Running Apollo Download Manager beside V1

Apollo Download Manager and the original Velocity Download Manager (V1) can be installed and run at the same time without sharing anything. Each has its own data, database, single-instance lock, IPC endpoint and browser registration (#27, ADR-0003).

One source of identity

branding.json at the repository root holds Apollo Download Manager's identity. The core reads it (velocity_core::branding), and src-tauri/tauri.conf.json must carry the same identifier and product name, which a test checks. A build runs as the development identity unless it is built with the release-identity feature, as packaging does; then the app, the engine, the torrent helper and the native host all run as the release identity, and src-tauri/tauri.release.conf.json carries it (PACKAGING.md, #81).

Field	Development builds	Release builds (packaging: Windows since #81, Linux since #82; macOS is #83)	V1, for comparison
Product name: window title, install folder, Apps & features entry	Apollo Download Manager (dev)	Apollo Download Manager (ADR-0018; "Velocity Download Manager V2" until 0.2.0)	Velocity Download Manager
Identifier: data folder, single-instance key, pipe name	`dev.velocity.downloadmanager.v2`	`com.velocity.downloadmanager.v2`	`com.velocity.downloadmanager`
Native-messaging host (#65)	`dev.velocity.download_manager_v2`	`com.velocity.download_manager_v2`	`com.velocity.download_manager`
Native host program and its registration (#65)	`velocity-native-host-v2`; manifests and, on Windows, `HKCU` keys named after Apollo DM's host (BROWSER_EXTENSION.md)	the same	`velocity-native-host`, named after V1's host
Firefox extension ID (#64, #240)	`apollo-download-manager@singlbase.com` (ADR-0020; `velocity-download-manager-v2@velocity.local` until 0.2.0)	the same	`velocity-download-manager@velocity.local`
Chrome extension IDs (#64, #240)	`fhhohpcahhmlijibcpppoddcklobfpld`, the Chrome Web Store's item, pinned by its key (BROWSER_EXTENSION.md)	the same	`eecopkg…`
Browser extension name (#64)	Apollo Download Manager (dev)	Apollo Download Manager	Velocity Download Manager

What derives from the identifier

Resource	Apollo DM	Where
Data folder	`<platform data dir>/<identifier>`. On Windows: `%APPDATA%\dev.velocity.downloadmanager.v2`	`velocity_core::paths::Paths` (it uses `dirs`, so the native host, which has no Tauri, finds the same folder)
Override for tests and portable setups	`VELOCITY_V2_DATA_DIR`, an absolute path. V1's `VELOCITY_DATA_DIR` never affects Apollo DM	`paths::DATA_DIR_ENV`
Database, checkpoints	`velocity.sqlite3` and `checkpoints/` inside the data folder (#26, #43)	`Paths::database`, `Paths::checkpoints_dir`
Single instance	Starting Apollo DM again focuses the running window	`tauri-plugin-single-instance`, keyed on the identifier
IPC endpoint	Windows: `\\.\pipe\<identifier>.ipc.<user>.<hash of the data folder>`. Unix: `<data folder>/ipc.sock`. The browser bridge listens on it (#65), and the native host finds this launch's token in `<data folder>/ipc.token`	`Paths::ipc_endpoint`

The release identifier starts with V1's identifier (com.velocity.downloadmanager + .v2). That's safe, because V1 uses its identifier exactly, never as a prefix: Apollo Download Manager's data folder sits next to V1's, never inside it, and the pipe names differ (PO decision on #27). Tests check every derived resource for exact non-collision.

Verified side by side (Windows, 2026-10-22)

The installed V1 0.1.0 and the Apollo Download Manager dev build ran at the same time on the PO's PC:

Separate data folders: V1 used %APPDATA%\com.velocity.downloadmanager (its database and engine files). Apollo Download Manager created %APPDATA%\dev.velocity.downloadmanager.v2 at startup. Apollo Download Manager's folder isn't inside V1's.
IPC: V1's pipe \\.\pipe\com.velocity.downloadmanager.ipc.… was present. Apollo Download Manager had no IPC server yet; #65 added it, on Apollo Download Manager's own pipe.
Single instance: a second Apollo Download Manager launch exited by itself with code 0, and one Apollo Download Manager process remained.
Closing: closing Apollo Download Manager through its window left V1 and its engine running and responding, with its pipe still present.
Not checked: closing V1 while Apollo Download Manager runs. V1 was in use on the PO's PC.

Linux and macOS side-by-side runs: NOT RUN.