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Grok 4.1 Fast

The slug x-ai/grok-4.1-fast still has a model card. It did not have a provider serving it on 27 Sep 2026.

Updated 2026-09-27

The card describes Grok 4.1 Fast as xAI’s tool-calling model for support and research, with a 2 million token window and reasoning that can be turned on or off. The endpoints API returned an empty list that day, so there was no input or output price to quote.

Calling the slug while it has zero endpoints fails. The closest live text models were Grok 4.5 at $2 / $6 per million tokens (500K context, higher rates past 200K) and Grok 4.7 at $1.60 / $4.80. Neither is a drop-in replacement for a 2M window.

Recheck https://openrouter.ai/x-ai/grok-4.1-fast before you delete the id from a config. An empty provider list can fill back in.

Questions

Is Grok 4.1 Fast available?

The card exists. On 27 Sep 2026 no endpoint was attached, so requests had nowhere to go.

What is the model id?

x-ai/grok-4.1-fast

What can I call instead?

x-ai/grok-4.5 was in service at $2 input and $6 output per million tokens, with a 500,000-token context.

Related

  • Grok API pricing

    Grok 4.5 on OpenRouter was $2 input and $6 output per million tokens on 27 Sep 2026, doubling after 200K prompt tokens. The slug is x-ai/grok-4.5.

  • AI model comparison

    A price and context comparison of DeepSeek V4, Qwen3.7 Max, GLM 5.2, Claude Sonnet 5, GPT-5.1, and Grok 4.5 on OpenRouter, checked 27 Sep 2026.

  • Coding agents

    OpenRouter’s coding-agent apps include Claude Code, OpenCode, and others. The agent is the client. The model is the slug you attach.

  • OpenRouter API URL

    The OpenRouter base URL is https://openrouter.ai/api/v1. Chat calls go to /chat/completions with a Bearer key.

Sources