StableMoney.Dev

Technical reference for engineers building with stablecoins

PYUSDFiat-backedRank #7

PayPal USD

Paxos Trust Company (for PayPal)

Market cap (static): ~$0.9B

EIP standards (ERC-20, permit, proxies…)

Overview

Most UX-focused stablecoin with deep fintech integration across PayPal and Venmo (400M+ users). Issued by Paxos (NYDFS-regulated). The Solana deployment uses Token Extensions (Token-2022) enabling confidential transfers, transfer hooks, and memo fields natively in the token program.

Features

Engineering-oriented breakdown of capabilities: standards, who they matter for, integration rationale, per-feature risks, and vetted external references (specs, docs, verified source).

Primary Ethereum verified source: Etherscan
FeatureStandardsAudienceWhy it mattersRisk / caveatReferences
Solana Token-2022 extensions
authorization
  • SPL Token-2022
BothSolana program features differ from EVM — wallets and programs must explicitly support Token-2022.Not all Solana tooling supports extensions; silent failures possible.
Confidential transfers
compliance
CorporatePrivacy feature when enabled changes indexing and compliance visibility — monitor Paxos rollout.Compliance tooling may not see amounts; regulatory uncertainty for travel rule.
Transfer hooks
compliance
  • Transfer Hook extension
CorporatePer-transfer program invocation enables allowlists and policy hooks — Solana integrators must account for compute and failure modes.Hook failure can block transfers; program upgrade risk.
Memo field transfers
authorization
UserAttach structured metadata to transfers — useful for settlement references and reconciliation.Memo abuse or PII in memos can create compliance issues for indexers.
Permanent delegate — Paxos
compliance
CorporateDelegate authority for regulatory freeze/seize on Solana — disclose to end users in custody products.Similar to centralized freeze on EVM Paxos tokens.
LayerZero OFT burn-and-mint
cross chain
  • LayerZero OFT
BothCross-chain PYUSD uses burn/mint pattern — follow LayerZero peer configuration like other OFT assets.Bridge risk if peers mis-set; verify official OFT deployment addresses.
PayPal/Venmo unified balance
compliance
UserCustodial UX layer — on-chain balance may not reflect app balance; integrations should not assume 1:1 with PayPal ledger.Off-chain ledger and on-chain wraps can diverge during incidents.
3.7% APY on PYUSD
yield
UserCustodial yield product — not on-chain DeFi yield; terms set by PayPal, not smart contracts.Yield can change; not FDIC insured; counterparty to PayPal/Paxos stack.

EIP / ERC support matrix

Standards support for PYUSD. Click an EIP to jump to the global deep-dive section.

StandardStatusNotes
ERC-20
Fungible token standard
ImplementedBroadly USDC-class integration surface with extra batch and legacy approval helpers.
EIP-712
Typed structured data signing
ImplementedWallets and relayers can reconstruct signing payloads without hardcoding mismatched hashes.
EIP-2612
Permit — gasless ERC-20 approval
ImplementedSame integration playbook as USDC permit for most DeFi routers.
EIP-3009
transferWithAuthorization
ImplementedEnables single-call sponsored payments comparable to USDC EIP-3009 integrations.
EIP-1967
Standard proxy storage slots
ImplementedExplorers and Tenderly can attach the correct implementation ABI when slots are standard.
EIP-1822
UUPS — universal upgradeable proxy
UnknownMinor gas and audit surface differences for forks.
ERC-4626
Tokenized yield vault standard
Not implementedOn-chain ERC-4626 integrations apply to other protocols, not base PYUSD.
EIP-1271
Signature validation for smart contracts
Not implementedMay lag USDS-style institutional smart-wallet ergonomics unless middleware wraps PYUSD.

Technical notes

Ethereum — ERC-20 FiatToken (Paxos standard) with assetProtection (freeze), supplyController (mint/burn), pausing. Solana — Token-2022 program address: TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb. Initialized extensions at mint creation: ConfidentialTransferMint (not yet active), TransferHookAccount (null program for future use), PermanentDelegate (Paxos authority), TransferFeeConfig (0% currently), MemoTransfer. LayerZero escrow on Solana: 6JHAfeFjJLrn9enjvBUsmqLSy8B8Wyobr4uXuPVKyjhT. Devnet contract: CXk2AMBfi3TwaEL2468s6zP8xq9NxTXjp9gjMgzeUynM.

Reserves & peg

Reserves
USD deposits, US Treasuries, cash equivalents
Collateral
Fiat (off-chain)
Peg mechanism
Hard 1:1 via Paxos redemption
Auditor
Withum (monthly attestation)

Ecosystem

DeFi integration
Kamino, Marginfi (Solana); Aave (Ethereum); emerging
Yield
3.7% APY via PayPal (custodial)

Risk factors

lowLow liquidity vs USDT/USDClowPaxos regulatory dependencylowLimited DeFi depth
Official documentation

Networks & contracts

Deployments by chain — primary rows are highlighted. Always verify addresses against issuer docs before mainnet integrations.

NetworkStandardContractExplorer
EthereumPrimary
ERC-20
0x6c3ea9036406852006290770BEdFcAbA0e23A0e8

Paxos FiatToken v1

View
SolanaPrimary
Token-2022
2b1kV6DkPAnxd5ixfnxCpjxmKwqjjaYmCZfHsFu24GXo

SPL Token Extensions program

View

Engineering deep dive

Integration notes

On Solana, PYUSD uses Token-2022 extensions—wallet and program support varies. On Ethereum, Paxos FiatToken patterns (freeze, pause) mirror other Paxos-issued assets.

Product surface

PayPal/Venmo custody and promotional yield are off-chain—on-chain integrations should still assume standard issuer controls.