hammer-editor: Open Source Publishing

What is hammer-editor?

Hammer is a free, open-source, local-first story editor for writers, built in Kotlin with Compose Multiplatform and shipped for Android, iOS, Windows, Linux and macOS, so a single draft stays with its author across phone and desktop.

What it is

Hammer is a multiplatform writing application for building stories. It lives in the Kotlin and Compose Multiplatform ecosystem, which means one shared codebase and one interface model produces native applications for Android, iOS, Windows, Linux and macOS rather than a separate editor per platform. The project is developed by Darkrock Studios, licensed under MIT, and distributed through the Google Play Store, F-Droid, the Apple App Store and the Microsoft Store, with direct .apk and .msi builds attached to GitHub releases. The homepage is hammer.ink.

The concrete problem it addresses is draft ownership across devices. Writing tools commonly lock a manuscript to one operating system or keep it on a vendor server, which forces an author to pick between drafting on a phone and editing on a desktop. Hammer is labelled local-first and offline in its topic list: stories live on the device, and sync moves them between the platforms an author already owns. The facts do not name a specific competing product that it replaces; what is documented is the platform spread and the offline-first storage model.

Key capabilities

Single Kotlin and Compose Multiplatform codebase targeting Android, iOS, Windows, Linux and macOS.
Local-first, offline storage of stories, per the local-first and offline topics.
Cross-device sync, per the sync topic.
Story creation and long-form writing workflows, per the story-creation, writing and writing-tool topics.
Distribution through Google Play, F-Droid, the App Store and the Microsoft Store, plus direct .apk and .msi downloads from the latest GitHub release.
Community localisation hosted on Crowdin, project hammer-editor, with a community Discord server linked from the README.
MIT licence, with continuous integration through .github/workflows/build.yml and quality reporting through Codacy and Codecov.

Who uses it and how

Novelists and fiction writers who draft on an Android phone and continue the same story on a Windows or Linux desktop, relying on sync rather than file transfer.
F-Droid users on de-Googled Android devices, who install com.darkrockstudios.apps.hammer.android without Google Play, or sideload hammer.apk directly.
Desktop writers on Windows who install from the Microsoft Store or the .msi, and macOS users who run the project alongside their existing toolchain.
Translators contributing locale strings through the Crowdin project, since the app ships badges for localisation coverage.
Contributors working in Kotlin and Compose Multiplatform who build from source via the GitHub Actions build workflow.

Getting started

Install from a storefront — Google Play, F-Droid, the App Store or the Microsoft Store — or grab the direct .apk or .msi from the latest GitHub release. Downloads and project links are collected at hammer.ink.

How it compares

The registry facts list no paid products that Hammer replaces, and they name no similar open-source editors. On the evidence available, Hammer stands alone in this registry as a Compose Multiplatform story editor.

When to use it — and when not to

Pick Hammer if the priority is a free MIT-licensed editor that keeps drafts on the device and works offline on the hardware already in hand. The README is sparse — a one-line description plus availability badges — and it documents no server component, database, object storage or mail configuration, so anyone expecting a documented self-hosted sync backend has no material to plan from, and the sync mechanism itself is not described in the facts. The repository also carries 54 open issues, so teams needing guaranteed real-time multi-author collaboration or a formally documented hosted service should look elsewhere first.

project readme (upstream, from github) — read inline

Hammer: A story editor

A simple tool for building stories.

MIT License

Available on:

Platform	App Store	Direct download
Android
iOS		—
Windows
macOS
Linux

Community

Join our Discord and help us by reporting bugs, making feature requests, and discussing the future of Hammer.

Or visit us on Reddit at r/hammereditor

Take a look at the Roadmap to see whats coming.

Multi-platform

This app is where ever you are. Your phone, tablet, desktop, laptop, this program can be installed and run, not simply a website-in-a-box, but instead using native client side technologies to provide the best experience possible.

Multi-Screen

Whether you are on a phone, tablet, or desktop, Hammer will make the best use of your screen space. Also supporting both light and dark modes.

Screen Shots

Offline first

I was frustrated with most of the story writing software I was finding as they were using web technologies (aka: Web Page in a box) which always seems to run into problems while being used offline for long periods of time. Hammer is designed from the ground up to be entirely local, no internet connection required, ever.

Transparent Data

Your data is yours. It's not stored in the cloud, or some opaque database. It is stored in simple, human readable files, just using files and folders to define the project structure. You can open your OSes file browser and take a look for your self. If this program went away today you would be able to easily interact with your data.

Intelligent Syncing between devices

Your data can be synchronized between devices allowing you to work on your story from anywhere, and have no fear of a change on one device, overwriting a change on another device.

Optional and Self hosted Syncing

Syncing is entirely optional, you can install the client and use it on one device, or you can install the server and sync your data between devices. You could even use some other service to sync your data, like Dropbox, Google Drive or syncthing. (however these will only work for syncing between desktop computers. Mobile clients will have to use the built in syncing protocol.)

It's all up to you. Instructions can be found here.

If you don't know how, or just don't want to setup your own server, we're also running an official syncing server.

Official Server: hammer.ink

This is also the best way to support the project! Subscribe to our Patreon in order to get instant access to this official Sync server.

This official server endeavors to be a reliable, and secure way to sync your projects. We perform regular backups, and of course encrypt all of our data both in transit, and at rest in our database. Let us manage the server, and you worry about writing!

Test Environment

~~We're also running a test environment here: test.hammer.ink which is always running the latest commit.~~

~~Do not use the test environment for real data! It will get cleared from time-to-time without notice!~~

🪨 Dark Rock Studios

Dark Rock Studios is all about building Free and Open Source Software.

🐛 Found bugs?
💡 Have suggestions?
📚 Want to help translate?
🎮 Interested in our other apps?
👉 Join our community of Open Source enthusiasts on Discord!

Development

Want to contribute? Great! Here are some instructions to get you started.

Having a problem?

Visit our support page.

Frequently asked questions

Is hammer-editor free to use?

hammer-editor is open source under the MIT licence. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does hammer-editor do?

A simple tool for building stories.

What is hammer-editor written in?

hammer-editor is primarily written in Kotlin. Its source is publicly available at https://github.com/Darkrock-Studios/hammer-editor, and it has 809 GitHub stars.