feat: Add feature gates for CLN, LND, fakewallet and LNbits backends (#638)

* feat: Add feature gates for CLN, LND, fakewallet and LNbits backends

.github/workflows/ci.yml

@@ -105,11 +105,19 @@ jobs:
             -p cdk-fake-wallet,
             --bin cdk-cli,
             --bin cdk-mintd,
-            --bin cdk-mintd --no-default-features --features swagger,
-            --bin cdk-mintd --no-default-features --features redis,
-            --bin cdk-mintd --no-default-features --features "redis swagger",
-            --bin cdk-mintd --no-default-features --features management-rpc,
-            --bin cdk-mintd --no-default-features --features redb,
+            --bin cdk-mintd --features redis,
+            --bin cdk-mintd --features redb,
+            --bin cdk-mintd --features "redis swagger redb",
+            --bin cdk-mintd --no-default-features --features lnd,
+            --bin cdk-mintd --no-default-features --features cln,
+            --bin cdk-mintd --no-default-features --features lnbits,
+            --bin cdk-mintd --no-default-features --features fakewallet,
+            --bin cdk-mintd --no-default-features --features "management-rpc lnd",
+            --bin cdk-mintd --no-default-features --features "management-rpc cln",
+            --bin cdk-mintd --no-default-features --features "management-rpc lnbits",
+            --bin cdk-mintd --no-default-features --features "swagger lnd",
+            --bin cdk-mintd --no-default-features --features "swagger cln",
+            --bin cdk-mintd --no-default-features --features "swagger lnbits",
             --bin cdk-mint-cli,
           ]
     steps:

CHANGELOG.md

@@ -10,6 +10,7 @@
 - Updated MSRV to 1.75.0 ([thesimplekid]).
 - cdk-sqlite: Do not use `UPDATE OR REPLACE` ([crodas]).
 - cdk: Refactor keyset init ([lollerfirst]).
+- Feature-gated lightning backends (CLN, LND, LNbits, FakeWallet) for selective compilation ([thesimplekid]).
 ### Added
 - Added redb feature to mintd in order to meet MSRV target ([thesimplekid]).
 - cdk-sqlite: In memory sqlite database ([crodas]).
@@ -17,6 +18,7 @@
 - cdk: Add tos_url setter to `MintBuilder` ([thesimplekid]).
 - Added optional "request" and "unit" fields to MeltQuoteBolt11Response [NUT Change](https://github.com/cashubtc/nuts/pull/235) ([thesimplekid]).
 - Added optional "amount" and "unit" fields to MintQuoteBolt11Response [NUT Change](https://github.com/cashubtc/nuts/pull/235) ([thesimplekid]).
+- Compile-time error when no lightning backend features are enabled ([thesimplekid]).
 ### Removed
 - Remove support for Memory Database in cdk ([crodas]).
 - Remove `AmountStr` ([crodas]).

crates/cdk-mintd/Cargo.toml

@@ -10,12 +10,17 @@ description = "CDK mint binary"
 rust-version = "1.75.0"
 
 [features]
-default = ["management-rpc"]
+default = ["management-rpc", "cln", "lnd", "lnbits", "fakewallet"]
+# Ensure at least one lightning backend is enabled
 swagger = ["cdk-axum/swagger", "dep:utoipa", "dep:utoipa-swagger-ui"]
 redis = ["cdk-axum/redis"]
 management-rpc = ["cdk-mint-rpc"]
 # MSRV is not commited to with redb enabled
 redb = ["dep:cdk-redb"]
+cln = ["dep:cdk-cln"]
+lnd = ["dep:cdk-lnd"]
+lnbits = ["dep:cdk-lnbits"]
+fakewallet = ["dep:cdk-fake-wallet"]
 
 [dependencies]
 anyhow.workspace = true
@@ -30,10 +35,10 @@ cdk-redb = { workspace = true, features = [
 cdk-sqlite = { workspace = true, features = [
     "mint",
 ] }
-cdk-cln.workspace = true
-cdk-lnbits.workspace = true
-cdk-lnd.workspace = true
-cdk-fake-wallet.workspace = true
+cdk-cln = { workspace = true, optional = true }
+cdk-lnbits = { workspace = true, optional = true }
+cdk-lnd = { workspace = true, optional = true }
+cdk-fake-wallet = { workspace = true, optional = true }
 cdk-axum.workspace = true
 cdk-mint-rpc = { workspace = true, optional = true }
 config = { version = "0.13.3", features = ["toml"] }

crates/cdk-mintd/src/config.rs

@@ -1,7 +1,9 @@
 use std::path::PathBuf;
 
 use bitcoin::hashes::{sha256, Hash};
-use cdk::nuts::{CurrencyUnit, PublicKey};
+#[cfg(feature = "fakewallet")]
+use cdk::nuts::CurrencyUnit;
+use cdk::nuts::PublicKey;
 use cdk::Amount;
 use cdk_axum::cache;
 use config::{Config, ConfigError, File};
@@ -46,9 +48,13 @@ impl std::fmt::Debug for Info {
 pub enum LnBackend {
     #[default]
     None,
+    #[cfg(feature = "cln")]
     Cln,
+    #[cfg(feature = "lnbits")]
     LNbits,
+    #[cfg(feature = "fakewallet")]
     FakeWallet,
+    #[cfg(feature = "lnd")]
     Lnd,
 }
 
@@ -57,9 +63,13 @@ impl std::str::FromStr for LnBackend {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s.to_lowercase().as_str() {
+            #[cfg(feature = "cln")]
             "cln" => Ok(LnBackend::Cln),
+            #[cfg(feature = "lnbits")]
             "lnbits" => Ok(LnBackend::LNbits),
+            #[cfg(feature = "fakewallet")]
             "fakewallet" => Ok(LnBackend::FakeWallet),
+            #[cfg(feature = "lnd")]
             "lnd" => Ok(LnBackend::Lnd),
             _ => Err(format!("Unknown Lightning backend: {}", s)),
         }
@@ -89,6 +99,7 @@ impl Default for Ln {
     }
 }
 
+#[cfg(feature = "lnbits")]
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct LNbits {
     pub admin_api_key: String,
@@ -98,6 +109,7 @@ pub struct LNbits {
     pub reserve_fee_min: Amount,
 }
 
+#[cfg(feature = "cln")]
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct Cln {
     pub rpc_path: PathBuf,
@@ -107,6 +119,7 @@ pub struct Cln {
     pub reserve_fee_min: Amount,
 }
 
+#[cfg(feature = "lnd")]
 #[derive(Debug, Clone, Serialize, Deserialize, Default)]
 pub struct Lnd {
     pub address: String,
@@ -116,6 +129,7 @@ pub struct Lnd {
     pub reserve_fee_min: Amount,
 }
 
+#[cfg(feature = "fakewallet")]
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct FakeWallet {
     pub supported_units: Vec<CurrencyUnit>,
@@ -127,6 +141,7 @@ pub struct FakeWallet {
     pub max_delay_time: u64,
 }
 
+#[cfg(feature = "fakewallet")]
 impl Default for FakeWallet {
     fn default() -> Self {
         Self {
@@ -140,10 +155,12 @@ impl Default for FakeWallet {
 }
 
 // Helper functions to provide default values
+#[cfg(feature = "fakewallet")]
 fn default_min_delay_time() -> u64 {
     1
 }
 
+#[cfg(feature = "fakewallet")]
 fn default_max_delay_time() -> u64 {
     3
 }
@@ -181,9 +198,13 @@ pub struct Settings {
     pub info: Info,
     pub mint_info: MintInfo,
     pub ln: Ln,
+    #[cfg(feature = "cln")]
     pub cln: Option<Cln>,
+    #[cfg(feature = "lnbits")]
     pub lnbits: Option<LNbits>,
+    #[cfg(feature = "lnd")]
     pub lnd: Option<Lnd>,
+    #[cfg(feature = "fakewallet")]
     pub fake_wallet: Option<FakeWallet>,
     pub database: Database,
     #[cfg(feature = "management-rpc")]
@@ -270,20 +291,24 @@ impl Settings {
 
         match settings.ln.ln_backend {
             LnBackend::None => panic!("Ln backend must be set"),
+            #[cfg(feature = "cln")]
             LnBackend::Cln => assert!(
                 settings.cln.is_some(),
                 "CLN backend requires a valid config."
             ),
+            #[cfg(feature = "lnbits")]
             LnBackend::LNbits => assert!(
                 settings.lnbits.is_some(),
                 "LNbits backend requires a valid config"
             ),
+            #[cfg(feature = "lnd")]
             LnBackend::Lnd => {
                 assert!(
                     settings.lnd.is_some(),
                     "LND backend requires a valid config."
                 )
             }
+            #[cfg(feature = "fakewallet")]
             LnBackend::FakeWallet => assert!(
                 settings.fake_wallet.is_some(),
                 "FakeWallet backend requires a valid config."

crates/cdk-mintd/src/env_vars.rs

@@ -1,416 +0,0 @@
-use std::env;
-use std::path::PathBuf;
-use std::str::FromStr;
-
-use anyhow::{anyhow, bail, Result};
-use cdk::nuts::CurrencyUnit;
-
-#[cfg(feature = "management-rpc")]
-use crate::config::MintManagementRpc;
-use crate::config::{
-    Cln, Database, DatabaseEngine, FakeWallet, Info, LNbits, Ln, LnBackend, Lnd, MintInfo, Settings,
-};
-
-pub const ENV_WORK_DIR: &str = "CDK_MINTD_WORK_DIR";
-
-pub const DATABASE_ENV_VAR: &str = "CDK_MINTD_DATABASE";
-pub const ENV_URL: &str = "CDK_MINTD_URL";
-pub const ENV_LISTEN_HOST: &str = "CDK_MINTD_LISTEN_HOST";
-pub const ENV_LISTEN_PORT: &str = "CDK_MINTD_LISTEN_PORT";
-pub const ENV_MNEMONIC: &str = "CDK_MINTD_MNEMONIC";
-pub const ENV_SECONDS_QUOTE_VALID: &str = "CDK_MINTD_SECONDS_QUOTE_VALID";
-pub const ENV_CACHE_SECONDS: &str = "CDK_MINTD_CACHE_SECONDS";
-pub const ENV_EXTEND_CACHE_SECONDS: &str = "CDK_MINTD_EXTEND_CACHE_SECONDS";
-pub const ENV_INPUT_FEE_PPK: &str = "CDK_MINTD_INPUT_FEE_PPK";
-pub const ENV_ENABLE_SWAGGER: &str = "CDK_MINTD_ENABLE_SWAGGER";
-// MintInfo
-pub const ENV_MINT_NAME: &str = "CDK_MINTD_MINT_NAME";
-pub const ENV_MINT_PUBKEY: &str = "CDK_MINTD_MINT_PUBKEY";
-pub const ENV_MINT_DESCRIPTION: &str = "CDK_MINTD_MINT_DESCRIPTION";
-pub const ENV_MINT_DESCRIPTION_LONG: &str = "CDK_MINTD_MINT_DESCRIPTION_LONG";
-pub const ENV_MINT_ICON_URL: &str = "CDK_MINTD_MINT_ICON_URL";
-pub const ENV_MINT_MOTD: &str = "CDK_MINTD_MINT_MOTD";
-pub const ENV_MINT_CONTACT_NOSTR: &str = "CDK_MINTD_MINT_CONTACT_NOSTR";
-pub const ENV_MINT_CONTACT_EMAIL: &str = "CDK_MINTD_MINT_CONTACT_EMAIL";
-pub const ENV_MINT_TOS_URL: &str = "CDK_MINTD_MINT_TOS_URL";
-// LN
-pub const ENV_LN_BACKEND: &str = "CDK_MINTD_LN_BACKEND";
-pub const ENV_LN_INVOICE_DESCRIPTION: &str = "CDK_MINTD_LN_INVOICE_DESCRIPTION";
-pub const ENV_LN_MIN_MINT: &str = "CDK_MINTD_LN_MIN_MINT";
-pub const ENV_LN_MAX_MINT: &str = "CDK_MINTD_LN_MAX_MINT";
-pub const ENV_LN_MIN_MELT: &str = "CDK_MINTD_LN_MIN_MELT";
-pub const ENV_LN_MAX_MELT: &str = "CDK_MINTD_LN_MAX_MELT";
-// CLN
-pub const ENV_CLN_RPC_PATH: &str = "CDK_MINTD_CLN_RPC_PATH";
-pub const ENV_CLN_BOLT12: &str = "CDK_MINTD_CLN_BOLT12";
-pub const ENV_CLN_FEE_PERCENT: &str = "CDK_MINTD_CLN_FEE_PERCENT";
-pub const ENV_CLN_RESERVE_FEE_MIN: &str = "CDK_MINTD_CLN_RESERVE_FEE_MIN";
-// LND environment variables
-pub const ENV_LND_ADDRESS: &str = "CDK_MINTD_LND_ADDRESS";
-pub const ENV_LND_CERT_FILE: &str = "CDK_MINTD_LND_CERT_FILE";
-pub const ENV_LND_MACAROON_FILE: &str = "CDK_MINTD_LND_MACAROON_FILE";
-pub const ENV_LND_FEE_PERCENT: &str = "CDK_MINTD_LND_FEE_PERCENT";
-pub const ENV_LND_RESERVE_FEE_MIN: &str = "CDK_MINTD_LND_RESERVE_FEE_MIN";
-// LNBits
-pub const ENV_LNBITS_ADMIN_API_KEY: &str = "CDK_MINTD_LNBITS_ADMIN_API_KEY";
-pub const ENV_LNBITS_INVOICE_API_KEY: &str = "CDK_MINTD_LNBITS_INVOICE_API_KEY";
-pub const ENV_LNBITS_API: &str = "CDK_MINTD_LNBITS_API";
-pub const ENV_LNBITS_FEE_PERCENT: &str = "CDK_MINTD_LNBITS_FEE_PERCENT";
-pub const ENV_LNBITS_RESERVE_FEE_MIN: &str = "CDK_MINTD_LNBITS_RESERVE_FEE_MIN";
-// Fake Wallet
-pub const ENV_FAKE_WALLET_SUPPORTED_UNITS: &str = "CDK_MINTD_FAKE_WALLET_SUPPORTED_UNITS";
-pub const ENV_FAKE_WALLET_FEE_PERCENT: &str = "CDK_MINTD_FAKE_WALLET_FEE_PERCENT";
-pub const ENV_FAKE_WALLET_RESERVE_FEE_MIN: &str = "CDK_MINTD_FAKE_WALLET_RESERVE_FEE_MIN";
-pub const ENV_FAKE_WALLET_MIN_DELAY: &str = "CDK_MINTD_FAKE_WALLET_MIN_DELAY";
-pub const ENV_FAKE_WALLET_MAX_DELAY: &str = "CDK_MINTD_FAKE_WALLET_MAX_DELAY";
-// Mint RPC Server
-#[cfg(feature = "management-rpc")]
-pub const ENV_MINT_MANAGEMENT_ENABLED: &str = "CDK_MINTD_MINT_MANAGEMENT_ENABLED";
-#[cfg(feature = "management-rpc")]
-pub const ENV_MINT_MANAGEMENT_ADDRESS: &str = "CDK_MINTD_MANAGEMENT_ADDRESS";
-#[cfg(feature = "management-rpc")]
-pub const ENV_MINT_MANAGEMENT_PORT: &str = "CDK_MINTD_MANAGEMENT_PORT";
-#[cfg(feature = "management-rpc")]
-pub const ENV_MINT_MANAGEMENT_TLS_DIR_PATH: &str = "CDK_MINTD_MANAGEMENT_TLS_DIR_PATH";
-
-impl Settings {
-    pub fn from_env(&mut self) -> Result<Self> {
-        if let Ok(database) = env::var(DATABASE_ENV_VAR) {
-            let engine = DatabaseEngine::from_str(&database).map_err(|err| anyhow!(err))?;
-            self.database = Database { engine };
-        }
-
-        self.info = self.info.clone().from_env();
-        self.mint_info = self.mint_info.clone().from_env();
-        self.ln = self.ln.clone().from_env();
-
-        #[cfg(feature = "management-rpc")]
-        {
-            self.mint_management_rpc = Some(
-                self.mint_management_rpc
-                    .clone()
-                    .unwrap_or_default()
-                    .from_env(),
-            );
-        }
-
-        match self.ln.ln_backend {
-            LnBackend::Cln => {
-                self.cln = Some(self.cln.clone().unwrap_or_default().from_env());
-            }
-            LnBackend::LNbits => {
-                self.lnbits = Some(self.lnbits.clone().unwrap_or_default().from_env());
-            }
-            LnBackend::FakeWallet => {
-                self.fake_wallet = Some(self.fake_wallet.clone().unwrap_or_default().from_env());
-            }
-            LnBackend::Lnd => {
-                self.lnd = Some(self.lnd.clone().unwrap_or_default().from_env());
-            }
-            LnBackend::None => bail!("Ln backend must be set"),
-        }
-
-        Ok(self.clone())
-    }
-}
-
-impl Info {
-    pub fn from_env(mut self) -> Self {
-        // Required fields
-        if let Ok(url) = env::var(ENV_URL) {
-            self.url = url;
-        }
-
-        if let Ok(host) = env::var(ENV_LISTEN_HOST) {
-            self.listen_host = host;
-        }
-
-        if let Ok(port_str) = env::var(ENV_LISTEN_PORT) {
-            if let Ok(port) = port_str.parse() {
-                self.listen_port = port;
-            }
-        }
-
-        if let Ok(mnemonic) = env::var(ENV_MNEMONIC) {
-            self.mnemonic = mnemonic;
-        }
-
-        if let Ok(cache_seconds_str) = env::var(ENV_CACHE_SECONDS) {
-            if let Ok(seconds) = cache_seconds_str.parse() {
-                self.http_cache.ttl = Some(seconds);
-            }
-        }
-
-        if let Ok(extend_cache_str) = env::var(ENV_EXTEND_CACHE_SECONDS) {
-            if let Ok(seconds) = extend_cache_str.parse() {
-                self.http_cache.tti = Some(seconds);
-            }
-        }
-
-        if let Ok(fee_str) = env::var(ENV_INPUT_FEE_PPK) {
-            if let Ok(fee) = fee_str.parse() {
-                self.input_fee_ppk = Some(fee);
-            }
-        }
-
-        if let Ok(swagger_str) = env::var(ENV_ENABLE_SWAGGER) {
-            if let Ok(enable) = swagger_str.parse() {
-                self.enable_swagger_ui = Some(enable);
-            }
-        }
-
-        self.http_cache = self.http_cache.from_env();
-
-        self
-    }
-}
-
-impl MintInfo {
-    pub fn from_env(mut self) -> Self {
-        // Required fields
-        if let Ok(name) = env::var(ENV_MINT_NAME) {
-            self.name = name;
-        }
-
-        if let Ok(description) = env::var(ENV_MINT_DESCRIPTION) {
-            self.description = description;
-        }
-
-        // Optional fields
-        if let Ok(pubkey_str) = env::var(ENV_MINT_PUBKEY) {
-            // Assuming PublicKey has a from_str implementation
-            if let Ok(pubkey) = pubkey_str.parse() {
-                self.pubkey = Some(pubkey);
-            }
-        }
-
-        if let Ok(desc_long) = env::var(ENV_MINT_DESCRIPTION_LONG) {
-            self.description_long = Some(desc_long);
-        }
-
-        if let Ok(icon_url) = env::var(ENV_MINT_ICON_URL) {
-            self.icon_url = Some(icon_url);
-        }
-
-        if let Ok(motd) = env::var(ENV_MINT_MOTD) {
-            self.motd = Some(motd);
-        }
-
-        if let Ok(nostr_key) = env::var(ENV_MINT_CONTACT_NOSTR) {
-            self.contact_nostr_public_key = Some(nostr_key);
-        }
-
-        if let Ok(email) = env::var(ENV_MINT_CONTACT_EMAIL) {
-            self.contact_email = Some(email);
-        }
-
-        if let Ok(tos_url) = env::var(ENV_MINT_TOS_URL) {
-            self.tos_url = Some(tos_url);
-        }
-
-        self
-    }
-}
-
-impl Ln {
-    pub fn from_env(mut self) -> Self {
-        // LnBackend
-        if let Ok(backend_str) = env::var(ENV_LN_BACKEND) {
-            if let Ok(backend) = backend_str.parse() {
-                self.ln_backend = backend;
-            }
-        }
-
-        // Optional invoice description
-        if let Ok(description) = env::var(ENV_LN_INVOICE_DESCRIPTION) {
-            self.invoice_description = Some(description);
-        }
-
-        // Amount fields
-        if let Ok(min_mint_str) = env::var(ENV_LN_MIN_MINT) {
-            if let Ok(amount) = min_mint_str.parse::<u64>() {
-                self.min_mint = amount.into();
-            }
-        }
-
-        if let Ok(max_mint_str) = env::var(ENV_LN_MAX_MINT) {
-            if let Ok(amount) = max_mint_str.parse::<u64>() {
-                self.max_mint = amount.into();
-            }
-        }
-
-        if let Ok(min_melt_str) = env::var(ENV_LN_MIN_MELT) {
-            if let Ok(amount) = min_melt_str.parse::<u64>() {
-                self.min_melt = amount.into();
-            }
-        }
-
-        if let Ok(max_melt_str) = env::var(ENV_LN_MAX_MELT) {
-            if let Ok(amount) = max_melt_str.parse::<u64>() {
-                self.max_melt = amount.into();
-            }
-        }
-
-        self
-    }
-}
-
-impl Cln {
-    pub fn from_env(mut self) -> Self {
-        // RPC Path
-        if let Ok(path) = env::var(ENV_CLN_RPC_PATH) {
-            self.rpc_path = PathBuf::from(path);
-        }
-
-        // BOLT12 flag
-        if let Ok(bolt12_str) = env::var(ENV_CLN_BOLT12) {
-            if let Ok(bolt12) = bolt12_str.parse() {
-                self.bolt12 = bolt12;
-            }
-        }
-
-        // Fee percent
-        if let Ok(fee_str) = env::var(ENV_CLN_FEE_PERCENT) {
-            if let Ok(fee) = fee_str.parse() {
-                self.fee_percent = fee;
-            }
-        }
-
-        // Reserve fee minimum
-        if let Ok(reserve_fee_str) = env::var(ENV_CLN_RESERVE_FEE_MIN) {
-            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
-                self.reserve_fee_min = reserve_fee.into();
-            }
-        }
-
-        self
-    }
-}
-
-impl Lnd {
-    pub fn from_env(mut self) -> Self {
-        if let Ok(address) = env::var(ENV_LND_ADDRESS) {
-            self.address = address;
-        }
-
-        if let Ok(cert_path) = env::var(ENV_LND_CERT_FILE) {
-            self.cert_file = PathBuf::from(cert_path);
-        }
-
-        if let Ok(macaroon_path) = env::var(ENV_LND_MACAROON_FILE) {
-            self.macaroon_file = PathBuf::from(macaroon_path);
-        }
-
-        if let Ok(fee_str) = env::var(ENV_LND_FEE_PERCENT) {
-            if let Ok(fee) = fee_str.parse() {
-                self.fee_percent = fee;
-            }
-        }
-
-        if let Ok(reserve_fee_str) = env::var(ENV_LND_RESERVE_FEE_MIN) {
-            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
-                self.reserve_fee_min = reserve_fee.into();
-            }
-        }
-
-        self
-    }
-}
-
-impl LNbits {
-    pub fn from_env(mut self) -> Self {
-        if let Ok(admin_key) = env::var(ENV_LNBITS_ADMIN_API_KEY) {
-            self.admin_api_key = admin_key;
-        }
-
-        if let Ok(invoice_key) = env::var(ENV_LNBITS_INVOICE_API_KEY) {
-            self.invoice_api_key = invoice_key;
-        }
-
-        if let Ok(api) = env::var(ENV_LNBITS_API) {
-            self.lnbits_api = api;
-        }
-
-        if let Ok(fee_str) = env::var(ENV_LNBITS_FEE_PERCENT) {
-            if let Ok(fee) = fee_str.parse() {
-                self.fee_percent = fee;
-            }
-        }
-
-        if let Ok(reserve_fee_str) = env::var(ENV_LNBITS_RESERVE_FEE_MIN) {
-            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
-                self.reserve_fee_min = reserve_fee.into();
-            }
-        }
-
-        self
-    }
-}
-
-impl FakeWallet {
-    pub fn from_env(mut self) -> Self {
-        // Supported Units - expects comma-separated list
-        if let Ok(units_str) = env::var(ENV_FAKE_WALLET_SUPPORTED_UNITS) {
-            if let Ok(units) = units_str
-                .split(',')
-                .map(|s| s.trim().parse())
-                .collect::<Result<Vec<CurrencyUnit>, _>>()
-            {
-                self.supported_units = units;
-            }
-        }
-
-        if let Ok(fee_str) = env::var(ENV_FAKE_WALLET_FEE_PERCENT) {
-            if let Ok(fee) = fee_str.parse() {
-                self.fee_percent = fee;
-            }
-        }
-
-        if let Ok(reserve_fee_str) = env::var(ENV_FAKE_WALLET_RESERVE_FEE_MIN) {
-            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
-                self.reserve_fee_min = reserve_fee.into();
-            }
-        }
-
-        if let Ok(min_delay_str) = env::var(ENV_FAKE_WALLET_MIN_DELAY) {
-            if let Ok(min_delay) = min_delay_str.parse() {
-                self.min_delay_time = min_delay;
-            }
-        }
-
-        if let Ok(max_delay_str) = env::var(ENV_FAKE_WALLET_MAX_DELAY) {
-            if let Ok(max_delay) = max_delay_str.parse() {
-                self.max_delay_time = max_delay;
-            }
-        }
-
-        self
-    }
-}
-
-#[cfg(feature = "management-rpc")]
-impl MintManagementRpc {
-    pub fn from_env(mut self) -> Self {
-        if let Ok(enabled) = env::var(ENV_MINT_MANAGEMENT_ENABLED) {
-            if let Ok(enabled) = enabled.parse() {
-                self.enabled = enabled;
-            }
-        }
-
-        if let Ok(address) = env::var(ENV_MINT_MANAGEMENT_ADDRESS) {
-            self.address = Some(address);
-        }
-
-        if let Ok(port) = env::var(ENV_MINT_MANAGEMENT_PORT) {
-            if let Ok(port) = port.parse::<u16>() {
-                self.port = Some(port);
-            }
-        }
-
-        if let Ok(tls_path) = env::var(ENV_MINT_MANAGEMENT_TLS_DIR_PATH) {
-            self.tls_dir_path = Some(tls_path.into());
-        }
-
-        self
-    }
-}

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

@@ -0,0 +1,44 @@
+//! CLN environment variables
+
+use std::env;
+use std::path::PathBuf;
+
+use crate::config::Cln;
+
+// CLN environment variables
+pub const ENV_CLN_RPC_PATH: &str = "CDK_MINTD_CLN_RPC_PATH";
+pub const ENV_CLN_BOLT12: &str = "CDK_MINTD_CLN_BOLT12";
+pub const ENV_CLN_FEE_PERCENT: &str = "CDK_MINTD_CLN_FEE_PERCENT";
+pub const ENV_CLN_RESERVE_FEE_MIN: &str = "CDK_MINTD_CLN_RESERVE_FEE_MIN";
+
+impl Cln {
+    pub fn from_env(mut self) -> Self {
+        // RPC Path
+        if let Ok(path) = env::var(ENV_CLN_RPC_PATH) {
+            self.rpc_path = PathBuf::from(path);
+        }
+
+        // BOLT12 flag
+        if let Ok(bolt12_str) = env::var(ENV_CLN_BOLT12) {
+            if let Ok(bolt12) = bolt12_str.parse() {
+                self.bolt12 = bolt12;
+            }
+        }
+
+        // Fee percent
+        if let Ok(fee_str) = env::var(ENV_CLN_FEE_PERCENT) {
+            if let Ok(fee) = fee_str.parse() {
+                self.fee_percent = fee;
+            }
+        }
+
+        // Reserve fee minimum
+        if let Ok(reserve_fee_str) = env::var(ENV_CLN_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/env_vars/common.rs

@@ -0,0 +1,13 @@
+//! Common environment variables
+
+pub const ENV_WORK_DIR: &str = "CDK_MINTD_WORK_DIR";
+pub const DATABASE_ENV_VAR: &str = "CDK_MINTD_DATABASE";
+pub const ENV_URL: &str = "CDK_MINTD_URL";
+pub const ENV_LISTEN_HOST: &str = "CDK_MINTD_LISTEN_HOST";
+pub const ENV_LISTEN_PORT: &str = "CDK_MINTD_LISTEN_PORT";
+pub const ENV_MNEMONIC: &str = "CDK_MINTD_MNEMONIC";
+pub const ENV_SECONDS_QUOTE_VALID: &str = "CDK_MINTD_SECONDS_QUOTE_VALID";
+pub const ENV_CACHE_SECONDS: &str = "CDK_MINTD_CACHE_SECONDS";
+pub const ENV_EXTEND_CACHE_SECONDS: &str = "CDK_MINTD_EXTEND_CACHE_SECONDS";
+pub const ENV_INPUT_FEE_PPK: &str = "CDK_MINTD_INPUT_FEE_PPK";
+pub const ENV_ENABLE_SWAGGER: &str = "CDK_MINTD_ENABLE_SWAGGER";

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

@@ -0,0 +1,55 @@
+//! FakeWallet environment variables
+
+use std::env;
+
+use cdk::nuts::CurrencyUnit;
+
+use crate::config::FakeWallet;
+
+// Fake Wallet environment variables
+pub const ENV_FAKE_WALLET_SUPPORTED_UNITS: &str = "CDK_MINTD_FAKE_WALLET_SUPPORTED_UNITS";
+pub const ENV_FAKE_WALLET_FEE_PERCENT: &str = "CDK_MINTD_FAKE_WALLET_FEE_PERCENT";
+pub const ENV_FAKE_WALLET_RESERVE_FEE_MIN: &str = "CDK_MINTD_FAKE_WALLET_RESERVE_FEE_MIN";
+pub const ENV_FAKE_WALLET_MIN_DELAY: &str = "CDK_MINTD_FAKE_WALLET_MIN_DELAY";
+pub const ENV_FAKE_WALLET_MAX_DELAY: &str = "CDK_MINTD_FAKE_WALLET_MAX_DELAY";
+
+impl FakeWallet {
+    pub fn from_env(mut self) -> Self {
+        // Supported Units - expects comma-separated list
+        if let Ok(units_str) = env::var(ENV_FAKE_WALLET_SUPPORTED_UNITS) {
+            if let Ok(units) = units_str
+                .split(',')
+                .map(|s| s.trim().parse())
+                .collect::<Result<Vec<CurrencyUnit>, _>>()
+            {
+                self.supported_units = units;
+            }
+        }
+
+        if let Ok(fee_str) = env::var(ENV_FAKE_WALLET_FEE_PERCENT) {
+            if let Ok(fee) = fee_str.parse() {
+                self.fee_percent = fee;
+            }
+        }
+
+        if let Ok(reserve_fee_str) = env::var(ENV_FAKE_WALLET_RESERVE_FEE_MIN) {
+            if let Ok(reserve_fee) = reserve_fee_str.parse::<u64>() {
+                self.reserve_fee_min = reserve_fee.into();
+            }
+        }
+
+        if let Ok(min_delay_str) = env::var(ENV_FAKE_WALLET_MIN_DELAY) {
+            if let Ok(min_delay) = min_delay_str.parse() {
+                self.min_delay_time = min_delay;
+            }
+        }
+
+        if let Ok(max_delay_str) = env::var(ENV_FAKE_WALLET_MAX_DELAY) {
+            if let Ok(max_delay) = max_delay_str.parse() {
+                self.max_delay_time = max_delay;
+            }
+        }
+
+        self
+    }
+}

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

@@ -0,0 +1,57 @@
+//! Info environment variables
+
+use std::env;
+
+use super::common::*;
+use crate::config::Info;
+
+impl Info {
+    pub fn from_env(mut self) -> Self {
+        // Required fields
+        if let Ok(url) = env::var(ENV_URL) {
+            self.url = url;
+        }
+
+        if let Ok(host) = env::var(ENV_LISTEN_HOST) {
+            self.listen_host = host;
+        }
+
+        if let Ok(port_str) = env::var(ENV_LISTEN_PORT) {
+            if let Ok(port) = port_str.parse() {
+                self.listen_port = port;
+            }
+        }
+
+        if let Ok(mnemonic) = env::var(ENV_MNEMONIC) {
+            self.mnemonic = mnemonic;
+        }
+
+        if let Ok(cache_seconds_str) = env::var(ENV_CACHE_SECONDS) {
+            if let Ok(seconds) = cache_seconds_str.parse() {
+                self.http_cache.ttl = Some(seconds);
+            }
+        }
+
+        if let Ok(extend_cache_str) = env::var(ENV_EXTEND_CACHE_SECONDS) {
+            if let Ok(seconds) = extend_cache_str.parse() {
+                self.http_cache.tti = Some(seconds);
+            }
+        }
+
+        if let Ok(fee_str) = env::var(ENV_INPUT_FEE_PPK) {
+            if let Ok(fee) = fee_str.parse() {
+                self.input_fee_ppk = Some(fee);
+            }
+        }
+
+        if let Ok(swagger_str) = env::var(ENV_ENABLE_SWAGGER) {
+            if let Ok(enable) = swagger_str.parse() {
+                self.enable_swagger_ui = Some(enable);
+            }
+        }
+
+        self.http_cache = self.http_cache.from_env();
+
+        self
+    }
+}

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

@@ -0,0 +1,56 @@
+//! Lightning Network common environment variables
+
+use std::env;
+
+use crate::config::Ln;
+
+// LN environment variables
+pub const ENV_LN_BACKEND: &str = "CDK_MINTD_LN_BACKEND";
+pub const ENV_LN_INVOICE_DESCRIPTION: &str = "CDK_MINTD_LN_INVOICE_DESCRIPTION";
+pub const ENV_LN_MIN_MINT: &str = "CDK_MINTD_LN_MIN_MINT";
+pub const ENV_LN_MAX_MINT: &str = "CDK_MINTD_LN_MAX_MINT";
+pub const ENV_LN_MIN_MELT: &str = "CDK_MINTD_LN_MIN_MELT";
+pub const ENV_LN_MAX_MELT: &str = "CDK_MINTD_LN_MAX_MELT";
+
+impl Ln {
+    pub fn from_env(mut self) -> Self {
+        // LnBackend
+        if let Ok(backend_str) = env::var(ENV_LN_BACKEND) {
+            if let Ok(backend) = backend_str.parse() {
+                self.ln_backend = backend;
+            }
+        }
+
+        // Optional invoice description
+        if let Ok(description) = env::var(ENV_LN_INVOICE_DESCRIPTION) {
+            self.invoice_description = Some(description);
+        }
+
+        // Amount fields
+        if let Ok(min_mint_str) = env::var(ENV_LN_MIN_MINT) {
+            if let Ok(amount) = min_mint_str.parse::<u64>() {
+                self.min_mint = amount.into();
+            }
+        }
+
+        if let Ok(max_mint_str) = env::var(ENV_LN_MAX_MINT) {
+            if let Ok(amount) = max_mint_str.parse::<u64>() {
+                self.max_mint = amount.into();
+            }
+        }
+
+        if let Ok(min_melt_str) = env::var(ENV_LN_MIN_MELT) {
+            if let Ok(amount) = min_melt_str.parse::<u64>() {
+                self.min_melt = amount.into();
+            }
+        }
+
+        if let Ok(max_melt_str) = env::var(ENV_LN_MAX_MELT) {
+            if let Ok(amount) = max_melt_str.parse::<u64>() {
+                self.max_melt = amount.into();
+            }
+        }
+
+        self
+    }
+}

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

@@ -0,0 +1,42 @@
+//! LNBits environment variables
+
+use std::env;
+
+use crate::config::LNbits;
+
+// LNBits environment variables
+pub const ENV_LNBITS_ADMIN_API_KEY: &str = "CDK_MINTD_LNBITS_ADMIN_API_KEY";
+pub const ENV_LNBITS_INVOICE_API_KEY: &str = "CDK_MINTD_LNBITS_INVOICE_API_KEY";
+pub const ENV_LNBITS_API: &str = "CDK_MINTD_LNBITS_API";
+pub const ENV_LNBITS_FEE_PERCENT: &str = "CDK_MINTD_LNBITS_FEE_PERCENT";
+pub const ENV_LNBITS_RESERVE_FEE_MIN: &str = "CDK_MINTD_LNBITS_RESERVE_FEE_MIN";
+
+impl LNbits {
+    pub fn from_env(mut self) -> Self {
+        if let Ok(admin_key) = env::var(ENV_LNBITS_ADMIN_API_KEY) {
+            self.admin_api_key = admin_key;
+        }
+
+        if let Ok(invoice_key) = env::var(ENV_LNBITS_INVOICE_API_KEY) {
+            self.invoice_api_key = invoice_key;
+        }
+
+        if let Ok(api) = env::var(ENV_LNBITS_API) {
+            self.lnbits_api = api;
+        }
+
+        if let Ok(fee_str) = env::var(ENV_LNBITS_FEE_PERCENT) {
+            if let Ok(fee) = fee_str.parse() {
+                self.fee_percent = fee;
+            }
+        }
+
+        if let Ok(reserve_fee_str) = env::var(ENV_LNBITS_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/env_vars/lnd.rs

@@ -0,0 +1,43 @@
+//! LND environment variables
+
+use std::env;
+use std::path::PathBuf;
+
+use crate::config::Lnd;
+
+// LND environment variables
+pub const ENV_LND_ADDRESS: &str = "CDK_MINTD_LND_ADDRESS";
+pub const ENV_LND_CERT_FILE: &str = "CDK_MINTD_LND_CERT_FILE";
+pub const ENV_LND_MACAROON_FILE: &str = "CDK_MINTD_LND_MACAROON_FILE";
+pub const ENV_LND_FEE_PERCENT: &str = "CDK_MINTD_LND_FEE_PERCENT";
+pub const ENV_LND_RESERVE_FEE_MIN: &str = "CDK_MINTD_LND_RESERVE_FEE_MIN";
+
+impl Lnd {
+    pub fn from_env(mut self) -> Self {
+        if let Ok(address) = env::var(ENV_LND_ADDRESS) {
+            self.address = address;
+        }
+
+        if let Ok(cert_path) = env::var(ENV_LND_CERT_FILE) {
+            self.cert_file = PathBuf::from(cert_path);
+        }
+
+        if let Ok(macaroon_path) = env::var(ENV_LND_MACAROON_FILE) {
+            self.macaroon_file = PathBuf::from(macaroon_path);
+        }
+
+        if let Ok(fee_str) = env::var(ENV_LND_FEE_PERCENT) {
+            if let Ok(fee) = fee_str.parse() {
+                self.fee_percent = fee;
+            }
+        }
+
+        if let Ok(reserve_fee_str) = env::var(ENV_LND_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/env_vars/management_rpc.rs

@@ -0,0 +1,37 @@
+//! Management RPC environment variables
+
+use std::env;
+
+use crate::config::MintManagementRpc;
+
+// Mint RPC Server environment variables
+pub const ENV_MINT_MANAGEMENT_ENABLED: &str = "CDK_MINTD_MINT_MANAGEMENT_ENABLED";
+pub const ENV_MINT_MANAGEMENT_ADDRESS: &str = "CDK_MINTD_MANAGEMENT_ADDRESS";
+pub const ENV_MINT_MANAGEMENT_PORT: &str = "CDK_MINTD_MANAGEMENT_PORT";
+pub const ENV_MINT_MANAGEMENT_TLS_DIR_PATH: &str = "CDK_MINTD_MANAGEMENT_TLS_DIR_PATH";
+
+impl MintManagementRpc {
+    pub fn from_env(mut self) -> Self {
+        if let Ok(enabled) = env::var(ENV_MINT_MANAGEMENT_ENABLED) {
+            if let Ok(enabled) = enabled.parse() {
+                self.enabled = enabled;
+            }
+        }
+
+        if let Ok(address) = env::var(ENV_MINT_MANAGEMENT_ADDRESS) {
+            self.address = Some(address);
+        }
+
+        if let Ok(port) = env::var(ENV_MINT_MANAGEMENT_PORT) {
+            if let Ok(port) = port.parse::<u16>() {
+                self.port = Some(port);
+            }
+        }
+
+        if let Ok(tls_path) = env::var(ENV_MINT_MANAGEMENT_TLS_DIR_PATH) {
+            self.tls_dir_path = Some(tls_path.into());
+        }
+
+        self
+    }
+}

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

@@ -0,0 +1,63 @@
+//! MintInfo environment variables
+
+use std::env;
+
+use crate::config::MintInfo;
+
+// MintInfo environment variables
+pub const ENV_MINT_NAME: &str = "CDK_MINTD_MINT_NAME";
+pub const ENV_MINT_PUBKEY: &str = "CDK_MINTD_MINT_PUBKEY";
+pub const ENV_MINT_DESCRIPTION: &str = "CDK_MINTD_MINT_DESCRIPTION";
+pub const ENV_MINT_DESCRIPTION_LONG: &str = "CDK_MINTD_MINT_DESCRIPTION_LONG";
+pub const ENV_MINT_ICON_URL: &str = "CDK_MINTD_MINT_ICON_URL";
+pub const ENV_MINT_MOTD: &str = "CDK_MINTD_MINT_MOTD";
+pub const ENV_MINT_CONTACT_NOSTR: &str = "CDK_MINTD_MINT_CONTACT_NOSTR";
+pub const ENV_MINT_CONTACT_EMAIL: &str = "CDK_MINTD_MINT_CONTACT_EMAIL";
+pub const ENV_MINT_TOS_URL: &str = "CDK_MINTD_MINT_TOS_URL";
+
+impl MintInfo {
+    pub fn from_env(mut self) -> Self {
+        // Required fields
+        if let Ok(name) = env::var(ENV_MINT_NAME) {
+            self.name = name;
+        }
+
+        if let Ok(description) = env::var(ENV_MINT_DESCRIPTION) {
+            self.description = description;
+        }
+
+        // Optional fields
+        if let Ok(pubkey_str) = env::var(ENV_MINT_PUBKEY) {
+            // Assuming PublicKey has a from_str implementation
+            if let Ok(pubkey) = pubkey_str.parse() {
+                self.pubkey = Some(pubkey);
+            }
+        }
+
+        if let Ok(desc_long) = env::var(ENV_MINT_DESCRIPTION_LONG) {
+            self.description_long = Some(desc_long);
+        }
+
+        if let Ok(icon_url) = env::var(ENV_MINT_ICON_URL) {
+            self.icon_url = Some(icon_url);
+        }
+
+        if let Ok(motd) = env::var(ENV_MINT_MOTD) {
+            self.motd = Some(motd);
+        }
+
+        if let Ok(nostr_key) = env::var(ENV_MINT_CONTACT_NOSTR) {
+            self.contact_nostr_public_key = Some(nostr_key);
+        }
+
+        if let Ok(email) = env::var(ENV_MINT_CONTACT_EMAIL) {
+            self.contact_email = Some(email);
+        }
+
+        if let Ok(tos_url) = env::var(ENV_MINT_TOS_URL) {
+            self.tos_url = Some(tos_url);
+        }
+
+        self
+    }
+}

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

@@ -0,0 +1,87 @@
+//! Environment variables module
+//!
+//! This module contains all environment variable definitions and parsing logic
+//! organized by component.
+
+mod common;
+mod info;
+mod ln;
+mod mint_info;
+
+#[cfg(feature = "cln")]
+mod cln;
+#[cfg(feature = "fakewallet")]
+mod fake_wallet;
+#[cfg(feature = "lnbits")]
+mod lnbits;
+#[cfg(feature = "lnd")]
+mod lnd;
+#[cfg(feature = "management-rpc")]
+mod management_rpc;
+
+use std::env;
+use std::str::FromStr;
+
+use anyhow::{anyhow, bail, Result};
+#[cfg(feature = "cln")]
+pub use cln::*;
+pub use common::*;
+#[cfg(feature = "fakewallet")]
+pub use fake_wallet::*;
+pub use ln::*;
+#[cfg(feature = "lnbits")]
+pub use lnbits::*;
+#[cfg(feature = "lnd")]
+pub use lnd::*;
+#[cfg(feature = "management-rpc")]
+pub use management_rpc::*;
+pub use mint_info::*;
+
+use crate::config::{Database, DatabaseEngine, LnBackend, Settings};
+
+impl Settings {
+    pub fn from_env(&mut self) -> Result<Self> {
+        if let Ok(database) = env::var(DATABASE_ENV_VAR) {
+            let engine = DatabaseEngine::from_str(&database).map_err(|err| anyhow!(err))?;
+            self.database = Database { engine };
+        }
+
+        self.info = self.info.clone().from_env();
+        self.mint_info = self.mint_info.clone().from_env();
+        self.ln = self.ln.clone().from_env();
+
+        #[cfg(feature = "management-rpc")]
+        {
+            self.mint_management_rpc = Some(
+                self.mint_management_rpc
+                    .clone()
+                    .unwrap_or_default()
+                    .from_env(),
+            );
+        }
+
+        match self.ln.ln_backend {
+            #[cfg(feature = "cln")]
+            LnBackend::Cln => {
+                self.cln = Some(self.cln.clone().unwrap_or_default().from_env());
+            }
+            #[cfg(feature = "lnbits")]
+            LnBackend::LNbits => {
+                self.lnbits = Some(self.lnbits.clone().unwrap_or_default().from_env());
+            }
+            #[cfg(feature = "fakewallet")]
+            LnBackend::FakeWallet => {
+                self.fake_wallet = Some(self.fake_wallet.clone().unwrap_or_default().from_env());
+            }
+            #[cfg(feature = "lnd")]
+            LnBackend::Lnd => {
+                self.lnd = Some(self.lnd.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"),
+        }
+
+        Ok(self.clone())
+    }
+}

crates/cdk-mintd/src/lib.rs

@@ -1,5 +1,6 @@
 //! Cdk mintd lib
 
+#[cfg(feature = "cln")]
 use std::path::PathBuf;
 
 pub mod cli;
@@ -7,6 +8,7 @@ pub mod config;
 pub mod env_vars;
 pub mod setup;
 
+#[cfg(feature = "cln")]
 fn expand_path(path: &str) -> Option<PathBuf> {
     if path.starts_with('~') {
         if let Some(home_dir) = home::home_dir().as_mut() {

crates/cdk-mintd/src/main.rs

@@ -14,6 +14,13 @@ use axum::Router;
 use bip39::Mnemonic;
 use cdk::cdk_database::{self, MintDatabase};
 use cdk::mint::{MintBuilder, MintMeltLimits};
+// Feature-gated imports
+#[cfg(any(
+    feature = "cln",
+    feature = "lnbits",
+    feature = "lnd",
+    feature = "fakewallet"
+))]
 use cdk::nuts::nut17::SupportedMethods;
 use cdk::nuts::nut19::{CachedEndpoint, Method as NUT19Method, Path as NUT19Path};
 use cdk::nuts::{ContactInfo, CurrencyUnit, MintVersion, PaymentMethod};
@@ -40,6 +47,17 @@ use utoipa::OpenApi;
 
 const CARGO_PKG_VERSION: Option<&'static str> = option_env!("CARGO_PKG_VERSION");
 
+// Ensure at least one lightning backend is enabled at compile time
+#[cfg(not(any(
+    feature = "cln",
+    feature = "lnbits",
+    feature = "lnd",
+    feature = "fakewallet"
+)))]
+compile_error!(
+    "At least one lightning backend feature must be enabled: cln, lnbits, lnd, or fakewallet"
+);
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
     let default_filter = "debug";
@@ -149,6 +167,7 @@ async fn main() -> anyhow::Result<()> {
     };
 
     match settings.ln.ln_backend {
+        #[cfg(feature = "cln")]
         LnBackend::Cln => {
             let cln_settings = settings
                 .cln
@@ -171,6 +190,7 @@ async fn main() -> anyhow::Result<()> {
 
             mint_builder = mint_builder.add_supported_websockets(nut17_supported);
         }
+        #[cfg(feature = "lnbits")]
         LnBackend::LNbits => {
             let lnbits_settings = settings.clone().lnbits.expect("Checked on config load");
             let lnbits = lnbits_settings
@@ -187,6 +207,7 @@ async fn main() -> anyhow::Result<()> {
 
             mint_builder = mint_builder.add_supported_websockets(nut17_supported);
         }
+        #[cfg(feature = "lnd")]
         LnBackend::Lnd => {
             let lnd_settings = settings.clone().lnd.expect("Checked at config load");
             let lnd = lnd_settings
@@ -204,6 +225,7 @@ async fn main() -> anyhow::Result<()> {
 
             mint_builder = mint_builder.add_supported_websockets(nut17_supported);
         }
+        #[cfg(feature = "fakewallet")]
         LnBackend::FakeWallet => {
             let fake_wallet = settings.clone().fake_wallet.expect("Fake wallet defined");
 

crates/cdk-mintd/src/setup.rs

@@ -1,17 +1,26 @@
-use std::collections::{HashMap, HashSet};
+#[cfg(feature = "fakewallet")]
+use std::collections::HashMap;
+#[cfg(feature = "fakewallet")]
+use std::collections::HashSet;
+#[cfg(feature = "lnbits")]
 use std::sync::Arc;
 
+#[cfg(feature = "cln")]
 use anyhow::anyhow;
 use async_trait::async_trait;
 use axum::Router;
+#[cfg(feature = "fakewallet")]
 use bip39::rand::{thread_rng, Rng};
 use cdk::cdk_lightning::MintLightning;
 use cdk::mint::FeeReserve;
+#[cfg(feature = "lnbits")]
 use cdk::mint_url::MintUrl;
 use cdk::nuts::CurrencyUnit;
+#[cfg(feature = "lnbits")]
 use tokio::sync::Mutex;
 
 use crate::config::{self, Settings};
+#[cfg(feature = "cln")]
 use crate::expand_path;
 
 #[async_trait]
@@ -24,6 +33,7 @@ pub trait LnBackendSetup {
     ) -> anyhow::Result<impl MintLightning>;
 }
 
+#[cfg(feature = "cln")]
 #[async_trait]
 impl LnBackendSetup for config::Cln {
     async fn setup(
@@ -50,6 +60,7 @@ impl LnBackendSetup for config::Cln {
     }
 }
 
+#[cfg(feature = "lnbits")]
 #[async_trait]
 impl LnBackendSetup for config::LNbits {
     async fn setup(
@@ -93,6 +104,7 @@ impl LnBackendSetup for config::LNbits {
     }
 }
 
+#[cfg(feature = "lnd")]
 #[async_trait]
 impl LnBackendSetup for config::Lnd {
     async fn setup(
@@ -122,6 +134,7 @@ impl LnBackendSetup for config::Lnd {
     }
 }
 
+#[cfg(feature = "fakewallet")]
 #[async_trait]
 impl LnBackendSetup for config::FakeWallet {
     async fn setup(