CLAP & VST3 distribution

VXN1 currently ships CLAP only. VST3 via clap-wrapper is the committed distribution path (ADR 0008), but the wrapper integration has not yet landed in xtask and there is no vendor/clap-wrapper submodule in the workspace. Treat the VST3 section below as the target state, not the current build.

CLAP build

vxn-clap is a cdylib linking vxn-engine, vxn-app, and vxn-ui-web. Built via cargo build --release, the resulting libvxn_clap.{dylib,so,dll} is packaged into a VXN1.clap bundle by xtask.

Bundle structure (macOS):

VXN1.clap/
└── Contents/
    ├── Info.plist
    ├── MacOS/
    │   └── VXN1
    └── PkgInfo

Windows and Linux ship the cdylib as a flat VXN1.clap file with no bundle wrapper.

VST3 build (planned, not yet shipping)

The committed plan (ADR 0008) is for xtask to invoke a vendored clap-wrapper build via CMake, with vendor/clap-wrapper and vendor/vst3sdk (pinned to VST3 3.8 — MIT-licensed since October 2025) as workspace submodules. The build will produce a single-binary bundled VST3 with the CLAP cdylib statically linked.

Planned requirements:

CMake ≥ 3.21.
A C++17 compiler (clang, MSVC, GCC).

Planned xtask invocations (none of these flags are accepted today):

# VST3 only (planned)
cargo xtask bundle --release --format vst3

# Both formats in one shot (planned)
cargo xtask bundle --release --format clap,vst3

# macOS universal binary (planned)
cargo xtask bundle --release --universal --format vst3

For the actual shipping CLAP build, see Installing VXN1.

Install locations

OS	CLAP (shipping)	VST3 (planned)
macOS	`~/Library/Audio/Plug-Ins/CLAP/VXN1.clap`	`~/Library/Audio/Plug-Ins/VST3/VXN1.vst3`
Windows	`%LOCALAPPDATA%\Programs\Common\CLAP\VXN1.clap`	`%LOCALAPPDATA%\Programs\Common\VST3\VXN1.vst3`
Linux	`~/.clap/VXN1.clap`	not planned for the first VST3 cut

Bundle identifier: labs.vulpus.vxn1.

Parameter identity

VST3 parameter IDs are derived from CLAP parameter IDs by hashing. The implication:

Renaming a CLAP parameter ID breaks VST3 automation in saved projects.

ADR 0008 commits to a soft stability policy: CLAP IDs won’t be renamed post-ship, except when called out in release notes. Pre-release, IDs are free to change.

If you’re writing host-side integrations against the VST3 binary, you can rely on stable hashed IDs from release to release.

Code signing

Pre-release builds are not signed. See Unsigned binaries for the macOS Gatekeeper workaround and Windows SmartScreen handling.

The release pipeline plan is:

macOS: codesign with a Developer ID Application certificate + notarisation via xcrun notarytool.
Windows: Authenticode signing of the .clap and .vst3.
Linux: no signing; SHA256SUMS in release artefacts.

Until release, expect to clear Gatekeeper quarantine by hand or build from source.

Plugin discovery

CLAP and VST3 both rely on filesystem scanning by the host. If VXN1 doesn’t appear after install:

Verify the install path matches the OS table above.
Confirm the host’s plugin search paths include the standard CLAP / VST3 directories (most hosts do this by default, but some Linux distros and locked-down corporate machines need explicit configuration).
On macOS, check the quarantine flag is cleared (see Unsigned binaries).
Force a plugin rescan in the host. Some hosts cache failure metadata and won’t retry until told to.

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