Prerequisites and Codex CLI¶

Prerequisites: - Basic terminal usage - Existing UV-managed Python project - codex CLI installed

What you'll learn: - Why this SDK depends on the Codex CLI - What environment variables matter - When to use path overrides

How The SDK Works At Runtime¶

The SDK launches codex exec --experimental-json as a subprocess and streams JSONL events over stdout.

Because of that: - Python import success is not enough - codex CLI must also be installed and reachable

Required Runtime Pieces¶

codex-sdk-unofficial
codex executable
Valid auth/config recognized by Codex CLI

Useful Constructor Options¶

from codex_sdk import Codex

codex = Codex(
    {
        "codex_path_override": "/absolute/path/to/codex",
        "base_url": "https://your-endpoint.example",
        "api_key": "your-api-key",
    }
)

Environment Behavior¶

By default: - SDK inherits your current process environment

If you pass env: - SDK uses only provided keys (plus required injected keys like originator/base url/api key)

Failure Modes¶

CLI not on PATH
CLI installed but wrong binary
Auth misconfiguration in environment
Running in restricted environment where subprocess spawn is blocked