claude-code-sdk-python/CHANGELOG.md

Changelog

0.1.4

Features

• Skip version check: Added CLAUDE_AGENT_SDK_SKIP_VERSION_CHECK environment variable to allow users to disable the Claude Code version check. Set this environment variable to skip the minimum version validation when the SDK connects to Claude Code. (Only recommended if you already have Claude Code 2.0.0 or higher installed, otherwise some functionality may break)
• SDK MCP server tool calls can now return image content blocks

0.1.3

Features

• Strongly-typed hook inputs: Added typed hook input structures (PreToolUseHookInput, PostToolUseHookInput, UserPromptSubmitHookInput, etc.) using TypedDict for better IDE autocomplete and type safety. Hook callbacks now receive fully typed input parameters

Bug Fixes

• Hook output field conversion: Fixed bug where Python-safe field names (async_, continue_) in hook outputs were not being converted to CLI format (async, continue). This caused hook control fields to be silently ignored, preventing proper hook behavior. The SDK now automatically converts field names when communicating with the CLI

Internal/Other Changes

• CI/CD: Re-enabled Windows testing in the end-to-end test workflow. Windows CI had been temporarily disabled but is now fully operational across all test suites

0.1.2

Bug Fixes

• Hook output fields: Added missing hook output fields to match the TypeScript SDK, including reason, continue_, suppressOutput, and stopReason. The decision field now properly supports both "approve" and "block" values. Added AsyncHookJSONOutput type for deferred hook execution and proper typing for hookSpecificOutput with discriminated unions

0.1.1

Features

• Minimum Claude Code version check: Added version validation to ensure Claude Code 2.0.0+ is installed. The SDK will display a warning if an older version is detected, helping prevent compatibility issues
• Updated PermissionResult types: Aligned permission result types with the latest control protocol for better type safety and compatibility

Improvements

• Model references: Updated all examples and tests to use the simplified claude-sonnet-4-5 model identifier instead of dated version strings

0.1.0

Introducing the Claude Agent SDK! The Claude Code SDK has been renamed to better reflect its capabilities for building AI agents across all domains, not just coding.

Breaking Changes

Type Name Changes

• ClaudeCodeOptions renamed to ClaudeAgentOptions: The options type has been renamed to match the new SDK branding. Update all imports and type references:

  # Before
  from claude_agent_sdk import query, ClaudeCodeOptions
  options = ClaudeCodeOptions(...)
  
  # After
  from claude_agent_sdk import query, ClaudeAgentOptions
  options = ClaudeAgentOptions(...)
  

System Prompt Changes

• Merged prompt options: The custom_system_prompt and append_system_prompt fields have been merged into a single system_prompt field for simpler configuration
• No default system prompt: The Claude Code system prompt is no longer included by default, giving you full control over agent behavior. To use the Claude Code system prompt, explicitly set:

  system_prompt={"type": "preset", "preset": "claude_code"}
  

Settings Isolation

• No filesystem settings by default: Settings files (settings.json, CLAUDE.md), slash commands, and subagents are no longer loaded automatically. This ensures SDK applications have predictable behavior independent of local filesystem configurations
• Explicit settings control: Use the new setting_sources field to specify which settings locations to load: ["user", "project", "local"]

For full migration instructions, see our migration guide.

New Features

• Programmatic subagents: Subagents can now be defined inline in code using the agents option, enabling dynamic agent creation without filesystem dependencies. Learn more
• Session forking: Resume sessions with the new fork_session option to branch conversations and explore different approaches from the same starting point. Learn more
• Granular settings control: The setting_sources option gives you fine-grained control over which filesystem settings to load, improving isolation for CI/CD, testing, and production deployments

Documentation

• Comprehensive documentation now available in the API Guide
• New guides for Custom Tools, Permissions, Session Management, and more
• Complete Python API reference

0.0.22

• Introduce custom tools, implemented as in-process MCP servers.
• Introduce hooks.
• Update internal Transport class to lower-level interface.
• ClaudeSDKClient can no longer be run in different async contexts.

0.0.19

• Add ClaudeCodeOptions.add_dirs for --add-dir
• Fix ClaudeCodeSDK hanging when MCP servers log to Claude Code stderr

0.0.18

• Add ClaudeCodeOptions.settings for --settings

0.0.17

• Remove dependency on asyncio for Trio compatibility

0.0.16

• Introduce ClaudeSDKClient for bidirectional streaming conversation
• Support Message input, not just string prompts, in query()
• Raise explicit error if the cwd does not exist

0.0.14

• Add safety limits to Claude Code CLI stderr reading
• Improve handling of output JSON messages split across multiple stream reads

0.0.13

• Update MCP (Model Context Protocol) types to align with Claude Code expectations
• Fix multi-line buffering issue
• Rename cost_usd to total_cost_usd in API responses
• Fix optional cost fields handling