Since 28 August, you can tell Claude or ChatGPT to lend your USDC on a Solana protocol and it will prepare the transaction for you to approve with a passkey. Since 31 August, the same is true for Grok, X's assistant. All three route through the same infrastructure: MoonPay's PayBox, connected to Kamino, a Solana lending market. No coverage we found put the full timeline in one place or checked what the custody model actually promises.
What changed, and when
MoonPay's payment layer for AI agents did not appear all at once. It rolled out in three dated steps, each confirmed in MoonPay's own newsroom and press materials rather than assembled from a single announcement:
| Date | What shipped |
|---|---|
| July 2026 | PayBox launches inside Claude and ChatGPT: onramp, swap, and pay through natural-language prompts |
| 28 August 2026 | Kamino, a Solana lending protocol, added. Claude and ChatGPT users can supply or borrow on Kamino from a conversation |
| 31 August 2026 | PayBox expands to Grok on X, MoonPay's third AI platform, with the same Solana DeFi access |
The mechanic is the same everywhere. A user writes something like "supply 500 USDC on Kamino" or "borrow USDC against my SOL." The assistant drafts the transaction. PayBox holds it until the user approves with a passkey, or, in a separate mode, executes it automatically inside limits the user set in advance.
The custody model, in MoonPay's own words
The part worth reading closely is what does and does not touch the AI provider. MoonPay's language is specific:
Funds and keys do not move outside the user's control, and access can be revoked at any time.
Keys are split using threshold cryptography and secured in enclaves, via infrastructure MoonPay attributes to Sodot. No single party, including MoonPay itself or the AI assistant, holds a complete key or can sign alone. Claude, ChatGPT, and Grok never receive a private key or a raw credential; they receive a prepared transaction and a place to send the user's approval.
Two modes, one real distinction
Always Ask requires a passkey approval for every transaction. Autonomous lets the assistant act inside limits the user configures, without asking each time. MoonPay's public materials describe both modes but do not publish specific dollar or frequency limits for Autonomous mode; those are set per user, not fixed by the platform.
Why Kamino specifically
Kamino is a Solana lending and leverage protocol: suppliers deposit into pooled markets, borrowers draw against them and pay interest that flows back to suppliers, and rates float with utilisation. It is not the newest or largest name in Solana DeFi, but it is the one MoonPay picked to be the first onchain yield product an AI assistant can operate directly, ahead of any lending market on Ethereum or the other chains PayBox already supports.
PayBox's broader reach extends past Solana. MoonPay's own materials list Solana alongside Ethereum, Base, Arbitrum, Polygon, Hyperliquid, Tempo, and Robinhood Chain for onramping, swaps, and cross-chain bridging. Kamino is the one DeFi position, specifically, that ships with natural-language support, and it is a Solana product.
PayBox is not limited to trading. MoonPay's materials describe payments for travel, restaurants, and shopping routed through x402, an open standard for machines to pay for services without a human filling out a checkout form. Lending on Kamino is the same idea applied to yield: an instruction in plain language becomes a signed transaction, without the user touching a wallet interface.
This is part of a wider push, not a Solana-only or MoonPay-only one. Coinbase, Stripe, Visa, and Mastercard have each announced comparable work on letting AI agents hold payment credentials and act on them, sometimes described under the same x402 umbrella. What is specific to this rollout is that the first live DeFi position inside any of the big three chat assistants sits on Solana, through Kamino, not on Ethereum or elsewhere.
Who cannot use it
The lending and yield feature is unavailable in the United States, the United Kingdom, the European Union, and Australia. MoonPay's materials state the restriction without detailing which specific rule in each jurisdiction it is responding to. Onramping and swaps through PayBox are broadly available; the DeFi lending layer through Kamino is the part carved out.
What other coverage left out
Individual outlets reported the Grok launch, the Kamino addition, or the original Claude and ChatGPT rollout as separate items, usually citing MoonPay's press release for whichever step prompted that day's story. We did not find one that stated the July, 28 August, and 31 August dates together, or that quoted MoonPay's specific custody language rather than paraphrasing it.
Market context
SOL traded at $100.94 as of 15:05 UTC on 4 September 2026, down 4.05% over 24 hours, for a market capitalisation of $59.09B. Nothing about this integration is priced into that move; three AI platforms gaining a lending connector is a usage and distribution story, not one that moves a token's price on the day it ships.