langchain-claude-code

LangChain chat model wrapper for the Claude Code Agent SDK. Use Claude Code as a drop-in LangChain BaseChatModel with full tool support, streaming, and LangGraph compatibility.

Prerequisites

Claude Code CLI (required):

npm install -g @anthropic-ai/claude-code

Installation

pip install langchain-claude-code

With example dependencies:

pip install langchain-claude-code[examples]

Authentication

Option 1: API Key (for Anthropic API users)

from langchain_claude_code import ClaudeCodeChatModel

model = ClaudeCodeChatModel(api_key="sk-ant-...")

Or set the environment variable:

export ANTHROPIC_API_KEY="sk-ant-..."

Option 2: OAuth Token (for Claude Max subscribers)

from langchain_claude_code import ClaudeCodeChatModel

model = ClaudeCodeChatModel(oauth_token="...")

Or set the environment variable:

export CLAUDE_CODE_OAUTH_TOKEN="..."

Quick Start

Basic Usage

import asyncio
from langchain_claude_code import ClaudeCodeChatModel
from langchain_core.messages import HumanMessage

async def main():
    model = ClaudeCodeChatModel(model="sonnet")
    response = await model.ainvoke([HumanMessage(content="What is 2 + 2?")])
    print(response.content)

asyncio.run(main())

With Tool Binding

from langchain_claude_code import ClaudeCodeChatModel
from langchain_community.tools.ddg_search.tool import DuckDuckGoSearchTool

model = ClaudeCodeChatModel(model="haiku")
model = model.bind_tools([DuckDuckGoSearchTool()])

response = await model.ainvoke([
    HumanMessage(content="Search for the latest news about AI")
])

Using Claude Code's Built-in Tools

from langchain_claude_code import ClaudeCodeChatModel, ClaudeTool

model = ClaudeCodeChatModel(
    model="sonnet",
    allowed_tools=[
        ClaudeTool.WEB_SEARCH,
        ClaudeTool.WEB_FETCH,
        ClaudeTool.BASH,
        ClaudeTool.READ,
        ClaudeTool.WRITE,
    ],
)

Streaming

async for chunk in model.astream([HumanMessage(content="Write a poem")]):
    print(chunk.content, end="", flush=True)

Configuration

Permission Modes

Security Note: When using acceptEdits or bypassPermissions, Claude Code will modify your filesystem without confirmation. Use these modes only in sandboxed environments or when you trust the input.

Available Tools

from langchain_claude_code import ClaudeTool

# File operations
ClaudeTool.READ
ClaudeTool.WRITE
ClaudeTool.EDIT
ClaudeTool.GLOB
ClaudeTool.GREP

# Shell
ClaudeTool.BASH
ClaudeTool.BASH_OUTPUT

# Web
ClaudeTool.WEB_SEARCH
ClaudeTool.WEB_FETCH

# Other
ClaudeTool.TASK
ClaudeTool.TODO_WRITE

Examples

See the examples/ directory for complete examples:

• bind_tools_example.py - Using LangChain tools with Claude Code
• deepagents_example.py - Integration with DeepAgents/LangGraph

License

MIT License - see LICENSE for details.