Writing fiction in a terminal is actually better than using a

Most AI writing tools force you into a linear chat history, but storytelling is actually a tree. You write a scene, decide you hate the direction, and want to branch off into a different plot point without deleting your previous work. I needed a tool that handled this "branching" mental model, so I built 1667. It's a full-screen terminal app specifically for long-form fiction that lets you manage multiple "takes" for every part of your story.

The core logic here is that you can explore alternate routes—like what happens if a character dies or refuses a job—and keep those versions intact. You simply select which path through the tree constitutes the actual storyline, and the tool exports that specific sequence to Markdown in your project folder.

If you're looking for a practical tutorial on how it handles data, here is the technical breakdown of the architecture:

Technical Implementation and Data Handling

1. Project Structure: All story data and configurations are stored in a local .1667/ directory. The exported Markdown files live right next to this folder for easy version control.
2. Security and Privacy: Provider secrets are kept in private machine files rather than the project folder. For those needing extra privacy, there is an optional Vault Password to encrypt project files at rest.
3. Process Management: To prevent data corruption, an OS-level lock ensures only one writer process can access a specific project at a time.
4. Transparency: A built-in request viewer lets you inspect the prompt being sent to the LLM before it goes out (minus the credentials).
5. Audit Trails: Every generated take includes a Generation Record, which logs the specific model and settings used for that exact piece of text.

For those who want to integrate this into their AI workflow, the tool supports a wide range of endpoints. It works with Anthropic and OpenAI-compatible APIs, but it's also great for local LLM agent setups using Ollama, LM Studio, llama.cpp, or KoboldCpp.

If you are migrating from other tools, it supports imports from Markdown, NovelAI archives, and SillyTavern chats and cards.

System Compatibility:

• OS: macOS, Linux, and Windows x64 (Version 0.9.5)
• Installation: Available via Shell/PowerShell installers or as an npm package.

The app is intentionally lean. There is no cloud sync, no account creation, and zero tracking. It’s just a local tool for writers who prefer a terminal environment over a browser. Since it's pre-1.0, it's still evolving, but it solves the primary pain point of linear AI chatting by treating a novel like a branching narrative.