Implementation:Apache Airflow BaseHook Interface

Knowledge Sources	Apache Airflow
Domains	Integration, Python_API
Last Updated	2026-02-08 00:00 GMT

Overview

Concrete tool for managing external service connections provided by the BaseHook class and provider discovery system.

Description

The BaseHook class is the abstract base for all hooks. It provides class methods for connection retrieval (get_connection), hook resolution (get_hook), and UI customization (get_connection_form_widgets, get_ui_field_behaviour). The discover_all_providers_from_packages function scans installed packages for provider metadata.

Usage

Subclass BaseHook to create hooks for new external services. Implement get_conn() to return the actual connection client.

Code Reference

Source Location

• Repository: Apache Airflow
• File: task-sdk/src/airflow/sdk/bases/hook.py
• Lines: L30-101

Signature

class BaseHook(LoggingMixin):
    def __init__(self, logger_name: str | None = None):
        super().__init__()
        self._log_config_logger_name = "airflow.task.hooks"
        self._logger_name = logger_name

    @classmethod
    def get_connection(cls, conn_id: str) -> Connection: ...

    @classmethod
    async def aget_connection(cls, conn_id: str) -> Connection: ...

    @classmethod
    def get_hook(cls, conn_id: str, hook_params: dict | None = None): ...

    def get_conn(self) -> Any: ...

    @classmethod
    def get_connection_form_widgets(cls) -> dict[str, Any]: ...

    @classmethod
    def get_ui_field_behaviour(cls) -> dict[str, Any]: ...

Import

from airflow.sdk.bases.hook import BaseHook

I/O Contract

Inputs

Name	Type	Required	Description
conn_id	str	Yes	Airflow connection identifier
logger_name	str or None	No	Custom logger name
hook_params	dict or None	No	Additional hook init parameters

Outputs

Name	Type	Description
Connection	Connection	Connection object with credentials
Client	Any	External service client from get_conn()
Form widgets	dict	Custom UI form fields

Usage Examples

Custom Hook Implementation

from airflow.sdk.bases.hook import BaseHook
import my_service_sdk

class MyServiceHook(BaseHook):
    conn_name_attr = "my_service_conn_id"
    default_conn_name = "my_service_default"
    conn_type = "my_service"
    hook_name = "My Service"

    def __init__(self, my_service_conn_id: str = default_conn_name):
        super().__init__()
        self.conn_id = my_service_conn_id

    def get_conn(self):
        conn = self.get_connection(self.conn_id)
        return my_service_sdk.Client(
            host=conn.host,
            token=conn.password,
        )

Related Pages

Implements Principle

• Principle:Apache_Airflow_Hook_Connection_Implementation

Requires Environment

• Environment:Apache_Airflow_Python_Runtime_Environment