---
id: slackeventsapi
version: "3.0.3"
license: MIT
license_treatment: permissive
maintenance: active
---

# slackeventsapi — Python Slack Events API adapter for Flask

License: permissive · Maintenance: active · Downloads: 74.1K/mo

## What it is and what it does

SlackEventsAPI is a Python adapter that sits between Slack's Events API and your application, handling the mechanics of receiving and parsing incoming events. It uses an event emitter framework (pyee) to let you register listener functions for specific event types—when Slack sends an event, the adapter routes it to your registered handler. The library includes built-in Flask integration, so you can either use its embedded server or bind it to an existing Flask app.

The package handles URL verification automatically when you first configure your Slack app, and it abstracts away common tasks like signature verification. However, the maintainers note an important caveat: event acknowledgement may require threading for stability in production. The project is actively maintained but officially recommends Bolt for Python as the preferred choice for new Slack app development, as Bolt covers a broader set of Slack platform features.

Use it for:

- Build a Slack bot that reacts to user actions like emoji reactions or message posts by attaching event listeners.
- Integrate Slack notifications into a Python web service by receiving Events API webhooks and triggering downstream workflows.
- Process Slack team events (user joins, channel creation) and sync them with an external database or logging system.
- Prototype Slack app event handling during development before committing to a larger framework.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Receives and parses events from Slack's Events API using an event emitter pattern, allowing you to attach listener functions to handle Slack events in Python.

Yes, if you need a lightweight, low-friction way to receive and handle Slack events in Python and are comfortable with the threading caveat for event acknowledgement. No, if you are starting a new production Slack app—the maintainers explicitly recommend Bolt for Python instead. Suitable for small-scale integrations, prototypes, or legacy projects already using this adapter.

## Install

pip install slackeventsapi
uv add slackeventsapi
poetry add slackeventsapi

## Installing slackeventsapi

Before you install: Low friction installation with only two runtime dependencies (flask and pyee). Actively maintained as of June 2026, though the maintainers recommend Bolt for Python as the preferred library for new projects.

License in practice: MIT license permits commercial and private use with minimal restrictions; you must include a copy of the license and copyright notice.

Quickstart:

pip install slackeventsapi

from slackeventsapi import SlackEventAdapter
import os

slack_events_adapter = SlackEventAdapter(
    os.environ["SLACK_SIGNING_SECRET"],
    endpoint="/slack/events"
)

@slack_events_adapter.on("reaction_added")
def handle_reaction(event_data):
    print(event_data["event"]["reaction"])

slack_events_adapter.start(port=3000)

Requires SLACK_SIGNING_SECRET environment variable and a Slack app with Event Subscriptions enabled; the documentation notes that stable event acknowledgement may require threading.

Verify before relying:

- Whether threading is required for your use case or only for certain event types
- Current adoption rate and whether Bolt for Python is now the de facto standard
- Performance characteristics under high event volume

## Package facts

- License: MIT (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 74.1K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

slack events api adapter, slack event listener python, receive slack events, slack event emitter, slack webhook handler, slack event subscription, slack bot event processing, slack-integration, event-driven, webhook-handler

[View on SkillFed](https://skillfed.io/packages/slackeventsapi) · [View on PyPI](https://pypi.org/project/slackeventsapi/)