get_session_info() returns no AI-generated title for sessions created via the Python SDK

[ritu456286]

Problem

Follow-up to #161, which was closed saying get_session_info() would return the AI-generated title via SDKSessionInfo.summary / custom_title (available since SDK v0.1.50+).

In practice it doesn't. For sessions driven by the Python SDK, get_session_info() never returns an AI-generated title — it falls back to the first prompt. The bundled CLI never writes the {"type":"ai-title", ...} line into the session JSONL during SDK-driven sessions, so there is nothing for get_session_info() to surface.

The read side (_internal/sessions.py) is fine — it does look for aiTitle and exposes it through custom_title. The bug is the write side: that line is never created.

Reproduction

• SDK: claude-agent-sdk 0.1.60
• Bundled CLI: cli.js 2.1.111
• Python 3.11.13, Linux

import asyncio
from pathlib import Path
from claude_agent_sdk import (
    ClaudeAgentOptions,
    ClaudeSDKClient,
    ResultMessage,
    get_session_info,
)

async def main():
    cwd = Path.cwd()
    async with ClaudeSDKClient(options=ClaudeAgentOptions(cwd=str(cwd))) as client:
        await client.query("Tell me about Python and its history")
        session_id = None
        async for msg in client.receive_response():
            if isinstance(msg, ResultMessage):
                session_id = msg.session_id

    info = get_session_info(session_id, directory=str(cwd))
    print(repr(info.summary))       # -> "Tell me about Python and its history"
    print(repr(info.custom_title))  # -> None

asyncio.run(main())

grep ai-title <session>.jsonl returns nothing — even after long sessions, even after await asyncio.sleep(100) before exit.

Workaround

The CLI does support an explicit control request that generates and persists the title. We can fire it right after client.query() so the title is fetched in parallel with the assistant response:

async with ClaudeSDKClient(options=options) as client:
    await client.query(prompt)

    # Fire title generation now; runs concurrently with the assistant turn.
    title_task = asyncio.create_task(
        client._query._send_control_request(
            {
                "subtype": "generate_session_title",
                "description": prompt,
                "persist": True,
            }
        )
    )

    async for msg in client.receive_response():
        if isinstance(msg, ResultMessage):
            session_id = msg.session_id

    result = await title_task
    print(result["title"])

# Now get_session_info() returns the AI title:
info = get_session_info(session_id, directory=str(cwd))
assert info.custom_title == result["title"]

This works reliably and the ai-title line is on disk by the time the call returns. But _query._send_control_request is private and the generate_session_title subtype isn't in the SDKControlRequest union, so we'd rather not depend on it.

What we'd like

1. Confirm whether there's a public API we missed for getting the AI-generated title from the SDK. We checked the public exports (get_session_info, list_sessions, rename_session, and the methods on ClaudeSDKClient) and didn't find one.

2. If not, please add a public client.get_session_title() method that generates the title in parallel with the assistant response — the way the CLI's interactive UI already does it (it just doesn't persist the result to the JSONL).

3. With that in place, please make get_session_info() actually return the AI title for SDK-driven sessions, so the resolution from Get summarized title of the chat #161 holds.