t4: terminal time tracking tool

Haskell library and command line tools for simple time tracking.

Storage uses very human-friendly yaml files in ~/.t4-data that can be edited manually:

memowe@rakete:~$ ls ~/.t4-data
2025-10-15.yml  2025-10-25.yml  2025-10-24.yml
2025-10-23.yml  2025-10-27.yml

$ cat ~/.t4-data/2025-10-27.yml 
- in:
    category: Writing t4 README
    tags:
    - t4
    - haskell
    - documentation
    time: 2025-10-27 10:24:57
- out:
    time: 2025-10-27 10:29:12
- in:
    category: Lunch break
    tags:
    - break
    - recreation
    - nom
    time: 2025-10-27 12:42:17

The project offers two command-line interfaces to edit these files for you and one read-only web API for future report visualizations.

Preparations

This is a standard GHC/cabal project with a core library and two executables t4/t5, so you can use the standard cabal commands to build dependencies, the project itself and run tests:

cabal build --only-dependencies --enable-tests
cabal build
cabal test --test-show-details=direct

You can also build the core library's Haddock API docs by yourself (although they are not extensively commented):

cabal haddock

Command-based terminal interface t4

You can run the command-based tool (terminal time tracking tool) without installing using cabal run t4 -- ARGUMENTS and install it via cabal install.

$ t4 --help
t4 - terminal time tracking tool

Usage: t4 COMMAND

  Simple interface for clocking in and out

Available options:
  -h,--help                Show this help text

Available commands:
  in                       Clocking in
  out                      Clocking out
  status                   Show current status
  categories               List all categories
  tags                     List all tags
  report                   Report

$ t4 status
IN (2025-10-27 10:24:57) [Writing t4 README] #t4 #haskell #documentation

Interactive terminal interface t5

You can run the interactive terminal interface (terminal time tracking tool terminal user interface) without installing using cabal run t5 and install it via cabal install.

$ t5
IN (2025-10-27 10:24:57) [Writing t4 README] #t4 #haskell #documentation
Spent: 4mi 5s
[o]ut - [u]pdate - report [c]ategories - report [t]ags - [q]uit: o
Spent: 4mi 15s
OUT (2025-10-27 10:29:12)

Hint: the interactive TUI uses auto completion when entering categories or tags. Try it using Tab.

JSON web API t4-api

This simple JSON API is a preparation for pretty report visualizations. Access it for now via cabal and inspect its swagger UI for details.

$ cabal run t4-api
T4 API Server starting...
  OpenAPI spec at:  http://localhost:8080/openapi.json
  Swagger UI at:    http://localhost:8080/swagger-ui
  API endpoints:    http://localhost:8080/*

Author and license

(c) 2025 Mirko Westermeier

Released under the MIT license. See LICENSE for details.