LangChain sample agent fails to build

[Alive-Fish]

Original issue: OfficeDev/microsoft-365-agents-toolkit#14847

Following the article https://learn.microsoft.com/en-us/microsoft-agent-365/developer/quickstart-nodejs-langchain

Created the LangChain sample from the toolkit samples gallery

npm run build fails with

> langchain-sample@2025.11.6 build
> tsc

src/client.ts:37:3 - error TS2769: No overload matches this call.
  The last overload gave the following error.
    Object literal may only specify known properties, and 'instructions' does not exist in type 'CreateAgentParams<Record<string, any>, undefined, AnyAnnotationRoot, ResponseFormat> & { responseFormat: ResponseFormat; middleware?: readonly AgentMiddleware<...>[] | undefined; }'.

37   instructions: `You are a helpful assistant with access to tools.
     ~~~~~~~~~~~~

  node_modules/langchain/dist/agents/index.d.cts:183:18
    183 declare function createAgent<StructuredResponseFormat extends Record<string, any> = Record<string, any>, StateSchema extends AnyAnnotationRoot | InteropZodObject | undefined = undefined, ContextSchema extends AnyAnnotationRoot | InteropZodObject = AnyAnnotationRoot, const TMiddleware extends readonly AgentMiddleware[] = readonly AgentMiddleware[]>(params: CreateAgentParams<StructuredResponseFormat, StateSchema, ContextSchema, ResponseFormat> & {
                         ~~~~~~~~~~~
    The last overload is declared here.

src/client.ts:73:43 - error TS2554: Expected 5 arguments, but got 4.
                                             ~~~~~~~~~~~~~~~~~~~~~

  node_modules/@microsoft/agents-a365-tooling-extensions-langchain/dist/esm/McpToolRegistrationService.d.ts:19:127
    19     addToolServersToAgent(agent: ReactAgent, authorization: Authorization, authHandlerName: string, turnContext: TurnContext, authToken: string): Promise<ReactAgent>;   
                                                                                                                                     ~~~~~~~~~~~~~~~~~
    An argument for 'authToken' was not provided.


Found 2 errors in the same file, starting at: src/client.ts:37

[pontemonti]

Hi @Alive-Fish , thanks for reporting this issue. This should be addressed with #56 - can you please retrieve the latest version of the sample and try again?

[pontemonti]

Closing this as it's been addressed.