Ghostlight: Codex/Claude-in-Browser capabilities for every Zed agent

[lbotinelly]

Hi Zed folks! I'm the author of Ghostlight, a local browser-control MCP server I built with a lot of help from AI coding agents.

Zed --ACP--> agent harness --MCP--> Ghostlight service --native messaging--> extension --CDP--> Chromium

Ghostlight is not tied to Codex, Claude, or any one model. With Ghostlight registered in Zed's context_servers, every agent harness running through ACP can use the same structured browser tools. Codex is simply the harness I used for this live demo. The integration belongs to the user, so it stays useful as agents and models change.

Those tools let an agent open controlled tabs, read pages, inspect console and network activity, fill forms, upload files, and click when asked. This bridges the awkward gap between code and the signed-in tools around it: GitHub, deployment dashboards, documentation, admin interfaces, and local or staging apps.

Ghostlight uses the Chromium profile where you're already signed in - not a clean automation profile, cloud browser, or copied cookies. Work stays inside visible Ghostlight tabs, while ordinary tabs stay outside its reach.

I'm a visual person, so I wanted its activity to communicate clearly. Clicks ripple, typing shimmers, drags leave a little comet trail, and longer operations have their own cues. A subtle border shows what the agent can control. You can take the wheel or kill the session at any time.

A few tasks I built it for:

Check whether the latest deployment completed successfully. Inspect the page and network activity, but do not change anything.

Open the staging site, complete the onboarding flow, fix any visible problems in the project, and repeat the flow to verify the result.

Fill out this GitHub discussion from the project context, then stop before posting so I can review it.

Try it in Zed

You need Chrome, Edge, Brave, or Chromium 116 or newer.

Install Ghostlight and register Zed:

npx -y ghostlight install --client zed

Then install Ghostlight in Browser, restart Zed, and give your preferred agent a read-only first task:

Open a new tab, go to my GitHub notifications, and summarize the three newest items. Do not mark anything as read or change anything.

If anything looks off:

npx -y ghostlight doctor

Why MCP?

Every ACP harness in Zed can use the same Ghostlight browser tools. I wanted the browser integration to belong to the user and remain useful even as agents and models change.

The local Rust service mediates calls and emits structured audit records. The unrestricted browser core needs no Ghostlight account, subscription, telemetry, or hosted runtime. Optional governance adds host-scoped read/action/write/execute grants and protected domains beneath the model.

• Repository and demo
• Chrome Web Store
• Trust Center
• More information about Ghostlight and my other projects: sylin.org

And the recursive detail: this exact draft was prepared by Codex running inside Zed over ACP, using Ghostlight to operate my signed-in GitHub session. It stopped before posting so I could review it and keep the final click.

What signed-in browser task would you give your preferred Zed agent first, and which browser action should always require confirmation?

Hard security questions and unflattering comparisons are welcome too.

[lbotinelly]

Ghostlight 0.8.0 is now public. The current topology is:

Zed -> agent harness -> ghostlight-mcp-connector -> ghostlight service
    -> ghostlight-browser-connector -> extension -> Chromium

The MCP edge now has exact local stdio state machines for revisions 2025-11-25 and 2026-07-28, while the persistent service stays protocol-neutral. Exact workspace identity, bounded browser-created child-tab continuity, and concrete recovery guidance make longer browser work easier to resume.

Install for Zed with npx -y ghostlight install --client zed, add Ghostlight in Browser, restart Zed, and try the read-only first task at https://sylin.org/ghostlight/.

Release: https://github.com/sylin-org/ghostlight/releases/tag/v0.8.0