Payments Glossary

Clear, factual, up-to-date definitions of key payment ecosystem terms: instant payment systems, CBDC, stablecoins, agentic commerce, and regulation.

Instant Payment Systems

pix

Pix is the instant payment system run by the Central Bank of Brazil, launched in November 2020, processing over 300 million daily transactions.

upi

UPI is India's real-time payments infrastructure run by NPCI, processing over 228 billion transactions annually in 2025.

qris

QRIS is Indonesia's national QR code payment standard launched by Bank Indonesia in 2019, now cross-border interoperable across ASEAN.

sepa instant

SEPA Instant Credit Transfer (SCT Inst) is the euro-area instant payments scheme, mandatory for all eurozone PSPs since October 2025.

e cny

The e-CNY is China's central bank digital currency — the world's first interest-bearing retail CBDC, classified as M1 since January 2026.

x402

x402 is an HTTP-native protocol that revives the 402 Payment Required status code for AI agent payments, now governed by the Linux Foundation.

apop

APOP (Agentic Payment Open Protocol) is the AI agent payment standard launched by UnionPay on April 3, 2026 as a rival to x402 and Google's AP2.

brics pay

BRICS Pay is the BRICS bloc's blockchain-based cross-border payments platform integrating member CBDCs and non-USD stablecoins.

stablecoins

Stablecoins are crypto tokens pegged 1:1 to a fiat currency (usually USD) used as a payment rail; total USD stablecoin supply exceeds $200 billion.

genius act

The GENIUS Act is the US federal law regulating payment stablecoins, signed in July 2025 with the NPRM published in April 2026.