The payments blockchain Tempo, jointly developed by major B2B payments platform Stripe and VC firm Paradigm, has launched its mainnet, The Block reported on March 18.

Tempo also introduced a Layer 1 blockchain specialised for large-scale payment processing and an open protocol for machine-to-machine payments jointly developed with Stripe.

Tempo also unveiled a payments directory listing more than 100 service providers, including model providers, developer infrastructure and data services.

Tempo was released on testnet in December. Earlier, in an October Series A round, Tempo raised $500 million at a $5 billion valuation. Thrive Capital, Greenoaks, Sequoia Capital and Ribbit Capital participated in the investment. Stripe and Paradigm did not participate.

Since the testnet release, Tempo has worked with design partners in payments, commerce and financial services to process real payment workloads using stablecoins.

Partners include Anthropic, DoorDash, Mastercard, Nubank, OpenAI, Ramp, Revolut, Shopify, Standard Chartered and Visa. The scope of cooperation spans global remittances, cross-border remittances, embedded finance and tokenised deposits.

Alongside the mainnet launch, the machine payments protocol (MPP) is an open standard for machine payments jointly developed with Stripe. It covers payment request, authorisation and settlement procedures so that agents and services can coordinate payments programmatically.

It was released as open source so that machine payments work consistently across different services and payment rails.

MPP runs on the Tempo blockchain but is designed not to be tied to any specific payment rail. Visa is expanding MPP to support card-based payments on its network. Stripe expanded it to payment methods on its platform such as cards and digital wallets, while Lightspark expanded it to bitcoin payments on the Lightning Network.