Is there a way to create/modify connections through Airflow API

Connection is actually a model which you can use to query and insert a new connection

from airflow import settings
from airflow.models import Connection
conn = Connection(
        conn_id=conn_id,
        conn_type=conn_type,
        host=host,
        login=login,
        password=password,
        port=port
) #create a connection object
session = settings.Session() # get the session
session.add(conn)
session.commit() # it will insert the connection object programmatically.

You can also add, delete, and list connections from the Airflow CLI if you need to do it outside of Python/Airflow code, via bash, in a Dockerfile, etc.

airflow connections --add ...

Usage:

airflow connections [-h] [-l] [-a] [-d] [--conn_id CONN_ID]
                    [--conn_uri CONN_URI] [--conn_extra CONN_EXTRA]
                    [--conn_type CONN_TYPE] [--conn_host CONN_HOST]
                    [--conn_login CONN_LOGIN] [--conn_password CONN_PASSWORD]
                    [--conn_schema CONN_SCHEMA] [--conn_port CONN_PORT]

https://airflow.apache.org/cli.html#connections

It doesn't look like the CLI currently supports modifying an existing connection, but there is a Jira issue for it with an active open PR on GitHub.

• AIRFLOW-2840 - cli option to update existing connection
• https://github.com/apache/incubator-airflow/pull/3684