Adapters And Models

Adapters let you keep the runtime generic while still using LangChain models, MCP-hosted tools, or custom provider SDKs.

fromLangchainModel(...)

Wrap a LangChain chat model so it matches the SDK's model contract.

import { fromLangchainModel } from "@cognipeer/agent-sdk";
import { ChatOpenAI } from "@langchain/openai";

const model = fromLangchainModel(
  new ChatOpenAI({
    model: "gpt-4o-mini",
    apiKey: process.env.OPENAI_API_KEY,
  })
);

The adapter normalizes message shape and can bind tools when the underlying model supports it.

fromLangchainTools(...)

Convert LangChain-compatible tools into SDK-native tools.

import { fromLangchainTools } from "@cognipeer/agent-sdk";

const sdkTools = fromLangchainTools(langchainTools);

This is the main bridge for MCP tooling as well.

withTools(...)

withTools(...) is a thin helper that binds tools to models which support native tool binding.

const modelWithTools = withTools(model, tools);

In most app code you will not call it directly because the runtime handles binding automatically.

MCP integration pattern

Use an MCP client to discover tools, then adapt them with fromLangchainTools(...).

import { MultiServerMCPClient } from "@langchain/mcp-adapters";
import { fromLangchainTools } from "@cognipeer/agent-sdk";

const client = new MultiServerMCPClient({ /* ... */ });
const tools = fromLangchainTools(await client.getTools());

That keeps MCP tools inside the same runtime surface as local tools, approvals, and traces.

Custom model contract

If you are not using LangChain, the model only needs an invoke(messages) method. bindTools(...) is optional but helpful.

const customModel = {
  async invoke(messages) {
    return {
      role: "assistant",
      content: "hello",
    };
  },
  bindTools(tools) {
    return this;
  },
};

The simpler this adapter stays, the easier your runtime becomes to reason about.

Guidance

• prefer fromLangchainModel(...) for mainstream provider integrations
• prefer fromLangchainTools(...) for MCP or LangChain tool ecosystems
• implement a custom adapter only when you need a provider not already covered by your stack
• keep provider-specific auth and transport logic outside prompts
• Agent API - Agent configuration options