Models / Grok 4.1 Fast ReasoningID: azure_ai/grok-4-1-fast-reasoning
reasoning model by xAI

Grok 4.1 Fast Reasoning

Grok 4.1 Fast Reasoning is a reasoning model made by xAI, served on nRouter.

PlaygroundQuick Start
Maker

xAI

Served On

Azure Foundry

Specifications

Context window, ranked against other reasoning models

Proportional scale: 0 to 1.05M tokens. Not ranked, no published context window: gpt-5.5-pro, gpt-5.6-cyber.

Context window

—

Max output

—

Modality

reasoning

Vision
Function calling
System prompt

Pricing

Rates are read live

Pricing for grok-4-1-fast-reasoning is fetched from the live catalogue on load, so it is never served from a cache that could outlive a repricing.

Availability

Not enough data yet

We have not collected enough health probes for this model to publish an uptime or latency figure. A percentage from a handful of samples is fabricated precision, so none is shown until the sample count supports one.

How Grok 4.1 Fast Reasoning is billed

Billed at the provider's list price, with no per-token markup.

Exact list price
Tokens settle at the published rate of the model that served your call.
Cache discounts passed through
Provider prompt-caching discounts reach your balance with no added fee.
Cost on every response
Each response carries the x-nr-request-cost header, so you can reconcile spend per request.

More from xAI

xai.grok-3xai.grok-3-mini-fastxai.grok-3-fastxai.grok-3-mini

Start building with grok-4-1-fast-reasoning

One API key, three steps. Choose your tool to begin.

  1. Get a key

    Create API key

  2. Set your API key

    export NROUTER_API_KEY="<YOUR_API_KEY>"

  3. Configure Claude Code

    Choose a tool, then copy its setup from the panel.

npm install -g @anthropic-ai/claude-code
Claude Code · azure_ai/grok-4-1-fast-reasoning
# Point Claude Code to nRouter gateway
export ANTHROPIC_BASE_URL="https://api.nrouter.ai"
export ANTHROPIC_API_KEY="$NROUTER_API_KEY"

# Launch with azure_ai/grok-4-1-fast-reasoning
claude --model azure_ai/grok-4-1-fast-reasoning