# Changelog

## 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:
  ```python
  # 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:
  ```python
  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](https://docs.claude.com/en/docs/claude-code/sdk/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](https://docs.claude.com/en/api/agent-sdk/subagents)
- **Session forking**: Resume sessions with the new `fork_session` option to branch conversations and explore different approaches from the same starting point. [Learn more](https://docs.claude.com/en/api/agent-sdk/sessions)
- **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](https://docs.claude.com/en/api/agent-sdk/overview)
- New guides for [Custom Tools](https://docs.claude.com/en/api/agent-sdk/custom-tools), [Permissions](https://docs.claude.com/en/api/agent-sdk/permissions), [Session Management](https://docs.claude.com/en/api/agent-sdk/sessions), and more
- Complete [Python API reference](https://docs.claude.com/en/api/agent-sdk/python)

## 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