Terminal support for CLI notifications via OSC9 (ESC ] 9 ; <message> BEL)

[adamalix]

Disclosure: I used codex CLI to gather the context to write this post. I tried to do it thoughtfully, and I verified its output to the best of my ability. This post in its entirety was written by me, a verifiable human. I don't have worldcoin tho.

Problem

Zed's Terminal doesn't currently support forwarding notifications from CLI's that emit OSC9 escaped messages (ESC ] 9 ; <message> BEL).

This adds friction for workflows which depend upon being notified of task completion. Zed users must manually poll for results by switching to & from the terminal running the process. This can cause Zed users to miss progress updates and possibly lose time.

Solving this problem will save Zed users time and make the built in terminal more broadly useful. This will hopefully drive retention to the editor because of its excellent terminal experience.

Example workflow

A popular workflow supported by this is coding with the codex CLI.

A developer prompts codex in a popular terminal (like ghostty, which supports parsing OSC9). They prompt codex, building up a plan which gives them high confidence. The developer agrees on the plan with codex and then asks the agent to run with the task.

The task will be long-running process and the developer wants to begin planning another task with an agent in a different tab. They open a tab and begin building the context required to perform another task.

The original codex loop gets stuck asking for permissions to execute a command. The developer receives a notification and unblocks the agent. They do this by clicking the notification and the pane / tab / window which sent the notification is activated. They accept the prompt and continue planning.

This is not possible today when using CLI agents within Zed terminal. Zed users do not receive a notification and may lose the time that the agent sits blocked until they notice.

My dream workflow

I'd love to be able to run the terminal in a zoomed-in mode (SHIFT+ESC) and either use panes to run multiple codex agents, or separate terminals. When an agent turn ends, or it needs to be unblocked, I'd receive a pop-up (much like the Agent Panel pop-ups today). Clicking the pop-up would activate the terminal pane or tab that sent the notification.

Context and possible implementation

Helpful context

• codex emits messages using OSC9.
• alacritty/vte doesn't handle parameter 9 in osc_dispatch ansi.rs
• Progress indicators also use OSC9 (ESC ] 9 ; 4 ; .... BEL), and this change could make it easier to implement progress indicators in the Zed terminal.

I think Zed depends on vte -- it lists a pinned fork, whose version aligns with a recent tag from the upstream repository.

How it could be implemented

In vte:

• Add a case for matching b"9" in osc_dispatch
• Extend the pub trait Handler with a fn that accepts a message

In alacritty_terminal:

• Bump vte version in Cargo.toml
• Add a new terminal event like Event::Notification(String) to alacritty_terminal/src/event.rs

In Zed:

• Map the new Alacritty::Notification event to a Zed terminal event in zed/crates/terminal/src/terminal.rs
  • Maybe strip control characters & truncate length??
• Use similar gating logic to zed/crates/agent_ui/src/acp/thread_view.rs
• Add a setting to show a pop-up when received by the terminal in zed/crates/settings_content/src/terminal.rs

[Konadu-Akwasi-Akuoko]

+1 to this. Coming from Ghostty where OSC9/OSC777 notifications work out of the box with Claude Code, the absence of this in Zed's terminal is worrying, especially when running long agentic tasks.

I use Claude Code, and it fires a Notification event (via OSC escape sequences) when it's idle or blocked on a permission prompt. In Ghostty, this surfaces as a native macOS desktop notification with no configuration needed. In Zed, there's no signal at all.

The workaround is setting up a Notification hook in ~/.claude/settings.json to call osascript or terminal-notifier, but this is purely an escape hatch and doesn't address the root issue. It also means the notification has no awareness of which Zed pane or tab triggered it, the workflow described above (clicking a notification and being taken to the right terminal pane) isn't achievable through hooks. On macos if you click on the osascript notifications it opens up the Finder app for you, which is terrible.

If this is pulled off, this would make Zed a first-class terminal for agentic CLI workflows (Claude Code, Codex, etc.) rather than requiring users to drop back into Ghostty or iTerm2, or using notification hook for a better notification experience.

I'll be happy to open a PR, if the maintainers will accept this proposal.

[Konadu-Akwasi-Akuoko]

Ok, I can see that there is an open PR here:
zed-industries/alacritty#2

I will try and pick it up, and see if I can get it merged

[adamalix]

My use case is now covered by agent threads & the new agent panel. Thanks so much!

[suryaashish-kubesense]

Are you getting notifications for the terminal agents?

[adamalix]

Yes, Agent Threads which use a Terminal agent send notifications via the Zed-native notifications feature