# Cashu NUTs (Notation, Usage, and Terminology)

These documents each specify parts of the Cashu protocol. Read the specifications for the legacy API [here](https://github.com/cashubtc/nuts/tree/74f26b81b6617db710fa1081eebc0c7203711213).

## Specifications

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

### Mandatory

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

### Optional

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

#### Wallets

- [Nutshell][py]
- [cdk]
- [cashu-ts][ts]
- [Macadamia][macadamia]
- [Minibits][minibits]
- [Cashu.me][cashume]
- [Sovran][sovran]

#### Mints

- [Nutshell][py]
- [cdk-mintd][cdk-mintd]
- [Nutmix][nutmix]

[py]: https://github.com/cashubtc/nutshell
[cashume]: https://cashu.me
[ts]: https://github.com/cashubtc/cashu-ts
[macadamia]: https://github.com/zeugmaster/macadamia
[minibits]: https://github.com/minibits-cash/minibits_wallet
[sovran]: https://github.com/SovranBitcoin/Sovran
[cdk]: https://github.com/cashubtc/cdk
[cdk-mintd]: https://github.com/cashubtc/cdk/tree/main/crates/cdk-mintd
[nutmix]: https://github.com/lescuer97/nutmix
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