default: first available general-purpose modelfast: low-latency model for interactive workloadspro: higher-quality paid model with larger limits or advanced capabilities- a concrete model ID, such as
gpt-5.4, when you need to pin routing, behavior, or cost
Live model catalog
Use the Models API when you need exact model IDs, current pricing, context windows, modalities, or capability flags:Models API
Learn how to read tiers, pricing, context windows, modalities, and capability flags.
When to use a specific ID
Use a concrete model ID only when you need to pin behavior for evaluation, routing, or cost controls. Before sending traffic, check the live model catalog and confirm the model supports the feature you need. For example:Access tiers
turbo models are fast models available to anonymous and free-token users. They are a good fit for low-latency and cost-sensitive workloads.
pro models are available on Pro subscriptions or paid balances. They may include larger context windows, reasoning, vision, JSON mode, streaming, or tool calling depending on the model record.
See Limits for rate limits and token availability by access type.