Developer ToolsJul 6, 2026
GPT-5.5 shows fixed-token clustering, hinting at performance issues
Codex telemetry shows GPT-5.5 clusters reasoning tokens at fixed boundaries, coinciding with performance degradation. Users on specific plans may be rerouted to GPT-5.4-Mini, eroding trust in service tiers.
Why now
This timing is critical as enterprise users rely on Codex for high-stakes reasoning, and the shift to profitability-driven downgrades threatens customer satisfaction.
Key signals
GPT-5.5 clusters reasoning tokens at fixed boundaries, suggesting hidden budget truncation.
OpenAI may downroute users to GPT-5.4-Mini based on profitability, affecting enterprise plans.