Projects

A project is a single .prj file plus the optional script(s) and media that go with it. The file stores every input, operator, target, connector, scene layout, and project-level setting; media files live separately and are referenced by path (see Media management in Getting Started).

The project format is human-readable XML. You can open a .prj in a text editor to inspect or hand-edit, and Composer will accept the result as long as the XML stays valid.

Saving a project

Composer Desktop offers two save commands from the File menu:

• File → Save (Ctrl+S) — writes the working .prj to its existing path, overwriting in place. The first save of an untitled project falls through to Save As… and prompts for a location.
• File → Save As… — writes the working .prj to a new path of your choice. The new path becomes the working file; the original is left untouched.

The on-disk format is human-readable XML. Every input, operator, target, connector, scene, layer, and project-level setting is serialised into a single .prj file; project scripts (.js) and media files are not embedded — they're referenced by path. For moving a project together with its media to another host, see Working across hosts below.

The default save location is the Projects subfolder of your Documents area, configurable as Projects directory in Settings → General. Avoid using the literal name default.prj — that file is reset on Composer updates and your work would be overwritten.

Backups Composer keeps around saves

Composer maintains three automatic backup mechanisms so a corrupt save, a lost edit, or a regrettable change can be recovered. The detailed reference is the Backup files page; the short version:

• <projectname>.bak — a rolling backup written next to the working .prj every ~5 minutes whenever the project has been modified. Controlled by Automatically create project backups in Settings → General (default: on). First port of call if a save goes wrong or a recent edit needs to come back.
• Autosave history — timestamped snapshots written to Projects/Autosave/<projectname>.<timestamp>.prj at the configured cadence (every 10 minutes by default), retained for 30 days / 30 entries by default. Configured on the Settings → Autosave tab, with an in-app restore UI on the same tab.
• Dated archive in BackupDirectory\<MachineName>\ — when Settings → General → Backup directory is set to an existing folder different from the projects directory, Composer additionally writes one dated copy per File → Save there, named <YYYY-MM-DD>_<projectname>.prj. Optional and off by default; useful for keeping copies on a separate drive or share that survive the working folder being deleted.

The three mechanisms run independently — leave them all on for layered safety, or trim back via the Settings tabs above.

Working across hosts

Project paths inside a .prj are stored verbatim, which makes a project tied to the host that authored it. Two helpers make moving a project portable:

• File → Consolidate Media — copies all referenced media into a Media/ folder next to the project and rewrites the project's references to relative paths. After consolidating, the project + Media/ folder is portable to any host.
• File → Export → Export project and assets… — duplicates the project plus every referenced media file into a target folder. Media lands in a Media/ subfolder; the .prj and any project script sit at the folder root. If Decklink Capture inputs are active, video snapshots export automatically into a Snapshots folder, including any Stillstore captures.

Subfolders inside the Projects directory are not supported; keep .prj files in the root and rely on Media/ for organization.

Transferring a project to a different machine

The recommended approach is:

1. Run File → Export → Export project and assets… to produce a self-contained folder.
2. Compress the exported folder into a .zip or .tar.gz.
3. Move the archive to the destination host and extract.

Both Composer Desktop and Composer Runtime can open and run the resulting project, and it works across platforms — a project authored on Windows Desktop runs as-is on a Linux Runtime host (provided every input / target type the project uses is supported on the destination platform).

Encrypted projects

Composer supports an encrypted project format with the .prjp extension. Both endpoints (the host that exports and the host that imports) must hold matching encryption keys; the import fails on a mismatch. Use File → Export encrypted project and File → Import encrypted project to round-trip a .prjp. This is intended for distributing projects to third parties without exposing the underlying configuration in plaintext.