@unbrowse/langchain-js

Unbrowse as native LangChain JS tools.

This is the JavaScript / TypeScript adapter for @langchain/core (a separate Python package, unbrowse-langchain, exists for the Python ecosystem).

It exposes three tools, shaped exactly like LangChain's StructuredTool / DynamicStructuredTool runtime surface — { name, description, schema, invoke(input), call(input) }:

| tool | input | does | | ----------------- | ------------------------------ | ----------------------------------------------------------- | | unbrowse_resolve| { url, intent } | resolve an intent + URL to a ranked endpoint shortlist | | unbrowse_execute| { endpoint_id, params? } | execute a resolved endpoint | | unbrowse_search | { query, url? } | resolve + execute, synthesized into ranked results |

schema is a plain JSON Schema object, so this package has no zod dependency. invoke is the modern Runnable method; call is the legacy alias — both are provided and both return a JSON string (LangChain tools return strings).

Install

npm install @unbrowse/langchain-js

Use — register with an agent

import { unbrowseTools } from '@unbrowse/langchain-js';
import { createReactAgent } from '@langchain/langgraph/prebuilt';
import { ChatOpenAI } from '@langchain/openai';

const llm = new ChatOpenAI({ model: 'gpt-4o' });

// Bind Unbrowse's tools straight into the agent's tools array:
const agent = createReactAgent({ llm, tools: unbrowseTools });

const out = await agent.invoke({
  messages: [{ role: 'user', content: 'Find the latest docs on x402 and summarize.' }],
});

You can also call a single tool directly:

import { unbrowseSearchTool } from '@unbrowse/langchain-js';

const json = await unbrowseSearchTool.invoke({ query: 'x402 payment spec' });
const results = JSON.parse(json);

Branded DynamicStructuredTool instances

unbrowseTools already matches LangChain's tool shape and works wherever a tools array is accepted. If you want genuine, branded DynamicStructuredTool instances (for type checks, tracing, or strict runtime guards), pass your own tool helper from @langchain/core:

import { tool } from '@langchain/core/tools';
import { createUnbrowseTools } from '@unbrowse/langchain-js';

const tools = createUnbrowseTools({ tool }); // 3 real DynamicStructuredTool instances

This package does not import @langchain/core itself — you supply the tool helper you already depend on, keeping this adapter dependency-free.

Configuration

| env | default | meaning | | -------------------------------- | -------------------------------- | ------------------------------------------ | | UNBROWSE_API_URL / UNBROWSE_BASE | https://beta-api.unbrowse.ai | Unbrowse API base | | UNBROWSE_API_KEY | — | Bearer auth | | UNBROWSE_X_PAYMENT / X_PAYMENT | — | x402 payment header | | UNBROWSE_DRYRUN=1 | — | deterministic offline result, no network |

License

MIT