Cashu NUTs (Notation, Usage, and Terminology)

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

Optional

#	Description	Wallets	Mints
07	Token state check	Nutshell, cashu-ts, cdk, Minibits, macadamia, Sovran	Nutshell, cdk-mintd, nutmix
08	Overpaid Lightning fees	Nutshell, cashu-ts, cdk, Minibits, macadamia	Nutshell, cdk-mintd, nutmix
09	Signature restore	Nutshell, cashu-ts, cdk, Cashu.me, Minibits, macadamia, Sovran	Nutshell, cdk-mintd, nutmix
10	Spending conditions	Nutshell, cdk, cashu-ts, Minibits, Sovran	Nutshell, cdk-mintd, nutmix
11	Pay-To-Pubkey (P2PK)	Nutshell, cashu-ts, cdk, Cashu.me, Minibits, Sovran	Nutshell, cdk-mintd, nutmix
12	DLEQ proofs	Nutshell, cashu-ts, cdk, Minibits	Nutshell, cdk-mintd, nutmix
13	Deterministic secrets	Nutshell, cashu-ts, cdk, macadamia, Minibits, Sovran	-
14	Hashed Timelock Contracts (HTLCs)	Nutshell, cashu-ts, cdk	Nutshell, cdk-mintd, nutmix
15	Partial multi-path payments (MPP)	Nutshell, cdk	Nutshell, cdk-mintd, nutmix
16	Animated QR codes	Cashu.me, macadamia, Minibits	-
17	WebSocket subscriptions	Nutshell, cashu-ts, cdk, Cashu.me, Minibits, Sovran	Nutshell, cdk-mintd, nutmix
18	Payment requests	cashu-ts, Cashu.me, cdk, Minibits, Sovran	-
19	Cached Responses	cashu-ts	Nutshell, cdk-mintd, nutmix
20	Signature on Mint Quote	cashu-ts, cdk, Nutshell	cdk-mintd, Nutshell, nutmix
21	Clear authentication	Nutshell, cashu-ts, cdk	Nutshell, cdk-mintd, nutmix
22	Blind authentication	Nutshell, cashu-ts, cdk	Nutshell, cdk-mintd, nutmix
23	Payment Method: BOLT11	Nutshell, cashu-ts, cdk, Cashu.me, Minibits, Sovran	Nutshell, cdk-mintd, nutmix
24	HTTP 402 Payment Required	-	-
25	Payment Method: BOLT12	cdk, cashu-ts	cdk-mintd
26	Payment Request Bech32m Encoding	cdk, cashu-ts, Sovran	-
27	Nostr Mint Backup	Cashu.me, cdk	-
28	Pay to Blinded Key (P2BK)	cdk, cashu-ts	-
29	Batched Mint	cdk, cashu-ts	Nutshell, cdk-mintd
30	Payment Method: Onchain	cdk, cashu-ts, Cashu.me	cdk-mintd

Wallets

• Nutshell
• cdk
• cashu-ts
• Macadamia
• Minibits
• Cashu.me
• Sovran

Mints

• Nutshell
• cdk-mintd
• Nutmix