# OUSD (Open USD) Wallet for iOS, Android & APK
> Gem Wallet is a self-custodial OUSD wallet for iOS, Android, and APK. Hold, send, and receive Open USD on Ethereum, Base, Solana, and Tempo with no account.
## What Is OUSD (Open USD)?
**OUSD (Open USD)** is a US dollar stablecoin created by Open Standard, an independent company founded by Coinbase, Mastercard, Shopify, Stripe, and Visa. The token itself is issued by Bridge, the stablecoin infrastructure company owned by Stripe. Open Standard announced the project in June 2026, and OUSD went live on September 30, 2026, on four networks at once: Ethereum, Base, Solana, and Tempo.
OUSD reserves are held at BlackRock, Lead Bank, and BNY, and Bridge publishes monthly reserve attestations at reserves.bridge.xyz/ousd. Businesses can mint and burn OUSD at a 1:1 rate with US dollars at no cost through Open Standard partners. The five founders committed more than $1 billion to OUSD liquidity at launch, and OUSD trades on Coinbase, Kraken, and Uniswap. Partners that adopt OUSD earn rewards in proportion to the OUSD supply and activity they bring to the network.
The ticker OUSD was in use before Open USD: Origin Dollar, a token from Origin Protocol, also trades as OUSD on Ethereum. The two are unrelated tokens with different contracts, so the contract address is the only reliable way to tell them apart. For a beginner-level overview of how OUSD compares with USDC and USDT, see our [Open USD guide](https://gemwallet.com/learn/what-is-open-usd-ousd-a-beginners-guide-to-the-stablecoin-backed-by-stripe-and-visa/).
## What Is an OUSD Wallet?
An **OUSD wallet** is an app that holds the private keys to your blockchain addresses and shows the Open USD balance on each of them. Because OUSD is issued separately on Ethereum, Base, Solana, and Tempo, a full OUSD wallet needs an address on each of these networks, and each address keeps its own OUSD balance. OUSD on Base and OUSD on Solana share a name and a dollar value, but they live on different ledgers.
In a self-custodial wallet, the private keys stay on your phone, not on an exchange server. Only the holder of the keys can sign a transfer, and the recovery phrase is the only thing you need to restore access.
Gem Wallet is a self-custodial OUSD wallet that derives all four OUSD addresses from one 12-word recovery phrase. Your keys are encrypted on your device, and the same phrase restores your Ethereum, Base, Solana, and Tempo addresses together if you change phones.
## OUSD on Ethereum, Base, Solana, and Tempo
**OUSD on Ethereum.** The [Ethereum](https://gemwallet.com/ethereum-wallet/) version is an ERC20 token on a 0x address, the same address that holds your ETH and other [ERC20 tokens](https://gemwallet.com/erc20-wallet/). Fees are paid in ETH.
**OUSD on Base.** [Base](https://gemwallet.com/base-wallet/) is an Ethereum layer 2 network, so your Base address looks exactly like your Ethereum address. The networks are still separate: OUSD sent on Base arrives only on Base. Fees are paid in ETH on Base.
**OUSD on Solana.** On [Solana](https://gemwallet.com/solana-wallet/), OUSD is issued natively with the Token-2022 program, the newer version of the [SPL token](https://gemwallet.com/spl-wallet/) standard, with no wrapped version. Solana addresses are base58 strings, not 0x addresses. Fees are paid in SOL.
**OUSD on Tempo.** [Tempo](https://gemwallet.com/tempo-wallet/) is a payments blockchain incubated by Paradigm and Stripe, and OUSD there is a TIP-20 token. Tempo has no native gas coin: fees are paid in USD stablecoins, and a basic transfer typically costs less than $0.001 with finality in about 0.6 seconds, according to tempo.xyz.
## OUSD Contract Addresses
| Network | OUSD contract | Address type | Fee paid in |
| --- | --- | --- | --- |
| Ethereum | 0x9f6F3991D525015a6F8CaF062C83b62fD3AC4436 | 0x (42 characters) | ETH |
| Base | 0xB2000000000000000000002fEb517dFeC7415344 | 0x (42 characters) | ETH |
| Solana | ousd2mJsPEckLHcSCDxyKD7NDGARZcfLbDZkKiatYHB | base58 | SOL |
| Tempo | 0x20c0000000000000000000006a37DA5C996874BE | 0x (42 characters) | USD stablecoins |
Data source: Open Standard, OUSD is live, as of October 2026.
Three of the four networks use the same 0x address format, so the address alone does not show which network a transfer goes to. When you withdraw OUSD from an exchange or send it to another person, pick the same network on both sides. A token named OUSD at any other contract is not Open USD.
## How OUSD Transfers and Fees Work
An OUSD transfer is a token transfer, so the network charges its fee in its own fee asset, not in OUSD. On Ethereum and Base you need a small amount of ETH, on Solana you need SOL, and on Tempo the fee is paid in a USD stablecoin. Moving OUSD from one network to another is not a regular transfer: sending OUSD from Base to a Solana address does not work, and moving it between networks takes a cross-chain swap.
Gem Wallet shows the network fee before you confirm a transfer, and its built-in DEX aggregator lets you [swap](https://gemwallet.com/swap/) OUSD for other assets such as [USDC](https://gemwallet.com/usdc-wallet/) without leaving the app. If you hold fiat rather than crypto, you can also [buy OUSD](https://gemwallet.com/buy-ousd/) with a card or a bank transfer on any of the four networks.
## Where Open Standard Restricts OUSD Promotion
Open Standard publishes a list of geo restrictions and prohibited use cases for its network partners. Partners may promote OUSD globally except in 21 listed regions, including the European Economic Area, Russia, and sanctioned jurisdictions, and may not promote it for 29 categories of use, such as gambling, prediction markets, and weapons. The rules apply to how partners promote OUSD. Check the current list before you use OUSD in a business.
**Download Gem Wallet and keep your Open USD on Ethereum, Base, Solana, and Tempo under your own keys.**