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Automerge RS

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This is a Rust library implementation of the Automerge file format and network protocol. Its focus is to support the creation of Automerge implementations in other languages, currently; WASM, JS and C. A libautomerge if you will.

The original Automerge project (written in JS from the ground up) is still very much maintained and recommended. Indeed it is because of the success of that project that the next stage of Automerge is being explored here. Hopefully Rust can offer a more performant and scalable Automerge, opening up even more use cases.


The project has 5 components:

  1. automerge - The main Rust implementation of the library.
  2. automerge-wasm - A JS/WASM interface to the underlying Rust library. This API is generally mature and in use in a handful of projects.
  3. automerge-js - This is a Javascript library using the WASM interface to export the same public API of the primary Automerge project. Currently this project passes all of Automerge's tests but has not been used in any real project or packaged as an NPM. Alpha testers welcome.
  4. automerge-c - This is a C library intended to be an FFI integration point for all other languages. It is currently a work in progress and not yet ready for any testing.
  5. automerge-cli - An experimental CLI wrapper around the Rust library. Currently not functional.


The magic of the architecture is built around the OpTree. This is a data structure which supports efficiently inserting new operations and realising values of existing operations. Most interactions with the OpTree are in the form of implementations of TreeQuery - a trait which can be used to traverse the OpTree and producing state of some kind. User facing operations are exposed on an Automerge object, under the covers these operations typically instantiate some TreeQuery and run it over the OpTree.


Please feel free to open issues and pull requests.

Running CI

The steps CI will run are all defined in ./scripts/ci. Obviously CI will run everything when you submit a PR, but if you want to run everything locally before you push you can run ./scripts/ci/run to run everything.

Running the JS tests

You will need to have node, yarn, rust and wasm-pack installed.

To build and test the rust library:

  $ cd automerge
  $ cargo test

To build and test the wasm library:

  ## setup
  $ cd automerge-wasm
  $ yarn

  ## building or testing
  $ yarn build
  $ yarn test

  ## without this the js library wont automatically use changes
  $ yarn link

  ## cutting a release or doing benchmarking
  $ yarn release

To test the js library. This is where most of the tests reside.

  ## setup
  $ cd automerge-js
  $ yarn
  $ yarn link "automerge-wasm"

  ## testing
  $ yarn test

And finally, to build and test the C bindings with CMake:

## setup
$ cd automerge-c
$ mkdir -p build
$ cd build
## building and testing
$ cmake --build . --target test_automerge

To add debugging symbols, replace Release with Debug. To build a shared library instead of a static one, replace OFF with ON.

The C bindings can be built and tested on any platform for which CMake is available but the steps for doing so vary across platforms and are too numerous to list here.


The edit-trace folder has the main code for running the edit trace benchmarking.

The old Rust project

If you are looking for the origional automerge-rs project that can be used as a wasm backend to the javascript implementation, it can be found here.