Per‑call entitlements emerge

Software sold to developers is starting to look less like a monthly seat plan and more like a metered utility bill for each agent request. QuickNode now offers Machine Payments Protocol access at $0.001 per request, with a session mode priced at $10 per million requests. (quicknode.com) Machine Payments Protocol, or MPP, uses the old HTTP 402 “Payment Required” response as a tollbooth: an agent asks for a resource, gets a payment challenge, pays, and retries. Alchemy said the model is aimed at paid API calls, blockchain queries, and model inference without API keys, billing dashboards, or manual account setup. (alchemy.com) On Solana, that pricing model is easier to run because the network’s base fee is 5,000 lamports per signature, and Solana’s payments docs put median transaction cost at about $0.001. Solana also says payments settle in about 400 milliseconds and can be fee-sponsored so users pay in stablecoins without first buying SOL. (solana.com 1) (solana.com 2) That changes what “access” means for a platform. Instead of provisioning a user into a bundled software tier, a server can tie entitlement to a single paid call, verify the payment, and return the result only for that request. (alchemy.com) (quicknode.com) The new split is visible in how providers are packaging the product. QuickNode says MPP is “additive” and does not replace its standard plans with service-level agreements, support, and higher rate limits; it is offering a second lane built for agents and one-off paid calls. (quicknode.com) Developers are also building around two distinct billing shapes. Dexter’s Solana MPP docs describe a “charge” mode where each API call settles individually, and a “session” mode where a user deposits once and then pays with signed vouchers, closing with two on-chain transactions regardless of request count. (docs.dexter.cash) That session design pushes the model past simple micropayments and toward streaming usage. Dexter says sessions are meant for high-frequency requests, agent orchestration, streaming data, and model inference, where per-call accounting still exists but settlement is batched. (docs.dexter.cash) The protocol fight is not settled. Alchemy says Coinbase’s x402, introduced in late 2024, is focused on on-chain stablecoin payments, while MPP was submitted as an Internet Engineering Task Force draft by Tempo and Stripe with pluggable payment rails that can include stablecoins, cards, and bank transfers. (alchemy.com) A recent Solana workshop repository shows how close this is getting to production plumbing. In one demo marketplace, paid routes return a 402 challenge, an agent signs a Solana USDC transfer, retries the request, and receives the resource; the same repo compares x402 with MPP and notes that MPP can support dynamic per-request pricing, server-paid fees, and payment splits. (github.com) The result is a billing map that tracks machine behavior more closely than human subscriptions do. When software is bought one request at a time, the entitlement is no longer the account — it is the call. (quicknode.com) (solana.com)