Codex: what it is, features, and how to use it with Geek Hub (2026)

Codex is an terminal coding agent (CLI) built for Large Language Model (LLM) workflows. OpenAI coding agent that helps you build and ship with AI. This Codex review covers what Codex is, key Codex features, who should use Codex, how to use Codex step by step, and how to connect Codex to Geek Hub when it supports an OpenAI-compatible endpoint. Official site: openai.com.

CLIUpdated 2026-08-11Official site

What is Codex?

Codex is OpenAI coding agent that helps you build and ship with AI. In practice, Codex works as an terminal coding agent (CLI) in the ecosystem of apps and agents that call LLMs over APIs.

People searching “what is Codex” usually compare Codex with other tools in the same cluster (CLI Agents). On public usage rankings (e.g. OpenRouter), Codex shows up there — adoption context, not Geek Hub token volumes.

If you want to run Codex with Claude, GPT, Gemini, or open-source models without locking to one vendor, the useful setup is: Codex + an OpenAI-compatible gateway (Geek Hub).

Key features of Codex

Codex features change with each release — always confirm in the official Codex docs (openai.com). As an terminal coding agent (CLI), Codex typically covers:

  • Codex: Terminal-native coding agent
  • Codex: Edit, refactor, and debug from the CLI
  • Codex: Client or settings for multiple LLM providers via a gateway

Who should use Codex?

Codex fits if you need an terminal coding agent (CLI) and care about model flexibility. Typical Codex audiences:

  • Codex for terminal-first software developers and programmers
  • Codex for people who refactor, debug, and commit with a CLI agent
  • Codex for multi-model users who want a unified LLM client via a gateway

How to use Codex

How to get started with Codex in most setups (adjust to Codex docs):

  • Install or open Codex from openai.com
  • Create an account or API access per Codex’s flow
  • Configure the model / provider inside Codex
  • If Codex supports an OpenAI-compatible base URL, point Codex at Geek Hub
  • Run a short workflow in Codex and check quality + cost

Codex pricing and plans

Codex pricing depends on the product (free, freemium, subscription, or open-source). Always check the official Codex page at openai.com before you decide.

Even when Codex is free or freemium, model usage via API is usually billed separately. That’s why many teams connect Codex to a gateway like Geek Hub: one key, many models, spend control.

How to use Codex with Geek Hub (OpenAI-compatible API)

Geek Hub is an LLM gateway with an OpenAI-compatible API. If Codex supports a custom provider or OpenAI-compatible base URL, connect Codex to Geek Hub and pick Claude, GPT, Gemini, or other catalog models with one API key — without switching tools.

That way Codex stays your terminal coding agent (CLI), and Geek Hub handles routing, cost, and model fallback.

  1. Create an account at app.geekhub.mx and generate an API key for Codex
  2. In Codex, open model / OpenAI-compatible provider settings
  3. Point Codex at base URL https://api.geekhub.mx/v1
  4. Paste your Geek Hub API key into Codex and pick a catalog model id
  5. Run a short test in Codex and check cost in the Geek Hub dashboard
# Codex → Geek Hub
OPENAI_BASE_URL=https://api.geekhub.mx/v1
OPENAI_API_KEY=gh_...
# example model id: anthropic/claude-sonnet-5
Get an API key

Codex FAQ

What is Codex?
Codex is an terminal coding agent (CLI). OpenAI coding agent that helps you build and ship with AI. See openai.com for product details.
Does Codex work with Geek Hub?
If Codex supports an OpenAI-compatible provider, yes: configure Codex with base URL https://api.geekhub.mx/v1 and your Geek Hub API key. If Codex only speaks closed proprietary APIs, this Codex guide is still a useful overview, but wiring may not apply.
How do I use Codex with Claude, GPT, or Gemini?
In Codex, pick a custom / OpenAI-compatible provider when available, point it at Geek Hub, and select the model id (e.g. anthropic/…, openai/…, google/…). That way Codex switches models without switching apps.
Is Codex free?
It depends on Codex’s plan. Many tools are freemium or open-source at the core; model tokens are paid to the provider or gateway. Check pricing at openai.com.
Does Geek Hub republish OpenRouter token volumes for Codex?
No. Public ranking volumes are not Geek Hub metrics. In Geek Hub you only see your account’s usage when calling models from Codex or other apps.

Codex vs similar tools