USD-backed ecash using stablesats

.env.example

@@ -55,6 +55,12 @@ LND_TLS_CERT_PATH="/../tls.cert"
 LND_GRPC_HOST="https://localhost:10004"
 
 
+STABLESATS_AUTH_BEARER=YOUR_AUTH_BEARER
+STABLESATS_GALOY_URL=YOUR_GALOY_URL
+STABLESATS_USD_WALLET_ID=YOUR_USD_WALLET_ID
+
+
+
 
 ### environment variables for the fedimint-cli
 CLI_FEDIMINT_CONNECTION="fed...."

moksha-core/src/model.rs

@@ -438,6 +438,11 @@ pub struct CashuErrorResponse {
     pub error: String,
 }
 
+#[derive(Debug, Serialize, Deserialize, Default, Clone)]
+pub struct InvoiceQuoteResult {
+    pub amount_in_cent: u64,
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{

moksha-mint/src/bin/moksha-mint.rs

@@ -1,8 +1,8 @@
 use mokshamint::{
     info::MintInfoSettings,
     lightning::{
-        AlbyLightningSettings, LightningType, LnbitsLightningSettings, LndLightningSettings,
-        StrikeLightningSettings,
+        stablesats::StablesatsSettings, AlbyLightningSettings, LightningType,
+        LnbitsLightningSettings, LndLightningSettings, StrikeLightningSettings,
     },
     MintBuilder,
 };
@@ -58,6 +58,12 @@ pub async fn main() -> anyhow::Result<()> {
                 .from_env::<StrikeLightningSettings>()
                 .expect("Please provide strike info");
             LightningType::Strike(strike_settings)
+        },
+        "Stablesats" => {
+            let settings = envy::prefixed("STABLESATS_")
+                .from_env::<StablesatsSettings>()
+                .expect("Please provide stablesats info");
+            LightningType::Stablesats(settings)
         }
         _ => panic!(
             "env MINT_LIGHTNING_BACKEND not found or invalid values. Valid values are Lnbits, Lnd, Alby, and Strike"

moksha-mint/src/error.rs

@@ -24,6 +24,9 @@ pub enum MokshaMintError {
     #[error("Failed to pay invoice {0} - Error {1}")]
     PayInvoice(String, LightningError),
 
+    #[error("Failed to pay invoice {0} - Error {1}")]
+    PayInvoiceStablesats(String, String), // FIXME
+
     #[error("DB Error {0}")]
     Db(#[from] rocksdb::Error),
 
@@ -59,6 +62,9 @@ pub enum MokshaMintError {
 
     #[error("Lightning Error {0}")]
     Lightning(#[from] LightningError),
+
+    #[error("Deserialize Error {0}")]
+    DeserializeResponse(String),
 }
 
 impl IntoResponse for MokshaMintError {

moksha-mint/src/lib.rs

@@ -4,7 +4,7 @@ use std::net::SocketAddr;
 use std::path::PathBuf;
 use std::sync::Arc;
 
-use axum::extract::{Query, State};
+use axum::extract::{Path, Query, State};
 use axum::routing::{get_service, post};
 use axum::Router;
 use axum::{routing::get, Json};
@@ -13,12 +13,14 @@ use error::MokshaMintError;
 use hyper::http::{HeaderName, HeaderValue};
 use hyper::Method;
 use info::{MintInfoResponse, MintInfoSettings, Parameter};
+use lightning::stablesats::StablesatsLightning;
 use lightning::{AlbyLightning, Lightning, LightningType, LnbitsLightning, StrikeLightning};
 use mint::{LightningFeeConfig, Mint};
 use model::{GetMintQuery, PostMintQuery};
 use moksha_core::model::{
-    CheckFeesRequest, CheckFeesResponse, Keysets, PaymentRequest, PostMeltRequest,
-    PostMeltResponse, PostMintRequest, PostMintResponse, PostSplitRequest, PostSplitResponse,
+    CheckFeesRequest, CheckFeesResponse, InvoiceQuoteResult, Keysets, PaymentRequest,
+    PostMeltRequest, PostMeltResponse, PostMintRequest, PostMintResponse, PostSplitRequest,
+    PostSplitResponse,
 };
 use secp256k1::PublicKey;
 
@@ -93,6 +95,21 @@ impl MintBuilder {
             Some(LightningType::Strike(strike_settings)) => Arc::new(StrikeLightning::new(
                 strike_settings.api_key.expect("STRIKE_API_KEY not set"),
             )),
+            Some(LightningType::Stablesats(settings)) => Arc::new(StablesatsLightning::new(
+                settings
+                    .auth_bearer
+                    .expect("STABLESATS_AUTH_BEARER not set")
+                    .as_str(),
+                settings
+                    .galoy_url
+                    .expect("STABLESATS_GALOY_URL not set")
+                    .as_str(),
+                settings
+                    .usd_wallet_id
+                    .expect("STABLESATS_USD_WALLET_ID not set")
+                    .as_str(),
+            )),
+
             Some(LightningType::Lnd(lnd_settings)) => Arc::new(
                 lightning::LndLightning::new(
                     lnd_settings.grpc_host.expect("LND_GRPC_HOST not set"),
@@ -171,6 +188,7 @@ fn app(mint: Mint, serve_wallet_path: Option<PathBuf>, prefix: Option<String>) -
         .route("/keysets", get(get_keysets))
         .route("/mint", get(get_mint).post(post_mint))
         .route("/checkfees", post(post_check_fees))
+        .route("/melt/:invoice", get(get_melt))
         .route("/melt", post(post_melt))
         .route("/split", post(post_split))
         .route("/info", get(get_info));
@@ -242,6 +260,16 @@ async fn post_check_fees(
     }))
 }
 
+async fn get_melt(
+    Path(invoice): Path<String>,
+    State(mint): State<Mint>,
+) -> Result<Json<InvoiceQuoteResult>, MokshaMintError> {
+    let quote = mint.lightning.get_quote(invoice.to_owned()).await?;
+    Ok(Json(InvoiceQuoteResult {
+        amount_in_cent: quote.amount_in_cent,
+    }))
+}
+
 async fn get_info(State(mint): State<Mint>) -> Result<Json<MintInfoResponse>, MokshaMintError> {
     let mint_info = MintInfoResponse {
         name: mint.mint_info.name,

moksha-mint/src/lightning/mod.rs

@@ -1,4 +1,5 @@
 use async_trait::async_trait;
+use moksha_core::model::InvoiceQuoteResult;
 use std::fmt::{self, Formatter};
 use tokio::sync::{MappedMutexGuard, Mutex, MutexGuard};
 use tonic_lnd::Client;
@@ -17,20 +18,25 @@ use lightning_invoice::{Bolt11Invoice as LNInvoice, SignedRawBolt11Invoice};
 mod alby;
 pub mod error;
 mod lnbits;
+pub mod stablesats;
 mod strike;
 
 #[cfg(test)]
 use mockall::automock;
 use std::{path::PathBuf, str::FromStr, sync::Arc};
 
-use self::{alby::AlbyClient, error::LightningError, lnbits::LNBitsClient, strike::StrikeClient};
+use self::{
+    alby::AlbyClient, error::LightningError, lnbits::LNBitsClient, stablesats::StablesatsSettings,
+    strike::StrikeClient,
+};
 
 #[derive(Debug, Clone)]
 pub enum LightningType {
     Lnbits(LnbitsLightningSettings),
     Alby(AlbyLightningSettings),
     Strike(StrikeLightningSettings),
     Lnd(LndLightningSettings),
+    Stablesats(StablesatsSettings),
 }
 
 impl fmt::Display for LightningType {
@@ -40,6 +46,7 @@ impl fmt::Display for LightningType {
             LightningType::Alby(settings) => write!(f, "Alby: {}", settings),
             LightningType::Strike(settings) => write!(f, "Strike: {}", settings),
             LightningType::Lnd(settings) => write!(f, "Lnd: {}", settings),
+            LightningType::Stablesats(settings) => write!(f, "Stablesats: {}", settings),
         }
     }
 }
@@ -58,6 +65,10 @@ pub trait Lightning: Send + Sync {
         LNInvoice::from_str(&payment_request)
             .map_err(|err| MokshaMintError::DecodeInvoice(payment_request, err))
     }
+
+    async fn get_quote(&self, _invoice: String) -> Result<InvoiceQuoteResult, MokshaMintError> {
+        Ok(Default::default())
+    }
 }
 
 #[derive(Deserialize, Serialize, Debug, Clone, Default)]