如何读取Slack Webhook请求中的自定义请求头与查询参数

使用curl向Slack频道的Webhook URL发送请求时携带了自定义请求头，但无法通过Slack Bolt框架读取这些自定义请求头及查询参数，尝试多种方式均未成功，求可行的读取方法。

相关代码 #

Python（Slack Bolt应用） #

from typing import Optional
import slack_sdk
import os
import logging
from pathlib import Path
from dotenv import load_dotenv
from slack_bolt import App
from slack_bolt.adapter.socket_mode import SocketModeHandler

logging.basicConfig(level=logging.DEBUG)
env_path = Path('.') / '.env'
load_dotenv(dotenv_path=env_path)

SLACK_VERIFICATION_TOKEN = os.environ['SLACK_VERIFICATION_TOKEN']
SLACK_SIGNING_SECRET = os.environ['SLACK_SIGNING_SECRET']
SLACK_BOT_TOKEN = os.environ['SLACK_BOT_TOKEN']
SLACK_APP_TOKEN = os.environ['SLACK_APP_TOKEN']

# Install the Slack app and get xoxb- token in advance
app = App(token=SLACK_BOT_TOKEN, signing_secret=SLACK_SIGNING_SECRET)
    
@app.event("message")
def handle_message(event, say, context):
    text = event["text"]
    channel = event["channel"]
    target_channel='#slave2_public'

    # Access query parameters
    # query_params = context.request.query
    # print("Query Parameters:", query_params)

    # Access headers from the event
    headers = event.get("headers")
    print("Headers:", headers)

    # Access headers
    # headers = context.request.headers
    # print("Headers:", headers)
        

if __name__ == "__main__":
    # export SLACK_APP_TOKEN=xapp-***
    # export SLACK_BOT_TOKEN=xoxb-***
    handler = SocketModeHandler(app, SLACK_APP_TOKEN)
    handler.start()

curl请求示例 #

curl -X POST -H 'Content-type: application/json' --data '{"text":"Hello, World!"}' -H "Channel_Name:slave1_private" <webhook URL>

解决方案 #

核心原因 #

Slack的Incoming Webhook机制是作为中间层转发消息：它接收你的curl请求后，仅提取消息内容（如text字段）转发到目标频道，不会保留自定义请求头、查询参数等元数据，因此你的Bolt应用无法从message事件中获取这些信息。同时，Socket Mode的Bolt应用通过WebSocket接收Slack格式化后的事件数据，本身也不包含原始请求的头和参数。

方案1：将自定义数据嵌入请求体 #

既然Webhook不传递头和参数，直接把自定义数据放到JSON请求体中，就能在Bolt的message事件里读取：

修改后的curl请求

curl -X POST -H 'Content-type: application/json' \
--data '{"text":"Hello, World!", "Channel_Name": "slave1_private"}' \
<webhook URL>

修改后的Bolt代码

@app.event("message")
def handle_message(event, say, context):
    text = event["text"]
    # 读取自定义字段
    channel_name = event.get("Channel_Name")
    print("Channel Name:", channel_name)
    # 其他业务逻辑...

如果Slack自动过滤了顶层自定义字段，可以用attachments字段携带：

curl -X POST -H 'Content-type: application/json' \
--data '{
    "text":"Hello, World!",
    "attachments": [
        {"text": "", "fields": [{"title": "Channel_Name", "value": "slave1_private", "short": true}]}
    ]
}' \
<webhook URL>

对应读取代码：

@app.event("message")
def handle_message(event, say, context):
    attachments = event.get("attachments", [])
    for att in attachments:
        for field in att.get("fields", []):
            if field["title"] == "Channel_Name":
                print("Channel Name:", field["value"])
    # 其他业务逻辑...

方案2：改用Slack API直接发送（弃用Webhook） #

如果必须使用请求头或查询参数，直接通过Slack API的chat.postMessage接口发送消息，同时将Bolt应用改为HTTP适配器模式，这样就能直接读取请求头和参数：

修改后的Bolt应用（HTTP适配器+Flask）

from typing import Optional
import slack_sdk
import os
import logging
from pathlib import Path
from dotenv import load_dotenv
from slack_bolt import App
from slack_bolt.adapter.flask import SlackRequestHandler
from flask import Flask, request

logging.basicConfig(level=logging.DEBUG)
env_path = Path('.') / '.env'
load_dotenv(dotenv_path=env_path)

SLACK_SIGNING_SECRET = os.environ['SLACK_SIGNING_SECRET']
SLACK_BOT_TOKEN = os.environ['SLACK_BOT_TOKEN']

# 初始化Bolt应用
bolt_app = App(token=SLACK_BOT_TOKEN, signing_secret=SLACK_SIGNING_SECRET)
# 初始化Flask应用和请求处理器
flask_app = Flask(__name__)
handler = SlackRequestHandler(bolt_app)

# 自定义路由处理请求
@flask_app.route("/send-message", methods=["POST"])
def send_message():
    # 直接读取请求头和查询参数
    headers = request.headers
    query_params = request.args
    print("Headers:", headers)
    print("Query Parameters:", query_params)
    
    # 获取请求体中的消息内容和频道
    req_body = request.get_json()
    text = req_body.get("text")
    channel = req_body.get("channel", "#slave1_private")
    
    # 调用Slack API发送消息
    with bolt_app.client.chat_postMessage(channel=channel, text=text) as resp:
        return {"status": "ok", "message": "sent"}

if __name__ == "__main__":
    flask_app.run(port=3000)

对应的curl请求

curl -X POST http://localhost:3000/send-message \
-H 'Content-type: application/json' \
-H "Channel_Name:slave1_private" \
--data '{"text":"Hello, World!", "channel": "#slave1_private"}'

内容的提问来源于stack exchange，提问作者vinod827