Vault & Outcome Tokens

USDT Collateral

All trading on Strike uses USDT as collateral. Before placing orders, your wallet must approve the Vault to spend USDT.

Approve USDT

// Idempotent — skips if allowance is already sufficient
client.vault().approve_usdt().await?;

This calls USDT.approve(vault, type(uint256).max). It checks the current allowance first and skips the transaction if approval is already set. Safe to call every time your bot starts.

Balance and Allowance

let signer = client.signer_address().unwrap();

let balance = client.vault().usdt_balance(signer).await?;
println!("USDT balance: {balance}");  // in wei (1 USDT = 1e18)

let allowance = client.vault().usdt_allowance(signer).await?;
println!("vault allowance: {allowance}");

You can query any address, not just the signer.

Outcome Tokens

Strike uses ERC-1155 outcome tokens — each market has a YES token ID and a NO token ID. Tokens are minted when batches clear and can be redeemed after market resolution.

Token IDs

let yes_id = client.tokens().yes_token_id(market_id).await?;
let no_id = client.tokens().no_token_id(market_id).await?;

Token Balances

let signer = client.signer_address().unwrap();

let yes_balance = client.tokens().balance_of(signer, yes_id).await?;
let no_balance = client.tokens().balance_of(signer, no_id).await?;

Token Approval for Selling

To place SellYes or SellNo orders, the OrderBook must be approved to transfer your outcome tokens:

let order_book = client.config().addresses.order_book;

// Check if already approved
let approved = client.tokens().is_approved_for_all(signer, order_book).await?;

if !approved {
    client.tokens().set_approval_for_all(order_book, true).await?;
}

Redemption

After a market is resolved via Pyth oracle, winning outcome tokens can be redeemed 1:1 for USDT. Losing tokens are worthless.

Check Balances

let signer = client.signer_address().unwrap();

// Returns (yes_balance, no_balance)
let (yes, no) = client.redeem().balances(market_id, signer).await?;
println!("YES: {yes}, NO: {no}");

Redeem

// Redeem winning tokens for USDT
client.redeem().redeem(market_id, amount).await?;

This calls Redemption.redeem(factoryMarketId, amount) on-chain.

Collateral Model Summary

In Strike, 1 YES + 1 NO = 1 USDT (fully collateralized). Both sides of the orderbook lock USDT — askers do NOT need to hold outcome tokens to sell. See Batch Auctions for details on how collateral flows during clearing.

Operation	Collateral
Bid at tick T	lots × T/100 × LOT_SIZE USDT
Ask at tick T	lots × (100-T)/100 × LOT_SIZE USDT
SellYes	YES tokens custodied by OrderBook
SellNo	NO tokens custodied by OrderBook
Redeem (winner)	1 token → 1 USDT
Redeem (loser)	worthless