On Codex, has anyone else experienced this? 5.6 (Terra or Luna) keeps stopping in the middle of execution because it mistakenly calls final. When I ask why it stopped, it says it called final by mistake. This started happening to me about two weeks ago.
I used 5.6 Terra, Medium, Standard and 5.6 Luna, Extra High, Fast
EricGT
September 8, 2026, 4:34pm
2
You are welcome to discuss Codex issues here. However, the official place to report and track Codex bugs is the OpenAI Codex GitHub issue tracker .
I asked ChatGPT to search for the closest related issue, and it identified:
opened 10:33AM - 11 Jul 26 UTC
bug
model-behavior
## Summary
Immediately after GPT-5.6 became available in my environment, long-r… unning coding sessions using the Codex endpoint began intermittently ending in the middle of a task after a successful tool call.
The endpoint returns a syntactically complete, successful response with:
- HTTP 200
- `stopReason: "stop"`
- a valid response ID
- `text_start` followed by `text_end`
- **no `text_delta` events and zero visible text**
- no provider/runtime diagnostics
Because the response is classified as a normal `stop`, the client correctly considers the agent turn complete even though the task is still in progress. Sending a follow-up such as `continue` immediately resumes the work.
This did not occur for me before the GPT-5.6 rollout. I am not claiming the rollout is definitively causal, but the regression began immediately after switching to GPT-5.6.
## Environment
- Client: Pi coding agent `0.80.6`
- Provider integration: `openai-codex` using ChatGPT subscription authentication
- Model: `gpt-5.6-terra`
- Reasoning effort: `medium`
- OS: Arch Linux
- Node: `v26.4.0`
- Transport during the captured reproduction: explicit SSE
- `httpIdleTimeoutMs`: `120000`
- IPv6: disabled system-wide
- Workload: long, multi-step coding task with many tool calls
- Session context at the captured occurrence: approximately 258k total tokens
## Captured stream evidence
A representative empty final response:
```json
{
"model": "openai-codex/gpt-5.6-terra",
"elapsedMs": 5120,
"stopReason": "stop",
"textChars": 0,
"thinkingChars": 0,
"contentTypes": ["thinking", "text"],
"streamEventCounts": {
"thinking_start": 1,
"thinking_end": 1,
"text_start": 1,
"text_end": 1
},
"usage": {
"input": 1406,
"output": 14,
"cacheRead": 257024,
"cacheWrite": 0,
"reasoning": 8,
"totalTokens": 258444
},
"responseId": "resp_03a93f16526e1365016a520f55ee088199a81683d3d457b0ff",
"diagnostics": null
}
```
The immediately preceding response was a normal tool-use response:
```json
{
"stopReason": "toolUse",
"textChars": 0,
"thinkingChars": 112,
"contentTypes": ["thinking", "toolCall"],
"streamEventCounts": {
"thinking_start": 1,
"thinking_delta": 6,
"thinking_end": 1,
"toolcall_start": 1,
"toolcall_delta": 346,
"toolcall_end": 1
}
}
```
The tool executed successfully. Pi then started the next model turn and received the empty successful final response above. There was no missing HTTP response and no truncated SSE event sequence.
## Observed behavior
1. The model performs several normal reasoning/tool-use steps.
2. A tool completes successfully.
3. The next Codex response returns `stop` with an empty text block.
4. The agent loop ends because the response is a successful completion.
5. The task remains incomplete.
6. A manual `continue` immediately resumes normal tool use.
7. The same empty-final condition can recur after additional progress.
Sometimes the transcript visually appears to stop after a thinking block, because the final text block exists but contains no text.
## Network and transport checks
I attempted to rule out a local connection failure:
- Changed Wi-Fi networks; the behavior persisted.
- IPv6 is disabled (`net.ipv6.conf.all.disable_ipv6 = 1`).
- IPv4 connectivity to `api.openai.com` completed normally.
- The captured reproduction had complete SSE lifecycle events and a successful `stop`, rather than a disconnect/error.
- Manual compaction was attempted, but the behavior persisted in the ongoing session.
These observations make this look more like an empty model/provider completion than a network timeout. A clean fresh-session/alternate-model comparison is still useful and I can provide additional results.
## Workaround
I implemented a Pi extension that detects this exact condition:
```text
assistant stopReason == "stop"
AND visible final text is empty
AND the run used one or more tools
```
When the agent becomes idle, the extension injects a hidden follow-up equivalent to:
```text
Your previous response ended successfully but contained no visible final text. Continue the existing task from its current state without repeating completed work.
```
This successfully resumes the task. The workaround initially allowed two retries, but the empty successful response sometimes recurred after the model made substantial additional progress, so I changed it to allow continued retries until manually stopped.
This confirms that the session/tool state remains usable and that a new model turn can continue normally; only the empty successful final response prematurely terminates the loop.
## Expected behavior
For an incomplete tool-driven task, the model should either:
1. emit another tool call,
2. emit a non-empty final/blocking response, or
3. return a retryable error if the response cannot be completed.
A successful `stop` containing an empty text block should not silently terminate an active task.
## Possibly related
- #27352 — Codex marks a turn complete while follow-up work is still needed.
- #26860 — model stops automatically mid-task without a useful final response.
The distinction in this report is the concrete wire-level signature: `text_start` → `text_end`, no `text_delta`, then successful `stop` immediately after tool use.
I can provide additional sanitized stream logs, response IDs, and A/B results across GPT-5.6 variants or earlier models if useful.
If that issue describes the same problem you are experiencing, consider adding a
If it does not match your problem closely enough, search the existing Codex issues for a better match. If you cannot find one, consider opening a new issue and include as much relevant information as possible, such as your Codex version, operating system, environment, reproduction steps, expected behavior, actual behavior, and any relevant logs or error messages.
I created a new bug report in the OpenAI Codex GitHub repository:
“GPT-5.6 Terra/Luna prematurely calls final during incomplete long-running tasks until Logout/Login” — Issue #43864 .
CRD13
September 19, 2026, 4:42am
4
it has been stopping after every command today - its painful
reaction to the GitHub issue itself, rather than only reacting to this forum topic. GitHub reactions can help the maintainers gauge how many users are affected.