[Feature] Support semantic prompt zones (OSC 133) for terminal prompt navigation

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

In long Claude Code sessions, there's no way to quickly jump between user prompts using terminal-native navigation. Every modern terminal emulator (Ghostty, iTerm2, Kitty, WezTerm, VS Code Terminal, Windows Terminal) supports "jump to prompt" via OSC 133 semantic prompt markers — but Claude Code doesn't emit them.

This means:

• Ghostty's jump_to_prompt action jumps to the shell prompt before claude was launched — skipping every prompt inside the session
• iTerm2's "Select Command Output" doesn't work
• VS Code Terminal's prompt navigation is broken
• Terminal scrollbar gutter marks (showing where prompts are) don't appear

Multiple open issues describe this same pain from different angles:

• #16784 — "Keyboard shortcut to navigate between user prompts"
• #19550 — "Add scroll to previous prompts navigation" (explicitly notes that terminal jump-to-prompt doesn't work)

Previously requested in #1465 (May 2025) and #22528 (Feb 2026) — both autoclosed by the inactivity/duplicate bot without any team response. Filing fresh because the feature gap persists and the prior issues are locked.

Proposed Solution

Emit OSC 133 sequences (A/B/C/D) around Claude Code's REPL cycle. Claude Code already emits OSC 8 (hyperlinks) and OSC 9;4 (progress bars), so the infrastructure for writing escape sequences to stdout exists.

The minimal implementation:

const OSC = '\x1b]';
const ST  = '\x07';  // BEL terminator (most compatible)

// Before rendering the prompt:
process.stdout.write(`${OSC}133;A${ST}`);

// After prompt text, before user input area:
process.stdout.write(`${OSC}133;B${ST}`);

// After user submits, before agent output:
process.stdout.write(`${OSC}133;C${ST}`);

// After agent output completes:
process.stdout.write(`${OSC}133;D;0${ST}`);

The full lifecycle maps cleanly to Claude Code's existing REPL:

| Phase | OSC 133 | Claude Code equivalent |
|-------|---------|----------------------|
| Prompt start | 133;A | Before rendering the input prompt / footer |
| Input start | 133;B | After prompt, cursor in text input area |
| Execution start | 133;C | User presses Enter, agent starts working |
| Execution end | 133;D;0 | Agent finishes, ready for next prompt |

Terminals that don't understand OSC 133 silently ignore these sequences (confirmed by fish shell's unconditional emission — PR #10352), so there's zero risk to unsupported terminals.

For additional VS Code Terminal integration, optionally emit the OSC 633 superset when $TERM_PROGRAM === "vscode".

Alternative Solutions

An in-app prompt navigator (as requested in #19550) would also work, but OSC 133 is complementary — it integrates with every terminal's existing navigation without any additional UI, and the implementation is ~4 lines of code.

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

I'm 30 prompts into a debugging session in Ghostty (nightly). I want to revisit an earlier prompt where I asked Claude to analyze a specific file. In any shell, I'd use my terminal's "jump to prompt" shortcut to hop between prompts — but in Claude Code, this jumps all the way back to the shell prompt where I typed claude, skipping every interaction inside the session. The only option is manual scrolling through hundreds of lines of output.

Additional Context

Terminal support for OSC 133 (de facto standard):
Ghostty, iTerm2, Kitty, WezTerm, VS Code Terminal, Windows Terminal, tmux, foot — full spec

Claude Code already emits other OSC sequences:

• OSC 8 for clickable hyperlinks (shipped)
• OSC 9;4 for progress bars (shipped)

Reference implementations:

• Ghostty's zsh integration — full state machine
• Fish shell OSC 133 — unconditional emission, zero terminal detection needed
• Semantic Prompts spec — canonical reference

This would also resolve or partially address #16784 and #19550 for users in terminals that support OSC 133.

\x1b]133;A;cl=line\x07

osascript -e 'tell application "System Events" to tell process "iTerm2" to click menu item "Set Mark" of menu "Marks and Annotations" of menu item "Marks and Annotations" of menu "Edit" of menu bar 1'