### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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? HEREDOC IS BROKEN MODEL CONSTSTANTLY ATTEMPTS TO USE HEREDOC TO EDIT FILES IT FAILS EVERY TIME THEN RETRIES HEREDOC WITH DIFFERENT QUOTING A SECOND TIME T

[BUG]

Status Open

Maintainer reply None cached

Activity 0 comments · opened Sep 22, 2026

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?

HEREDOC IS BROKEN MODEL CONSTSTANTLY ATTEMPTS TO USE HEREDOC TO EDIT FILES IT FAILS EVERY TIME THEN RETRIES HEREDOC WITH DIFFERENT QUOTING A SECOND TIME THEN FINALLY SAYS "OH WAIT I HAVE AN EXPLICIT MEMORY INSTRUCTING ME TO NEVER USE HEREDOC" THEN IT FINALLY USES THE EDIT TOOL.

What Should Happen?

CLAUDE SHOULD USE THE EDIT TOOL

Error Messages/Logs

Steps to Reproduce

Ask Claude to make any edit at all to any file

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information