Proposal: experimental local cross-session messaging via UDS #16447
Description
What variant of Codex are you using?
CLI
What feature would you like to see?
Background
Currently, Codex sessions are isolated. Multiple CLI instances on the same machine cannot communicate or coordinate.
Proposal
Introduce an experimental, local-only cross-session messaging mechanism using Unix Domain Sockets (UDS).
Goal:
One session can send a text message to another, and the receiving agent sees it directly in its conversation context.
Scope (Stage 0)
Keep the first version minimal:
- Local machine only (UDS)
- Plain text messages only
- No persistence
- Top-level sessions only
- No file transfer or structured payloads
User-facing behavior
Two new tools:
list_sessions— discover other sessionssend_session_message(target, message)— send a message
Behavior
When a message is received:
- It is injected into the target session’s conversation context
- The agent sees it as a normal input on the next turn and can respond
Questions
Would appreciate feedback on:
- Is injecting messages into the conversation context acceptable?
- Should this reuse existing
InterAgentCommunication, or be separate? - Is UDS a reasonable transport for a first step?
Next step
If this direction makes sense, I can follow up with a small, feature-flagged PR implementing Stage 0.
Additional information
No response