Surety

Credit lines for AI agents, backed by guarantors.

Agents borrow USDC against guarantor stake. Surety holds the funds and manages loans in its server ledger; deposits and withdrawals settle on Solana.

Create an agentLend USDC

Live ledger

Server ledger · recorded loans
Total repaidReading Solana
Repaid
—
Open
—
Defaulted
—
Repaid to the pool
Loans written
Agents
Outstanding loans
Live server ledger. Custodial USDC; transfers settle on Solana. Refreshes every 15 seconds.

01How a line works

Follow one loan
from deposit to repayment.

Five accounts and the real formulas: 1% per 30 days, split 50/25/25. Play it through, then switch to the default and watch whose money pays.

Step 1 of 5 · day 0
Lenders
$0.00
Deposited$0.00
Earned$0.00
Guarantor
Stake$0.00
Free$0.00
Fee locked$0.00
Pool
Liquidity$0.00
Lent out$0.00
Share price1.000000
Reserve
Balance$0.00
AgentNo line
$0.00
Line$0.00
Owes$0.00

Ledger

day 0 · 0 entries
Transfers in this simulation, oldest first
AmountKindRouteNote
Transfers appear here as they land.

A simulation, not live data. Every number comes from the credit model: 1% per 30 days, a 50/25/25 fee split and the score formula.

02Latest loans

Every loan is public.

Read from the service ledger on every refresh. Deposits and withdrawals settle on Solana.

The eight newest loans on Server ledger
TimeAgentAmountTermFeeStatus
All activity

03Three ways in

Borrow, back, or lend.

Each role puts a different amount at risk and earns from the same fee.

Run an agent

Create an agent
$5–$500per loan, for 1 to 30 days
  • Register the agent’s key, then take a seat or name a guarantor.
  • The fee is 1% per 30 days, fixed the moment it borrows.
  • Repay on time and the 0–1000 score climbs.

Guarantee an agent

Become a guarantor
25%of every fee your agents pay
  • Lock at least $10 of USDC as pool shares.
  • Vouch lines out of that stake for agents you trust.
  • If an agent you back defaults, your stake pays first.

Lend to the pool

Lend USDC
50%of every fee goes to the pool
  • Deposit USDC for pool shares; every repaid fee lifts their price.
  • Defaults are covered by guarantor stake before they reach you.
  • Withdraw any time; within 7 days of a deposit it costs 0.5%.

The fee

Where every fee goes.

$50 for 7 days → fee $0.116667

  • Lenders

    50%

    $0.058333 · lifts the share price

  • Guarantor

    25%

    $0.029166 · claimable by the guarantor

  • Reserve

    25%

    $0.029168 · takes the rounding

04The score

A score computed from the record.

0 to 1000, computed from repayment history. Move the inputs to explore the scoring formula.

660Strong
New
0–149
Fair
150–399
Good
400–599
Strong
600–799
Excellent
800–1000
Try a record
$2,400·d
8
$250
60d
9
0
DefaultedA default pins the score at 0, for good.

score = clamp(0, 1000, sum of terms), or 0 after a default. Same function as get_score in the program.

  • Dollar-days repaid240 / 400
  • Week-long loans160 / 200
  • Backing at risk50 / 150
  • Time enrolled120 / 150
  • On-time repayments90 / 100
  • Late repayments0 / 0
Score660 / 1000

05What holds

Three rules, checked live.

The test suite checks these after every transaction. The rows below check them again against the pool right now.

Lost by lenders

A default is paid from the guarantor's locked stake first. Lenders lose money only if a stake runs out.

Pool share price

USDC per pool share. It started at 1.000000. Fees push it up and defaults are covered before they reach it.

Vault covers every claim

USDC in the vault covers lender liquidity, the reserve, unclaimed guarantor fees and seat bonds.

Checked against Server ledger every 15 seconds.

All invariants

Give your agent a record worth having.

Register it in one transaction. Take a seat or ask a guarantor you know, then let every repayment build its score.

Create an agentRead the protocol
Create an agentRead the protocol