[BUG] JetBrains/IntelliJ plugin terminal: Claude output truncated or lost with no scrollback recovery, plus duplicated text after resize

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?

Bug report draft — Claude Code JetBrains plugin terminal rendering

File at: https://github.com/anthropics/claude-code/issues

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Title

JetBrains/IntelliJ plugin terminal: Claude output truncated or lost with no
scrollback recovery, plus duplicated text after resize

Summary

Running Claude Code in the terminal provided by the Claude Code JetBrains plugin
inside IntelliJ IDEA produces corrupted output. Symptoms, in rough order of
severity:

1. Output is lost and unrecoverable. Text streamed from Claude is cut off or

missing entirely, and scrolling back does not recover it — the content is not
retained in scrollback. Long responses effectively cannot be read in full.

1. Text is duplicated. Previously rendered blocks reappear on screen. This

looks like a display-layer problem rather than Claude emitting the text twice,
and it is noticeably worse after resizing the terminal panel.

1. User input is also affected. Text typed into the prompt is sometimes

truncated mid-word before submission, so the corruption is not limited to the
output stream.

Because the lost output is absent from scrollback rather than merely mis-painted,
this appears to be more than a redraw bug — content seems to be dropped from the
terminal buffer itself.

Environment

• Claude Code CLI: 2.1.220
• Claude Code JetBrains plugin: 0.1.11-beta

(jars dated 2025-09-12, installed at
%LOCALAPPDATA%\JetBrains\IntelliJIdea2025.2\plugins\claude-code-jetbrains-plugin)

• IDE: IntelliJ IDEA 2025.2 (a 2026.1 config directory also exists on this machine,

but the plugin is installed only under 2025.2)

• OS: Windows Server 2019 Standard, 10.0.17763
• Shell: Windows PowerShell 5.1.17763.9020
• Model in use: Opus 5 (1M context)
• Output is long-form markdown: numbered lists, headings, tables, fenced code blocks

Steps to reproduce

1. Open a project in IntelliJ IDEA 2025.2 with the Claude Code plugin installed.
2. Start Claude Code in the plugin-provided terminal.
3. Ask a question whose answer is long enough to scroll the viewport — e.g. a

multi-item numbered list with headings and tables, several hundred lines.

1. Attempt to scroll back through the completed response.
2. Separately, resize the terminal panel (drag the tool-window divider) during or

after streaming.

Observed: parts of the response are missing, and scrolling back does not reveal
them. After a resize, already-rendered blocks appear duplicated.

Expected: the full response renders once, remains available in scrollback, and
resizing reflows existing content without losing or duplicating it.

Isolated to the plugin terminal

Running the same Claude Code version (2.1.220) in PowerShell directly, outside
IntelliJ, does not exhibit the problem — no truncation, no lost output, no
duplication. Every symptom above is specific to the terminal provided by the
JetBrains plugin.

Practical workaround: run Claude Code in a standalone PowerShell window rather than
the plugin-provided terminal.

Open questions

• Whether the duplication occurs without a resize is unknown — resizing makes it

clearly worse, but resize has not been confirmed as the sole trigger.

• No screenshot available — capturing one is impractical given the nature of the

corruption.

What Should Happen?

I should be able to scroll back to view Claude's previous conversation smoothly.

Error Messages/Logs

Steps to Reproduce

Install Claude Code plugin in Intelli, version 0.1.14, which as far as I can tell, is the only version available in IntelliJ.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.220

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_