On April 21, blockchain analytics firm Nansen announced a comprehensive upgrade to its on-chain data API, introducing a pay-per-use model based on the x402 protocol and PayAI infrastructure. According to BlockBeats, this new system allows users to make small payments in USDC for immediate access to wallet profiles, token flows, and smart money signals, eliminating the need for monthly subscriptions, mandatory approvals, or long-term contracts.
Nansen highlighted that traditional subscription models are not user-friendly for AI agents and developers. AI agents often require intermittent queries followed by idle periods, while developers face uncertain future demands during prototype testing, and researchers are locked into unnecessary fixed costs. The new solution is built around the open-source payment standard x402: when a request is made to access a paid endpoint, the server returns a 402 Payment Required status code, specifying the amount, currency, and chain information. The client completes an on-chain USDC transaction and provides a payment receipt to access the data. This entire request-invoice-payment-delivery process is fully programmable, allowing AI agents to autonomously complete payments.
Nansen's API offers two pricing tiers, both settled in USDC on the Base or Solana chains. The basic tier charges $0.01 per call, providing access to core data such as token filtering, wallet balances and history, DEX transactions, and profit and loss summaries. The advanced tier charges $0.05 per call, unlocking exclusive signals like smart money net flows, position distribution, and profit and loss leaderboards. In practical applications, a smart money alert system costs approximately $0.15 per run, wallet profile analysis about $0.07, and token research around $0.07.