[BUG] Cowork: saved session fails to reload with "Prompt is too long" error

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The session was created normally and completed successfully. On reopening the Claude Desktop app and navigating back to the Cowork tab, the session appears in the sidebar but cannot be resumed. Session is unrecoverable from the UI. The .jsonl file exists locally and contains all the conversation data, but Cowork attempts to replay the full raw history as a prompt, exceeding the model's context limit.

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What Should Happen?

Implement context truncation or summarization when reloading long sessions, similar to how long conversations are handled in the Chat tab. At minimum, show a warning with an option to load a truncated version.

Error Messages/Logs

Steps to Reproduce

1. Start a Cowork session and work on a moderately long task (multi-step, many tool calls)
2. Close and reopen the Claude Desktop app
3. Navigate to Cowork and attempt to resume the previous session
4. Observe the "Prompt is too long" error, session does not load

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

Claude 1.1.3189 (1b7b58) 2026-02-14T00:09:46.000Z

Claude Code Version

Claude 1.1.3189 (1b7b58) 2026-02-14T00:09:46.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_