The Termux:API add-on provides command line access to device API:s:

* Read and send sms messages from your terminal.
* Access device GPS location sensor from scripts.
* Pipe the result of commands into the device text-to-speech engine.
* Vibrate the device when something interesting happens.
* Access the system clipboard from shell scripts.
* List contacts from the system contact list.

Besides installing this app an additional package is required to install inside Termux:
$ apt install termux-api

See the following documentation about available API commands:
termux.com/add-on-api.html

NOTE: This is an add-on which requires that the main Termux app is installed to use.
From version Termux:API 0.28:
Add support for termux-keystore.
All versions
September 28, 2018
September 6, 2018
June 24, 2018
June 15, 2018
June 9, 2018
April 9, 2017