open its editor.
Tap the PAIR chip. homecrate opens a camera scanner.
Point it at the Mac’s QR code.

The plugin reconnects to the Mac by itself within a couple of seconds. You only do this once — the address is remembered, and every hc_vstpipe instance in every project uses it.

The pairing scanner is video only. It never touches the audio input, so pairing can’t disturb monitoring or an armed track.

If you’d rather type an address than scan one, the scanner also accepts a plain host:port string.

[SCREENSHOT: QR pairing — companion app showing its code, iPad scanner overlay]

Going back to local

If you paired to a remote Mac and later want the plugin to use the companion on this machine again, tap the LOCAL chip in the editor. It resets the address back to the default.

Using It as an Effect

This is the ordinary case: a compressor, EQ, reverb, saturator or amp sim on an audio track.

Open a plugin slot on the track and load homecrate: hc_vstpipe.
Open its editor.
Pick your plugin from the list.

Audio from that track now runs through the plugin on the Mac and comes back processed. Everything else about the slot behaves normally — it sits in the chain in slot order, and it’s included in mixdowns and exports. See AUv3 Plugins Overview for how slots are ordered.

Mono plugins keep your stereo chain intact. If the plugin you pick only handles one channel, the companion runs two linked copies — one per side — and keeps their parameters locked together. You don’t have to do anything; a mono plugin simply won’t collapse your stereo image.

Using It as an Instrument

hc_vstpipe can also host a VST instrument driven by a MIDI track. Because it can receive MIDI as well as audio, it shows up in the instrument picker on MIDI tracks alongside homecrate’s own instruments.

Create a MIDI track — see MIDI Tracks Overview.
Set its instrument to homecrate: hc_vstpipe.
Open the editor and bind a VST instrument.

Notes and controller messages from the piano roll route through to the plugin on the Mac, and its audio comes back on that track.

The project’s tempo and transport position travel with it, so tempo-synced arpeggiators, delays and LFOs inside the hosted plugin lock to your song rather than free-running.

The Plugin Picker

Tap CHANGE to open the browser (it’s open by default until you bind something, then it collapses to keep parameters front and centre).

Control	What it does
Search field	Filters by plugin name or manufacturer
A–Z rail	Jump to a letter down the right edge of the list
Format bar	Filter by plugin format, when you have more than one
RESCAN	Re-scan the Mac for newly installed plugins
CHANGE / HIDE	Show or collapse the browser once a plugin is bound
EDIT	Opens the plugin’s own native editor on the Mac

If the list is empty, scan in the companion app or tap RESCAN.

The scanner is protected against bad plugins: if one crashes the scan, it gets blacklisted so it can’t crash the scan again on the next attempt. A single misbehaving plugin can’t lock you out of the rest of your library.

[SCREENSHOT: Plugin picker — search field, format filter bar, A–Z sectioned plugin list]

Parameters and Automation

Once a plugin is bound, its parameters appear in the PARAMETERS section of the editor as sliders, with a count next to the heading.

The companion is the authority on parameter values, since it owns the actual plugin. That has a useful consequence: if you tweak a knob in the plugin’s native editor on the Mac, homecrate picks the change up within a couple of seconds and the sliders catch up on their own. You can work in whichever editor you prefer.

Those same parameters also appear as automation targets in the clip editors, so you can draw automation on a hosted VST’s parameters the same way you would on a first-party plugin. Dense automation is safe: homecrate paces the updates it sends to the companion, and always makes sure the final value of a move lands.

If the parameter list is empty and the plugin definitely has controls, update the companion app to the current version.

Saving With Your Project

Everything about the binding persists:

The plugin you chose and its parameter values save into your homecrate project, and replay automatically when you reopen it.
The companion also remembers the binding on its side, so if you quit and reopen the companion, the same plugin comes back on the same slot.

You can quit the companion, restart the Mac, or come back to a project a month later and pick up where you left off.

Connection behaviour

The connection looks after itself. If the companion isn’t running, or the network drops, or you put the iPad down for a while, the plugin keeps retrying in the background — backing off gently rather than hammering — and rebinds your plugin as soon as it gets through. It also survives stopping and starting the transport. There’s a RETRY chip in the editor if you want to force an immediate attempt.

Latency and Connection Quality

The editor shows the current address and the current latency on one line, next to the status dot.

Same Mac — the audio never goes over the network at all, so there’s effectively no added delay. In practice this feels the same as a plugin hosted inside the DAW, and there’s nothing to configure.
Over a network — sending audio to another machine and back takes time, so there’s a small unavoidable delay that depends on your Wi-Fi. It’s very usable for mixing and for playing parts in; it is not going to match a wired desktop setup.

For remote connections a UDP / TCP chip appears. UDP is the default — try it first. If the connection is unstable, switch to TCP and see whether it settles; use whichever behaves better on your network. If neither is stable, the problem is the network itself.

Known Limitations

Worth knowing before you plan a session around this.

No USB cable connection. You cannot connect an iPad or iPhone to the Mac with a cable and use it as the audio path. The connection is either the same machine, or over the network — there is no cable option, and it isn’t something you’ve set up wrongly. If your Wi-Fi is poor, the answer is a better network, not a cable.
Apple Silicon Macs only. There’s no Intel build of the companion, and none is planned.
Parameter automation on macOS isn’t fully verified yet. Automating a hosted plugin’s parameters is expected to work when homecrate is running on the Mac itself, but it hasn’t been confirmed on that platform the way it has elsewhere. If you’re relying on it, test your session first. On iPad and iPhone it’s verified.
Stereo in, stereo out. Each hc_vstpipe instance runs as a stereo insert (or stereo instrument). There’s no mono-insert mode, no MIDI-effect mode, and no way to record on the companion side.
The companion is early. Version 0.1.0. It updates itself from homecrate.app, so keep it current — several rough edges get fixed there rather than in the app.

Tips

If both can run on the Mac, do that. The same-machine path is dramatically lower latency than any network path, and it needs no setup at all.
Let the companion finish its first plugin scan before you go looking for plugins. It’s slow once and instant afterwards.
Use EDIT to open the plugin’s real editor on the Mac for detailed dialling in, then use homecrate’s sliders for the handful of parameters you actually want to automate.
Bind the plugin before you start drawing automation — the automation targets are built from whatever plugin is currently bound, so switching plugins changes the available targets.
Instruments and effects both work, but a CPU-heavy instrument is the best argument for the same-Mac setup — you get desktop-class processing without it costing your iPad anything.
If the status dot is orange, check the companion is actually running before you go near network settings. That’s the usual answer.
Keep an eye on the latency readout when working over Wi-Fi. If it climbs, try the other connection mode with the UDP / TCP chip, or move closer to the router.