$ pip3 install things-cli
# or
$ git clone https://github.com/thingsapi/things-cli && cd things-cli && make install

% things-cli inbox
 -  To-Do in Inbox with Checklist Items  ( Inbox )
 -  To-Do in Inbox  ( Inbox )

% things-cli --recursive areas
- Area 3 ()
  - Todo in Area 3 (Area 3)
- Area 2 ()
- Area 1 ()
  - Project in Area 1 (Area 1)
    - Todo in Area 1 (Project in Area 1)
    - Heading (Project in Area 1)
      - To-Do in Heading (Heading)
  - To-Do in Area 1 (Area 1)

% things-cli --json today|jq
[
  {
    "uuid": "5pUx6PESj3ctFYbgth1PXY",
    "type": "to-do",
    "title": "To-Do in Today",
    "status": "incomplete",
    "notes": "With\nNotes",
    "start": "Anytime",
    "start_date": "2021-03-28",
    "deadline": null,
    "stop_date": null,
    "created": "2021-03-28 21:11:22",
    "modified": "2021-03-28 21:11:30"
  }
]

% things-cli --csv --recursive all > all.csv && open all.csv

% things-cli --opml --recursive all > all.opml && open all.opml

% things-cli --gantt --recursive all > all.mmd && mmdc -i all.mmd -o all.png && open all.png

% things-cli -h
usage: cli.py [-h] [-p FILTER_PROJECT] [-a FILTER_AREA] [-t FILTER_TAG] [-e] [-o] [-j] [-c] [-g] [-r] [-d DATABASE] [--version] command ...

Simple read-only Thing 3 CLI.

positional arguments:
  command
    inbox               Shows inbox tasks
    today               Shows todays tasks
    upcoming            Shows upcoming tasks
    anytime             Shows anytime tasks
    completed           Shows completed tasks
    someday             Shows someday tasks
    canceled            Shows canceled tasks
    trash               Shows trashed tasks
    todos               Shows all todos
    all                 Shows all tasks
    areas               Shows all areas
    projects            Shows all projects
    logbook             Shows completed tasks
    logtoday            Shows tasks completed today
    tags                Shows all tags ordered by their usage
    deadlines           Shows tasks with due dates
    feedback            Give feedback
    search              Searches for a specific task

optional arguments:
  -h, --help            show this help message and exit
  -p FILTER_PROJECT, --filter-project FILTER_PROJECT
                        filter by project
  -a FILTER_AREA, --filter-area FILTER_AREA
                        filter by area
  -t FILTER_TAG, --filtertag FILTER_TAG
                        filter by tag
  -e, --only-projects   export only projects
  -o, --opml            output as OPML
  -j, --json            output as JSON
  -c, --csv             output as CSV
  -g, --gantt           output as mermaid-js GANTT
  -r, --recursive       in-depth output
  -d DATABASE, --database DATABASE
                        set path to database
  --version, -v         show program's version number and exit