The .thrl File Format

.thrl is Throughline’s own project format: one file holding everything: Beats, Characters, Settings, Structures, Arcs, Sparks, and even your recycling bin. Every project you work on is a .thrl file saved wherever you choose, so your whole project is always portable, shareable, and ready to open on any other Throughline install. See Projects & Files for how creating, opening, and saving work.

No lock-in

Your project already is the file, and it contains all the data of your project.

Need a separate copy to send someone? Use Save a Copy…, or export a .thrl from the Deliver Workspace.

Readable by any AI

Every .thrl file carries a guide written for AI readers, so your story can be fully understood and processed by an LLM of your choice. The guide holds:

• The rules of the story model: how Beats pile under Structure Cards, how relationships and their feelings change from Beat to Beat, what an Arc’s charge means, and how Sparks become cards.
• The story order, already worked out, so a model never has to sort the Beats itself.
• The Beat numbers you see in the app, so a model talks about “Beat 12” exactly as you do.
• The names behind every id, for Characters and Beats.

Throughline writes the guide fresh with every save and ignores it when it opens a file, so it never gets in the way. Old .thrl files always open in newer versions of Throughline. See Throughline and AI for all the ways AI can work with your project.

Autosaves

Throughline keeps regular autosaves of your open project in a folder named <project name>_autosaves, right next to your .thrl file. Pick an interval (5, 10, 15, 30 minutes, 1 or 2 hours, or once a day) and how many to keep, both in Settings → General → Autosaves.

Every autosave is itself a normal .thrl file: double-click one to open it as its own project. Copies kept because of a decision, such as (legacy THRL 1.5) or (changed elsewhere), carry that label in their name and are never deleted automatically.

Restore from Autosave, in the project menu, lists your autosaves by time. Restoring keeps your current state in the autosaves folder first, so you can always go back. See Autosaves for the details.