Stake and credit limits
A member's credit limit is bounded by its stake. The formula, defaults, and what x207 does not promise.
Every member locks a stake in USDT. The stake is the cash that covers the member's debts. A member's credit limit says how much it can owe at once.
The rule
limit <= stakeThe limit never exceeds the stake. A debtor's own stake therefore covers the debt if it defaults.
The formula
limit = min(limit_cap,
stake * base_limit_ratio / 10000 + settled_history * limit_growth / 10000,
stake)Defaults: base_limit_ratio 8000, limit_growth 1000, limit_cap 1,000,000,000 (1000 credit). settled_history grows only when a member settles in cash. Cycle clearing does not raise it, so trading in circles to inflate a limit does not work.
So a new member starts at 80% of its stake, and the limit grows with a record of cash settlement, up to the stake and the cap. A deployed circle can use other parameters.
Headroom
headroom = max(0, limit - outstanding_debt - bundle reservations)Headroom is what a member can still spend now.
What this costs
Capital locked is at least 125% of the debt a member can run up (stake over limit at the default ratio). x207 is not undercollateralised credit. It is netting with collateral: less value moves, the stake is the guarantee, and credit above stake is not built in the current version.
Leaving
A member calls request_exit, waits out the circle's exit rules, then withdraw_stake.
Source
Residual and settlement
After netting, only the residual moves in USDT. Debtors pay inside the payment window, creditors claim to NEAR or NEAR Intents, defaults are covered from stake.
x402 scheme
x207 is a binding of the x402 batch-settlement scheme on the network x207:<circleId>. Headers, entry fields, facilitator endpoints and reason codes.