Add Sequential Thinking MCP tool for structured problem-solving (#4143)

Author: AsharibAli

packages/components/nodes/tools/MCP/SequentialThinking/SequentialThinkingMCP.ts

@@ -0,0 +1,98 @@
+import { Tool } from '@langchain/core/tools'
+import { ICommonObject, INode, INodeData, INodeOptionsValue, INodeParams } from '../../../../src/Interface'
+import { getNodeModulesPackagePath } from '../../../../src/utils'
+import { MCPToolkit } from '../core'
+
+class SequentialThinking_MCP implements INode {
+    label: string
+    name: string
+    version: number
+    description: string
+    type: string
+    icon: string
+    category: string
+    baseClasses: string[]
+    documentation: string
+    inputs: INodeParams[]
+
+    constructor() {
+        this.label = 'Sequential Thinking MCP'
+        this.name = 'sequentialThinkingMCP'
+        this.version = 1.0
+        this.type = 'Sequential Thinking MCP Tool'
+        this.icon = 'sequentialthinking.svg'
+        this.category = 'Tools (MCP)'
+        this.description =
+            'MCP server that provides a tool for dynamic and reflective problem-solving through a structured thinking process'
+        this.documentation = 'https://github.com/modelcontextprotocol/servers/tree/main/src/sequentialthinking'
+        this.inputs = [
+            {
+                label: 'Available Actions',
+                name: 'mcpActions',
+                type: 'asyncMultiOptions',
+                loadMethod: 'listActions',
+                refresh: true
+            }
+        ]
+        this.baseClasses = ['Tool']
+    }
+
+    //@ts-ignore
+    loadMethods = {
+        listActions: async (nodeData: INodeData, options: ICommonObject): Promise<INodeOptionsValue[]> => {
+            try {
+                const toolset = await this.getTools(nodeData, options)
+                toolset.sort((a: any, b: any) => a.name.localeCompare(b.name))
+
+                return toolset.map(({ name, ...rest }) => ({
+                    label: name.toUpperCase(),
+                    name: name,
+                    description: rest.description || name
+                }))
+            } catch (error) {
+                console.error('Error listing actions:', error)
+                return [
+                    {
+                        label: 'No Available Actions',
+                        name: 'error',
+                        description: 'No available actions, please refresh'
+                    }
+                ]
+            }
+        }
+    }
+
+    async init(nodeData: INodeData, _: string, options: ICommonObject): Promise<any> {
+        const tools = await this.getTools(nodeData, options)
+
+        const _mcpActions = nodeData.inputs?.mcpActions
+        let mcpActions = []
+        if (_mcpActions) {
+            try {
+                mcpActions = typeof _mcpActions === 'string' ? JSON.parse(_mcpActions) : _mcpActions
+            } catch (error) {
+                console.error('Error parsing mcp actions:', error)
+            }
+        }
+
+        return tools.filter((tool: any) => mcpActions.includes(tool.name))
+    }
+
+    async getTools(_nodeData: INodeData, _options: ICommonObject): Promise<Tool[]> {
+        const packagePath = getNodeModulesPackagePath('@modelcontextprotocol/server-sequential-thinking/dist/index.js')
+
+        const serverParams = {
+            command: 'node',
+            args: [packagePath]
+        }
+
+        const toolkit = new MCPToolkit(serverParams, 'stdio')
+        await toolkit.initialize()
+
+        const tools = toolkit.tools ?? []
+
+        return tools as Tool[]
+    }
+}
+
+module.exports = { nodeClass: SequentialThinking_MCP }

packages/components/nodes/tools/MCP/SequentialThinking/sequentialthinking.svg

@@ -63,6 +63,7 @@
         "@modelcontextprotocol/server-brave-search": "^0.6.2",
         "@modelcontextprotocol/server-github": "^2025.1.23",
         "@modelcontextprotocol/server-postgres": "^0.6.2",
+        "@modelcontextprotocol/server-sequential-thinking": "^0.6.2",
         "@modelcontextprotocol/server-slack": "^2025.1.17",
         "@notionhq/client": "^2.2.8",
         "@opensearch-project/opensearch": "^1.2.0",