0.11.7

## 🧑 Human-in-the-Loop (HITL) Support 
This release introduces human-in-the-loop functionality for tool execution, allowing users to configure certain tools are requiring approvals or specify per-agent requirements. This feature introduces two new `LettaMessage` types:  
* `ApprovalRequestMessage` (for the agent to request an approval) 
* `ApprovalResponseMessage` (for the client to either provide or deny an approval)

Example of approving a tool call: 
```python
response = client.agents.messages.create(
    agent_id=agent.id,
    messages=[{
        "type": "approval",
        "approve": True,
        "approval_request_id": "message-abc123",
    }]
)
```
See the full documentation [here](https://docs.letta.com/guides/agents/human-in-the-loop). 

## 📁 Agent File (`.af`) v2 
The Agent File schema has been migrated to a v2 version, and now supportsgroups (multi-agent) and files ([#4249](https://github.com/letta-ai/letta/commit/d32b57f941c342a52e5c786ef76a77cf445a94a6)).

## 🔎 Archival memory search 
Improvements to archival memory search with support for tags, timestamps, and hybrid search: 

- **Tag-Based Search and Insert**: Agents can now insert and search archival memories with arbitrary string tags ([#4300](https://github.com/letta-ai/letta/commit/bc649ebf45b66ff80fa962605d354635eb0495ab), [#4285](https://github.com/letta-ai/letta/commit/6d9b0bdc3a40bc16b1756b6d7db35062a365a57e))
- **Temporal Filtering**: Support for timestamp-based filtering of archival memories ([#4330](https://github.com/letta-ai/letta/commit/2a34b7ec138a25a988e75f1e17f6a4ff8a56e552), [#4398](https://github.com/letta-ai/letta/commit/b8311395e81eec7aee9eb66a0a405ef7a564ae14))
- **Hybrid Search**: New archival search endpoint with hybrid search functionality ([#4390](https://github.com/letta-ai/letta/commit/a84cd7c93fdebd77405ee4d2e9b04a1c8f7021cd))

## 🧠 Model and provider support 
- **GPT-5 Optimization**: Improved GPT-5 support with proper context window handling and reasoning effort configuration ([#4344](https://github.com/letta-ai/letta/commit/a2f3a094b75ee0d4c15ccb5f2b9f63314915651f), [#4379](https://github.com/letta-ai/letta/commit/abb298e970d0daff412a3a24fa13cf06efa9a4c6), [#4380](https://github.com/letta-ai/letta/commit/3113610943a6c8921dced21289cdadaa87f8cb60))
- **DeepSeek Support**: Migration of DeepSeek to new agent loop architecture ([#4266](https://github.com/letta-ai/letta/commit/6fc3ea506c7ddb146b0ba2b2ab1576128cfed527))
- **Enhanced Anthropic Support**: Better native reasoning support and tool schema formatting ([#4331](https://github.com/letta-ai/letta/commit/d5580654ede2e9f4c8d62813750d574ce9a7514d), [#4378](https://github.com/letta-ai/letta/commit/5548b4f006085db7ad482bd4e1ba3dc109d3efa2))
- **Extended Thinking**: Fixed various issues with extended thinking mode for Anthropic ([#4341](https://github.com/letta-ai/letta/commit/79331eedc3922fe11128e8ae199ed327eda589c1))
- **MCP Tool Schema**: Fixed MCP tool schema formatting for Anthropic streaming ([#4378](https://github.com/letta-ai/letta/commit/5548b4f006085db7ad482bd4e1ba3dc109d3efa2))
- **Gemini Improvements**: Enhanced error handling and retry logic ([#4323](https://github.com/letta-ai/letta/commit/4ad32eda83906f23540176e6dbd79d2f53e69c6a), [#4397](https://github.com/letta-ai/letta/commit/b7dca5937952b33fec9c229bb051aa622cb48b2a))

## 🧩 Misc improvements
- **Refactored Streaming Logic**: Improved streaming route architecture ([#4369](https://github.com/letta-ai/letta/commit/d242620638fdd91189f319031ade08b316f4233a))
- **Better Error Handling**: Enhanced error propagation in streaming responses ([#4253](https://github.com/letta-ai/letta/commit/a455e7cd5e6f788262d0dfa630b5f41e8cafef41))
- **Tool Return Limits**: Reduced default tool return size to prevent token overflow ([#4383](https://github.com/letta-ai/letta/commit/eefd2fafadfa61da7b7c02063fdb525d7018ad9c))
- **Embedding Support**: Enable overriding embedding config on Agent File import ([#4224](https://github.com/letta-ai/letta/commit/8b1cfdb7f4213608c2cfb5b65883b5a9721ed488))
- **Tool Type Filtering**: Ability to list and filter tools by type ([#4036](https://github.com/letta-ai/letta/commit/3c016eae351d7a030e1ca5e9aab0cc21e8740ca9))
- **Tool De-duplication**: Automatic de-duplication of tool rules ([#4282](https://github.com/letta-ai/letta/commit/1a2bebf781b2e3b612e2a04cd36a1abfcda8d568))