n8n MCP Server

Instructions

Implementation Reference

• src/tools/variables.ts:26-71 (handler)

  The implementation of the `n8n_list_variables` tool, including tool registration, input schema validation, and the handler function that calls the n8n API to list variables.

    server.registerTool(
      'n8n_list_variables',
      {
        title: 'List n8n Variables',
        description: `List all environment variables.
  
  Variables are accessible in workflows using $vars.variableName syntax.
  
  Args:
    - limit (number): Maximum results (default: 100)
    - cursor (string, optional): Pagination cursor
  
  Returns:
    List of variables with id, key, and value.`,
        inputSchema: ListVariablesSchema,
        annotations: {
          readOnlyHint: true,
          destructiveHint: false,
          idempotentHint: true,
          openWorldHint: false
        }
      },
      async (params: z.infer<typeof ListVariablesSchema>) => {
        const queryParams: Record<string, unknown> = { limit: params.limit };
        if (params.cursor) queryParams.cursor = params.cursor;
        
        const response = await get<N8nPaginatedResponse<N8nVariable>>('/variables', queryParams);
        
        const formatted = response.data.map(formatVariable).join('\n');
        const output = {
          count: response.data.length,
          variables: response.data,
          nextCursor: response.nextCursor
        };
        
        let text = `Found ${response.data.length} variable(s):\n\n${formatted}`;
        if (response.nextCursor) {
          text += `\n\n_More results available. Use cursor: ${response.nextCursor}_`;
        }
        
        return {
          content: [{ type: 'text', text }],
          structuredContent: output
        };
      }
    );