Nanocodex is a headless, library-first SDK for building products around one deliberately supported OpenAI coding-agent stack. It is not a provider abstraction and it is not an app server. The public product is an embeddable agent with an owned lifecycle; the native CLI/TUI, browser apps, Python and JavaScript packages, durable actors, sandboxes, voice client, and evaluation harness are consumers that prove the same contract.

The important difference from assembling a model client and a loop is what the caller does **not** have to rebuild:

• no passing previous messages, response IDs, or tool results back on every turn;
• no separate state machine for prompt ordering, steering, compaction, reconnect replay, or partially completed responses;
• no coupling between receiving a typed result and consuming an event stream;
• no orphaned shell sessions or subprocess trees when a turn is canc