Does Codex functions.exec return the App Server command/exec result schema?

I’m trying to identify the supported result contract for programmatic tool calls inside Codex—not the ChatGPT API or the Responses API.

The official App Server documentation shows that command/exec returns:

{
  "exitCode": 0,
  "stdout": "...",
  "stderr": ""
}

Reference:

In the Codex environment I’m using, functions.exec can invoke nested tools such as shell_command and apply_patch, but its declared return type is only Promise<unknown>.

Could someone clarify:

  1. Does the fulfilled value from nested shell_command map exactly to App Server command/exec, a commandExecution item, or another internal wrapper?
  2. If this mapping exists, what source file, generated type, version, or commit defines it?
  3. How can a client determine whether stdout and stderr are complete or truncated? Does a completed result guarantee that all output was delivered?
  4. What is the exact result schema and postcondition contract for nested apply_patch?
  5. Are returned JavaScript values guaranteed to be ordinary non-Proxy objects, structured-clone values, or another documented representation?
  6. Is this result contract versioned or covered by a compatibility guarantee?

If these are intentionally internal and unsupported contracts, confirmation of that would also answer the question.