Ctrl+V clipboard paste fails on macOS - sandbox-exec blocks hiservices XPC service

Description:

Pressing Ctrl+V to paste an image from clipboard fails with "No image found in clipboard" even when an image is present. The issue is that Claude Code's sandbox-exec profile blocks access to com.apple.hiservices-xpcservice, which is required for clipboard operations.

Environment:

• macOS 26.2 (25C56, tested on multiple terminals: WezTerm, Terminal.app)
• Claude Code version: 2.1.2
• claude doctor reports all checks pass

Reproduction steps:

1. Take a screenshot with Cmd+Shift+4 (or Cmd+Ctrl+Shift+4)
2. Verify clipboard has image: osascript -e 'clipboard info' shows «class PNGf»
3. In Claude Code, press Ctrl+V
4. Error: "No image found in clipboard"

Root cause analysis:

Running osascript -e 'clipboard info' from within Claude Code fails with:

Connection Invalid error for service com.apple.hiservices-xpcservice
Error received in message reply handler: Connection invalid

The same command works perfectly in a regular terminal outside Claude Code.

Investigation revealed:

1. Claude Code sets SANDBOX_RUNTIME=1 environment variable for all child processes
2. Commands are wrapped with sandbox-exec -p <profile> bash -c <command>
3. The sandbox profile does not allow mach-lookup for com.apple.hiservices-xpcservice
4. This blocks all clipboard access via osascript from sandboxed processes

Relevant code found in binary strings:

let A=["SANDBOX_RUNTIME=1","TMPDIR=/tmp/claude"];
// ...
let z=h9_.default.quote(["env",...Z,"sandbox-exec","-p",Q,F,"-c",R]);

Claude Code uses these osascript commands for clipboard access (from binary strings):

osascript -e 'the clipboard as «class PNGf»'
osascript -e 'set png_data to (the clipboard as «class PNGf»)'

Manually verified:

• osascript -e 'clipboard info' returns valid PNG data («class PNGf», 109696, ...) when run outside Claude Code
• The same command fails with the XPC connection error when run from within Claude Code
• Clipboard paste worked briefly after switching from npm to brew installation, then stopped working (subsequent brew reinstalls did not fix it)

What doesn't help:

• Setting "sandbox": { "enabled": false } in ~/.claude/settings.json - the sandbox-exec wrapping is hardcoded
• Granting terminal apps Accessibility/Automation permissions in System Settings
• Reinstalling Claude Code via brew
• Different terminal emulators

Suggested fix:

Add clipboard XPC service access to the sandbox profile:

(allow mach-lookup (global-name "com.apple.hiservices-xpcservice"))

Or exclude clipboard-related osascript commands from sandboxing.

Workaround:

Use an MCP server or skill that accesses the clipboard outside of Claude Code's sandboxed bash context (e.g., pngpaste via a custom tool).

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Note: This bug report was created with assistance from Claude Code itself. The root cause analysis (sandbox-exec blocking XPC services, binary string extraction, tracing the SANDBOX_RUNTIME=1 environment variable) was performed by Claude Code. The osascript command results and the intermittent behavior after switching package managers were manually verified by the reporter.