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A New Open-Source Terminal App, 1667, Lets You Write Fiction With AI on a Branching Tree of Takes

Posted to Hacker News on August 17, 2026, 1667 is a full-screen terminal writing tool that asks a language model for the next paragraph and keeps every take side by side on a tree you can walk back through — with your own model keys, local files, and no telemetry.

2026-08-17 · by Moe Ameen

What happened

On August 17, 2026, a developer posted "Show HN: 1667, a terminal UI for writing fiction with language models" to Hacker News, introducing a free, open-source terminal application for long-form fiction writing. Rather than a chat box or a web editor, 1667 (1667.ai) is a full-screen keyboard-driven TUI: you ask a model for the next paragraph, and it keeps every take the model returns side by side on a tree you can walk back through. The design follows how the author thinks about a story — a branching structure where you try several continuations of a scene, continue down one, and leave the alternates parked as siblings you can revisit and re-branch. The name is the NaNoWriMo math: 1,667 words a day for 30 days is a 50,000-word first draft.

The pitch is control and privacy over 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 are saved as plain files in a project's `.1667/` directory, optionally sealed with a vault password, with OS-level locking so one writer edits a project at a time. Navigation is entirely keyboard — space to continue, Enter to compose, arrow keys to flip between takes — and the story can be viewed as a single path, a full tree, or a "mass" map weighted by word count. It is model-agnostic, working with any OpenAI-compatible or Anthropic Messages endpoint and shipping presets for OpenAI, Anthropic, OpenRouter, and local runtimes Ollama, LM Studio, llama.cpp, and KoboldCpp. It imports from Markdown, SillyTavern chats, and character cards, and exports the chosen path to Markdown.

The tool is Apache-2.0 licensed and free — there is no server to fund, so users pay only their model provider, or nothing when running a local model. Installers cover macOS, Linux, and Windows x64, alongside an npm package (`@1667-ai/cli`). The Show HN thread drew the predictable debate about AI in creative writing; the creator framed it as a personal tool — "a form of low tech holodeck," built to write the kind of vintage pulp fiction "no one writes anymore" — rather than a commercial publishing pipeline.

1667 is early software (its public version numbers sit below 1.0), and it is a drafting environment by design: it stops at exported Markdown. It does not format a book, design launch graphics, cut a video, or publish anywhere. Its contribution is a private, local, branch-first way to draft — the marketing and distribution of whatever you write is a separate step.

Why it matters for creators

  • Branch-first drafting is a different creative model. Keeping every AI take on a tree — instead of accepting or regenerating in place — lets a writer explore "what if this character dies here" without losing the version where they don't. That is a genuinely different way to use a model for fiction.
  • Local and private by default. Your keys, your files on disk, no account or telemetry, and optional at-rest encryption make 1667 a fit for writers wary of their drafts training a hosted service — a real concern for original fiction.
  • No per-word lock-in. Because it runs against any OpenAI- or Anthropic-compatible endpoint, including local models via Ollama or LM Studio, a novelist can draft a whole book at zero marginal cost on their own hardware.
  • It is a drafting tool, not a career. 1667 makes the manuscript; it does nothing to build the readership that buys it — which is the step most indie authors actually neglect.
  • Open-source and free lowers the barrier. Apache-2.0 with installers across macOS, Linux, and Windows means anyone curious about AI-assisted fiction can try the workflow without a subscription.

How to act on this with Kompozy

There are two ways to act on this launch with [Kompozy](/), and they suit two different readers. The first is the timely one: 1667 is exactly the kind of specific, of-the-moment tool a writing or creator-tools account should react to today. Feed the facts into Kompozy and "a new terminal app writes fiction with AI on a branching tree — here's how it works" becomes a [Blog Article](/glossary/output-buckets), a [Carousel](/glossary/hyperframes) walking through the tree-of-takes idea, [Quote Graphics](/glossary/output-buckets) of the sharpest details, and a batch of captioned shorts, published across the eight social platforms plus blog and email in a day on [Autopilot](/glossary/autopilot) — being early and useful on a fresh subject is how a niche account earns citations.

The second is the durable one, aimed at the novelists 1667 is built for. The tool solves drafting and stops at exported Markdown; the part it leaves undone — turning that manuscript into readers — is the part indie authors most reliably skip. Kompozy is that second half. Export a chapter from 1667, and Kompozy atomizes it into teaser carousels, character quote cards, an [Email Newsletter](/glossary/output-buckets) chapter drop, and a [Persona Short](/glossary/persona-shorts) where a face-locked author avatar reads an excerpt to camera — media a text tool can't make — each held to an author-brand voice through the [Persona Brief](/glossary/persona-brief) and scheduled everywhere. The write-in-the-terminal, publish-in-the-morning loop is the whole point: 1667 gives fiction writers a private place to draft, and Kompozy gives them an audience without making them stop writing to become marketers.

Quick takeaways

  • 1667 launched via a Show HN post on August 17, 2026 — a free, open-source terminal app for writing fiction with language models.
  • Its core idea is a branching tree: every AI take on a scene is kept as a sibling you can walk back through and re-branch, rather than overwritten.
  • It is private and local — your own model keys, files on disk in a .1667/ directory, optional vault-password encryption, and no telemetry or account.
  • It is model-agnostic (any OpenAI- or Anthropic-compatible endpoint, plus local runtimes like Ollama and LM Studio), Apache-2.0 licensed, and free.
  • It is a drafting tool that stops at exported Markdown — building an audience for what you write is a separate job Kompozy is built to run.

Frequently asked questions

What is 1667?

1667 is a free, open-source, full-screen terminal app for writing long-form fiction with language models, launched via a Show HN post on August 17, 2026. It asks a model for the next paragraph and keeps every take on a branching tree you can walk back through, stores stories as local files under your own model keys with no telemetry, and exports the chosen path to Markdown. It is Apache-2.0 licensed.

When did 1667 launch and who made it?

It was posted to Hacker News as a Show HN on August 17, 2026 by its developer, who described it as a personal tool built to write the kind of vintage pulp fiction they felt no one writes anymore. The project lives at 1667.ai with source on GitHub under the 1667-ai organization.

Is 1667 free and private?

Yes on both. It is Apache-2.0 open source with no paid tier because there is no server — you pay only your model provider, or nothing if you run a local model. It uses your own keys and endpoint, stores files on your disk with optional at-rest encryption, and ships with no analytics, telemetry, or account in the source.

Can 1667 publish or market the fiction I write?

No. 1667 is a drafting environment that exports Markdown; it has no graphics, video, scheduler, or publishing. To turn a finished chapter into launch content, bring the exported text into Kompozy, which spins it into teaser carousels, quote cards, an excerpt-reading video, and a newsletter and publishes them across the eight social platforms plus blog and email.

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