Message models are missing 'timestamp' field

[danielsiwiec]

This timestamp field is present in the JSONL file, but the Message types are missing it. Adding it, would be helpful for use cases where the actual Message timestamp is important (ex. displaying a timeline)

[danielsiwiec]

I'm happy to submit a PR for this, if there's an agreement this is useful to have

[vikramsingh117]

greetings, @danielsiwiec do you mind checking this out? also should I prepare tests?
although i did mock it

 {
    "type": "assistant",
    "timestamp": 1734300000123,
    "parent_tool_use_id": None,
    "message": {
        "role": "assistant",
        "model": "fake-model",
        "content": [
            {"type": "text", "text": "hello"}
        ]
    }
}
msg = parse_message(raw)
print(type(msg).__name__)
print("timestamp:", getattr(msg, "timestamp", None))
print("model:", getattr(msg, "model", None))
print("content:", getattr(msg, "content", None))

AssistantMessage timestamp: 1734300000123 model: fake-model content: [TextBlock(text='hello')]

[enioxt]

Hi! 👋

I can add the missing timestamp field to Message models.

Analysis

Message models in agent SDK should include timestamp for tracking message timing and sequencing.

Implementation Plan

1. Add timestamp field to Message model (datetime type)
2. Populate on message creation
3. Update serialization/deserialization
4. Add tests for timestamp handling
5. Update type hints + documentation

Questions

1. ISO 8601 format or Unix timestamp?
2. Should it be optional (backwards compat) or required?
3. Timezone: UTC or preserve original?

Background

Experienced with Anthropic SDK patterns, maintained EGOS v.2 with comprehensive message tracking.

Timeline: 2 days

Happy to implement!

[danielsiwiec]

thanks @vikramsingh117 , @enioxt. I already have a PR for this here
@ashwin-ant or @dicksontsai - would love a review on this PR 🙏