Grok 4.1 Fast Reasoning

Reasoning model by xAI.

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

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

Maker

xAI

Served On: Azure Foundry

Specifications

Context window, ranked against other reasoning models

Insufficient data

No published context window for this model or its peers.

Context window

—

Max output

—

Modality

reasoning

Vision
Function calling
System prompt

Benchmarks & performance rankings

Empirical intelligence benchmarks and category leaderboard placements for Grok 4.1 Fast Reasoning.

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Leaderboard placements
#143
textScore: 0%
Recommended by nRouter Smart Routing: . Key operational strength: .

Benchmarks

LMSYS Chatbot Arena (text)Rank #143 · Score 1408
Source: huggingface.co · Leaderboard: 2026-10-152026-10-15

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

grok-4-1-fast-non-reasoning

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

Questions? Answers.

What is Grok 4.1 Fast Reasoning?

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

How much does Grok 4.1 Fast Reasoning cost?

Grok 4.1 Fast Reasoning is billed at the provider's list price on nRouter with no per-token markup — tokens settle at the exact upstream rate. Input and output rates are read live, so see the pricing section above for the current figures.

Does Grok 4.1 Fast Reasoning support tool calling and structured outputs?

Yes. Grok 4.1 Fast Reasoning supports tool calling (function calling), so it can invoke external tools and APIs during a conversation.

What inputs and outputs does Grok 4.1 Fast Reasoning support?

Grok 4.1 Fast Reasoning takes text as input and returns text as output.

How do I use Grok 4.1 Fast Reasoning via nRouter?

Use any OpenAI-compatible client: point it at https://api.nrouter.ai/v1 with your nRouter API key and set the model to "azure_ai/grok-4-1-fast-reasoning". The quick-start panel above has a copy-paste curl command for this model.

Where is the Grok 4.1 Fast Reasoning documentation?

Start at nrouter.ai/docs. The quick-start guide (nrouter.ai/docs/getting-started/quick-start) covers API keys and your first request, and the API reference (nrouter.ai/docs/api-reference) lists every parameter.