Pearl Lend

Draft the loan offer

A Pearl loan is a pawn-shop loan and this desk is honest about it: the borrower locks collateral C in a Taproot vault, the lender sends principal P to the borrower, and the borrower repays P + interest to reclaim the collateral. Both are PRL, so there is no price oracle and no liquidation math to get wrong — the vault must always be able to pay the lender back, which is why collateral must cover the full repayment plus your chosen ratio. Two script paths move the coins: a 2-of-2 repay leaf (both sign the repayment) and a lender-only default leaf behind a CSV timelock of term + grace blocks. Interest is grain-exact integer math, computed once at origination.

Network Borrower key 64-hex x-only pubkey. Collateral owner; signs the repayment. Lender key 64-hex x-only pubkey. Co-signs repayment; sole key on the default leaf. Borrower payout address prl1… where principal goes and collateral change returns. Lender payout address prl1… where repayment (or the default sweep) lands. Principal (PRL) APR (%) Simple annual rate. 10 = 10%. Term (blocks) 194 s per block. 10000 ≈ 22.5 days. Grace (blocks) Extra blocks after term before the lender may sweep. 144 ≈ 8h. Collateral ratio (%) Minimum collateral vs principal. 150 = 150%. Collateral (PRL) Must cover the full repayment and the ratio above. Memo Optional, stored in the descriptor only (max 280 chars).

Lock the collateral

The borrower sends the full collateral to the vault address in their own wallet, then records the lock transaction here. The desk verifies the vault actually holds the collateral before the loan proceeds.

Blockbook base URL GET-only reads. Stored locally. Lock txid Lock vout Locked value (PRL) Must equal the collateral in the offer.

Fund the loan

The lender sends the principal to the borrower's payout address — a normal PRL payment, made in the lender's own wallet. The desk can build the unsigned payment for you, or you can record a txid you made yourself.

Send exactly
To (borrower)

Build the unsigned payment (optional)

Fee rate (grains/vB) Change address prl1… your own address for change.

Your UTXOs (JSON) From Blockbook /api/v2/utxo/<address>. Each needs spk (hex), priv (32-byte hex) and internalXOnly (64-hex) to sign.

Unsigned payment

Sign this hex in your wallet (or with the key below), then broadcast it yourself. This desk never sees your keys unless you paste them.

Fee
Change

Record the funding

Funding txid

Track the loan

Read-only. The desk polls Blockbook for the vault UTXO and the chain height, then shows exactly where the loan stands. Nothing here can move coins.

Blockbook base URL

Repay the loan

The borrower proposes the repayment — lender gets exactly principal + interest, the borrower keeps the change — signs it, and hands the proposal to the lender. The lender's copy of this desk re-verifies the borrower's signature against the repayment digest before co-signing; a bad signature refuses assembly, never a half-signed broadcast. Exchange the proposal JSON by any channel you trust.

Lock txid Lock vout Vault value (PRL) Fee rate (grains/vB)

Close the loan

Default claim (lender only)

After term + grace blocks from the lock's confirmation, the lender alone may sweep the vault. The desk checks maturity against Blockbook and refuses early claims unless you tick the override — and then it says so on the record.

Lock txid Lock vout Vault value (PRL) Fee rate (grains/vB) Blockbook base URL Lender signing key 32-byte hex private key or 12/24-word mnemonic. Wiped after signing.

I know the loan is not mature — build the claim anyway (it will not confirm until the CSV delay passes) Builder tip (optional): add a 1% tip for the builder, paid to prl1p62v09vuzyd8kdz9l23jaf3kph4wwx6jqcmhkkhg8lhr2qlxky8psu3zw9d as its own output of this claim. The lender receives the collateral minus the fee and the tip. Off by default; repayments and mutual closes never carry a tip.

Lender receives
Fee
Builder tip: none
Claim txid

Mutual close (both agree)

Early repayment, a negotiated haircut, a refinance — any split you both agree on is a valid 2-of-2 spend of the repay leaf. Splits + fee must equal the vault value exactly.

Lock txid Lock vout Vault value (PRL) Fee rate (grains/vB)

Splits (JSON) [{"address":"prl1…","valuePRL":"12.5"}, …]

Standalone verifier

No trust required: paste any loan descriptor and any signed transaction. The desk re-derives the vault, recomputes the digest, and checks every signature.

Descriptor JSON Signed tx hex

Prevouts (JSON) [{"txid":"…","vout":0,"value":"grains","spk":"hex"}] — the vault output being spent.

Honest limits

No oracle, by design. Principal and collateral are both PRL, so there is no price to feed and no liquidation cascade. If you want cross-asset loans, this desk is not the tool.
The lender's protection is overcollateralization, not legal recourse. Collateral must cover the full repayment — a borrower who repays reclaims the excess; a borrower who defaults forfeits it.
CSV maturity is measured from the lock transaction's confirmation height. The default claim is consensus-invalid before term + grace blocks pass; the desk refuses to build it early unless you override explicitly.
Manual coordination. There is no messaging, no order book, no watchtower. Proposals and descriptors move by whatever channel you and your counterparty trust. The desk verifies, it does not vouch.
The builder tip is optional and default-claim-only: 1% of the collateral, only when the lender checks the box, paid as its own output to the builder address printed next to the checkbox. Repayments and mutual closes never carry one — their outputs are the two parties' agreed amounts.
Keys. Nothing is stored: pasted keys live in memory only and are wiped after signing. Prefer signing in your own wallet and pasting only signatures and x-only pubkeys.