How to use langchain v1 `createAgent` with SAP AI SDK?

[florian-richter]

Describe the Question

I want to update my project from langchain v0 to v1.
In your documentation (https://sap.github.io/ai-sdk/docs/js/langchain), you say that the same langchain version as used by the SDK should be used (which is v1).
The previous createReactAgent from langgraph is deprecated and should be replaced by createAgent (https://docs.langchain.com/oss/javascript/releases/langgraph-v1#deprecation-of-createreactagent).
createAgent requires a model parameter which seems to be incompatible with the SAP AI SDK.

Could you provide some guidance how to use the SAP AI SDK with createAgent (preferably also in the documentation and not just in this issue)?

[davidkna-sap]

Thanks for opening an issue @florian-richter!

In our testing providing an langchain orchestration client as the model parameter of createAgent should work:

import { OrchestrationClient } from "@sap-ai-sdk/langchain";
import { createAgent } from "langchain";
import { HumanMessage } from "@langchain/core/messages";

const orchestrationConfig = {
  promptTemplating: {
    model: {
      name: "gpt-4o",
    },
  },
};

const model = new OrchestrationClient(orchestrationConfig);

const agent = createAgent({
  model,
  tools: [],
});

agent
  .invoke({
    messages: [new HumanMessage("Hello, world!")],
  })
  .then((response) => {
    console.log(response);
  });

The sample code for RAG has also recently been updated to use createAgent, but I will create a BLI to ensure this will also get documented on the main documentation website in the future.

[florian-richter]

That's good to know, but how do you handle the type conflict? For me it shows this error for the code you provided:

No overload matches this call.
  The last overload gave the following error.
    Type 'OrchestrationClient' is not assignable to type 'string | LanguageModelLike'.
      Type 'OrchestrationClient' is not assignable to type 'LanguageModelLike'.
        Property 'lc_runnable' is protected but type 'Runnable<RunInput, RunOutput, CallOptions>' is not a class derived from 'Runnable<RunInput, RunOutput, CallOptions>'.ts(2769)
types.d.cts(137, 3): The expected type comes from property 'model' which is declared here on type 'CreateAgentParams<Record<string, any>, undefined, AnyAnnotationRoot, ResponseFormat> & { responseFormat: ResponseFormat; middleware?: readonly AgentMiddleware<...>[] | undefined; }'
index.d.cts(183, 18): The last overload is declared here.

I am using this tsconfig.json:

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "esModuleInterop": true,
    "strict": true,
    "skipLibCheck": true,
    "sourceMap": true,
    "allowJs": true
  },
  "exclude": ["node_modules"]
}

and these version:

npm ls | grep langchain
├── @langchain/community@1.0.7
├── @langchain/core@1.1.4
├── @langchain/langgraph@1.0.4
├── @langchain/mcp-adapters@1.0.3
├── @langfuse/langchain@4.4.9
├── @sap-ai-sdk/langchain@2.3.0
├── langchain@1.1.5

[davidkna-sap]

Please try updating the (transitive) langchain/langgraph versions in your lockfile to ensure the SDKs and langchain packages depend on the same package version. I was not able to reproduce the issue with your tsconfig and a similar set of direct dependencies.

[florian-richter]

Interesting. I will try again and let you know if I can reproduce the error or if it was caused by my project setup.

[florian-richter]

The example code gives no errors when I set up a minimal, fresh project. So the issue is in my project's setup.

[florian-richter]

@davidkna-sap Actually the problem is also in the example above. There seems to be a mismatch when using CommonJS (see this gist: https://gist.github.com/florian-richter/2c12a0deb4aa438bd9feb679fd807080).

[davidkna-sap]

As far as I can tell the issue is that @sap-ai-sdk/langchain is type: "module" thus typescript uses the esm typescript type definitions whereas your parent package use the cjs type definitions which don't appear to be compatible with each other.

You may be able to work around this issue by using the .mts file extension for the relevant files. For progress on cjs support in the SDK packages please follow #567.