The original Grok 4 API model identified as grok-4-0709 was retired on May 15, 2026. xAI’s migration table says requests using that legacy identifier are now served by grok-4.3 with low reasoning effort. A resolving old identifier therefore does not prove that the original Grok 4 model still handles the request.
For a current coding decision, record the model actually served rather than labeling the result simply “Grok 4.” Verify the active identifier and access route in current xAI documentation, then run a representative repository task: trace an existing flow, change related files, run checks, repair one failure, and explain the diff. Keep the framework, prompt, context, and acceptance tests constant when comparing another model.
Separate model behavior from context retrieval, tool adapters, permissions, and execution. Polished output is not proof that code ran. Require independent checks and preserve traces showing which model identifier served the request.
Do not import capabilities from a newer Grok release into the retired original model. The useful answer now is lifecycle-aware: evaluate the currently served model under its own name, save the configuration and date, and review all generated code. Recheck the mapping whenever xAI changes its migration guidance.
Source: xAI Grok Model Retirement. Last checked: September 16, 2026 (documentation review; no API or model test).
