In one embodiment, techniques include receiving, by a computing device associated with a payment service system, a request to create a blockchain-enforced contract corresponding to a new transaction between a merchant and a customer. Techniques include generating, based on analysis using machine-learned models of a transaction history associated with the merchant, a condition of the blockchain-enforced contract requisite for completion of the new transaction. Techniques includes generating the blockchain-enforced contract including the condition. Techniques include providing the blockchain-enforced contract to nodes in a blockchain network. Techniques include creating a blockchain transaction addressed to the blockchain-enforced contract and including information regarding the condition. Techniques include providing the blockchain transaction to the nodes. Techniques include receiving confirmation that the nodes have validated the blockchain transaction. Techniques include causing a value associated with the new transaction to be transferred to a merchant account associated with the merchant.