A free, open-source, full-screen terminal app for writing fiction with language models — every AI take is kept on a branching tree you can walk back through, with your own model keys and files stored locally.
Last verified · 2026-08-17 · by Moe Ameen
1667 (1667.ai) is a keyboard-driven terminal application for writing long-form fiction with language models. Instead of a chat window or a web editor, it gives a novelist a full-screen TUI where you ask a model for the next paragraph, then keep every take it returns side by side on a tree you can walk back through. The mental model is a branching narrative: you try several continuations of a scene, pick one path forward, and the alternates stay parked as siblings you can return to and re-branch. Only an explicit delete removes a take — nothing is silently discarded. The name is the NaNoWriMo arithmetic: 1,667 words a day for 30 days is a 50,000-word first draft.
The tool is built around author control and privacy rather than a hosted service. Per the project, it is "your keys, your endpoint, your files on your disk. No analytics, no telemetry, no account anywhere in the source." Stories live as plain files in a project's `.1667/` directory, optionally sealed at rest with a vault password, and a project uses OS-level locking so only one writer edits it at a time. You navigate with the keyboard — space continues the draft, Enter opens a composer, the arrow keys flip between takes — and the story map can be viewed three ways: a single selected path, the full tree of branches, or a "mass" map weighted by word count. A settings panel exposes temperature, token limits, and context window.
It is model-agnostic. 1667 works with anything behind an OpenAI-compatible or Anthropic Messages endpoint, and ships presets for OpenAI, Anthropic, OpenRouter, and local runtimes — Ollama, LM Studio, llama.cpp, and KoboldCpp — plus a custom endpoint, so you can run a hosted frontier model or a model on your own machine at no per-word cost. It can import existing work from Markdown, SillyTavern chats, and character cards, and export the selected path back out to Markdown. The project is Apache-2.0 licensed and free — there is no server to pay for, so you pay only whatever your model provider charges, or nothing if you run locally. It builds on Bun and Node, with installers for macOS, Linux, and Windows x64 and an npm package (`@1667-ai/cli`).
The honest boundary: 1667 is a drafting environment. It is unusually good at exploring a story's branches and holding the whole draft in a private, local, keyboard-first workspace — and it stops at exported Markdown. It does not build the launch graphics, cut a reading to camera, size anything for a feed, or publish to a single channel. Turning a finished manuscript into an audience is a separate job.
A finished 1667 manuscript is the private half of an author's job; building the readers who buy it is the public half, and that is where [Kompozy](/) picks up. Fiction writers under-market almost universally — the draft ships and the book launches into silence — because turning a novel into a promotional cadence means designing graphics, cutting video, and posting for weeks, none of which a drafting tool does. Export the path you chose in 1667 to Markdown, bring it into Kompozy, and one chapter becomes a launch campaign: a brand-exact [Carousel](/glossary/hyperframes) of the opening hook, [Quote Graphics](/glossary/output-buckets) built from your sharpest lines and character voice, an [Email Newsletter](/glossary/output-buckets) chapter drop for your mailing list, native Text Posts and a thread teasing the premise, and — because Kompozy generates media a text tool can't — a [Persona Short](/glossary/persona-shorts) or [Persona Frames](/glossary/persona-frames) video where your face-locked author avatar reads an excerpt to camera. Each asset is reframed to 9:16, 1:1, and 16:9 and published across the eight social platforms plus blog and email from one queue on [Autopilot](/glossary/autopilot).
The pairing is clean because the two tools govern opposite ends and never overlap. 1667 keeps the writing local, private, and under your keys; Kompozy's [Persona Brief](/glossary/persona-brief) keeps the *marketing* voice consistent — your author brand, not your prose style — across every derived post, with a per-post review gate so nothing ships off-tone. For a serialized fiction writer the loop is even tighter: draft the next chapter in the terminal tonight, and let Kompozy fan tomorrow's teaser, quote card, and excerpt reading across every feed in the morning, so an audience compounds while you keep writing instead of stopping to become a marketer.
1667 is a free, open-source, full-screen terminal app for writing long-form fiction with language models. It keeps every AI-generated take on a branching tree you can walk back through, stores stories as local files under your own model keys with no telemetry or account, and exports the path you choose to Markdown. It is Apache-2.0 licensed and runs on macOS, Linux, and Windows.
Anything behind an OpenAI-compatible or Anthropic Messages endpoint. It ships presets for OpenAI, Anthropic, and OpenRouter, plus local runtimes Ollama, LM Studio, llama.cpp, and KoboldCpp, and a custom endpoint — so you can use a hosted frontier model or run a model on your own machine at no per-word cost.
Yes. 1667 is Apache-2.0 open source with no paid tier, because there is no server to run — you pay only whatever your chosen model provider charges, or nothing at all if you run a model locally. It installs via shell/PowerShell installers or the @1667-ai/cli npm package.
No. 1667 is a local drafting environment that exports Markdown; it has no graphics, no video, no scheduler, and no publishing. To turn a finished chapter into launch content, bring the exported text into Kompozy, which spins it into carousels, quote cards, an excerpt-reading video, and a newsletter and publishes them across the eight social platforms plus blog and email.
Export the chapter to Markdown and feed it into Kompozy. It atomizes the writing into teaser carousels, quote graphics from your best lines, a Persona Short where your author avatar reads an excerpt, native posts, and a newsletter drop — each held to your author-brand voice via the Persona Brief and scheduled across every platform, so audience-building runs while you keep drafting.