Channels API - Shannon

Overview

The Channels API lets you integrate Shannon with external messaging platforms. Create channels to connect Slack workspaces or LINE accounts, and Shannon will automatically process incoming messages through its agent system.

Features

Slack integration with event subscription and bot messaging
LINE integration with webhook-based messaging
HMAC signature verification for secure inbound webhooks
Agent routing via agent_name config to direct messages to specific agents
Per-user isolation with unique constraint on type + name per user
Credential security — credentials are never exposed in API responses

Create Channel

Create a new messaging channel.

curl -X POST http://localhost:8080/api/v1/channels \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  -d '{
    "type": "slack",
    "name": "My Slack Channel",
    "credentials": {
      "signing_secret": "your-slack-signing-secret",
      "bot_token": "xoxb-your-bot-token",
      "app_id": "A0123456789"
    },
    "config": {
      "agent_name": "research-agent"
    }
  }'

Request Body

Field	Type	Required	Description
`type`	string	Yes	Channel type: `"slack"` or `"line"`
`name`	string	Yes	Channel display name
`credentials`	object	Yes	Platform-specific credentials (see below)
`config`	object	No	Optional configuration (e.g., `agent_name`)

Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "user_id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "type": "slack",
  "name": "My Slack Channel",
  "config": {
    "agent_name": "research-agent"
  },
  "enabled": true,
  "created_at": "2026-03-10T10:00:00Z",
  "updated_at": "2026-03-10T10:00:00Z"
}

The credentials field is never returned in API responses for security. Store your credentials securely on your side.

List Channels

List all channels for the authenticated user.

curl http://localhost:8080/api/v1/channels \
  -H "Authorization: Bearer <token>"

Response

[
  {
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "user_id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
    "type": "slack",
    "name": "My Slack Channel",
    "config": {
      "agent_name": "research-agent"
    },
    "enabled": true,
    "created_at": "2026-03-10T10:00:00Z",
    "updated_at": "2026-03-10T10:00:00Z"
  }
]

Get Channel

Get details of a specific channel.

curl http://localhost:8080/api/v1/channels/{id} \
  -H "Authorization: Bearer <token>"

Response

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "user_id": "7c9e6679-7425-40de-944b-e07fc1f90ae7",
  "type": "slack",
  "name": "My Slack Channel",
  "config": {
    "agent_name": "research-agent"
  },
  "enabled": true,
  "created_at": "2026-03-10T10:00:00Z",
  "updated_at": "2026-03-10T10:00:00Z"
}

Update Channel

Update an existing channel. All fields are optional — only provided fields will be updated.

curl -X PUT http://localhost:8080/api/v1/channels/{id} \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer <token>" \
  -d '{
    "name": "Renamed Slack Channel",
    "config": {
      "agent_name": "financial-agent"
    },
    "enabled": false
  }'

Request Body

Field	Type	Required	Description
`name`	string	No	New channel name
`credentials`	object	No	New platform credentials
`config`	object	No	New configuration
`enabled`	boolean	No	Enable or disable the channel

Response

Returns the updated channel object (same schema as Get Channel).

Delete Channel

Delete a channel permanently.

curl -X DELETE http://localhost:8080/api/v1/channels/{id} \
  -H "Authorization: Bearer <token>"

Response

{
  "message": "Channel deleted"
}

(HTTP 200 OK with JSON body)

Inbound Webhook

Receive messages from external platforms. This endpoint is called by Slack or LINE when a user sends a message.

POST /api/v1/channels/{channel_id}/webhook

This endpoint requires no authentication. Instead, each platform uses its own HMAC signature verification to ensure requests are genuine.

Response

{
  "status": "dispatched"
}

The webhook validates the inbound request, extracts the message, and dispatches it to Shannon’s agent system asynchronously. The response is returned immediately.

Credential Formats

Slack Credentials

{
  "signing_secret": "your-slack-signing-secret",
  "bot_token": "xoxb-your-bot-token",
  "app_id": "A0123456789"
}

Field	Description
`signing_secret`	Found in your Slack app’s Basic Information page
`bot_token`	Bot user OAuth token (starts with `xoxb-`)
`app_id`	Your Slack app ID

LINE Credentials

{
  "channel_secret": "your-line-channel-secret",
  "channel_access_token": "your-line-channel-access-token"
}

Field	Description
`channel_secret`	Found in your LINE Developer Console channel settings
`channel_access_token`	Long-lived channel access token from LINE Developer Console

Webhook Behavior

Slack

Signature verification: Validates X-Slack-Request-Timestamp and X-Slack-Signature headers using HMAC-SHA256 with the channel’s signing_secret
Clock skew: Requests older than 5 minutes are rejected
URL verification: Automatically responds to Slack’s url_verification challenge during app setup
Bot filtering: Messages from bots are ignored to prevent loops
Supported events: message and app_mention

LINE

Signature verification: Validates X-Line-Signature header using HMAC-SHA256 (base64-encoded) with the channel’s channel_secret
Reply behavior: Sends a “Thinking…” reply immediately using the reply token
Message handling: Processes the first text message from the event payload

Agent Routing

Set the agent_name field in the channel’s config to route incoming messages to a specific agent:

{
  "config": {
    "agent_name": "research-agent"
  }
}

If agent_name is not set, messages are handled by Shannon’s default agent routing.

Channel Response Object

Field	Type	Description
`id`	string (UUID)	Unique channel identifier
`user_id`	string (UUID)	Owner user ID (optional)
`type`	string	Channel type: `"slack"` or `"line"`
`name`	string	Channel display name
`config`	object	Channel configuration
`enabled`	boolean	Whether the channel is active
`created_at`	string (ISO 8601)	Creation timestamp
`updated_at`	string (ISO 8601)	Last update timestamp

Error Responses

Status	Error	Description
400	Invalid request	Missing required fields or invalid channel type
401	Unauthorized	Missing or invalid authentication
403	Forbidden	Cannot access another user’s channel
404	Channel not found	Invalid channel ID
409	Conflict	Duplicate channel (same user + type + name)
500	Internal server error	Server-side failure

All errors follow the standard format:

{
  "error": "error message here"
}

Getting Started

Tasks

Streaming

Agents

Sessions

Swarm

Skills

Schedules

HITL Review

Channels

Tools

Daemon WebSocket

Reference

Documentation Index

​Overview

​Features

​Create Channel

​Request Body

​Response

​List Channels

​Response

​Get Channel

​Response

​Update Channel

​Request Body

​Response

​Delete Channel

​Response

​Inbound Webhook

​Response

​Credential Formats

​Slack Credentials

​LINE Credentials

​Webhook Behavior

​Slack

​LINE

​Agent Routing

​Channel Response Object

​Error Responses

​Next Steps

Submit Tasks

Agents

Overview

Features

Create Channel

Request Body

Response

List Channels

Response

Get Channel

Response

Update Channel

Request Body

Response

Delete Channel

Response

Inbound Webhook

Response

Credential Formats

Slack Credentials

LINE Credentials

Webhook Behavior

Slack

LINE

Agent Routing

Channel Response Object

Error Responses

Next Steps