Grok 4.6 Lands in Cursor With a One-Week 2x Usage Window

SpaceXAI released Grok 4.6 on August 12, 2026, and it is already in the Cursor model picker. The company, publishing at x.ai, positions the model for long-running agents and more ambitious interactive and visual work, and it is offering 2x included usage in Cursor and Grok Build for the first week. API pricing starts at $2 per million input tokens and $6 per million output tokens. (SpaceXAI; Cursor)

This is a post-training step on the Grok 4.5 line, not a claim that one model now wins every coding benchmark. Use it this week if you want a cheaper frontier option for multi-step agent work in Cursor. Keep a bake-off against GPT-5.6 Sol Max and Fable 5 on your own terminal-heavy tasks before you change a default.

Key Takeaways

• Grok 4.6 is live today in Cursor, Grok Build, the API at x.ai, and partner gateways including OpenRouter, Vercel, and Cloudflare. (SpaceXAI; Grok 4.6 docs)
• Cursor access is on all plans, per SpaceXAI's model overview. (Grok 4.6 docs)
• First-week promo: 2x included usage inside Cursor and Grok Build. The launch posts do not publish a calendar end date beyond "the first week." (SpaceXAI; Cursor)
• API model name is grok-4.6. Context window is 500,000 tokens. Knowledge cutoff is February 1, 2026. Inputs are text and image; output is text, with no text output limit. (Grok 4.6 docs; xAI release notes)
• Standard API rates are $2 input / $0.50 cached input / $6 output per million tokens below 200,000 prompt tokens, and $4 / $1 / $12 at or above that threshold, billed for all tokens in the request. (Grok 4.6 model page)
• Reasoning effort supports low, medium, high (default), and xhigh. SpaceXAI says reasoning cannot be disabled. (Reasoning docs)
• The headline benchmark claim is narrow: SpaceXAI's launch post says Grok 4.6 matches GPT-5.6 Sol on the Artificial Analysis Intelligence Index, a composite of nine benchmarks. The same page's table labels that comparison column GPT-5.6 Sol Max, at 61 vs 61. Fable 5 Max still leads the index at 62. (SpaceXAI)

Where You Can Use It Today

(SpaceXAI; Cursor; Grok 4.6 docs)

Grok Build installs from SpaceXAI's CLI:

curl -fsSL https://x.ai/cli/install.sh | bash

(SpaceXAI)

Do not conflate this first-week 2x window with Cursor's permanent doubled Cursor Models pool from July. That pool doubling is a separate plan change. The Grok 4.6 posts describe a launch offer inside Cursor and Grok Build; they do not say whether the two multipliers stack.

Pricing, Context, and Reasoning

The 200,000-token threshold is a cliff: SpaceXAI says requests whose prompt reaches that size are billed at the higher rate for all tokens in the request, not only the overflow. Context window is 500,000 tokens. (Grok 4.6 model page; xAI release notes)

The launch posts also mention a fast variant at twice the price. The published API model page currently documents grok-4.6 with the long-context rates above, and does not list a separate fast-variant model ID. Treat "twice the price" as a launch-post claim until you see a named SKU in the picker or the docs. (SpaceXAI; Cursor; Grok 4.6 model page)

For API users, SpaceXAI recommends setting a prompt_cache_key (Responses API) or the x-grok-conv-id header (Chat Completions) so multi-turn agent loops hit the same server and actually get cache discounts. (Grok 4.6 docs)

How Grok 4.6 Compares on Published Benchmarks

These figures are from SpaceXAI's launch table. The company says competitor scores are the best of self-reported or publicly available results. They are not an independent bake-off on your codebase.

(SpaceXAI)

The useful read is the shape, not a crown. Grok 4.6 closes most of the gap on Grok 4.5, ties the launch table's GPT-5.6 Sol Max column on the composite intelligence index, and still trails Sol Max and Fable 5 Max on DeepSWE and Terminal-Bench. If your work looks like long-horizon software engineering in a terminal, those two rows are the ones to test before you switch a default. If your work looks like turning a product idea into a first visual pass, that is the job SpaceXAI is selling.

What SpaceXAI Says Changed

SpaceXAI says Grok 4.6 got a longer supplemental training run than Grok 4.5, then used Grok 4.5 to regenerate supervised-fine-tuning trajectories across reasoning efforts, agent harnesses, and domains including STEM, software engineering, and knowledge work. Reinforcement learning covered knowledge work, general coding, and domain-specific environments such as kernel optimization, web development, and computer-aided design. (SpaceXAI; Cursor)

The product claim that follows is about persistence, not peak IQ. SpaceXAI says the model stays with complex tasks across many steps, is especially strong at turning a broad product idea into a working first version, and showed more self-testing and verification on longer trajectories. It also says first passes on visual and interactive projects are stronger than with Grok 4.5. Those are vendor observations from internal tests, not a public eval you can rerun. (SpaceXAI)

How a Reader Uses This

If you already live in Cursor, use the first-week window. Pick Grok 4.6 from the model picker and rerun one real task you already trust: a multi-file feature, a visual UI pass, or a long agent loop that usually needs babysitting. Compare it against your current default on the same prompt. The promo is the reason to do that now rather than later.

If your bottleneck is terminal-heavy agent work, do not take the composite index as the decision. SpaceXAI's own table has GPT-5.6 Sol Max at 34.6% on Terminal-Bench v3.0 versus 26% for Grok 4.6 High. Run that class of task yourself. Cursor's router write-up already argues that no single model wins every turn; this release does not change that.

If you call the API, pin grok-4.6 and watch the 200k cliff. A long agent transcript that crosses 200,000 prompt tokens doubles input, cache, and output rates for the whole request. Set a cache key. Keep a cheaper model in the router for short tool-calling turns.

What This Announcement Does Not Establish

The launch posts do not publish a calendar end date for the 2x Cursor / Grok Build offer, a named fast-variant model ID, or an independent benchmark suite. They also do not say how the first-week 2x offer interacts with Cursor's existing first-party usage pool. SpaceXAI's safety section says safeguards were improved and calibrated, with a wider pre-deployment test suite, but it does not publish those test results here.

Sources

• SpaceXAI, "Introducing Grok 4.6" (August 12, 2026): https://x.ai/news/grok-4-6
• Cursor, "Introducing Grok 4.6" (August 12, 2026): https://cursor.com/blog/grok-4-6
• SpaceXAI, Grok 4.6 overview: https://docs.x.ai/developers/grok-4-6
• SpaceXAI, Grok 4.6 model page (pricing, context, rate limits): https://docs.x.ai/developers/models/grok-4.6
• SpaceXAI, API models list: https://docs.x.ai/developers/models
• SpaceXAI, release notes (August, Grok 4.6): https://docs.x.ai/developers/release-notes
• SpaceXAI, reasoning effort docs: https://docs.x.ai/developers/model-capabilities/text/reasoning