## Why
[#30867](https://github.com/openai/codex/pull/30867) makes
`submit_inter_agent_communication` the common outbound sink for
multi-agent v2 communications. This follow-up uses that single point to
log every communication lifecycle without requiring new hooks as spawn,
messaging, follow-up, or result paths evolve.
For each communication, the logs need to identify its type, sender and
receiver threads, and content, while correlating the successful send
with receipt by the destination mailbox. The logging path must not query
externally supplied time providers because those calls can be expensive
for app-server clients.
## What changed
- Added structured `INFO` events on the OpenTelemetry-exported
`codex_otel.agent_communication` target for `spawn`, `message`,
`followup`, and `result` communications.
- Logged successful sends from `submit_inter_agent_communication` with
the communication kind, sender and receiver thread IDs, content, and
submission ID.
- Logged receives after the communication has been enqueued in the
receiver mailbox, using the same submission ID.
- Avoided time-provider calls and other asynchronous work in the logging
path.
- Narrowed ordinary spawn and send-input APIs to `Vec<UserInput>` so
`Op::InterAgentCommunication` cannot bypass the context-bearing
centralized path.
The refactor does not change submission IDs, capacity checks, last-task
bookkeeping, mailbox ordering, protocol types, rollout data, or
model-visible context.
## Event shape
Illustrative JSON representation of the two independently emitted
records:
```json
[
{
"event.name": "codex.agent_communication",
"communication_id": "019f20e1-40d1-7890-a123-456789abcdef",
"kind": "spawn",
"state": "send",
"sender_thread_id": "019f20df-fbe1-7890-a123-456789abcdef",
"receiver_thread_id": "019f20e1-3f79-7890-a123-456789abcdef",
"content": "inspect the repository"
},
{
"event.name": "codex.agent_communication",
"communication_id": "019f20e1-40d1-7890-a123-456789abcdef",
"state": "receive"
}
]
```
Consumers join the receive record to the send record by
`communication_id` for the immutable communication metadata.
## Testing
- Extended the existing end-to-end multi-agent v2 spawn test to verify
content, both thread IDs, and a correlated send/receive submission ID.
- Re-ran focused control and handler coverage for direct messages,
follow-up tasks, and completion results.
## Why
Multi-agent v2 communications currently use separate outbound paths:
direct messages, follow-up tasks, and completion results go through
`send_inter_agent_communication`, while a spawn's initial message goes
through the generic input submission path. That split makes it difficult
to add complete communication lifecycle logging in one place.
This refactor makes `submit_inter_agent_communication` the common sink
for those paths, preparing the follow-up observability work discussed in
[#30516](https://github.com/openai/codex/pull/30516).
## What changed
- Routed all current outbound `InterAgentCommunication` paths in
`AgentControl`—direct messages, follow-up tasks, completion results, and
multi-agent v2 spawn initial messages—through
`submit_inter_agent_communication`.
- Centralized the actual submission and last-task-message bookkeeping
there, providing one place for the follow-up PR to instrument
communication creation and successful enqueue.
- Left non-communication input handling and the multi-agent v1 spawn
flow unchanged.
## Testing
- `just test -p codex-core 'agent::control::tests::'` (51 passed)
- `just test -p codex-core
'suite::subagent_notifications::encrypted_multi_agent_v2_spawn_sends_agent_message_to_child'`
(passed)
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/30867).
* #30872
* __->__ #30867
## Summary
- require a Pong within 60 seconds for established Noise Rendezvous
WebSockets on both the harness and executor
- bound steady-state WebSocket writes and harness event delivery so
backpressure cannot mask the deadline
- classify executor disconnects with bounded reasons and feed them into
the existing reconnect metric and structured log
- cover silent peers, responsive peers, continuous non-Pong traffic, and
local application backpressure
## Why
The existing periodic Pings did not track Pongs, so a half-open or
blackholed connection could remain stuck until the operating system's
TCP timeout. This adds the smallest explicit liveness contract without
new spans, RTT histograms, feature flags, or TCP diagnostics.
## Testing
- `just test -p codex-exec-server` on devbox `richard-6` — 300 passed, 2
skipped
- `just fix -p codex-exec-server`
- `just fmt`
- independent correctness, performance/security, and YAGNI reviews — no
findings
Michael Bolin