Codex Chrome: read_page fails when BROWSER_USE_TINYSKY_ENABLED=1 disables dom_cua

[CatcherITGF]

Problem

The Codex Chrome integration's read_page fails when the Codex Node REPL is configured with BROWSER_USE_TINYSKY_ENABLED = "1":

Cannot read properties of undefined (reading 'get_visible_dom')

Opening tabs, navigating, going back, listing tabs, and closing tabs still work. Reading the page fails before a DOM snapshot can be obtained.

Environment

• macOS, Apple Silicon
• Executor v1.6.10
• codex-cli 0.155.1
• Codex Chrome plugin 26.915.31945
• Google Chrome 153.0.8010.48
• Executor's built-in Codex Chrome preset, using codex app-server and the plugin's browser-client.mjs

Relevant Codex configuration:

[mcp_servers.node_repl.env]
BROWSER_USE_TINYSKY_ENABLED = "1"

Reproduction

1. Configure the Codex Chrome preset in Executor with a working local Codex/Chrome installation.
2. Enable the setting above in the Codex configuration used by the integration.
3. Call navigate with https://example.com and retain the returned tab ID.
4. Call read_page with that tab ID.

Actual result: the error above. Expected result: a page snapshot, or an actionable compatibility error if the configured browser API is unsupported.

Diagnosis

The installed Executor browser projection implements read_page as:

await __tab.dom_cua.get_visible_dom()

In the installed Codex browser service, enabling TinySky sets these API support overrides:

{
  "Tab.ax": true,
  "Tab.cua": false,
  "Tab.dom_cua": false
}

The browser client hides disabled API members, so tab.dom_cua is undefined. Executor's click, typing, keypress, and scrolling projections also reference dom_cua, although those commands were not individually tested with TinySky enabled.

Related: #1837 explains that dom_cua was selected because the plugin documentation at that time marked ax unsupported on the Chrome extension backend. This appears to be a compatibility gap with the enabled TinySky mode rather than a Chrome connectivity failure.

Verified workaround

Override the setting only for Executor's Codex Chrome integration by changing its spawn arguments to:

[
  "app-server",
  "-c",
  "mcp_servers.node_repl.env.BROWSER_USE_TINYSKY_ENABLED=\"0\""
]

This leaves the global Codex configuration unchanged. After applying the override through Executor's MCP server configuration API, the following succeeded:

• Navigate to https://example.com.
• Read the DOM snapshot and obtain the Learn more link's node ID.
• Click that node and verify navigation to IANA's Example Domains page.
• Read the destination page and close the test tab.