Feishu (Lark) Integration

OpenPollen supports Feishu (Lark) Bot via plugin, using WebSocket long-polling to receive events without requiring a public IP.

Prerequisites

1. A Feishu Open Platform custom enterprise application
2. Bot capability enabled for the application
3. App ID and App Secret obtained

Create Feishu Application

1. Log in to Feishu Open Platform (or Lark Developer for international)
2. Create a custom enterprise application
3. Add Bot capability under "Add App Capabilities"
4. Note down App ID and App Secret
5. Under "Events & Callbacks", add the event im.message.receive_v1 (receive messages)
6. Set the event receiving method to Long Connection (WebSocket)
7. Request the following permissions and publish the app version:
   • im:message — Read and send messages
   • im:message.group_at_msg — Receive @bot messages in group chats
   • im:resource — Access resources (images) in messages

Configuration

Configure Feishu in openpollen.json:

{
  "channels": {
    "feishu": {
      "enabled": true,
      "appId": "${FEISHU_APP_ID}",
      "appSecret": "${FEISHU_APP_SECRET}",
      "groupPolicy": "mention"
    }
  }
}

Field	Type	Default	Description
enabled	boolean	false	Enable Feishu
appId	string	—	App ID
appSecret	string	—	App Secret
groupPolicy	string	mention	Group message policy

Group Message Policy

Value	Behavior
mention	Only respond when @mentioned (recommended)
all	Respond to all messages in group

Usage

After starting OpenPollen, the Feishu Bot connects automatically via WebSocket:

openpollen start

Direct Messages

Send messages directly to the bot.

Group Chat

@mention the bot + your message (when groupPolicy is mention).

Message Format

• Receiving: Text messages and image messages supported
• Replying: Replies in plain text format
• Length limit: Replies exceeding 18,000 characters are auto-truncated
• Image handling: Feishu images are automatically downloaded locally for Agent analysis

Session Management

The following commands are available in Feishu conversations:

Command	Description
/new	Reset session, start a new conversation
/resume	List historical sessions
/resume 1	Resume the 1st historical session

Testing

# Check Feishu channel status
openpollen channel list

# Send test message via Gateway API
openpollen channel test feishu

FAQ

Bot not responding to group messages

Check the groupPolicy setting. If set to mention, you need to @mention the bot. Also verify the app has the im:message.group_at_msg permission.

Connection failure

1. Verify appId and appSecret are correct
2. Confirm event receiving method is set to Long Connection
3. Check for HTTP proxy settings (Feishu SDK doesn't support HTTP proxy to HTTPS). If set, unset them:

   unset http_proxy https_proxy HTTP_PROXY HTTPS_PROXY

Replies truncated

Feishu has message length limits. OpenPollen auto-truncates replies exceeding 18,000 characters with a truncation notice.

No reply after sending image

Verify the app has the im:resource permission and the Agent's model provider supports image recognition.