Status bar / token counter freezes during long single Write tool calls (desktop app)Status bar / token counter freezes during long single Write tool calls (desktop app)

Summary

During a long agent turn, when the model issues a single Write tool call with a large payload (e.g. a ~200-line markdown file), the Claude Code desktop app status bar stops updating mid-turn: no token counter, no "Thinking" / "Flibbertigibbeting" indicator, no active tool name. The underlying agent loop keeps running normally; the tool call completes and the file lands correctly. A single keystroke into the input box (even just typing "OK") unsticks the UI and the status indicator + tool activity reappear.

Environment

• Client: Claude Code desktop app (GUI, not TUI/terminal)
• Platform: Windows 11, model Opus 4.6 (1M context)
• Project: Long-running multi-turn session with agent subagents; the freeze happens specifically during end-of-session Write calls for large workflow files

Reproduction

1. Start a long session (agent dispatching subagents, multiple tool calls already in the turn)
2. Have the model Write a new file with ~150-250 lines of markdown prose (e.g. a session handoff prompt, a long log entry)
3. Watch the status bar during that single Write call

Observed: Status bar + token counter + tool activity indicator all go blank mid-call. The Write itself succeeds silently — file lands on disk correctly. No error reported.

Expected: Status bar continues to stream token count + show the active Write tool name, same as any other tool call.

Workaround

Any keystroke in the input box (even a single letter, Enter not required) snaps the UI back to live. The typed keystroke is delivered to the model as a real user message on the next turn — so it isn't purely a display artifact, the input path is also stalled until the keystroke arrives.

Frequency

Reliably reproducible on end-of-session protocol in this project. Seen on 2 consecutive sessions at the exact same step (writing a ~200-line NEXT_SESSION_PROMPT.md as the final tool call before commit). Does not seem to happen on short Write calls (<100 lines) or on Edit calls regardless of size.

Related but not duplicate

• #25286 — TUI input freeze via terminal renderer (different client; this report is the desktop GUI)
• #26224 — generic hang complaints (no specific trigger identified)
• #23985 / #23987 — long-session buffer rendering (closed; performance-related, not specific to single Write calls)

Additional context

Agent subagents (Agent tool) were running earlier in the same turn. Tool call sequence before the stall: ~60 tool calls over ~25 min (subagent dispatch + review loops + git commits). The stall happens specifically on the single Write call that ships the large payload, not on surrounding smaller calls.