Summary
warp-notify.sh (both v2.0.0 and legacy/) emits OSC 777 by writing to /dev/tty. In current Claude Code builds, hook subprocesses are spawned without a controlling terminal, so the write fails with Device not configured (ENXIO) and notifications are silently dropped.
Diagnostic
I instrumented a Stop hook in ~/.claude/settings.json to probe the hook execution environment:
tty=not a tty
devtty_exists=yes
devtty_writable=yes (test -w only checks file perms, not openability)
WARP_CLIENT_VERSION=v0.2026.05.18.05.32.stable_02
WARP_CLI_AGENT_PROTOCOL_VERSION=1
plain_osc_exit=1 stderr=/dev/tty: Device not configured
structured_osc_exit=1 stderr=/dev/tty: Device not configured
should_use_structured() returns true (env vars present, build is past the broken-release threshold) — the gate is not at fault.- Both the legacy
notify;<title>;<body> and the v2.0.0 warp://cli-agent JSON formats fail at the same > /dev/tty redirect.
- macOS Notifications permission for Warp is enabled.
Repro
- Add a
Stop hook to ~/.claude/settings.json that just runs printf '\033]777;notify;test;hi\007' > /dev/tty.
- End any Claude Code turn.
- No banner; if you redirect stderr to a file, you'll see
Device not configured.
Suggested direction
Hook subprocesses can't reach the user's terminal directly. Options to consider:
- Write to stdout instead of
/dev/tty. Whether Warp would render OSC from a captured stream depends on how Claude Code forwards hook stdout — needs investigation.
- Detect ENXIO and fall back to a transport that doesn't require a TTY (e.g.,
osascript on macOS, an OS-level toast on Linux/Windows).
- Coordinate with Anthropic on a documented "notification channel" hook output schema so plugins don't have to side-channel through
/dev/tty.
Environment
- macOS: Darwin 25.4.0
- Warp: v0.2026.05.18.05.32.stable_02 (stable)
- Plugin:
warp@claude-code-warp v2.0.0
- Claude Code: Opus 4.7 (1M context) CLI
Summary
warp-notify.sh(both v2.0.0 andlegacy/) emits OSC 777 by writing to/dev/tty. In current Claude Code builds, hook subprocesses are spawned without a controlling terminal, so the write fails withDevice not configured(ENXIO) and notifications are silently dropped.Diagnostic
I instrumented a
Stophook in~/.claude/settings.jsonto probe the hook execution environment:tty=not a tty
devtty_exists=yes
devtty_writable=yes (test -w only checks file perms, not openability)
WARP_CLIENT_VERSION=v0.2026.05.18.05.32.stable_02
WARP_CLI_AGENT_PROTOCOL_VERSION=1
plain_osc_exit=1 stderr=/dev/tty: Device not configured
structured_osc_exit=1 stderr=/dev/tty: Device not configured
should_use_structured()returns true (env vars present, build is past the broken-release threshold) — the gate is not at fault.notify;<title>;<body>and the v2.0.0warp://cli-agentJSON formats fail at the same> /dev/ttyredirect.Repro
Stophook to~/.claude/settings.jsonthat just runsprintf '\033]777;notify;test;hi\007' > /dev/tty.Device not configured.Suggested direction
Hook subprocesses can't reach the user's terminal directly. Options to consider:
/dev/tty. Whether Warp would render OSC from a captured stream depends on how Claude Code forwards hook stdout — needs investigation.osascripton macOS, an OS-level toast on Linux/Windows)./dev/tty.Environment
warp@claude-code-warpv2.0.0