e257-fi / tackler   1.0.1

Apache License 2.0 Website GitHub

Tackler plain text accounting | Mirror, please use https://gitlab.com/e257/accounting/tackler for issues and PRs

Scala versions: 2.13 2.12
Scala.js versions: 1.x 0.6

Build status Coverage Maven Central
ScalaDoc: tackler-core ScalaDoc: tackler-api Scala.js


Tackler Ain’t Calculator and Kernel for Ledger Equivalent Records.
Why not? Because it uses simplified Ledger syntax.

In other words, Tackler is accounting engine and reporting tool for text based double-entry accounting.

Tackler’s website

See Tackler’s web site for user information and documentation.

Why Tackler?

Tackler’s idea is provide simple, reliable and trustworthy engine to process text-based human readable accounting records.

Simple means that Tackler’s journal format is semantically concise and easy for humans to reason about and that Tackler provides minimum set of features which are needed for its operation.

Reliable means that Tackler’s behaviour is well known, tested and it is documented.

Trustworthy means that Tackler must provide correct and trustworthy results always. Tackler’s result should be possible to verify, ideally in cryptographically secure way.

All that said, Tackler can be used easily with command line interface for normal personal accounting data sets.

Tackler Goals

  • Minimal feature set, very simple and well defined input format

    • Tackler input journal is supposed to be produced by software and to be audited by human.
      However, it must be possible to edit the journal by hand.

  • Well known and defined behaviour

  • Extensive user and developer documentation

  • Error free, reliable and resilient

    • Near perfect code and permutation test coverage

  • Good performance

    • Must be able to process hundreds of thousands of records with reasonable processing time and memory footprint

    • Must have linear processing time characteristics

    • Assumption: All transactions can be held in memory

  • Provides backend and core components for text based accounting processing

  • JVM and Multi platform support: Linux and Arm-Linux, it should be possible to run it on Windows

  • GIT is used for data distribution and storage

Implementation language of Tackler is Scala and journal parsing is done with ANTLR4.

Documentation and Quick Start Guides

See Tackler’s web site for all user information and documentation.

Developer related information is listed here.

Todo, TEPs and Roadmap

Tackler’s outstanding todo items are kept in todo files. Major new ideas, enhancement ideas and plans are tracked and planned in Tackler Enhancement Proposals (TEP).


Extremely loosely defined roadmap is following:

  • Reporting Server as separate project

  • Extending support for Units

  • Profit and Loss (PnL) tracking

    • Automatic conversions between different base units

    • Support for unit handling with commodities

  • Extending support for Currencies and Commodities

    • Price database


For release information and version history details, see CHANGELOG.

Tackler-core is intended to be used as for component to implement server systems. Tackler-api is released for JVM and JS environments, and it is intended to be used on the client enviroments.

See Server API and Client API for additional information.

Dependency settings for SBT are:

libraryDependencies += "fi.e257" %%  "tackler-core" % "version-number"
libraryDependencies += "fi.e257" %%% "tackler-api"  % "version-number"

These are released on Maven Central Repository.

Tackler is under development, however complex backward non-compatible changes to Journal file format should be rare. At the moment Tackler is used in production for operational data set.

Configuration files, command line interface and Client API (data models and JSON serialization) are more likely to subject of change.


If you find a security issue in Tackler, please report it as outlined in Security Policy.

Contributing to Tackler

Contributions to the project are most welcome. See CONTRIBUTING how you could help.

Your pull requests and patches can be merged only if you can certify the Developer Certificate of Origin (DCO), Version 1.1.

By signing-off your commit you certify DCO and acknowlegde that you have the rights to submit your pull requsted or patch as an open-source patch, as stated in Developer Certificate of Origin.

Certifying DCO is done by adding a Signed-off-by line to every git commit message:

Signed-off-by: gitlab-account <[email protected]>

If you set your user.name and user.email correctly in git config, then git will automatically include that line for you with git commit -s. You can also create a git commit.template with appropriate content. These settings can be done per repository basis, so they don’t have to be globally set in your system.

Please make sure that you sign-off all your commits on your merge/pull request.


See THANKS for full list of credits.


Copyright 2016-2023 E257.FI Contributors

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at


Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
See the License for the specific language governing permissions and
limitations under the License.