Reading through OpenGradient's architecture docs today, a small detail in the payment section stopped me from moving to the next page. LLM inference payments settle through x402 using OPG tokens on Base Sepolia. Sepolia is Ethereum's testnet. Not mainnet Base.
The SDK documentation confirms the same thing, instructing developers to fund their wallets with Base Sepolia OPG tokens specifically for these payments.
That detail matters because OPG is not a testnet token anymore. It listed for spot trading on Binance on May 22, 2026, and trades with real daily volume in the tens of millions of dollars. The token carries real market value while the actual inference payment rail it was built to power is still running on a test network.
I do not read this as a red flag. Infrastructure usually lags token listings, and PIPE settlement for ML inference already runs natively on the OpenGradient chain itself, which is a separate and apparently more mature rail. But it does mean the headline use case most people associate with OPG, paying for verified LLM calls, is not yet something happening with real economic weight on a production network.
The gap between a live, liquid token and a still-testnet payment rail for its primary advertised function is the part worth watching as 2026 continues.