MoonPay PayBox Launches in Grok, Bringing Solana Swaps and Kamino Earn to X Users

MoonPay's PayBox payment vault is now live in Grok, xAI's AI assistant embedded in X, making it the third major AI platform to carry the tool after Claude and ChatGPT. Announced August 31, all Grok users can onramp fiat, swap tokens, bridge assets across chains, and access Solana DeFi protocols, including Kamino Finance KMNO$0.025-0.8% Earn yield, through natural-language commands.

What Grok Users Can Do With PayBox on Solana

PayBox connects Grok to a user's self-custodial wallet, payment cards, and credentials. Supported transactions include onramping fiat to stablecoins such as PYUSD, swapping to SOL, bridging funds across chains, and accessing Kamino lending markets to earn yield on USDC. Non-financial tasks such as booking flights and restaurant reservations route through the same interface.

The transaction flow separates AI preparation from user authorization. Grok prepares the transaction; no funds move until the user approves with a passkey scoped to that specific action, which expires after use.

Two permission configurations are available. In "Always Ask" mode, every transaction requires a fresh passkey approval. In "Autonomous" mode, the AI acts within user-defined spending limits without prompting for each action; any change to those limits requires passkey re-approval.

Kamino Earn Comes to Grok, With Restrictions in US, UK, EU, and Australia

The Kamino Earn integration added to PayBox for Claude and ChatGPT on August 27 now extends to Grok. Users in eligible markets can instruct Grok to deposit USDC into Kamino lending markets or manage borrow positions through conversation.

The lending and yield feature is unavailable in the United States, United Kingdom, European Union, and Australia.

MoonPay CEO Ivan Soto-Wright framed the expansion as a recognition that AI is becoming the primary interface through which people navigate the internet, and that payments need to follow.

Security Model: MPC Keys, TEEs, and Per-Transaction Passkeys

Wallet keys are secured through multiparty computation and trusted execution environments via Sodot infrastructure, which MoonPay acquired in 2026. Per the official press release, the Sodot system secures more than $50 billion in assets across more than 10 million wallets. Card transactions use Visa's agentic commerce protocol, which keeps raw card numbers out of the AI's processing context. Neither MoonPay nor the AI can unilaterally move user funds.

PayBox Across Claude, ChatGPT, and Now Grok

PayBox launched with Claude and ChatGPT in July 2026, as covered at the time. The Kamino lending integration followed on those two platforms on August 27. Today's expansion carries both capabilities to Grok.

Supported networks include Solana and EVM-compatible chains: Ethereum, Hyperliquid, Tempo, Base, Robinhood Chain, Arbitrum, and Polygon.