Short answer
Codex CLI is OpenAI’s open-source (Apache-2.0) coding agent. It runs OpenAI models, or local models through Ollama or LM Studio, inside a strict sandbox, and it pairs with an IDE extension and a cloud agent. AirCode CLI is AirLLM’s proprietary terminal agent: it routes every step through AirLLM’s routing models and is built for unattended loops with limits on iterations, time and cost.
Codex can also use Air Router as its provider, so you can keep Codex and add routing.
At a glance
| Aspect | AirCode CLI | Codex CLI |
|---|---|---|
| Made by | AirLLM | OpenAI |
| Interfaces | Full-screen terminal app, headless aircode run, and editors that support the Agent Client Protocol (aircode acp). AirCode Studio, a desktop app on the same agent, is coming soon. | Terminal CLI, an IDE extension for VS Code, Cursor and Windsurf, the ChatGPT desktop app, and Codex Web, a cloud agent. |
| Platforms | macOS (Apple Silicon and Intel) and Linux x86_64. The Developer Guide also documents a Windows 11 x64 installer. | macOS, Linux and Windows (native, with a Windows sandbox, or under WSL2), on x86_64 and arm64. |
| License | Proprietary, licensed under section 10 of AirLLM’s Terms. | Open source under the Apache-2.0 license. |
| Models | AirLLM routing models through one AirLLM key: airllm-auto by default, plus airllm-agent, airllm-anthropic and airllm-openai. | OpenAI models (a recommended model by default) with a reasoning-effort setting; local models through --oss with Ollama or LM Studio. |
| Custom endpoints | Model requests go through AirLLM, so there are no separate upstream providers to configure. | Custom providers in ~/.codex/config.toml; current releases need a Responses-compatible endpoint. |
| Agent workflow | Plan and read-only modes, loops that run until a check passes, fix-on-save, Git checkpoints, /revert and /rewind, MCP, project memory, resumable sessions. | Sandbox modes and approval settings, AGENTS.md, MCP, codex exec for scripts, resumable and forkable sessions, /review, web search and image input. |
| Pricing model | Uses the plan and budget of the AirLLM API key you sign in with: Free, monthly and usage-based plans (see AirLLM pricing). | Sign in with a ChatGPT plan (included with usage limits) or use an API key at standard API pricing (see OpenAI’s pricing page). |
How the agent workflows differ
Both are terminal coding agents built mostly in Rust, and both read your project, plan, edit files, run commands and report back. They differ in what they treat as the default way of working.
AirCode: loops, checks and limits
AirCode is built for work that keeps going without you. aircode loop "make the tests pass" --until "npm test" repeats until the check passes or a limit is reached: --max-iter (10 by default), --max-cost (5.00) and --max-minutes (60). With --checkpoint git, it captures progress in Git and can revert agent-made regressions.
aircode watch --check "npm test" runs your check on every save and starts a fix iteration when it fails. Project-provided MCP servers and check commands stay off until you approve them, and /revert undoes the agent’s last edit.
Codex CLI: sandboxing and approvals
Codex puts its sandbox front and center. By default it writes only inside the workspace and has no network access; --sandbox switches between read-only, workspace-write and full access, and approval settings decide when it asks you first. On macOS it uses Seatbelt, and on Linux bwrap with seccomp.
For automation, codex exec runs in a read-only sandbox by default, emits JSONL with --json, can validate output against a schema with --output-schema, and can resume a previous run. OpenAI’s docs recommend creating Git checkpoints before and after a task so you can revert changes.
Shared ground
Both support MCP (Codex with STDIO and Streamable HTTP servers; AirCode with stdio and streamable HTTP), both read project instructions (AGENTS.md for Codex; AIRCODE.md, plus AGENTS.md, for AirCode), and both resume earlier sessions.
Models and routing
Codex CLI runs OpenAI’s models. You choose the model with /model, -m or model in the config file, and tune model_reasoning_effort. It can also run local open-weight models through Ollama or LM Studio, or a custom provider you define.
AirCode sends every request through AirLLM, where the default routing model, airllm-auto, matches each step to a suitable model across supported providers. airllm-openai keeps requests within OpenAI’s model family, and airllm-anthropic within Anthropic’s. The routing models page explains each one, and What is an LLM router? covers the idea behind them.
Platforms and availability
Codex CLI is available today on macOS, Linux and Windows, installed with a shell or PowerShell script, npm or Homebrew. Signing in with ChatGPT gives you plan access; signing in with an API key bills at standard API rates and leaves out the cloud features.
AirCode CLI is available today for macOS and Linux, with a Windows 11 x64 installer in the Developer Guide. You sign in with aircode login and choose which AirLLM API key it uses. AirCode Studio is coming soon for macOS, Windows and Linux.
When to choose each
Choose Codex CLI if…
- You want an open-source agent you can read, build and modify under Apache-2.0.
- You already have a ChatGPT plan and want Codex in the terminal, the IDE and the cloud.
- You want to run local models through Ollama or LM Studio.
Choose AirCode CLI if…
- You want each step routed to a suitable model across providers, without choosing one yourself.
- You run long, unattended jobs: loops until the tests pass and fix-on-save, with limits on iterations, time and cost.
- You want one AirLLM key and one bill for the agent and for other tools you route through Air Router.
You don’t have to choose: Codex CLI with Air Router
Codex can use Air Router as a custom provider. Current Codex releases only accept endpoints that implement the Responses API, and Air Router serves /v1/responses, so set wire_api = "responses". Provider settings belong in your user-level ~/.codex/config.toml, because a project’s own config file ignores them.
# airllm-openai stays on OpenAI models; airllm-auto routes across providers
model = "airllm-openai"
model_provider = "airllm"
[model_providers.airllm]
name = "AirLLM"
base_url = "https://api.airllm.ai/v1"
env_key = "AIRLLM_API_KEY"
wire_api = "responses"Then export AIRLLM_API_KEY with your AirLLM key and start codex. The Codex setup guide has the steps for each operating system, and the Codex CLI router guide explains what routing changes.
About this comparison. Compiled from each product’s public documentation on October 20, 2026. Details change often, so check the sources below. Product names and trademarks belong to their owners.
Frequently asked questions
Is Codex CLI open source?
Yes. Its GitHub repository is licensed under Apache-2.0. AirCode is proprietary software licensed under section 10 of AirLLM’s Terms.
Can Codex CLI use Air Router?
Yes. Add an airllm provider to ~/.codex/config.toml with base_url = "https://api.airllm.ai/v1" and wire_api = "responses", then export your AirLLM key.
Which routing model should I use with Codex?
airllm-openai keeps requests within OpenAI’s model family; airllm-auto routes across supported providers.
Can both agents run in CI?
Yes. AirCode has aircode run with --json or --ndjson output, and Codex has codex exec with --json output.
Does AirCode read AGENTS.md?
AirCode uses an AIRCODE.md file, created with /init, and also loads AGENTS.md. Codex reads AGENTS.md files at the global and project level.
Related
Codex CLI router
Point Codex CLI at Air Router with a Responses-compatible provider.
ProductAirCode CLI
AirLLM's AI coding agent for the terminal.
ComparisonAirCode vs Claude Code
How AirCode compares with Anthropic's coding agent.
KnowledgeWhat is an LLM router?
How routing sends each request to a suitable model.
Sources
- AirLLM — AirCode CLI
- AirLLM Developer Guide — AirCode CLI and AirCode Studio
- AirLLM Terms — section 10, AirCode software license
- openai/codex on GitHub (README and license)
- Codex docs — CLI
- Codex docs — Authentication
- Codex docs — Pricing
- Codex docs — Models
- Codex docs — Advanced configuration
- Codex docs — Gateway compatibility
- Codex docs — Approvals and security
- Codex docs — Non-interactive mode
Try AirCode, or keep Codex and add routing
Install AirCode CLI, or add Air Router to Codex as a custom provider. One AirLLM key covers both.