I’m documenting what appears to be a reproducible regression in long-running, tool-enabled ChatGPT Web “Chat” turns.
## Summary
Since approximately August 20, 2026, long-running Chat turns that use tools/custom MCP/connectors have repeatedly stopped interacting with tools after about 25–26 minutes. In our own testing, the underlying MCP/server can remain healthy and recoverable; what expires appears to be the Chat turn’s ability to continue tool interaction.
This does not appear to be specific to one custom MCP. Similar 23–26 minute stops have been reported with MCP and with other tool paths, and multiple Plus/Pro users have reported the same timing.
## Timeline / observations
- **Aug 5:** public reports already show a short execution window around **25:42–25:50** for MCP/browser-style runs.
- **Around Aug 20:** multiple users report a clear regression from hour-scale `High` executions to repeated **~25–26 minute** stops.
- **Aug 20:** OpenAI Status recorded **“Elevated Errors for Thinking mode in ChatGPT.”** I am not claiming this incident caused the regression; the timing is simply notable.
- **Aug 21 onward:** additional Plus and Pro users report repeated stops around 25–26 minutes, including users who previously obtained **~100+ minute** executions.
- **September:** the behavior is still reproducible in tool-enabled Chat.
A particularly useful A/B report on this forum showed the same account previously getting a **102m26s** Chat execution with a `stream_handoff`/worker path, then repeated **25m50s / 26m04s / 26m43s** stops after the regression, while Work on the same account still received long-running worker execution:
Another report reproduces comparable **23–26 minute** stops with Secure MCP and Bash while the underlying gateway remains healthy:
## What we can reproduce
1. Start a normal ChatGPT Web Chat on GPT-5.6 Sol High (Plus/Pro).
2. Use a long-running custom MCP/tool workflow.
3. Keep the underlying MCP service alive and externally observable.
4. Around 25–26 minutes, Chat stops being able to interact with tools / reports that it ran out of time to use tools.
5. The MCP/runtime itself may still be healthy. A later continuation can reconnect/reuse state, which distinguishes this from the MCP process being killed.
We have also seen public reports of comparable stops using Bash/other tool paths, so this does not look like an MCP-server timeout.
Broader corroboration is not confined to English-language reports: users on ComputerBase (German) and LINUX DO (Chinese) have independently described the same ~25–26 minute behavior.
## Why Work is not a practical workaround
Work is explicitly designed for long-running agentic execution, and in A/B tests it can keep working far longer than normal Chat. However, Work/agent surfaces do not currently provide equivalent access to custom developer apps/MCP connectors. OpenAI’s current developer-mode documentation says agent mode will not use custom apps.
So developers are left in a capability gap:
- **Chat:** custom MCP/developer tooling is available, but long-running tool interaction can terminate at ~25–26 minutes.
- **Work:** durable/hour-scale execution is available, but custom MCP/developer tooling is not equivalent/available.
There are also reports of a custom Secure MCP tunnel working in normal Chat but failing/expiring when used from Work, which makes this look like a surface/routing restriction rather than an inherent MCP limitation.
## What I’m asking OpenAI to clarify
1. Is ~25–26 minutes an intentional supported limit for tool-enabled turns in normal Chat, or a regression/admission-routing issue?
2. Did Chat’s long-run worker/`stream_handoff` admission policy change around Aug 20?
3. If the limit is intentional, can it be documented?
4. Is custom MCP/developer-tool support planned for Work so long-running agent execution can use the same user-defined tooling available in normal Chat?
5. Is there a supported way today to get durable long-running execution + custom MCP in ChatGPT Web?
I’m deliberately **not** claiming OpenAI “added a 25-minute limit” as a policy. The evidence is consistent with a short foreground execution window that previously could be promoted to a durable worker, with affected Chat sessions no longer receiving that promotion reliably.
If staff want timestamps, reproduction traces, MCP health evidence, or A/B Chat-vs-Work details, I can provide them.




