Vertex AI Adds Grok 4.6 Preview With a Lower Listed Cache Rate

Teams that want to buy Grok 4.6 through Google Cloud can now do so through Vertex AI Model Garden. The new route lists a lower cached-input price than SpaceXAI’s direct API for prompts up to 200,000 tokens, although Google Cloud currently classifies the offering as Preview.

A fourth distribution route

SpaceXAI announced Grok 4.6 availability through Vertex AI on August 21. Google Cloud’s release notes list it in Model Garden as a Preview offering, meaning the addition expands where customers can obtain the existing model rather than introducing a new model release.

The Google Cloud listing follows a quick widening of Grok 4.6 distribution. SpaceXAI released it through its own API on August 12; GitHub Copilot added it on August 14; and Amazon Bedrock made it generally available on August 19. Vertex AI gives organizations already using Google Cloud’s model platform another purchasing and deployment path.

The rate card changes at 200,000 tokens

The direct API’s lower schedule has a boundary. For prompts above 200,000 tokens, SpaceXAI lists direct-API rates of $4 per million input tokens, $1 per million cached input tokens, and $12 per million output tokens. That threshold is relevant because SpaceXAI says Grok 4.6 supports a 500,000-token context window—the amount of text a model can consider in one request.

Cached input generally matters when an application sends the same material repeatedly, such as persistent instructions or accumulated working context. The listed price alone does not determine a workload’s bill: actual cost depends on prompt length and on how often requests use cached tokens. Buyers comparing the two routes therefore need to model their own request patterns rather than treating the 20-cent difference as a blanket discount.

Preview status remains the practical constraint

For now, the Vertex AI route is explicitly a Preview offering. The immediate decision is less about whether Grok 4.6 exists on Google Cloud than whether a Preview service fits a team’s production requirements. The announcement establishes availability and a listed rate card; it does not turn the Google Cloud route into a generally available service.