Cashu NUTs (Notation, Usage, and Terminology)

June 23, 2026 ยท View on GitHub

These documents each specify parts of the Cashu protocol. Read the specifications for the legacy API here.

Specifications

Wallets and mints MUST implement all mandatory specs and CAN implement optional specs.

Mandatory

NUT #Description
00Cryptography and Models
01Mint public keys
02Keysets and fees
03Swapping tokens
04Minting tokens
05Melting tokens
06Mint info

Optional

#DescriptionWalletsMints
07Token state checkNutshell, cashu-ts, cdk, Minibits, macadamia, SovranNutshell, cdk-mintd, nutmix
08Overpaid Lightning feesNutshell, cashu-ts, cdk, Minibits, macadamiaNutshell, cdk-mintd, nutmix
09Signature restoreNutshell, cashu-ts, cdk, Cashu.me, Minibits, macadamia, SovranNutshell, cdk-mintd, nutmix
10Spending conditionsNutshell, cdk, cashu-ts, Minibits, SovranNutshell, cdk-mintd, nutmix
11Pay-To-Pubkey (P2PK)Nutshell, cashu-ts, cdk, Cashu.me, Minibits, SovranNutshell, cdk-mintd, nutmix
12DLEQ proofsNutshell, cashu-ts, cdk, MinibitsNutshell, cdk-mintd, nutmix
13Deterministic secretsNutshell, cashu-ts, cdk, macadamia, Minibits, Sovran-
14Hashed Timelock Contracts (HTLCs)Nutshell, cashu-ts, cdkNutshell, cdk-mintd, nutmix
15Partial multi-path payments (MPP)Nutshell, cdkNutshell, cdk-mintd, nutmix
16Animated QR codesCashu.me, macadamia, Minibits-
17WebSocket subscriptionsNutshell, cashu-ts, cdk, Cashu.me, Minibits, SovranNutshell, cdk-mintd, nutmix
18Payment requestscashu-ts, Cashu.me, cdk, Minibits, Sovran-
19Cached Responsescashu-tsNutshell, cdk-mintd, nutmix
20Signature on Mint Quotecashu-ts, cdk, Nutshellcdk-mintd, Nutshell, nutmix
21Clear authenticationNutshell, cashu-ts, cdkNutshell, cdk-mintd, nutmix
22Blind authenticationNutshell, cashu-ts, cdkNutshell, cdk-mintd, nutmix
23Payment Method: BOLT11Nutshell, cashu-ts, cdk, Cashu.me, Minibits, SovranNutshell, cdk-mintd, nutmix
24HTTP 402 Payment Required--
25Payment Method: BOLT12cdk, cashu-tscdk-mintd
26Payment Request Bech32m Encodingcdk, cashu-ts, Sovran-
27Nostr Mint BackupCashu.me, cdk-
28Pay to Blinded Key (P2BK)cdk, cashu-ts-
29Batched Mintcdk, cashu-tsNutshell, cdk-mintd
30Payment Method: Onchaincdk, cashu-ts, Cashu.mecdk-mintd

Wallets

Mints