feat: nwc backend

.github/workflows/ci.yml

@@ -109,6 +109,7 @@ jobs:
             -p cdk-cln,
             -p cdk-lnd,
             -p cdk-strike,
+            -p cdk-nwc,
             -p cdk-lnbits,
             -p cdk-fake-wallet,
             -p cdk-payment-processor,
@@ -344,6 +345,7 @@ jobs:
             -p cdk-cln,
             -p cdk-lnd,
             -p cdk-strike,
+            -p cdk-nwc,
             -p cdk-mint-rpc,
             -p cdk-sqlite,
             -p cdk-mintd,

Cargo.toml

@@ -52,6 +52,7 @@ cdk-lnbits = { path = "./crates/cdk-lnbits", version = "=0.13.0" }
 cdk-lnd = { path = "./crates/cdk-lnd", version = "=0.13.0" }
 cdk-ldk-node = { path = "./crates/cdk-ldk-node", version = "=0.13.0" }
 cdk-strike = { path = "./crates/cdk-strike", version = "=0.13.0" }
+cdk-nwc = { path = "./crates/cdk-nwc", version = "=0.13.0" }
 cdk-fake-wallet = { path = "./crates/cdk-fake-wallet", version = "=0.13.0" }
 cdk-ffi = { path = "./crates/cdk-ffi", version = "=0.13.0" }
 cdk-payment-processor = { path = "./crates/cdk-payment-processor", default-features = true, version = "=0.13.0" }

README.md

@@ -25,6 +25,7 @@ The project is split up into several crates in the `crates/` directory:
     * [**cdk-lnbits**](./crates/cdk-lnbits/): [LNbits](https://lnbits.com/) Lightning backend for mint. **Note: Only LNBits v1 API is supported.**
     * [**cdk-ldk-node**](./crates/cdk-ldk-node/): LDK Node Lightning backend for mint.
     * [**cdk-strike**](./crates/cdk-strike/): Strike Lightning backend for mint with BTC and USD support.
+    * [**cdk-strike**](./crates/cdk-nwc): Nostr Wallet Connect (NWC) Lightning backend for mint.
     * [**cdk-fake-wallet**](./crates/cdk-fake-wallet/): Fake Lightning backend for mint. To be used only for testing, quotes are automatically filled.
     * [**cdk-mint-rpc**](./crates/cdk-mint-rpc/): Mint management gRPC server and cli.
 * Binaries:

crates/cdk-integration-tests/Cargo.toml

@@ -28,8 +28,9 @@ cdk-axum = { workspace = true, features = ["auth"] }
 cdk-sqlite = { workspace = true }
 cdk-redb = { workspace = true }
 cdk-fake-wallet = { workspace = true }
+cdk-nwc = { workspace = true }
 cdk-common = { workspace = true, features = ["mint", "wallet", "auth"] }
-cdk-mintd = { workspace = true, features = ["cln", "lnd", "fakewallet", "grpc-processor", "auth", "lnbits", "management-rpc", "sqlite", "postgres", "ldk-node", "prometheus", "strike"] }
+cdk-mintd = { workspace = true, features = ["cln", "lnd", "fakewallet", "grpc-processor", "auth", "lnbits", "management-rpc", "sqlite", "postgres", "ldk-node", "prometheus", "strike", "nwc"] }
 futures = { workspace = true, default-features = false, features = [
     "executor",
 ] }

crates/cdk-integration-tests/src/bin/start_regtest_mints.rs

@@ -294,6 +294,7 @@ fn create_ldk_settings(
         lnd: None,
         ldk_node: Some(ldk_config),
         fake_wallet: None,
+        nwc: None,
         grpc_processor: None,
         database: cdk_mintd::config::Database::default(),
         auth_database: None,

crates/cdk-integration-tests/src/shared.rs

@@ -215,6 +215,7 @@ pub fn create_fake_wallet_settings(
         lnd: None,
         ldk_node: None,
         fake_wallet: fake_wallet_config,
+        nwc: None,
         grpc_processor: None,
         database: Database {
             engine: DatabaseEngine::from_str(database).expect("valid database"),
@@ -270,6 +271,7 @@ pub fn create_cln_settings(
         lnd: None,
         ldk_node: None,
         fake_wallet: None,
+        nwc: None,
         grpc_processor: None,
         database: cdk_mintd::config::Database::default(),
         auth_database: None,
@@ -320,6 +322,7 @@ pub fn create_lnd_settings(
         ldk_node: None,
         lnd: Some(lnd_config),
         fake_wallet: None,
+        nwc: None,
         grpc_processor: None,
         database: cdk_mintd::config::Database::default(),
         auth_database: None,

crates/cdk-mintd/Cargo.toml

@@ -11,7 +11,7 @@ rust-version.workspace = true
 readme = "README.md"
 
 [features]
-default = ["management-rpc", "cln", "lnd", "lnbits", "fakewallet", "grpc-processor", "sqlite", "strike"]
+default = ["management-rpc", "cln", "lnd", "lnbits", "fakewallet", "grpc-processor", "sqlite", "strike", "nwc"]
 # Database features - at least one must be enabled
 sqlite = ["dep:cdk-sqlite"]
 postgres = ["dep:cdk-postgres"]
@@ -24,6 +24,7 @@ fakewallet = ["dep:cdk-fake-wallet"]
 ldk-node = ["dep:cdk-ldk-node"]
 grpc-processor = ["dep:cdk-payment-processor", "cdk-signatory/grpc"]
 sqlcipher = ["sqlite", "cdk-sqlite/sqlcipher"]
+nwc = ["dep:cdk-nwc"]
 # MSRV is not committed to with swagger enabled
 swagger = ["cdk-axum/swagger", "dep:utoipa", "dep:utoipa-swagger-ui"]
 auth = ["cdk/auth", "cdk-axum/auth", "cdk-sqlite?/auth", "cdk-postgres?/auth"]
@@ -48,6 +49,7 @@ cdk-lnd = { workspace = true, optional = true }
 cdk-ldk-node = { workspace = true, optional = true }
 cdk-fake-wallet = { workspace = true, optional = true }
 cdk-strike = { workspace = true, optional = true }
+cdk-nwc = { workspace = true, optional = true }
 cdk-axum.workspace = true
 cdk-signatory.workspace = true
 cdk-mint-rpc = { workspace = true, optional = true }

crates/cdk-mintd/example.config.toml

@@ -85,7 +85,7 @@ max_connections = 20
 connection_timeout_seconds = 10
 
 [ln]
-# Required ln backend `cln`, `lnd`, `fakewallet`, 'lnbits', 'ldknode', 'strike'
+# Required ln backend `cln`, `lnd`, `fakewallet`, 'lnbits', 'ldknode', 'strike', 'nwc'
 ln_backend = "fakewallet"
 # min_mint=1
 # max_mint=500000
@@ -159,6 +159,11 @@ reserve_fee_min = 1
 min_delay_time = 1
 max_delay_time = 3
 
+# [nwc]
+# nwc_uri = "nostr+walletconnect://..."
+# fee_percent = 0.02
+# reserve_fee_min = 1
+
 # [grpc_processor]
 # gRPC Payment Processor configuration
 # supported_units = ["sat"]

crates/cdk-mintd/src/config.rs

@@ -140,6 +140,8 @@ pub enum LnBackend {
     GrpcProcessor,
     #[cfg(feature = "strike")]
     Strike,
+    #[cfg(feature = "nwc")]
+    Nwc,
 }
 
 impl std::str::FromStr for LnBackend {
@@ -161,6 +163,8 @@ impl std::str::FromStr for LnBackend {
             "grpcprocessor" => Ok(LnBackend::GrpcProcessor),
             #[cfg(feature = "strike")]
             "strike" => Ok(LnBackend::Strike),
+            #[cfg(feature = "nwc")]
+            "nwc" => Ok(LnBackend::Nwc),
             _ => Err(format!("Unknown Lightning backend: {s}")),
         }
     }
@@ -305,6 +309,14 @@ fn default_webserver_port() -> Option<u16> {
     Some(8091)
 }
 
+#[cfg(feature = "nwc")]
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+pub struct Nwc {
+    pub nwc_uri: String,
+    pub fee_percent: f32,
+    pub reserve_fee_min: Amount,
+}
+
 #[cfg(feature = "fakewallet")]
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FakeWallet {
@@ -492,6 +504,8 @@ pub struct Settings {
     pub lnd: Option<Lnd>,
     #[cfg(feature = "ldk-node")]
     pub ldk_node: Option<LdkNode>,
+    #[cfg(feature = "nwc")]
+    pub nwc: Option<Nwc>,
     #[cfg(feature = "fakewallet")]
     pub fake_wallet: Option<FakeWallet>,
     pub grpc_processor: Option<GrpcProcessor>,
@@ -638,6 +652,13 @@ impl Settings {
                     "Strike backend requires a valid config."
                 )
             }
+            #[cfg(feature = "nwc")]
+            LnBackend::Nwc => {
+                assert!(
+                    settings.nwc.is_some(),
+                    "NWC backend requires a valid config."
+                )
+            }
         }
 
         Ok(settings)

crates/cdk-mintd/src/env_vars/mod.rs

@@ -25,6 +25,8 @@ mod lnbits;
 mod lnd;
 #[cfg(feature = "management-rpc")]
 mod management_rpc;
+#[cfg(feature = "nwc")]
+mod nwc;
 #[cfg(feature = "prometheus")]
 mod prometheus;
 #[cfg(feature = "strike")]
@@ -54,6 +56,8 @@ pub use lnd::*;
 #[cfg(feature = "management-rpc")]
 pub use management_rpc::*;
 pub use mint_info::*;
+#[cfg(feature = "nwc")]
+pub use nwc::*;
 #[cfg(feature = "prometheus")]
 pub use prometheus::*;
 #[cfg(feature = "strike")]
@@ -156,6 +160,10 @@ impl Settings {
             LnBackend::Strike => {
                 self.strike = Some(self.strike.clone().unwrap_or_default().from_env());
             }
+            #[cfg(feature = "nwc")]
+            LnBackend::Nwc => {
+                self.nwc = Some(self.nwc.clone().unwrap_or_default().from_env());
+            }
             LnBackend::None => bail!("Ln backend must be set"),
             #[allow(unreachable_patterns)]
             _ => bail!("Selected Ln backend is not enabled in this build"),

crates/cdk-mintd/src/env_vars/nwc.rs

@@ -0,0 +1,32 @@
+//! NWC environment variables
+
+use std::env;
+
+use crate::config::Nwc;
+
+// NWC environment variables
+pub const ENV_NWC_URI: &str = "CDK_MINTD_NWC_URI";
+pub const ENV_NWC_FEE_PERCENT: &str = "CDK_MINTD_NWC_FEE_PERCENT";
+pub const ENV_NWC_RESERVE_FEE_MIN: &str = "CDK_MINTD_NWC_RESERVE_FEE_MIN";
+
+impl Nwc {
+    pub fn from_env(mut self) -> Self {
+        if let Ok(nwc_uri) = env::var(ENV_NWC_URI) {
+            self.nwc_uri = nwc_uri;
+        }
+
+        if let Ok(fee_str) = env::var(ENV_NWC_FEE_PERCENT) {
+            if let Ok(fee) = fee_str.parse() {
+                self.fee_percent = fee;
+            }
+        }
+
+        if let Ok(reserve_fee_str) = env::var(ENV_NWC_RESERVE_FEE_MIN) {
+            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
+                self.reserve_fee_min = reserve_fee.into();
+            }
+        }
+
+        self
+    }
+}

crates/cdk-mintd/src/lib.rs

@@ -21,7 +21,8 @@ use cdk::mint::{Mint, MintBuilder, MintMeltLimits};
     feature = "lnd",
     feature = "ldk-node",
     feature = "fakewallet",
-    feature = "grpc-processor"
+    feature = "grpc-processor",
+    feature = "nwc"
 ))]
 use cdk::nuts::nut17::SupportedMethods;
 use cdk::nuts::nut19::{CachedEndpoint, Method as NUT19Method, Path as NUT19Path};
@@ -30,7 +31,8 @@ use cdk::nuts::nut19::{CachedEndpoint, Method as NUT19Method, Path as NUT19Path}
     feature = "lnbits",
     feature = "lnd",
     feature = "ldk-node",
-    feature = "fakewallet"
+    feature = "fakewallet",
+    feature = "nwc"
 ))]
 use cdk::nuts::CurrencyUnit;
 #[cfg(feature = "auth")]
@@ -581,6 +583,22 @@ async fn configure_lightning_backend(
 
             return Ok((mint_builder, webhook_routers));
         }
+        #[cfg(feature = "nwc")]
+        LnBackend::Nwc => {
+            let nwc_settings = settings.clone().nwc.expect("NWC config defined");
+            let nwc = nwc_settings
+                .setup(settings, CurrencyUnit::Sat, None, work_dir, None)
+                .await?;
+
+            mint_builder = configure_backend_for_unit(
+                settings,
+                mint_builder,
+                CurrencyUnit::Sat,
+                mint_melt_limits,
+                Arc::new(nwc),
+            )
+            .await?;
+        }
         LnBackend::None => {
             tracing::error!(
                 "Payment backend was not set or feature disabled. {:?}",
@@ -639,7 +657,8 @@ async fn configure_backend_for_unit(
         feature = "fakewallet",
         feature = "grpc-processor",
         feature = "ldk-node",
-        feature = "strike"
+        feature = "strike",
+        feature = "nwc"
     ))]
     {
         let nut17_supported = SupportedMethods::default_bolt11(unit);

crates/cdk-mintd/src/setup.rs

@@ -18,7 +18,8 @@ use cdk::nuts::CurrencyUnit;
     feature = "cln",
     feature = "lnd",
     feature = "ldk-node",
-    feature = "fakewallet"
+    feature = "fakewallet",
+    feature = "nwc"
 ))]
 use cdk::types::FeeReserve;
 
@@ -369,3 +370,28 @@ impl config::Strike {
         Ok((strike, webhook_router))
     }
 }
+
+#[cfg(feature = "nwc")]
+#[async_trait]
+impl LnBackendSetup for config::Nwc {
+    async fn setup(
+        &self,
+        settings: &Settings,
+        unit: CurrencyUnit,
+        _runtime: Option<std::sync::Arc<tokio::runtime::Runtime>>,
+        _work_dir: &Path,
+        _kv_store: Option<Arc<dyn MintKVStore<Err = cdk::cdk_database::Error> + Send + Sync>>,
+    ) -> anyhow::Result<cdk_nwc::NWCWallet> {
+        let fee_reserve = FeeReserve {
+            min_fee_reserve: self.reserve_fee_min,
+            percent_fee_reserve: self.fee_percent,
+        };
+
+        let internal_settlement_only = settings.ln.internal_settlement_only;
+
+        let nwc =
+            cdk_nwc::NWCWallet::new(&self.nwc_uri, fee_reserve, unit, internal_settlement_only)
+                .await?;
+        Ok(nwc)
+    }
+}

crates/cdk-nwc/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "cdk-nwc"
+version.workspace = true
+edition.workspace = true
+authors = ["CDK Developers"]
+license.workspace = true
+homepage = "https://github.com/cashubtc/cdk"
+repository = "https://github.com/cashubtc/cdk.git"
+rust-version.workspace = true # MSRV
+description = "CDK nwc backend"
+readme = "README.md"
+
+[dependencies]
+nwc = "0.43.0"
+async-trait.workspace = true
+bitcoin.workspace = true
+cdk-common = { workspace = true, features = ["mint"] }
+futures.workspace = true
+tokio.workspace = true
+tokio-util.workspace = true
+tracing.workspace = true
+thiserror.workspace = true
+serde_json.workspace = true
+tokio-stream = { workspace = true, features = ["sync"] }
+rustls.workspace = true