Skip to content
AnnouncementSomnia Oracle settles event contracts onchain, in minutes, with receipts.

The stablecoin marketson Somnia settle in.

USDso is issued and operated by Frax on frxUSD infrastructure. It is the quote and settlement asset for markets on Somnia, from spot pairs to event contracts and Somnia Lend.

Read the USDso docsSee it on Explorer
USDsoLive
USDsoStablecoin for markets on Somnia
Issuer
Frax, on frxUSD infrastructure
Minting
1:1 against approved stablecoins
Network
Somnia mainnet · 5031
Decimals
18
Standard
ERC-20

USDso holders are not entitled to reserve yield.

One dollar asset for quoting,settling and moving balances.

Spot pairs quote in USDso and event contracts settle in it, so balances can move between Somnia markets without converting out of the settlement asset.

  • Spot pairs
    Quote in USDso
    Event contracts
    Redeem at 1 USDso
    Perpetuals
    Cross-margin collateral

    Quote, settle, move

    Balances can move between Somnia markets without converting out of the settlement asset.

  • Issuer
    Frax
    Infrastructure
    frxUSD
    Venues integrate
    Standard ERC-20

    Reserves managed by the issuer

    Frax issues and operates USDso and holds and manages the reserves. Venues do not run issuance themselves.

  • Approved protocols
    Share by holdings
    Somnia Foundation
    Remainder
    Wallet holders
    Not entitled

    Reserve yield follows holdings

    Approved protocols can receive a share of reserve yield based on the USDso their contracts hold over time. Holding USDso in a wallet does not earn that yield.

How reserve yieldis shared.

Frax’s reserves earn yield. Each day Frax mints that yield as USDso into a public split contract. Shares are set from onchain holdings, not a fixed percentage split.

  1. Measured hourly

    USDso held by each registered protocol’s counted contracts is read every hour, with total supply.

  2. Shared by holdings

    A protocol’s share of a day’s yield is its average USDso held over the day, as a fraction of average total supply.

  3. Foundation remainder

    Yield on USDso held outside registered protocols goes to the Somnia Foundation.

  4. Paid daily

    Shares are set on the split the following day (UTC), then the day’s minted yield is paid.

USDso holders are not entitled to reserve yield. Allocations under the Yield Allocation Framework are discretionary and may change.

Registered recipients such as dreamDEX, Somnia Lend and Prophecy are shown with every payment on Somnia Explorer. Shares change daily; no single day is a fixed split.

Integrate a standard ERC-20.Trade, lend and settle with it.

Use the published mainnet address like any ERC-20 with viem or ethers. Minting is one-to-one against approved stablecoins through Frax.

  • Trade, lend, settle

    Use USDso as quote and collateral on Somnia Markets, supply it on Somnia Lend, and redeem winning event contracts for 1 USDso.

  • Read and transfer with standard tooling

    Read balances and transfer with standard tooling. Venues do not run issuance themselves.

  • Protocol holdings can earn a share

    Registered protocols such as dreamDEX and Somnia Lend can receive yield in proportion to counted contract holdings. Adding a protocol needs Somnia approval; no public application process is published yet.

usdso.tstypescript
import { createPublicClient, http, erc20Abi } from 'viem'
import { somnia } from './chains' // chain ID 5031
const USDSO = '0x00000022dA000002656c64D9eA6011ea952D008A'
const client = createPublicClient({
chain: somnia, transport: http(),
})
const balance = await client.readContract({
address: USDSO, abi: erc20Abi,
functionName: 'balanceOf', args: [account],
})

Published mainnet address · works with viem or ethers

Addresses anddurable facts.

Addresses, decimals and issuer details stay fixed. For supply, holders and yield paid, prefer Somnia Explorer.

USDso on Explorer
Token factsSomnia docs
Symbol
USDso
Decimals
18
Somnia mainnet
Chain ID 5031
Address
0x00000022dA000002656c64D9eA6011ea952D008A
Tokyo mainnet
Chain ID 50321 · bridged synthetic via Hyperlane warp route
Issuer
Frax, on frxUSD infrastructure
Minting
One-to-one against approved stablecoins through Frax
Split contract
0x44D650A2cE847098c26e6E874A308F280817D4ac
Somnia ExplorerLive
≈3.21MCirculating supply, USDso
≈31,123Reserve yield generated to date, USDsoSince 22 Apr 2026

Totals read from Somnia Explorer, not an APY. Live figures change; check Explorer.

Read the docs.Verify on Explorer.

The USDso docs cover issuance, the Yield Allocation Framework and the mainnet address. Every payment from the split contract is public on Somnia Explorer.

USDso docsUSDso on Explorer

USDso is issued and operated by Frax. USDso holders are not entitled to reserve yield. Allocations under the Yield Allocation Framework are discretionary and may change. Use of USDso is governed by the USDso Terms of Service.