Modal has released Spindle, an open-source, Tinker-compatible training server that runs in a team’s Modal workspace. Users write their own training loop, while Spindle handles distributed training; Modal says teams can customize the server and pay for GPU time instead of per-token API pricing.
Modal reports lower costs than Tinker in several workloads, including a 63% reduction for one DAPO-math setup and 25% for an eight-client search-agent setup. These are Modal’s own comparisons, and the company says Spindle is still in beta.
Why it matters
Teams running repeated model-training experiments can use Spindle to run custom training loops on Modal and may lower costs by sharing GPU capacity; actual savings depend on workload, and Modal’s comparisons are vendor-reported.
