changelog update (#192)

Co-authored-by: Claude <noreply@anthropic.com>

Author: ashwin-ant

CHANGELOG.md

@@ -1,5 +1,48 @@
 # 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.

README.md

@@ -10,7 +10,7 @@ pip install claude-agent-sdk
 
 **Prerequisites:**
 - Python 3.10+
-- Node.js 
+- Node.js
 - Claude Code: `npm install -g @anthropic-ai/claude-code`
 
 ## Quick Start
@@ -59,7 +59,7 @@ options = ClaudeAgentOptions(
 )
 
 async for message in query(
-    prompt="Create a hello.py file", 
+    prompt="Create a hello.py file",
     options=options
 ):
     # Process tool use and results
@@ -271,6 +271,15 @@ See [examples/quick_start.py](examples/quick_start.py) for a complete working ex
 
 See [examples/streaming_mode.py](examples/streaming_mode.py) for comprehensive examples involving `ClaudeSDKClient`. You can even run interactive examples in IPython from [examples/streaming_mode_ipython.py](examples/streaming_mode_ipython.py).
 
+## Migrating from Claude Code SDK
+
+If you're upgrading from the Claude Code SDK (versions < 0.1.0), please see the [CHANGELOG.md](CHANGELOG.md#010) for details on breaking changes and new features, including:
+
+- `ClaudeCodeOptions` → `ClaudeAgentOptions` rename
+- Merged system prompt configuration
+- Settings isolation and explicit control
+- New programmatic subagents and session forking features
+
 ## License
 
 MIT