Felipe Coury 48f117d0a2 perf(tui): defer startup skills refresh (#18370)
# Summary

This removes startup `skills/list` from the critical path to first
input. In release measurements, median startup-to-input time improved
from `307.5 ms` to `191.0 ms` across 30 measured runs with 5 warmups.

# Background

Startup currently waits for a forced `skills/list` app-server request
before scheduling the first usable TUI frame. That makes skill metadata
freshness part of the process-launch-to-input path, even though the
prompt can safely accept normal input before skill metadata has finished
loading.

I measured startup from process launch until the TUI reports that the
user can type. The measurement harness watched the startup measurement
record, killed Codex after a successful sample, and enforced a timeout
so repeated runs would not leave TUI processes behind. The debug runs
had enough outliers that I used median as the primary signal and ran a
baseline self-compare to understand the noise floor.

# Why skills/list

The `skills/list` cut was the best practical optimization because it
improved startup without changing the important readiness contract: when
the prompt is shown, it is still backed by an active session. Only
enrichment data arrives later.

| Candidate | Result | Decision |
| --- | --- | --- |
| Defer startup `skills/list` | Debug median improved from `524.0 ms` to
`348.0 ms`; release median improved from `307.5 ms` to `191.0 ms`. |
Keep |
| Defer fresh `thread/start` | Debug median improved from `494.0 ms` to
`256.0 ms`, but the prompt could appear before an active thread was
attached. | Reject as too risky for this PR |
| Avoid forced skills config reload | Debug median moved from `509.0 ms`
to `512.0 ms`. | Reject as neutral |
| Skip fresh history metadata | Debug median moved from `496.5 ms` to
`531.5 ms`. | Reject as regression/noise |
| Defer app-server startup | Not implemented because it would only
permit a loading frame unless the TUI gained a deliberate pre-server
state. | Out of scope |

# Implementation

`App::refresh_startup_skills` now clones the app-server request handle,
spawns a background task, and issues the same forced `skills/list`
request after the first frame is scheduled. When the request completes,
the task sends `AppEvent::SkillsListLoaded` back through the normal app
event queue.

The existing skills response handling still converts the app-server
response, updates the chat widget, and emits invalid `SKILL.md`
warnings. Explicit user-initiated skills refreshes still use the
existing synchronous app command path, so callers that intentionally
requested fresh skill state do not race ahead of their own refresh.

# Tradeoffs

The main tradeoff is a narrow theoretical race at startup: skill mention
completion depends on a background `skills/list` response, so it could
briefly show stale or empty metadata if opened before that response
arrives. In manual testing, pressing `$` as soon as possible after
launch still showed populated skill metadata, so this risk appears
minimal in normal use. Plain input remains available immediately, and
the UI updates through the existing skills response path once the
refresh completes.

This PR does not change how skills are discovered, cached,
force-reloaded, displayed, enabled, or warned about. It only changes
when the startup refresh is allowed to complete relative to the first
usable TUI frame.

# Verification

- `cargo test -p codex-tui`
48f117d0a2 · 2026-04-17 16:55:00 -03:00
5,500 Commits
2026-04-14 01:45:41 +00:00
2026-03-26 16:50:07 -07:00
2025-04-16 12:56:08 -04:00
2025-04-16 12:56:08 -04:00
2026-04-14 01:45:41 +00:00
2026-03-10 04:11:31 +00:00
2026-04-07 10:55:58 -07:00

npm i -g @openai/codex
or brew install --cask codex

Codex CLI is a coding agent from OpenAI that runs locally on your computer.

Codex CLI splash


If you want Codex in your code editor (VS Code, Cursor, Windsurf), install in your IDE.
If you want the desktop app experience, run codex app or visit the Codex App page.
If you are looking for the cloud-based agent from OpenAI, Codex Web, go to chatgpt.com/codex.


Quickstart

Installing and running Codex CLI

Install globally with your preferred package manager:

# Install using npm
npm install -g @openai/codex
# Install using Homebrew
brew install --cask codex

Then simply run codex to get started.

You can also go to the latest GitHub Release and download the appropriate binary for your platform.

Each GitHub Release contains many executables, but in practice, you likely want one of these:

  • macOS
    • Apple Silicon/arm64: codex-aarch64-apple-darwin.tar.gz
    • x86_64 (older Mac hardware): codex-x86_64-apple-darwin.tar.gz
  • Linux
    • x86_64: codex-x86_64-unknown-linux-musl.tar.gz
    • arm64: codex-aarch64-unknown-linux-musl.tar.gz

Each archive contains a single entry with the platform baked into the name (e.g., codex-x86_64-unknown-linux-musl), so you likely want to rename it to codex after extracting it.

Using Codex with your ChatGPT plan

Run codex and select Sign in with ChatGPT. We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Business, Edu, or Enterprise plan. Learn more about what's included in your ChatGPT plan.

You can also use Codex with an API key, but this requires additional setup.

Docs

This repository is licensed under the Apache-2.0 License.

S
Description
No description provided
Readme Apache-2.0 156 MiB
Languages
Rust 96.1%
Python 2.9%
Shell 0.3%
Starlark 0.2%
TypeScript 0.2%
Other 0.1%