Show remaining Codex credits / usage in the CLI statusline

Feature request

Please add a Codex CLI statusline field that shows remaining Codex plan usage / credit balance, similar to how Claude Code surfaces remaining usage directly in the terminal.

Today the CLI can show useful local/session state such as model, reasoning level, current directory, git branch, and context remaining. However, remaining Codex usage or credits are not available as a first-class statusline item. Users have to leave the terminal and open Codex Settings → Usage / Credits to understand whether they are close to a plan or purchased-credit limit.

Why this matters

For long agentic coding sessions, remaining usage is operationally important. It affects whether a user should:

• continue with the current model or switch to a cheaper/smaller one
• enable or avoid fast mode
• compact/reset context before continuing
• pause work before hitting a limit mid-task
• buy credits or wait for included usage to reset

This is especially important because Codex usage varies heavily with task size, context size, model choice, fast mode, and long-running agent workflows.

Suggested statusline fields

Add one or more selectable /statusline fields, for example:

status_line = [
  "model-with-reasoning",
  "codex-credits-remaining",
  "codex-usage-remaining",
  "context-remaining",
  "current-dir",
]

Possible rendered examples:

gpt-5.4 high · Credits $12.40 · Context 72% left · ~/repo

or

gpt-5.4 high · Codex usage 63% left · Credits $12.40 · ~/repo

Notes

• If exact usage cannot be fetched cheaply or reliably, a stale/last-known value with a timestamp would still be useful.
• If there are separate windows/limits, showing the most constraining limit first would be helpful.
• If an organization/workspace has no credit data available, the field could be omitted or show usage unavailable.
• This is related to broader usage/limits visibility requests such as #15281, but specifically asks for a statusline field so users can monitor budget without leaving the CLI.

Comparison

Claude Code surfaces remaining usage in the terminal. Codex should have comparable terminal-native budget visibility.