No description
Find a file
Lina Tawfik 404c50bce0
Fix FastAPI SSE streaming compatibility (fixes #4)
Remove anyio.create_task_group() from receive_messages() to fix the
RuntimeError "Attempted to exit cancel scope in a different task than
it was entered in" when using the SDK with FastAPI's SSE streaming.

The issue occurred because FastAPI can move async generators between
different asyncio tasks during the streaming lifecycle, which conflicts
with anyio's cancel scope tracking.

Changes:
- Remove task group usage from receive_messages()
- Read stderr sequentially after stdout completes
- Add test to ensure no task groups are used
- Fix existing test expectation for buffer overflow

This is a minimal fix that maintains compatibility while solving the
core issue. The trade-off is that stderr is read after stdout instead
of concurrently, but this is unlikely to cause issues in practice.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-07-01 00:04:50 -07:00
.github/workflows chore: cleanup 2025-06-29 14:35:44 +07:00
examples cost_usd -> total_cost_usd in example 2025-06-25 15:18:52 -04:00
src/claude_code_sdk Fix FastAPI SSE streaming compatibility (fixes #4) 2025-07-01 00:04:50 -07:00
tests Fix FastAPI SSE streaming compatibility (fixes #4) 2025-07-01 00:04:50 -07:00
.gitignore Initial Python SDK import 2025-06-12 00:16:19 -07:00
LICENSE Initial Python SDK import 2025-06-12 00:16:19 -07:00
pyproject.toml chore: bump version to 0.0.13 2025-06-27 18:21:23 -07:00
README.md fix: update the tool list in README.md 2025-06-27 06:30:54 +10:00

Claude Code SDK for Python

Python SDK for Claude Code. See the Claude Code SDK documentation for more information.

Installation

pip install claude-code-sdk

Prerequisites:

  • Python 3.10+
  • Node.js
  • Claude Code: npm install -g @anthropic-ai/claude-code

Quick Start

import anyio
from claude_code_sdk import query

async def main():
    async for message in query(prompt="What is 2 + 2?"):
        print(message)

anyio.run(main)

Usage

Basic Query

from claude_code_sdk import query, ClaudeCodeOptions, AssistantMessage, TextBlock

# Simple query
async for message in query(prompt="Hello Claude"):
    if isinstance(message, AssistantMessage):
        for block in message.content:
            if isinstance(block, TextBlock):
                print(block.text)

# With options
options = ClaudeCodeOptions(
    system_prompt="You are a helpful assistant",
    max_turns=1
)

async for message in query(prompt="Tell me a joke", options=options):
    print(message)

Using Tools

options = ClaudeCodeOptions(
    allowed_tools=["Read", "Write", "Bash"],
    permission_mode='acceptEdits'  # auto-accept file edits
)

async for message in query(
    prompt="Create a hello.py file", 
    options=options
):
    # Process tool use and results
    pass

Working Directory

from pathlib import Path

options = ClaudeCodeOptions(
    cwd="/path/to/project"  # or Path("/path/to/project")
)

API Reference

query(prompt, options=None)

Main async function for querying Claude.

Parameters:

  • prompt (str): The prompt to send to Claude
  • options (ClaudeCodeOptions): Optional configuration

Returns: AsyncIterator[Message] - Stream of response messages

Types

See src/claude_code_sdk/types.py for complete type definitions:

  • ClaudeCodeOptions - Configuration options
  • AssistantMessage, UserMessage, SystemMessage, ResultMessage - Message types
  • TextBlock, ToolUseBlock, ToolResultBlock - Content blocks

Error Handling

from claude_code_sdk import (
    ClaudeSDKError,      # Base error
    CLINotFoundError,    # Claude Code not installed
    CLIConnectionError,  # Connection issues
    ProcessError,        # Process failed
    CLIJSONDecodeError,  # JSON parsing issues
)

try:
    async for message in query(prompt="Hello"):
        pass
except CLINotFoundError:
    print("Please install Claude Code")
except ProcessError as e:
    print(f"Process failed with exit code: {e.exit_code}")
except CLIJSONDecodeError as e:
    print(f"Failed to parse response: {e}")

See src/claude_code_sdk/_errors.py for all error types.

Available Tools

See the Claude Code documentation for a complete list of available tools.

Examples

See examples/quick_start.py for a complete working example.

License

MIT