n8n Workflow Agent

Run an n8n workflow webhook as a LangBot AgentRunner.

Runner ID

plugin:langbot-team/N8nAgent/default

Configuration

Field	Type	Required	Default	Description
webhook-url	string	yes	''	n8n webhook URL
auth-type	select	yes	none	Authentication type (none/basic/jwt/header)
basic-username	string	no	''	Basic auth username
basic-password	secret	no	''	Basic auth password
jwt-secret	secret	no	''	JWT secret
jwt-algorithm	string	no	HS256	JWT algorithm
header-name	string	no	''	Custom header name
header-value	secret	no	''	Custom header value
timeout	integer	no	120	Request timeout (seconds)
output-key	string	no	response	Response output key
langbot-assets-enabled	boolean	no	false	Register a short-lived LangBot asset token for each run and inject it into the webhook payload
langbot-assets-gateway-host	string	no	0.0.0.0	Host for the local LangBot Asset Gateway
langbot-assets-gateway-port	integer	no	8765	Port for the local LangBot Asset Gateway
langbot-assets-gateway-request-timeout	integer	no	60	Timeout for individual gateway tool calls
langbot-assets-token-ttl	integer	no	3600	Lifetime of each run token in seconds
langbot-assets-input-name	string	no	langbot_asset_run_token	Webhook payload field that receives the run token

LangBot Asset Callback Through n8n MCP Client Tool

n8n can call back into LangBot assets through the SDK Asset Gateway, the same mechanism the Dify runner uses. The gateway is a run-token-authorized MCP server (POST /mcp, JSON-RPC) that exposes the run-authorized LangBot tools: langbot_list_assets, langbot_get_current_event, langbot_history_page, langbot_retrieve_knowledge, langbot_get_tool_detail, and langbot_call_tool.

How it works

1. When langbot-assets-enabled is true, this runner registers a short-lived, run-scoped token before calling the webhook and injects it into the webhook payload under langbot-assets-input-name (default langbot_asset_run_token).
2. The n8n workflow consumes the webhook, reads that field, and passes it as the run_token argument on every LangBot MCP tool call.
3. The runner removes the token when the run ends. Tool calls without a valid token are rejected by the gateway.

The gateway accepts the token either via an Authorization: Bearer header or via a run_token tool-call argument. Because n8n credentials are static and cannot carry a per-run header, use the run_token argument approach (same as Dify).

Build the n8n workflow

The n8n workflow behind the webhook must use an AI Agent node with an MCP Client Tool node attached:

1. Webhook trigger node — receives the LangBot payload, including langbot_asset_run_token. Respond when the last node finishes so the asset callbacks happen inside the request window (before the token is revoked).

2. MCP Client Tool node (n8n version >= 1.2, defaultVersion 1.3):

   • Transport: HTTP Streamable.
   • Endpoint: the public URL that routes to the gateway /mcp, e.g. https://example.com/mcp.
   • Authentication: None (the token travels as a tool argument, not a header).

3. AI Agent node — attach the MCP Client Tool. In the system prompt, instruct the agent to pass run_token on every LangBot tool call, for example:

   For every LangBot MCP tool call, set run_token exactly to:
   {{ $json.langbot_asset_run_token }}
   Call langbot_list_assets first when you need to discover available LangBot
   assets for the current run.
   

4. Return the agent output in the webhook response (streaming type: item/end chunks, or a JSON object keyed by output-key).

Configure LangBot

Select the n8n runner on the LangBot pipeline and set:

webhook-url = <your n8n webhook URL>
auth-type = none
timeout = 120
langbot-assets-enabled = true
langbot-assets-gateway-host = 0.0.0.0
langbot-assets-gateway-port = 8765
langbot-assets-gateway-request-timeout = 60
langbot-assets-token-ttl = 3600
langbot-assets-input-name = langbot_asset_run_token

The public MCP endpoint configured in the n8n MCP Client Tool node must route to this same gateway instance. The runner only injects the short-lived token into the webhook payload; it does not create or update the n8n MCP Client Tool node.

Limitations

• n8n Cloud (and any n8n that cannot reach localhost) needs a public HTTPS URL for the gateway /mcp endpoint. Temporary tunnel URLs are for testing only.
• The run token is short-lived and run-scoped, injected only while LangBot calls the webhook and revoked when the run finishes. The workflow must complete its asset callbacks within the webhook request.
• The gateway exposes only the assets permitted by the current run: current event, history page, knowledge retrieval, tool detail, and tool call.
• n8n's MCP Client Tool uses the official MCP SDK (StreamableHTTPClientTransport). Verify the initialize + tools/list handshake against your gateway once when setting it up.

Legacy Runner

Migrated from n8n-service-api in LangBot.