Codex CLI + First-Tree
Codex CLI is OpenAI's terminal coding agent. It's fast and capable — and like any agent, it's only as good as the context it has. Here's how to give it your team's.
Codex CLI brings OpenAI's coding agent into your terminal — it reads your repo, writes code, runs commands, all from natural-language instructions. It's one of the strongest ways to put an agent to work on real code. But out of the box it knows your files, not your team: not the decisions you've made, not who owns what, not the conventions you settled on months ago. This page is about closing that gap.
What Codex CLI gives you
A capable agent that lives where your code does. It can navigate the repo, make changes across files, run your tests, and iterate — the same loop you'd run by hand, faster. For a single developer on a well-understood codebase, that's often enough.
Where it starts from zero
The limit shows up the moment context matters beyond the current files. Codex CLI doesn't know that your team standardized on one pattern, that a previous approach was tried and reverted, or who's responsible for the module it's about to touch. So it infers — and on a team, those inferences drift: the agent makes different calls depending on who's running it and what's in their local setup. That's not a Codex CLI flaw; team knowledge is simply a different layer than the agent itself.
What First-Tree adds
First-Tree is an open-source orchestration platform for teams shipping with humans and agents side by side. It gives them a shared workspace to coordinate in, turns GitHub issues and PRs into the queue the right agent picks up, and keeps a living context tree — a Git repo where every directory is a domain and every file is a node capturing decisions, designs, and ownership, each with an owner in frontmatter. That tree is the persistent, versioned, owned memory any agent reads to understand your codebase. Codex CLI reads it and does the work; First-Tree coordinates and remembers around it. Different layers, working together.
The combination: a Codex CLI session that plugs into your First-Tree workspace — picking up work from your GitHub queue and loading the context tree before it touches a line.
Codex CLI executes the work; First-Tree routes it and makes sure it's
working from your team's actual decisions instead of guessing. Load the
relevant NODE.md nodes at the start of a session and the
agent reasons with your conventions in hand — and because it's plain
Git, you get review, history, and ownership for free.
Use it across your whole agent stack
Because First-Tree is framework-agnostic, the same tree that feeds Codex CLI today feeds Claude Code, a Pydantic AI agent, or whatever you adopt next. That's the real value when a team runs multiple agents: one shared source of context instead of re-teaching each tool separately. It's the same shared-context problem the AI agent teams approach is built around, and it's open source.