send_user_message_async

Assess

Tools

An asynchronous messaging tool that lets Codex notify a developer without blocking its current turn.

Why it's here

Placed in Assess: 1 article(s) of evidence from 1 source(s), led by framework updates, with 0 in the last 30 days. Confidence 24%. Low accumulated evidence, so it defaults conservatively pending more signal.

Evidence (1)

6The New Stack·8/19/2026framework_update
Codex tests asynchronous developer messaging while continuing work
OpenAI is testing an async messaging tool for Codex that lets the agent ask a developer a question, keep working on unrelated tasks, and incorporate the reply later. The change, merged into the public Codex repository, replaces blocking input flow with a non-blocking message acceptance model, though the feature is not yet broadly announced or tied to a specific release target.