FFile13
Legal

License

File13 is free and open-source software, released under the MIT License. You can read the source, build it yourself, modify it, and redistribute it — the only condition is that the copyright and permission notice below travel with the code.

MIT License · Copyright © 2026 Shawn M. Brown

The MIT License

Copyright © 2026 Shawn M. Brown

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

The canonical copy lives in the LICENSE file in the repository.

The App Store version

File13 is also distributed as a notarized build on the Mac App Store. That build is a paid convenience — a one-time File13 Pro in-app purchase unlocks unlimited mailboxes and the bundled file13 command-line tool. Buying it supports development; it is not required to use the software. The complete source is available under the MIT License above, and you are free to build it yourself at no cost.

Operating responsibly

File13 performs operations that can permanently alter your mailboxes — deleting, archiving, moving messages, and changing flags. Confirmation prompts, a buffered undo window, dry-run modes, and VIP protections are aids, not guarantees. Likewise, any AI-assisted suggestion is advisory and may be wrong. You remain responsible for every action you take, and for keeping backups of anything you cannot afford to lose. As stated above, the software is provided without warranty of any kind.

Contact

Questions, bug reports, and contributions: dev@snxt.ai.