🔥🔥🔥🔥 Starting from 2026-07-13 , Codex's (to Server) response speed dropped threefold ( ⬇️ 3X). 🔥🔥🔥

What version of the Codex App are you using (From “About Codex” dialog)?

26.715.31925

What subscription do you have?

200USD Pro

What platform is your computer?

MacOS 26.5.2 ARM

What issue are you seeing?

Codex GPT-5.6-Sol / 5.5-Pro latency regression / slow SSE streaming

I am seeing a significant latency regression when using Codex with gpt-5.6-sol.

This is not just subjective slowness. I compared recent local telemetry against my July 13 baseline using Cockpit/Codex request logs.

Current measurement

Measured at: 2026-07-18 13:21-13:22 (New York time)

| Metric | Current 30-minute window | July 13 baseline |
|---|---:|---:|
| First response median | 11.1s | 2.7s |
| First response P90 | 40.3s | 19s |
| Full request median | 20.1s | 11.4s |
| Full request P90 | 98.8s | 38s |

Current state

• Around 44 established local Codex/Cockpit connections.
• 21 requests started within the last 60 minutes but had not completed.
• 15 of those had not yet received the first streaming chunk.
• No recent 429 Too Many Requests errors were observed.
• No recent server_is_overloaded errors were observed.
• Some failures were cyber_policy, but those appear unrelated to the latency issue.

Summary

The severe overload / 429 errors appear reduced, but streaming latency has not returned to the July 13 baseline. The main remaining issue is high tail latency: first chunks and full completions are still much slower than before, especially at P90.

This affects active Codex development sessions because many tasks wait a long time before receiving the first response, even when the request eventually succeeds with HTTP 200.

Question

Is there an ongoing GPT-5.6 Sol / Codex streaming latency issue, especially for SSE-based streaming? If so, is there a recommended workaround or expected recovery timeline?

What steps can reproduce the bug?

NA

What is the expected behavior?

_No response_

Additional information

Feedback ID : 019e2c27-8d57-7ff1-8189-26d8db36913f