bridge.ts•4.31 kB
import { INodeExecutionData, IDataObject } from 'n8n-workflow';
export class N8NMCPBridge {
/**
* Convert n8n workflow data to MCP tool arguments
*/
static n8nToMCPToolArgs(data: IDataObject): any {
// Handle different data formats from n8n
if (data.json) {
return data.json;
}
// Remove n8n-specific metadata
const { pairedItem, ...cleanData } = data;
return cleanData;
}
/**
* Convert MCP tool response to n8n execution data
*/
static mcpToN8NExecutionData(mcpResponse: any, itemIndex: number = 0): INodeExecutionData {
// Handle MCP content array format
if (mcpResponse.content && Array.isArray(mcpResponse.content)) {
const textContent = mcpResponse.content
.filter((c: any) => c.type === 'text')
.map((c: any) => c.text)
.join('\n');
try {
// Try to parse as JSON if possible
const parsed = JSON.parse(textContent);
return {
json: parsed,
pairedItem: itemIndex,
};
} catch {
// Return as text if not JSON
return {
json: { result: textContent },
pairedItem: itemIndex,
};
}
}
// Handle direct object response
return {
json: mcpResponse,
pairedItem: itemIndex,
};
}
/**
* Convert n8n workflow definition to MCP-compatible format
*/
static n8nWorkflowToMCP(workflow: any): any {
return {
id: workflow.id,
name: workflow.name,
description: workflow.description || '',
nodes: workflow.nodes?.map((node: any) => ({
id: node.id,
type: node.type,
name: node.name,
parameters: node.parameters,
position: node.position,
})),
connections: workflow.connections,
settings: workflow.settings,
metadata: {
createdAt: workflow.createdAt,
updatedAt: workflow.updatedAt,
active: workflow.active,
},
};
}
/**
* Convert MCP workflow format to n8n-compatible format
*/
static mcpToN8NWorkflow(mcpWorkflow: any): any {
return {
name: mcpWorkflow.name,
nodes: mcpWorkflow.nodes || [],
connections: mcpWorkflow.connections || {},
settings: mcpWorkflow.settings || {
executionOrder: 'v1',
},
staticData: null,
pinData: {},
};
}
/**
* Convert n8n execution data to MCP resource format
*/
static n8nExecutionToMCPResource(execution: any): any {
return {
uri: `execution://${execution.id}`,
name: `Execution ${execution.id}`,
description: `Workflow: ${execution.workflowData?.name || 'Unknown'}`,
mimeType: 'application/json',
data: {
id: execution.id,
workflowId: execution.workflowId,
status: execution.finished ? 'completed' : execution.stoppedAt ? 'stopped' : 'running',
mode: execution.mode,
startedAt: execution.startedAt,
stoppedAt: execution.stoppedAt,
error: execution.data?.resultData?.error,
executionData: execution.data,
},
};
}
/**
* Convert MCP prompt arguments to n8n-compatible format
*/
static mcpPromptArgsToN8N(promptArgs: any): IDataObject {
return {
prompt: promptArgs.name || '',
arguments: promptArgs.arguments || {},
messages: promptArgs.messages || [],
};
}
/**
* Validate and sanitize data before conversion
*/
static sanitizeData(data: any): any {
if (data === null || data === undefined) {
return {};
}
if (typeof data !== 'object') {
return { value: data };
}
// Remove circular references
const seen = new WeakSet();
return JSON.parse(JSON.stringify(data, (_key, value) => {
if (typeof value === 'object' && value !== null) {
if (seen.has(value)) {
return '[Circular]';
}
seen.add(value);
}
return value;
}));
}
/**
* Extract error information for both n8n and MCP formats
*/
static formatError(error: any): any {
return {
message: error.message || 'Unknown error',
type: error.name || 'Error',
stack: error.stack,
details: {
code: error.code,
statusCode: error.statusCode,
data: error.data,
},
};
}
}