Grok 4.1 Fast Reasoning is a xAI model tracked in Sim. It supports a 1M token context window. Pricing starts at $1.25/1M input tokens and $2.5/1M output tokens. Key capabilities include Temperature 0-2, Tool choice, Structured outputs. Best for long-context retrieval, large documents, and high-memory workflows.
Best forBest for long-context retrieval, large documents, and high-memory workflows.
Temperature0 to 2
Reasoning effortNot supported
VerbosityNot supported
Thinking levelsNot supported
Structured outputsSupported
Tool choiceSupported
Computer useNot supported
Deep researchNot supported
Memory supportSupported
Max output tokensNot published
Frequently asked questions
Grok 4.1 Fast Reasoning is a xAI model available in Sim. Grok 4.1 Fast Reasoning is a xAI model tracked in Sim. It supports a 1M token context window. Pricing starts at $1.25/1M input tokens and $2.5/1M output tokens. Key capabilities include Temperature 0-2, Tool choice, Structured outputs.
Grok 4.1 Fast Reasoning is listed at $1.25/1M input tokens, $0.2/1M cached input tokens, and $2.5/1M output tokens.
Grok 4.1 Fast Reasoning supports a context window of 1M tokens in Sim. In an agent, this determines how much conversation history, tool outputs, and retrieved documents the model can hold in a single call.
Grok 4.1 Fast Reasoning supports the following capabilities in Sim: Temperature 0-2, Tool choice, Structured outputs.
Best for long-context retrieval, large documents, and high-memory workflows. When used in a Sim workflow, it can be selected in any Agent block from the model picker.