refactor: Update tool type references and add prompt listing methods in BaseConnector

Author: zandko

src/adapters/langchain_adapter.ts

@@ -4,7 +4,7 @@ import type {
   CallToolResult,
   EmbeddedResource,
   ImageContent,
-  Tool as McpTool,
+  Tool as MCPTool,
   TextContent,
 } from '@modelcontextprotocol/sdk/types.js'
 import type { ZodTypeAny } from 'zod'
@@ -78,7 +78,7 @@ export class LangChainAdapter extends BaseAdapter<StructuredToolInterface> {
    * Convert a single MCP tool specification into a LangChainJS structured tool.
    */
   protected convertTool(
-    mcpTool: McpTool,
+    mcpTool: MCPTool,
     connector: BaseConnector,
   ): StructuredToolInterface | null {
     // Filter out disallowed tools early.

src/agents/mcp_agent.ts

@@ -2,7 +2,7 @@ import type { BaseLanguageModelInterface, LanguageModelLike } from '@langchain/c
 import type {
   BaseMessage,
 } from '@langchain/core/messages'
-import type { StructuredToolInterface } from '@langchain/core/tools'
+import type { StructuredToolInterface, ToolInterface } from '@langchain/core/tools'
 import type { AgentFinish, AgentStep } from 'langchain/agents'
 import type { MCPClient } from '../client.js'
 import type { BaseConnector } from '../connectors/base.js'
@@ -54,7 +54,6 @@ export class MCPAgent {
     llm: BaseLanguageModelInterface
     client?: MCPClient
     connectors?: BaseConnector[]
-    serverName?: string
     maxSteps?: number
     autoInitialize?: boolean
     memoryEnabled?: boolean
@@ -328,7 +327,7 @@ export class MCPAgent {
         try {
           logger.debug('Starting agent step execution')
           const nextStepOutput = await this.agentExecutor._takeNextStep(
-            nameToToolMap,
+            nameToToolMap as Record<string, ToolInterface>,
             inputs,
             intermediateSteps,
           )

src/connectors/base.ts

@@ -117,6 +117,24 @@ export abstract class BaseConnector {
     return { content: res.content, mimeType: res.mimeType }
   }
 
+  async listPrompts() {
+    if (!this.client) {
+      throw new Error('MCP client is not connected')
+    }
+
+    logger.debug('Listing prompt')
+    return await this.client.listPrompts()
+  }
+
+  async getPrompt(name: string, args: Record<string, any>) {
+    if (!this.client) {
+      throw new Error('MCP client is not connected')
+    }
+
+    logger.debug(`Getting prompt ${name}`)
+    return await this.client.getPrompt({ name, arguments: args })
+  }
+
   /** Send a raw request through the client. */
   async request(method: string, params: Record<string, any> | null = null, options?: RequestOptions) {
     if (!this.client) {