claude-code-sdk-python/CHANGELOG.md

Changelog

0.1.18

Internal/Other Changes

• Docker-based test infrastructure: Added Docker support for running e2e tests in containerized environments, helping catch Docker-specific issues (#424)
• Updated bundled Claude CLI to version 2.0.72

0.1.17

New Features

• UserMessage UUID field: Added uuid field to UserMessage response type, making it easier to use the rewind_files() method by providing direct access to message identifiers needed for file checkpointing (#418)

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.70

0.1.16

Bug Fixes

• Rate limit detection: Fixed parsing of the error field in AssistantMessage, enabling applications to detect and handle API errors like rate limits. Previously, the error field was defined but never populated from CLI responses (#405)

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.68

0.1.15

New Features

• File checkpointing and rewind: Added enable_file_checkpointing option to ClaudeAgentOptions and rewind_files(user_message_id) method to ClaudeSDKClient and Query. This enables reverting file changes made during a session back to a specific checkpoint, useful for exploring different approaches or recovering from unwanted modifications (#395)

Documentation

• Added license and terms section to README (#399)

0.1.14

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.62

0.1.13

Bug Fixes

• Faster error handling: CLI errors (e.g., invalid session ID) now propagate to pending requests immediately instead of waiting for the 60-second timeout (#388)
• Pydantic 2.12+ compatibility: Fixed PydanticUserError caused by McpServer type only being imported under TYPE_CHECKING (#385)
• Concurrent subagent writes: Added write lock to prevent BusyResourceError when multiple subagents invoke MCP tools in parallel (#391)

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.59

0.1.12

New Features

• Tools option: Added tools option to ClaudeAgentOptions for controlling the base set of available tools, matching the TypeScript SDK functionality. Supports three modes:
  • Array of tool names to specify which tools should be available (e.g., ["Read", "Edit", "Bash"])
  • Empty array [] to disable all built-in tools
  • Preset object {"type": "preset", "preset": "claude_code"} to use the default Claude Code toolset
• SDK beta support: Added betas option to ClaudeAgentOptions for enabling Anthropic API beta features. Currently supports "context-1m-2025-08-07" for extended context window

0.1.11

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.57

0.1.10

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.53

0.1.9

Internal/Other Changes

• Updated bundled Claude CLI to version 2.0.49

0.1.8

Features

• Claude Code is now included by default in the package, removing the requirement to install it separately. If you do wish to use a separately installed build, use the cli_path field in Options.

0.1.7

Features

• Structured outputs support: Agents can now return validated JSON matching your schema. See https://docs.claude.com/en/docs/agent-sdk/structured-outputs. (#340)
• Fallback model handling: Added automatic fallback model handling for improved reliability and parity with the TypeScript SDK. When the primary model is unavailable, the SDK will automatically use a fallback model (#317)
• Local Claude CLI support: Added support for using a locally installed Claude CLI from ~/.claude/local/claude, enabling development and testing with custom Claude CLI builds (#302)

0.1.6

Features

• Max budget control: Added max_budget_usd option to set a maximum spending limit in USD for SDK sessions. When the budget is exceeded, the session will automatically terminate, helping prevent unexpected costs (#293)
• Extended thinking configuration: Added max_thinking_tokens option to control the maximum number of tokens allocated for Claude's internal reasoning process. This allows fine-tuning of the balance between response quality and token usage (#298)

Bug Fixes

• System prompt defaults: Fixed issue where a default system prompt was being used when none was specified. The SDK now correctly uses an empty system prompt by default, giving users full control over agent behavior (#290)

0.1.5

Features

• Plugin support: Added the ability to load Claude Code plugins programmatically through the SDK. Plugins can be specified using the new plugins field in ClaudeAgentOptions with a SdkPluginConfig type that supports loading local plugins by path. This enables SDK applications to extend functionality with custom commands and capabilities defined in plugin directories

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