MoonPay’s PayBox payment vault is now live inside Grok, xAI’s assistant embedded in X, making Grok the third major AI platform to carry the tool after Anthropic’s Claude and OpenAI’s ChatGPT. Announced August 31, the integration lets all Grok users onramp fiat to stablecoins, swap tokens, bridge assets across chains, and reach Solana DeFi including Kamino Finance Earn yield through natural-language commands, alongside non-financial tasks such as booking flights and restaurant reservations. PayBox connects Grok to a user’s self-custodial wallet, payment cards and credentials; Grok prepares each transaction, but no funds move until the user approves with a passkey scoped to that action and set to expire after use. Always Ask mode requires a fresh passkey for every transaction, while Autonomous mode lets the AI act within user-defined spending limits, with any limit change requiring passkey re-approval. The Kamino Earn integration first added to PayBox on Claude and ChatGPT on August 27 now extends to Grok, though lending and yield remain unavailable in the United States, United Kingdom, European Union and Australia. Wallet keys are secured through multiparty computation and trusted execution environments via Sodot infrastructure, which MoonPay acquired in 2026 and which the company says secures more than $50 billion across more than 10 million wallets; card flows use Visa’s agentic commerce protocol so raw card numbers stay out of the AI’s processing context. Supported networks include Solana and EVM-compatible chains such as Ethereum, Hyperliquid, Tempo, Base, Robinhood Chain, Arbitrum and Polygon. MoonPay CEO Ivan Soto-Wright framed the expansion as recognition that AI is becoming the primary interface for navigating the internet and that payments need to follow.