Merge pull request #413 from naturallaw777/copilot/harden-btcpay-nbxplorer-integration

Harden BTCPay/NBXplorer secret handling and deterministic config generation

CHANGELOG.md

@@ -51,50 +51,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Clarify GitHub is the dev mirror of the Gitea stable repo
 [1.0.6]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.6
 
-
-## [1.0.6] - 2026-08-07
-
-### Added
-- Iso: fix replaceStrings length mismatch in cleanVersion
-- Promote virtual machine trial option in README
-- Improve installer VM compatibility
-- Trim redundant dev-vs-stable Gitea explanations in README
-- Add Arean.Ai to AI tools used for development
-- Prefix OS version badge with 'v' (v1.0.5)
-- Match OS version badge styling to service modal version badges
-- Place OS version badge inline right after the Hub title
-- Center OS version badge under the Hub title
-- Strengthen entropy section: add DYOR emphasis and hardware wallet verification note
-- Add 'About Bitcoin wallet entropy' section to README
-- README: balance intro between Bitcoin sovereignty and sovereign computing
-
-### Changed
-- Removed temp patch file
-
-### Fixed
-- Harden error handling and sanitize exception details across security endpoints (CWE-209)
-- Sanitize exception handling in verify-integrity and security-reset (CWE-209)
-- Sanitize api_security_reset errors to prevent exception information exposure (CWE-209)
-- Use canonical prefix containment check for CodeQL path-injection
-- Pass sanitized abs_path to os.chown to resolve CodeQL path injection at 4338
-- Add CodeQL-recognized path sanitization for domain_name
-- Remove domain substring check for CodeQL incomplete-url
-- Use sentinel for njalla header check (CodeQL incomplete-url-substring)
-- Prevent reflected XSS in lnurl-qr print endpoint
-- Hash root password instead of storing in clear text (CWE-312)
-- Separate web auth hash from system password file
-- Fix Matrix Hub admin API credentials
-- Fix CWE-78: replace subprocess call with Synapse Admin API in create-user endpoint
-
-### Documentation
-- Add SECURITY.md detailing security policy and best practices
-- Versioned CDN downloads + add CDN upload script
-- Correct active development workflow
-- Make repo references mirror-neutral for Gitea readers
-- Clarify GitHub is the dev mirror of the Gitea stable repo
-[1.0.6]: https://git.sovransystems.com/Sovran_Systems/Sovran_SystemsOS/releases/tag/v1.0.6
-
-
 ## [1.0.5] - 2026-08-04
 
 ### Added

flake.lock

@@ -18,32 +18,6 @@
         "type": "github"
       }
     },
-    "extra-container": {
-      "inputs": {
-        "flake-utils": [
-          "nix-bitcoin",
-          "flake-utils"
-        ],
-        "nixpkgs": [
-          "nix-bitcoin",
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1766155727,
-        "narHash": "sha256-XGp4HHH6D6ZKiO5RnMzqYJYnZB538EnEflvlTsOKpvo=",
-        "owner": "erikarvstedt",
-        "repo": "extra-container",
-        "rev": "b450bdb24fca1076973c852d87bcb49b8eb5fd49",
-        "type": "github"
-      },
-      "original": {
-        "owner": "erikarvstedt",
-        "ref": "0.14",
-        "repo": "extra-container",
-        "type": "github"
-      }
-    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": [
@@ -65,47 +39,6 @@
         "type": "github"
       }
     },
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
-    "nix-bitcoin": {
-      "inputs": {
-        "extra-container": "extra-container",
-        "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs_2",
-        "nixpkgs-25_05": "nixpkgs-25_05",
-        "nixpkgs-unstable": "nixpkgs-unstable"
-      },
-      "locked": {
-        "lastModified": 1785177868,
-        "narHash": "sha256-zlAZZkokXpeHHBP8Nt4MvLXOn1Js1qVi81VPjtVbRV8=",
-        "owner": "fort-nix",
-        "repo": "nix-bitcoin",
-        "rev": "360e30fee5ba32f9fecc89bc35628195d9d2dbbe",
-        "type": "github"
-      },
-      "original": {
-        "owner": "fort-nix",
-        "ref": "release",
-        "repo": "nix-bitcoin",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1785590095,
@@ -121,29 +54,13 @@
         "type": "github"
       }
     },
-    "nixpkgs-25_05": {
-      "locked": {
-        "lastModified": 1767313136,
-        "narHash": "sha256-16KkgfdYqjaeRGBaYsNrhPRRENs0qzkQVUooNHtoy2w=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "ac62194c3917d5f474c1a844b6fd6da2db95077d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-25.05",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1785734586,
+        "lastModified": 1786201459,
-        "narHash": "sha256-ODZkEK9Gy50yg6h98u7KkitZ3oc/uuTFK00bh1CRdNA=",
+        "narHash": "sha256-CiOTEjmwAmG2AWnaIno9YaCJJmpca2FXPhMAsnrolCg=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "531670d871c0e29724a02f3cbcac170adc65b58c",
+        "rev": "8b8c811c7c2541c30382c5de7ed26be055569c60",
         "type": "github"
       },
       "original": {
@@ -153,45 +70,13 @@
         "type": "github"
       }
     },
-    "nixpkgs-unstable": {
-      "locked": {
-        "lastModified": 1784453100,
-        "narHash": "sha256-zpGZb8FYui+i8KLtC0nlcmb0voR2zB80Qn8pe7lzIbk=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "b471514bed69eff5255c8e63c1f80e5fe56c616f",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixpkgs-unstable",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1782847189,
+        "lastModified": 1786106723,
-        "narHash": "sha256-twXPFqFsrrY5r28Zh7Homgcp2gUMBgQ6WDS98Q/3xFI=",
+        "narHash": "sha256-zDSUbpoeo/9ZmD2+wXnzxoo1+uhL8vxc0b8yuYMKYq0=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "b6018f87da91d19d0ab4cf979885689b469cdd41",
+        "rev": "f13ff45afd1bb73e640eaa08a7066dbed07e3238",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-25.11",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
-    "nixpkgs_3": {
-      "locked": {
-        "lastModified": 1785828668,
-        "narHash": "sha256-8fsyqeO+mJqvIzeO4xIpgJe/f7MTbbVTEC6RT6WSXNs=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "e72e4f299401a3689d4b3d5fc6496b11db7064eb",
         "type": "github"
       },
       "original": {
@@ -201,7 +86,7 @@
         "type": "github"
       }
     },
-    "nixpkgs_4": {
+    "nixpkgs_3": {
       "locked": {
         "lastModified": 1784555310,
         "narHash": "sha256-/FCliTPgiuV1owejZFNx3Ch9irdvkOfOFl+HHZ+DrtM=",
@@ -220,8 +105,8 @@
     "nixvim": {
       "inputs": {
         "flake-parts": "flake-parts",
-        "nixpkgs": "nixpkgs_4",
+        "nixpkgs": "nixpkgs_3",
-        "systems": "systems_2"
+        "systems": "systems"
       },
       "locked": {
         "lastModified": 1785763201,
@@ -240,28 +125,12 @@
     "root": {
       "inputs": {
         "btc-clients": "btc-clients",
-        "nix-bitcoin": "nix-bitcoin",
+        "nixpkgs": "nixpkgs_2",
-        "nixpkgs": "nixpkgs_3",
         "nixpkgs-stable": "nixpkgs-stable",
         "nixvim": "nixvim"
       }
     },
     "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
-    },
-    "systems_2": {
       "locked": {
         "lastModified": 1774449309,
         "narHash": "sha256-brhZ8DmuGtzkCYHJg4HEd602amKm89Y9ytsFZ5uWD1w=",

flake.nix

@@ -3,13 +3,12 @@
 
 	inputs = {
 		nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-		nix-bitcoin.url = "github:fort-nix/nix-bitcoin/release";
 		nixvim.url = "github:nix-community/nixvim";
 		btc-clients.url = "github:emmanuelrosa/btc-clients-nix";
 		nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-26.05";
 	};
 
-	outputs = { self, nixpkgs, nix-bitcoin, nixvim, btc-clients, nixpkgs-stable, ... }:
+	outputs = { self, nixpkgs, nixvim, btc-clients, nixpkgs-stable, ... }:
 
 	let
 		overlay-stable = final: prev: {
@@ -22,7 +21,7 @@
 	{
 		nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
 			modules = [
-				{ nixpkgs.hostPlatform = "x86_64-linux"; }
+				{ nixpkgs.hostPlatform = "x86_64-linux"; nixpkgs.overlays = [ overlay-stable ]; }
 				self.nixosModules.Sovran_SystemsOS
 				./hardware-configuration.nix
 				./role-state.nix
@@ -32,10 +31,9 @@
 
 		nixosConfigurations.sovran_systemsos-iso = nixpkgs.lib.nixosSystem {
 			modules = [
-				{ nixpkgs.hostPlatform = "x86_64-linux"; }
+				{ nixpkgs.hostPlatform = "x86_64-linux"; nixpkgs.overlays = [ overlay-stable ]; }
-				({ config, pkgs, ... }: { nixpkgs.overlays = [ overlay-stable ]; })
 				./iso/common.nix
-				nix-bitcoin.nixosModules.default
+				./modules/bitcoin
 				nixvim.nixosModules.nixvim
 			];
 		};
@@ -46,7 +44,7 @@
 					nixpkgs.overlays = [ overlay-stable ];
 				})
 				./configuration.nix
-				nix-bitcoin.nixosModules.default
+				./modules/bitcoin
 				nixvim.nixosModules.nixvim
 			];
 			config = {
@@ -58,13 +56,21 @@
 			};
 		};
 
-		nixosTests.nwc-wallets-port-collision =
+		checks.x86_64-linux = let
-			import ./nix/tests/nwc-wallets-port-collision.nix {
+			pkgs = import nixpkgs {
-				inherit nixpkgs;
 				system = "x86_64-linux";
 			};
-
+			fetchNodeModules =
-		checks.x86_64-linux.nwc-wallets-port-collision =
+				pkgs.callPackage ./packages/build-support/fetch-node-modules.nix {};
-			self.nixosTests.nwc-wallets-port-collision;
+			mempoolPkgs =
+				pkgs.callPackage ./packages/mempool { inherit fetchNodeModules; };
+		in {
+			bitcoin-btcpay-hardening = import ./tests/bitcoin-btcpay-hardening.nix {
+				inherit nixpkgs overlay-stable;
+			};
+			mempool-backend = mempoolPkgs.mempool-backend;
+			mempool-frontend = mempoolPkgs.mempool-frontend;
+			rtl = pkgs.callPackage ./packages/rtl { inherit fetchNodeModules; };
+		};
 	};
 }

modules/bitcoin-core.nix

@@ -1,7 +1,7 @@
 { config, pkgs, lib, ... }:
 
 lib.mkIf config.sovran_systemsOS.features.bitcoin-core {
-  
+  # Vendored nix-bitcoin now uses nixpkgs directly; no nix-bitcoin.pkgs indirection.
-  services.bitcoind.package = lib.mkForce config.nix-bitcoin.pkgs.bitcoind;
+  # Use standard bitcoind from nixpkgs (override to knots if desired via pkgs.bitcoind-knots)
-
+  services.bitcoind.package = lib.mkForce pkgs.bitcoind;
 }

modules/bitcoin/bitcoind-rpc-public-whitelist.nix

@@ -0,0 +1,70 @@
+# RPC calls that are safe for public use
+# Vendored from nix-bitcoin - do not fetch from upstream at runtime
+[
+  "echo"
+  "getinfo"
+  "getindexinfo"
+  "help"
+  "ping"
+  "uptime"
+  # Blockchain
+  "getbestblockhash"
+  "getblock"
+  "getblockchaininfo"
+  "getblockcount"
+  "getblockfilter"
+  "getblockfrompeer"
+  "getblockhash"
+  "getblockheader"
+  "getblockstats"
+  "getchaintips"
+  "getchaintxstats"
+  "getdeploymentinfo"
+  "getdifficulty"
+  "getmempoolancestors"
+  "getmempooldescendants"
+  "getmempoolentry"
+  "getmempoolinfo"
+  "getrawmempool"
+  "gettxout"
+  "gettxoutproof"
+  "gettxoutsetinfo"
+  "scantxoutset"
+  "verifytxoutproof"
+  # Mining
+  "getblocktemplate"
+  "getmininginfo"
+  "getnetworkhashps"
+  # Network
+  "getnetworkinfo"
+  "getnodeaddresses"
+  "getpeerinfo"
+  # Rawtransactions
+  "analyzepsbt"
+  "combinepsbt"
+  "combinerawtransaction"
+  "converttopsbt"
+  "createpsbt"
+  "createrawtransaction"
+  "decodepsbt"
+  "decoderawtransaction"
+  "decodescript"
+  "finalizepsbt"
+  "fundrawtransaction"
+  "getrawtransaction"
+  "joinpsbts"
+  "sendrawtransaction"
+  "signrawtransactionwithkey"
+  "testmempoolaccept"
+  "utxoupdatepsbt"
+  # Util
+  "createmultisig"
+  "deriveaddresses"
+  "estimatesmartfee"
+  "getdescriptorinfo"
+  "signmessagewithprivkey"
+  "validateaddress"
+  "verifymessage"
+  # Zmq
+  "getzmqnotifications"
+]

modules/bitcoin/bitcoind.nix

@@ -0,0 +1,506 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  options = {
+    services.bitcoind = {
+      enable = mkEnableOption "Bitcoin daemon";
+      address = mkOption {
+        type = types.str;
+        default = "127.0.0.1";
+        description = "Address to listen for peer connections.";
+      };
+      port = mkOption {
+        type = types.port;
+        default = if !cfg.regtest then 8333 else 18444;
+        defaultText = "if !cfg.regtest then 8333 else 18444";
+        description = "Port to listen for peer connections.";
+      };
+      onionPort = mkOption {
+        type = types.nullOr types.port;
+        # When the bitcoind onion service is enabled, add an onion-tagged socket
+        # to distinguish local connections from Tor connections
+        default = if (config.nix-bitcoin.onionServices.bitcoind.enable or false) then 8334 else null;
+        description = ''
+          Port to listen for Tor peer connections.
+          If set, inbound connections to this port are tagged as onion peers.
+        '';
+      };
+      listen = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Listen for peer connections at `address:port`
+          and `address:onionPort` (if {option}`onionPort` is set).
+        '';
+      };
+      listenWhitelisted = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Listen for peer connections at `address:whitelistedPort`.
+          Peers connected through this socket are automatically whitelisted.
+        '';
+      };
+      whitelistedPort = mkOption {
+        type = types.port;
+        default = 8335;
+        description = "See `listenWhitelisted`.";
+      };
+      getPublicAddressCmd = mkOption {
+        type = types.str;
+        default = "";
+        description = ''
+          Bash expression which outputs the public service address to announce to peers.
+          If left empty, no address is announced.
+        '';
+      };
+      package = mkOption {
+        type = types.package;
+        default = pkgs.bitcoind;
+        defaultText = "pkgs.bitcoind";
+        description = ''
+          The package providing bitcoind binaries.
+
+          You can use this option to select other bitcoind-compatible implementations.
+          Example:
+          ```nix
+          services.bitcoind.package = pkgs.bitcoind-knots;
+          ```
+        '';
+      };
+      extraConfig = mkOption {
+        type = types.lines;
+        default = "";
+        example = ''
+          par=16
+          logips=1
+        '';
+        description = "Extra lines appended to {file}`bitcoin.conf`.";
+      };
+      dataDir = mkOption {
+        type = types.path;
+        default = "/var/lib/bitcoind";
+        description = "The data directory for bitcoind.";
+      };
+      rpc = {
+        address = mkOption {
+          type = types.str;
+          default = "127.0.0.1";
+          description = ''
+            Address to listen for JSON-RPC connections.
+          '';
+        };
+        port = mkOption {
+          type = types.port;
+          default = if !cfg.regtest then 8332 else 18443;
+          defaultText = "if !cfg.regtest then 8332 else 18443";
+          description = "Port to listen for JSON-RPC connections.";
+        };
+        threads = mkOption {
+          type = types.nullOr types.ints.u16;
+          default = null;
+          description = "The number of threads to service RPC calls.";
+        };
+        allowip = mkOption {
+          type = types.listOf types.str;
+          default = [ "127.0.0.1" ];
+          description = ''
+            Allow JSON-RPC connections from specified sources.
+          '';
+        };
+        users = mkOption {
+          default = {};
+          description = ''
+            Allowed users for JSON-RPC connections.
+          '';
+          example = {
+            alice = {
+              passwordHMAC = "f7efda5c189b999524f151318c0c86$d5b51b3beffbc02b724e5d095828e0bc8b2456e9ac8757ae3211a5d9b16a22ae";
+              rpcwhitelist = [ "sendtoaddress" "getnewaddress" ];
+            };
+          };
+          type = with types; attrsOf (submodule ({ name, ... }: {
+            options = {
+              name = mkOption {
+                type = types.str;
+                default = name;
+                example = "alice";
+                description = ''
+                  Username for JSON-RPC connections.
+                '';
+              };
+              passwordHMAC = mkOption {
+                type = types.str;
+                example = "f7efda5c189b999524f151318c0c86$d5b51b3beffbc02b724e5d095828e0bc8b2456e9ac8757ae3211a5d9b16a22ae";
+                description = ''
+                  Password HMAC-SHA-256 for JSON-RPC connections. Must be a string of the
+                  format `<SALT-HEX>$<HMAC-HEX>`.
+                '';
+              };
+              passwordHMACFromFile = mkOption {
+                type = lib.types.bool;
+                internal = true;
+                default = false;
+              };
+              rpcwhitelist = mkOption {
+                type = types.listOf types.str;
+                default = [];
+                description = ''
+                  List of allowed rpc calls for each user.
+                  If empty list, rpcwhitelist is disabled for that user.
+                '';
+              };
+            };
+          }));
+        };
+      };
+      regtest = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Enable regtest mode.";
+      };
+      network = mkOption {
+        readOnly = true;
+        default = if cfg.regtest then "regtest" else "mainnet";
+      };
+      makeNetworkName = mkOption {
+        readOnly = true;
+        default = mainnet: regtest: if cfg.regtest then regtest else mainnet;
+      };
+      proxy = mkOption {
+        type = types.nullOr types.str;
+        default = if cfg.tor.proxy then config.nix-bitcoin.torClientAddressWithPort else null;
+        description = "Connect through SOCKS5 proxy";
+      };
+      i2p = mkOption {
+        type = types.enum [ false true "only-outgoing" ];
+        default = false;
+        description = ''
+          Enable peer connections via i2p.
+          With `only-outgoing`, incoming i2p connections are disabled.
+        '';
+      };
+      dataDirReadableByGroup = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          If enabled, data dir content is readable by the bitcoind service group.
+          Warning: This disables bitcoind's wallet support.
+        '';
+      };
+      sysperms = mkOption {
+        type = types.nullOr types.bool;
+        default = null;
+        description = ''
+          Create new files with system default permissions, instead of umask 077
+          (only effective with disabled wallet functionality)
+        '';
+      };
+      disablewallet = mkOption {
+        type = types.nullOr types.bool;
+        default = null;
+        description = ''
+          Do not load the wallet and disable wallet RPC calls
+        '';
+      };
+      dbCache = mkOption {
+        type = types.nullOr (intAtLeast 4);
+        default = null;
+        example = 4000;
+        description = "Override the default database cache size in MiB.";
+      };
+      prune = mkOption {
+        type = types.ints.unsigned;
+        default = 0;
+        example = 10000;
+        description = ''
+          Automatically prune block files to stay under the specified target size in MiB.
+          Value 0 disables pruning.
+        '';
+      };
+      txindex = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Enable the transaction index.";
+      };
+      zmqpubrawblock = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "tcp://127.0.0.1:28332";
+        description = "ZMQ address for zmqpubrawblock notifications";
+      };
+      zmqpubrawtx = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "tcp://127.0.0.1:28333";
+        description = "ZMQ address for zmqpubrawtx notifications";
+      };
+      assumevalid = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "00000000000000000000e5abc3a74fe27dc0ead9c70ea1deb456f11c15fd7bc6";
+        description = ''
+          If this block is in the chain assume that it and its ancestors are
+          valid and potentially skip their script verification.
+        '';
+      };
+      addnodes = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        example = [ "ecoc5q34tmbq54wl.onion" ];
+        description = "Add nodes to connect to and attempt to keep the connections open";
+      };
+      discover = mkOption {
+        type = types.nullOr types.bool;
+        default = null;
+        description = "Discover own IP addresses";
+      };
+      addresstype = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "bech32";
+        description = "The type of addresses to use";
+      };
+      user = mkOption {
+        type = types.str;
+        default = "bitcoin";
+        description = "The user as which to run bitcoind.";
+      };
+      group = mkOption {
+        type = types.str;
+        default = cfg.user;
+        description = "The group as which to run bitcoind.";
+      };
+      cli = mkOption {
+        readOnly = true;
+        type = types.package;
+        default = pkgs.writers.writeBashBin "bitcoin-cli" ''
+          exec ${cfg.package}/bin/bitcoin-cli -datadir='${cfg.dataDir}' "$@"
+        '';
+        defaultText = "(See source)";
+        description = "Binary to connect with the bitcoind instance.";
+      };
+      tor = nbLib.tor;
+    };
+  };
+
+  cfg = config.services.bitcoind;
+  nbLib = config.nix-bitcoin.lib;
+  secretsDir = config.nix-bitcoin.secretsDir;
+
+  i2pSAM = config.services.i2pd.proto.sam;
+
+  configFile = builtins.toFile "bitcoin.conf" ''
+    # We're already logging via journald
+    nodebuglogfile=1
+    logtimestamps=0
+
+    startupnotify=/run/current-system/systemd/bin/systemd-notify --ready
+
+    ${optionalString cfg.regtest ''
+      regtest=1
+      [regtest]
+    ''}
+    ${optionalString (cfg.dbCache != null) "dbcache=${toString cfg.dbCache}"}
+    prune=${toString cfg.prune}
+    ${optionalString cfg.txindex "txindex=1"}
+    ${optionalString (cfg.sysperms != null) "sysperms=${if cfg.sysperms then "1" else "0"}"}
+    ${optionalString (cfg.disablewallet != null) "disablewallet=${if cfg.disablewallet then "1" else "0"}"}
+    ${optionalString (cfg.assumevalid != null) "assumevalid=${cfg.assumevalid}"}
+
+    # Connection options
+    listen=${if (cfg.listen || cfg.listenWhitelisted) then "1" else "0"}
+    ${optionalString cfg.listen
+      "bind=${cfg.address}:${toString cfg.port}"}
+    ${optionalString (cfg.listen && cfg.onionPort != null)
+      "bind=${cfg.address}:${toString cfg.onionPort}=onion"}
+    ${optionalString cfg.listenWhitelisted
+      "whitebind=${cfg.address}:${toString cfg.whitelistedPort}"}
+    ${optionalString (cfg.proxy != null) "proxy=${cfg.proxy}"}
+    ${optionalString (cfg.i2p != false) "i2psam=${nbLib.addressWithPort i2pSAM.address i2pSAM.port}"}
+    ${optionalString (cfg.i2p == "only-outgoing") "i2pacceptincoming=0"}
+
+    ${optionalString (cfg.discover != null) "discover=${if cfg.discover then "1" else "0"}"}
+    ${lib.concatMapStrings (node: "addnode=${node}\n") cfg.addnodes}
+
+    # RPC server options
+    rpcbind=${cfg.rpc.address}
+    rpcport=${toString cfg.rpc.port}
+    rpcconnect=${cfg.rpc.address}
+    ${optionalString (cfg.rpc.threads != null) "rpcthreads=${toString cfg.rpc.threads}"}
+    rpcwhitelistdefault=0
+    ${concatMapStrings (user: ''
+        ${optionalString (!user.passwordHMACFromFile) "rpcauth=${user.name}:${user.passwordHMAC}"}
+        ${optionalString (user.rpcwhitelist != [])
+          "rpcwhitelist=${user.name}:${lib.strings.concatStringsSep "," user.rpcwhitelist}"}
+      '') (builtins.attrValues cfg.rpc.users)
+    }
+    ${lib.concatMapStrings (rpcallowip: "rpcallowip=${rpcallowip}\n") cfg.rpc.allowip}
+
+    # Wallet options
+    ${optionalString (cfg.addresstype != null) "addresstype=${cfg.addresstype}"}
+
+    # ZMQ options
+    ${optionalString (cfg.zmqpubrawblock != null) "zmqpubrawblock=${cfg.zmqpubrawblock}"}
+    ${optionalString (cfg.zmqpubrawtx != null) "zmqpubrawtx=${cfg.zmqpubrawtx}"}
+
+    # Extra options
+    ${cfg.extraConfig}
+  '';
+
+  zmqServerEnabled = (cfg.zmqpubrawblock != null) || (cfg.zmqpubrawtx != null);
+
+  intAtLeast = n: types.addCheck types.int (x: x >= n) // {
+    name = "intAtLeast";
+    description = "integer >= ${toString n}";
+  };
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package (hiPrio cfg.cli) ];
+
+    services.bitcoind = mkMerge [
+      (mkIf cfg.dataDirReadableByGroup {
+        disablewallet = true;
+        sysperms = true;
+      })
+      {
+        rpc.users.privileged = {
+          passwordHMACFromFile = true;
+        };
+        rpc.users.public = {
+          passwordHMACFromFile = true;
+          rpcwhitelist = import ./bitcoind-rpc-public-whitelist.nix;
+        };
+      }
+    ];
+
+    services.i2pd = mkIf (cfg.i2p != false) {
+      enable = true;
+      proto.sam.enable = true;
+    };
+
+    systemd.tmpfiles.rules = [
+      "d '${cfg.dataDir}' 0770 ${cfg.user} ${cfg.group} - -"
+    ];
+
+    systemd.services.bitcoind = rec {
+      wants = [
+        "network-online.target"
+        # Use `wants` instead of `requires` for `nix-bitcoin-secrets.target`
+        # so that bitcoind and all dependent services are not restarted when
+        # the secrets target restarts.
+        # The secrets target always restarts when deploying with one of the methods
+        # in ./deployment.
+        #
+        # TODO-EXTERNAL: Instead of `wants`, use a future systemd dependency type
+        # that propagates initial start failures but no restarts
+        "nix-bitcoin-secrets.target"
+      ];
+      after = wants;
+      wantedBy = [ "multi-user.target" ];
+
+      preStart = let
+        extraRpcauth = concatMapStrings (name: let
+          user = cfg.rpc.users.${name};
+        in optionalString user.passwordHMACFromFile ''
+            hmacPayload="$(readValidatedRpcHmac '${secretsDir}/bitcoin-HMAC-${name}')" || exit 1
+            printf '%s\n' "rpcauth=${user.name}:$hmacPayload"
+          ''
+        ) (builtins.attrNames cfg.rpc.users);
+      in ''
+        ${optionalString cfg.dataDirReadableByGroup ''
+          if [[ -e '${cfg.dataDir}/blocks' ]]; then
+            chmod -R g+rX '${cfg.dataDir}/blocks'
+          fi
+        ''}
+
+        readValidatedRpcHmac() {
+          local hmacFile="$1"
+          local hmacPayload
+
+          if [[ ! -e "$hmacFile" ]]; then
+            echo "Error: Bitcoin RPC HMAC file is missing: $hmacFile" >&2
+            return 1
+          fi
+          if [[ ! -r "$hmacFile" ]]; then
+            echo "Error: Bitcoin RPC HMAC file is unreadable: $hmacFile" >&2
+            return 1
+          fi
+
+          hmacPayload="$(<"$hmacFile")"
+          if [[ -z "$hmacPayload" ]]; then
+            echo "Error: Bitcoin RPC HMAC file is empty: $hmacFile" >&2
+            return 1
+          fi
+          if [[ ! "$hmacPayload" =~ ^[[:xdigit:]]+\$[[:xdigit:]]+$ ]]; then
+            echo "Error: Bitcoin RPC HMAC file has invalid format: $hmacFile" >&2
+            return 1
+          fi
+
+          printf '%s\n' "$hmacPayload"
+        }
+
+        cfg=$(
+          cat ${configFile}
+          ${extraRpcauth}
+          echo
+          ${optionalString (cfg.getPublicAddressCmd != "") ''
+            echo "externalip=$(${cfg.getPublicAddressCmd})"
+          ''}
+        )
+        confFile='${cfg.dataDir}/bitcoin.conf'
+        if [[ ! -e $confFile || $cfg != $(cat $confFile) ]]; then
+          install -o '${cfg.user}' -g '${cfg.group}' -m 640 <(echo "$cfg") $confFile
+        fi
+      '';
+
+      # Enable RPC access for group
+      postStart = ''
+        chmod g=r '${cfg.dataDir}/${optionalString cfg.regtest "regtest/"}.cookie'
+      '' + (optionalString cfg.regtest) ''
+        chmod g=x '${cfg.dataDir}/regtest'
+      '';
+
+      serviceConfig = nbLib.defaultHardening // {
+        Type = "notify";
+        NotifyAccess = "all";
+        User = cfg.user;
+        Group = cfg.group;
+        TimeoutStartSec = "30min";
+        TimeoutStopSec = "30min";
+        ExecStart = "${cfg.package}/bin/bitcoind -datadir='${cfg.dataDir}'";
+        Restart = "on-failure";
+        UMask = mkIf cfg.dataDirReadableByGroup "0027";
+        ReadWritePaths = [ cfg.dataDir ];
+      } // nbLib.allowedIPAddresses cfg.tor.enforce
+        // optionalAttrs zmqServerEnabled nbLib.allowNetlink;
+    };
+
+    users.users.${cfg.user} = {
+      isSystemUser = true;
+      group = cfg.group;
+    };
+    users.groups.${cfg.group} = {};
+    users.groups.bitcoinrpc-public = {};
+
+    nix-bitcoin.operator.groups = [ cfg.group ];
+
+    nix-bitcoin.secrets = {
+      bitcoin-rpcpassword-privileged.user = cfg.user;
+      bitcoin-rpcpassword-public = {
+        user = cfg.user;
+        group = "bitcoinrpc-public";
+      };
+
+      bitcoin-HMAC-privileged.user = cfg.user;
+      bitcoin-HMAC-public.user = cfg.user;
+    };
+    nix-bitcoin.generateSecretsCmds.bitcoind = ''
+      makeBitcoinRPCPassword privileged
+      makeBitcoinRPCPassword public
+    '';
+  };
+}

modules/bitcoin/btcpayserver.nix

@@ -0,0 +1,328 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.services = {
+    nbxplorer = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable nbxplorer, a lightweight API for Bitcoin HD wallets.
+
+          Access API documentation here:
+          {option}`services.nbxplorer.address`:{option}`services.nbxplorer.port`
+        '';
+      };
+      address = mkOption {
+        type = types.str;
+        default = "127.0.0.1";
+        description = "Address to listen on.";
+      };
+      port = mkOption {
+        type = types.port;
+        default = 24444;
+        description = "Port to listen on.";
+      };
+      package = mkOption {
+        type = types.package;
+        default = pkgs.stable.nbxplorer;
+        defaultText = "pkgs.stable.nbxplorer";
+        description = "The package providing nbxplorer binaries.";
+      };
+      dataDir = mkOption {
+        type = types.path;
+        default = "/var/lib/nbxplorer";
+        description = "The data directory for nbxplorer.";
+      };
+      # TODO-EXTERNAL:
+      # The shortcut link `main` in the datadir has changed to a directory
+      # in version 2.3.3.
+      # Add a dummy symlink, if it does not already exist, to be compatible with older modules.
+      # When the old system uses a link and the new system a directory, switching fails with:
+      #   mv: cannot move '/var/lib/nbxplorer/Main' to '/var/lib/nbxplorer/.Main.tmp':
+      #   No such file or directory
+      #
+      # Remove this option when it is irrelevant (i.e. when the old system will never
+      # be nix-bitcoin <=0.0.91)
+      addNetworkSymlink = mkOption {
+        readOnly = true;
+        default = pkgs.stable.nbxplorer != cfg.nbxplorer.package;
+        description = ''
+          Whether to add a compatibility symlink (like `${cfg.nbxplorer.dataDir}/Main`)
+          to the dataDir.
+          This is enabled by default if the nbxplorer package is set to the version-locked package.
+        '';
+      };
+      user = mkOption {
+        type = types.str;
+        default = "nbxplorer";
+        description = "The user as which to run NBXplorer.";
+      };
+      group = mkOption {
+        type = types.str;
+        default = cfg.nbxplorer.user;
+        description = "The group as which to run NBXplorer.";
+      };
+      tor = nbLib.tor;
+    };
+
+    btcpayserver = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable BTCPay Server, a self-hosted, open-source payment processor.
+
+          Extra recommendations:
+          - Enable `services.btcpayserver.lightningBackend` to provide Lightning payment support.
+          - Secure this service if the instance is publically accessible. For example, set
+            {option}`services.btcpayserver.address` to `127.0.0.1` and use a reverse proxy
+            that enforces TLS (Transport Layer Security).
+        '';
+      };
+      package = mkOption {
+        type = types.package;
+        default = pkgs.stable.btcpayserver;
+        defaultText = "pkgs.stable.btcpayserver";
+        description = "The package providing BTCPay Server binaries.";
+      };
+      address = mkOption {
+        type = types.str;
+        default = "127.0.0.1";
+        description = "Address to listen on.";
+      };
+      port = mkOption {
+        type = types.port;
+        default = 23000;
+        description = "Port to listen on.";
+      };
+      lightningBackend = mkOption {
+        type = types.nullOr (types.enum [ "lnd" ]);
+        default = null;
+        description = ''
+          The lightning node to use as a backend.
+          Enables the node service if not already enabled.
+        '';
+      };
+      lbtc = mkOption {
+        readOnly = true;
+        default = false;
+        description = ''
+          Enable Liquid support.
+        '';
+      };
+      dataDir = mkOption {
+        type = types.path;
+        default = "/var/lib/btcpayserver";
+        description = "The data directory for BTCPay Server.";
+      };
+      user = mkOption {
+        type = types.str;
+        default = "btcpayserver";
+        description = "The user as which to run BTCPay Server.";
+      };
+      group = mkOption {
+        type = types.str;
+        default = cfg.btcpayserver.user;
+        description = "The group as which to run BTCPay Server.";
+      };
+      tor = nbLib.tor;
+    };
+  };
+
+  cfg = {
+    inherit (config.services)
+      nbxplorer
+      btcpayserver
+      bitcoind;
+  };
+
+  nbLib = config.nix-bitcoin.lib;
+  secretsDir = config.nix-bitcoin.secretsDir;
+
+in {
+  inherit options;
+
+  config = mkMerge [
+    (mkIf cfg.nbxplorer.enable {
+      systemd.tmpfiles.rules = [
+        "d '${cfg.nbxplorer.dataDir}' 0770 ${cfg.nbxplorer.user} ${cfg.nbxplorer.group} - -"
+      ] ++ optional cfg.nbxplorer.addNetworkSymlink
+        "L+ '${cfg.nbxplorer.dataDir}/Main' - - - - '${cfg.nbxplorer.dataDir}/main'";
+
+      systemd.services.nbxplorer = let
+        configFile = builtins.toFile "nbxplorer-config" ''
+          network=${cfg.bitcoind.network}
+          btcrpcuser=${cfg.bitcoind.rpc.users.btcpayserver.name}
+          btcrpcurl=http://${nbLib.addressWithPort cfg.bitcoind.rpc.address cfg.bitcoind.rpc.port}
+          btcnodeendpoint=${nbLib.addressWithPort cfg.bitcoind.address cfg.bitcoind.whitelistedPort}
+          bind=${cfg.nbxplorer.address}
+          port=${toString cfg.nbxplorer.port}
+          postgres=User ID=${cfg.nbxplorer.user};Host=/run/postgresql;Database=nbxplorer
+        '';
+      in rec {
+        wantedBy = [ "multi-user.target" ];
+        requires = [ "postgresql.target" ];
+        wants = [ "bitcoind.service" ];
+        after = requires ++ wants ++ [ "nix-bitcoin-secrets.target" ];
+        preStart = ''
+          install -m 600 ${configFile} '${cfg.nbxplorer.dataDir}/settings.config'
+          printf '%s\n' "btcrpcpassword=$(<${secretsDir}/bitcoin-rpcpassword-btcpayserver)" \
+            >> '${cfg.nbxplorer.dataDir}/settings.config'
+        '';
+        serviceConfig = nbLib.defaultHardening // {
+          ExecStart = ''
+            ${cfg.nbxplorer.package}/bin/nbxplorer --conf=${cfg.nbxplorer.dataDir}/settings.config \
+              --datadir='${cfg.nbxplorer.dataDir}'
+          '';
+          RuntimeDirectory = "nbxplorer";
+          StateDirectory = "nbxplorer";
+          User = cfg.nbxplorer.user;
+          Group = cfg.nbxplorer.group;
+          Restart = "on-failure";
+          RestartSec = "10s";
+          ReadWritePaths = [ cfg.nbxplorer.dataDir ];
+          MemoryDenyWriteExecute = false;
+        } // nbLib.allowedIPAddresses cfg.nbxplorer.tor.enforce;
+      };
+
+      services.bitcoind = {
+        enable = true;
+        listenWhitelisted = true;
+        txindex = true;
+      };
+
+      users.users.${cfg.nbxplorer.user} = {
+        isSystemUser = true;
+        group = cfg.nbxplorer.group;
+      };
+      users.groups.${cfg.nbxplorer.group} = {};
+    })
+
+    (mkIf cfg.btcpayserver.enable {
+      services.nbxplorer.enable = true;
+
+      services.bitcoind = {
+        listenWhitelisted = true;
+        rpc.users.btcpayserver = {
+          name = "btcpayserver";
+          passwordHMACFromFile = true;
+          rpcwhitelist = [
+            "getblockchaininfo"
+            "getblock"
+            "getblockhash"
+            "getblockheader"
+            "getblockstats"
+            "gettransaction"
+            "getrawtransaction"
+            "sendrawtransaction"
+            "getblockcount"
+            "getbestblockhash"
+            "getnetworkinfo"
+            "getpeerinfo"
+            "estimatesmartfee"
+            "getmempoolinfo"
+            "getmempoolentry"
+            "getrawmempool"
+            "gettxout"
+            "scantxoutset"
+            "importmulti"
+            "listunspent"
+            "getwalletinfo"
+            "listtransactions"
+            "listreceivedbyaddress"
+            "getnewaddress"
+            "uptime"
+            "getrpcinfo"
+          ];
+        };
+      };
+
+      systemd.tmpfiles.rules = [
+        "d '${cfg.btcpayserver.dataDir}' 0770 ${cfg.btcpayserver.user} ${cfg.btcpayserver.group} - -"
+      ];
+
+      systemd.services.btcpayserver = let
+        nbExplorerUrl = "http://${nbLib.addressWithPort cfg.nbxplorer.address cfg.nbxplorer.port}/";
+        configFile = builtins.toFile "btcpayserver-config" (
+          ''
+            network=${cfg.bitcoind.network}
+            bind=${cfg.btcpayserver.address}
+            port=${toString cfg.btcpayserver.port}
+            socksendpoint=${config.nix-bitcoin.torClientAddressWithPort}
+            btcexplorerurl=${nbExplorerUrl}
+            explorer.postgres=User ID=${cfg.nbxplorer.user};Host=/run/postgresql;Database=nbxplorer
+            postgres=User ID=${cfg.btcpayserver.user};Host=/run/postgresql;Database=btcpayserver
+          '' + optionalString (cfg.btcpayserver.lightningBackend == "lnd")
+            (
+              "btclightning=type=lnd-rest;"
+              + "server=https://${nbLib.address config.services.lnd.restAddress}:${toString config.services.lnd.restPort}/;"
+              + "macaroonfilepath=/run/lnd/btcpayserver.macaroon;"
+              + "certfilepath=${config.services.lnd.certPath}\n"
+            )
+        );
+      in rec {
+        wantedBy = [ "multi-user.target" ];
+        requires = [ "postgresql.target" "nbxplorer.service" ];
+        wants = optional (cfg.btcpayserver.lightningBackend == "lnd") "lnd.service";
+        after = requires ++ wants;
+        serviceConfig = nbLib.defaultHardening // {
+          ExecStart = ''
+            ${cfg.btcpayserver.package}/bin/btcpayserver --conf=${configFile} \
+              --datadir='${cfg.btcpayserver.dataDir}'
+          '';
+          RuntimeDirectory = "btcpayserver";
+          StateDirectory = "btcpayserver";
+          User = cfg.btcpayserver.user;
+          Group = cfg.btcpayserver.group;
+          Restart = "on-failure";
+          RestartSec = "10s";
+          ReadWritePaths = [ cfg.btcpayserver.dataDir ];
+          MemoryDenyWriteExecute = false;
+        } // nbLib.allowedIPAddresses cfg.btcpayserver.tor.enforce;
+      };
+
+      services.postgresql = {
+        enable = true;
+        ensureDatabases = [ "btcpayserver" "nbxplorer" ];
+        ensureUsers = [
+          { name = cfg.btcpayserver.user; ensureDBOwnership = true; }
+          { name = cfg.nbxplorer.user; ensureDBOwnership = true; }
+        ];
+      };
+
+      users.users.${cfg.btcpayserver.user} = {
+        isSystemUser = true;
+        group = cfg.btcpayserver.group;
+        extraGroups = optional (cfg.btcpayserver.lightningBackend == "lnd") config.services.lnd.group;
+      };
+      users.groups.${cfg.btcpayserver.group} = {};
+
+      nix-bitcoin.secrets = {
+        bitcoin-rpcpassword-btcpayserver = {
+          user = cfg.bitcoind.user;
+          group = cfg.nbxplorer.group;
+        };
+        bitcoin-HMAC-btcpayserver.user = cfg.bitcoind.user;
+      };
+      nix-bitcoin.generateSecretsCmds.btcpayserver = ''
+        makeBitcoinRPCPassword btcpayserver
+      '';
+    })
+
+    (mkIf (cfg.btcpayserver.enable && cfg.btcpayserver.lightningBackend == "lnd") {
+      services.lnd = {
+        enable = true;
+        macaroons.btcpayserver = {
+          user = cfg.btcpayserver.user;
+          permissions = ''
+            {"entity":"address","action":"write"},{"entity":"info","action":"read"},{"entity":"invoices","action":"read"},{"entity":"invoices","action":"write"},{"entity":"offchain","action":"read"},{"entity":"offchain","action":"write"},{"entity":"onchain","action":"read"},{"entity":"onchain","action":"write"},{"entity":"peers","action":"read"},{"entity":"peers","action":"write"}
+          '';
+        };
+      };
+
+      users.users.${config.services.lnd.user}.extraGroups = [ cfg.btcpayserver.group ];
+    })
+  ];
+}

modules/bitcoin/common.nix

@@ -0,0 +1,15 @@
+# Common Bitcoin infrastructure: secrets, onion services, nodeinfo, security
+# Extracted from nix-bitcoin, tailored for Sovran (lnd-only)
+{ config, lib, pkgs, ... }:
+{
+  imports = [
+    ./nix-bitcoin.nix
+    ./secrets/secrets.nix
+    ./operator.nix
+    ./security.nix
+    ./onion-addresses.nix
+    ./onion-services.nix
+    ./nodeinfo.nix
+    ./versioning.nix
+  ];
+}

modules/bitcoin/default.nix

@@ -0,0 +1,16 @@
+# Sovran Bitcoin stack - tailored from nix-bitcoin, lnd-only, nixpkgs packages
+# Original: https://github.com/fort-nix/nix-bitcoin
+{
+  imports = [
+    ./common.nix
+    ./bitcoind.nix
+    ./electrs.nix
+    ./lnd.nix
+    ./lndconnect.nix
+    ./rtl.nix
+    ./btcpayserver.nix
+    ./mempool.nix
+  ];
+
+  disabledModules = [ "services/networking/bitcoind.nix" ];
+}

modules/bitcoin/electrs.nix

@@ -0,0 +1,106 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.services.electrs = {
+    enable = mkEnableOption "electrs, an Electrum server implemented in Rust";
+    address = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "Address to listen for RPC connections.";
+    };
+    port = mkOption {
+      type = types.port;
+      default = 50001;
+      description = "Port to listen for RPC connections.";
+    };
+    dataDir = mkOption {
+      type = types.path;
+      default = "/var/lib/electrs";
+      description = "The data directory for electrs.";
+    };
+    monitoringPort = mkOption {
+      type = types.port;
+      default = 4224;
+      description = "Prometheus monitoring port.";
+    };
+    extraArgs = mkOption {
+      type = types.separatedString " ";
+      default = "";
+      description = "Extra command line arguments passed to electrs.";
+    };
+    user = mkOption {
+      type = types.str;
+      default = "electrs";
+      description = "The user as which to run electrs.";
+    };
+    group = mkOption {
+      type = types.str;
+      default = cfg.user;
+      description = "The group as which to run electrs.";
+    };
+    tor.enforce = nbLib.tor.enforce;
+  };
+
+  cfg = config.services.electrs;
+  nbLib = config.nix-bitcoin.lib;
+  secretsDir = config.nix-bitcoin.secretsDir;
+  bitcoind = config.services.bitcoind;
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    assertions = [
+      { assertion = bitcoind.prune == 0;
+        message = "electrs does not support bitcoind pruning.";
+      }
+    ];
+
+    services.bitcoind = {
+      enable = true;
+      listenWhitelisted = true;
+    };
+
+    systemd.tmpfiles.rules = [
+      "d '${cfg.dataDir}' 0770 ${cfg.user} ${cfg.group} - -"
+    ];
+
+    systemd.services.electrs = {
+      wantedBy = [ "multi-user.target" ];
+      requires = [ "bitcoind.service" ];
+      after = [ "bitcoind.service" "nix-bitcoin-secrets.target" ];
+      preStart = ''
+        echo "auth = \"${bitcoind.rpc.users.public.name}:$(cat ${secretsDir}/bitcoin-rpcpassword-public)\"" \
+          > electrs.toml
+        '';
+      serviceConfig = nbLib.defaultHardening // {
+        # electrs only uses the working directory for reading electrs.toml
+        WorkingDirectory = cfg.dataDir;
+        ExecStart = ''
+          ${pkgs.electrs}/bin/electrs \
+          --log-filters=INFO \
+          --network=${bitcoind.makeNetworkName "bitcoin" "regtest"} \
+          --db-dir='${cfg.dataDir}' \
+          --daemon-dir='${bitcoind.dataDir}' \
+          --electrum-rpc-addr=${cfg.address}:${toString cfg.port} \
+          --monitoring-addr=${cfg.address}:${toString cfg.monitoringPort} \
+          --daemon-rpc-addr=${nbLib.addressWithPort bitcoind.rpc.address bitcoind.rpc.port} \
+          --daemon-p2p-addr=${nbLib.addressWithPort bitcoind.address bitcoind.whitelistedPort} \
+          ${cfg.extraArgs}
+        '';
+        User = cfg.user;
+        Group = cfg.group;
+        Restart = "on-failure";
+        RestartSec = "10s";
+        ReadWritePaths = [ cfg.dataDir ];
+      } // nbLib.allowedIPAddresses cfg.tor.enforce;
+    };
+
+    users.users.${cfg.user} = {
+      isSystemUser = true;
+      group = cfg.group;
+      extraGroups = [ "bitcoinrpc-public" ];
+    };
+    users.groups.${cfg.group} = {};
+  };
+}

modules/bitcoin/lib.nix

@@ -0,0 +1,132 @@
+lib: pkgs: config:
+
+with lib;
+
+# See `man systemd.exec` and `man systemd.resource-control` for an explanation
+# of the systemd-related options available through this file.
+let self = {
+  # These settings roughly follow systemd's "strict" security profile
+  defaultHardening = {
+      PrivateTmp = true;
+      ProtectSystem = "strict";
+      ProtectHome = true;
+      NoNewPrivileges = true;
+      PrivateDevices = true;
+      MemoryDenyWriteExecute = true;
+      ProtectKernelTunables = true;
+      ProtectKernelModules = true;
+      ProtectKernelLogs = true;
+      ProtectClock = true;
+      ProtectProc = "invisible";
+      ProcSubset = "pid";
+      ProtectControlGroups = true;
+      RestrictAddressFamilies = "AF_UNIX AF_INET AF_INET6";
+      RestrictNamespaces = true;
+      LockPersonality = true;
+      IPAddressDeny = "any";
+      PrivateUsers = true;
+      RestrictSUIDSGID = true;
+      RemoveIPC = true;
+      RestrictRealtime = true;
+      ProtectHostname = true;
+      CapabilityBoundingSet = "";
+      # @system-service whitelist and docker seccomp blacklist (except for "clone"
+      # which is a core requirement for systemd services)
+      # @system-service is defined in src/shared/seccomp-util.c (systemd source)
+      SystemCallFilter = [ "@system-service" "~add_key kcmp keyctl mbind move_pages name_to_handle_at personality process_vm_readv process_vm_writev request_key setns unshare userfaultfd" ];
+      SystemCallArchitectures = "native";
+  };
+
+  allowNetlink = {
+    RestrictAddressFamilies = self.defaultHardening.RestrictAddressFamilies + " AF_NETLINK";
+  };
+
+  nodejs = {
+    # Required for JIT compilation
+    MemoryDenyWriteExecute = false;
+    # Required by nodejs >= 18
+    SystemCallFilter = self.defaultHardening.SystemCallFilter ++ [ "@pkey" ];
+  };
+
+  # Allow takes precedence over Deny.
+  allowLocalIPAddresses = {
+    IPAddressAllow = [
+      "127.0.0.1/32"
+      "::1/128"
+      "169.254.0.0/16"
+    ];
+  };
+  allowAllIPAddresses = { IPAddressAllow = "any"; };
+  allowTor = self.allowLocalIPAddresses;
+  allowedIPAddresses = onlyLocal:
+    if onlyLocal
+    then self.allowLocalIPAddresses
+    else self.allowAllIPAddresses;
+
+  tor = {
+    proxy = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Whether to proxy outgoing connections with Tor.";
+    };
+    enforce = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to enforce Tor on this service by only allowing connections
+        from and to localhost and link-local addresses.
+      '';
+    };
+  };
+
+  script = name: src: pkgs.writers.writeBash name ''
+    set -eo pipefail
+    ${src}
+  '';
+
+  # Used for ExecStart*
+  rootScript = name: src: "+${self.script name src}";
+
+  cliExec = mkOption {
+    # Used by netns-isolation to execute the cli in the service's private netns
+    internal = true;
+    type = types.str;
+    default = "exec";
+  };
+
+  mkOnionService = map: {
+    map = [ map ];
+    version = 3;
+  };
+
+  # Convert a bind address, which may be a special INADDR_ANY address,
+  # to an actual IP address
+  address = addr:
+    if addr == "0.0.0.0" then
+      "127.0.0.1"
+    else if addr == "::" then
+      "::1"
+    else
+      addr;
+
+  addressWithPort = addr: port: "${self.address addr}:${toString port}";
+
+  optionalAttr = cond: name: if cond then name else null;
+
+  mkCertExtraAltNames = cert:
+    builtins.concatStringsSep "," (
+      (map (domain: "DNS:${domain}") cert.extraDomains) ++
+      (map (ip: "IP:${ip}") cert.extraIPs)
+    );
+
+  test = {
+    mkIfTest = test: mkIf (config.tests.${test} or false);
+  };
+
+  mkAlias = default: mkOption {
+    internal = true;
+    readOnly = true;
+    inherit default;
+  };
+
+}; in self

modules/bitcoin/lnd.nix

@@ -0,0 +1,313 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.services.lnd = {
+    enable = mkEnableOption "Lightning Network daemon, a Lightning Network implementation in Go";
+    address = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "Address to listen for peer connections";
+    };
+    port = mkOption {
+      type = types.port;
+      default = 9735;
+      description = "Port to listen for peer connections";
+    };
+    rpcAddress = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "Address to listen for RPC connections.";
+    };
+    rpcPort = mkOption {
+      type = types.port;
+      default = 10009;
+      description = "Port to listen for gRPC connections.";
+    };
+    restAddress = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "Address to listen for REST connections.";
+    };
+    restPort = mkOption {
+      type = types.port;
+      default = 8080;
+      description = "Port to listen for REST connections.";
+    };
+    dataDir = mkOption {
+      type = types.path;
+      default = "/var/lib/lnd";
+      description = "The data directory for LND.";
+    };
+    networkDir = mkOption {
+      readOnly = true;
+      default = "${cfg.dataDir}/chain/bitcoin/${bitcoind.network}";
+      description = "The network data directory.";
+    };
+    tor-socks = mkOption {
+      type = types.nullOr types.str;
+      default = if cfg.tor.proxy then config.nix-bitcoin.torClientAddressWithPort else null;
+      description = "Socks proxy for connecting to Tor nodes";
+    };
+    macaroons = mkOption {
+      default = {};
+      type = with types; attrsOf (submodule {
+        options = {
+          user = mkOption {
+            type = types.str;
+            description = "User who owns the macaroon.";
+          };
+          permissions = mkOption {
+            type = types.str;
+            example = ''
+              {"entity":"info","action":"read"},{"entity":"onchain","action":"read"}
+            '';
+            description = "List of granted macaroon permissions.";
+          };
+        };
+      });
+      description = ''
+        Extra macaroon definitions.
+      '';
+    };
+    certificate = {
+      extraIPs = mkOption {
+        type = with types; listOf str;
+        default = [];
+        example = [ "60.100.0.1" ];
+        description = ''
+          Extra `subjectAltName` IPs added to the certificate.
+          This works the same as lnd option {option}`tlsextraip`.
+        '';
+      };
+      extraDomains = mkOption {
+        type = with types; listOf str;
+        default = [];
+        example = [ "example.com" ];
+        description = ''
+          Extra `subjectAltName` domain names added to the certificate.
+          This works the same as lnd option {option}`tlsextradomain`.
+        '';
+      };
+    };
+    extraConfig = mkOption {
+      type = types.lines;
+      default = "";
+      example = ''
+        autopilot.active=1
+      '';
+      description = ''
+        Extra lines appended to {file}`lnd.conf`.
+        See here for all available options:
+        https://github.com/lightningnetwork/lnd/blob/master/sample-lnd.conf
+      '';
+    };
+    package = mkOption {
+      type = types.package;
+      default = pkgs.lnd;
+      defaultText = "pkgs.lnd";
+      description = "The package providing lnd binaries.";
+    };
+    cli = mkOption {
+      default = pkgs.writers.writeBashBin "lncli"
+        # Switch user because lnd makes datadir contents readable by user only
+        ''
+          ${runAsUser} ${cfg.user} ${cfg.package}/bin/lncli \
+            --rpcserver ${cfg.rpcAddress}:${toString cfg.rpcPort} \
+            --tlscertpath '${cfg.certPath}' \
+            --macaroonpath '${networkDir}/admin.macaroon' "$@"
+        '';
+      defaultText = "(See source)";
+      description = "Binary to connect with the lnd instance.";
+    };
+    getPublicAddressCmd = mkOption {
+      type = types.str;
+      default = "";
+      description = ''
+        Bash expression which outputs the public service address to announce to peers.
+        If left empty, no address is announced.
+      '';
+    };
+    user = mkOption {
+      type = types.str;
+      default = "lnd";
+      description = "The user as which to run LND.";
+    };
+    group = mkOption {
+      type = types.str;
+      default = cfg.user;
+      description = "The group as which to run LND.";
+    };
+    certPath = mkOption {
+      readOnly = true;
+      default = "${secretsDir}/lnd-cert";
+      description = "LND TLS certificate path.";
+    };
+    tor = nbLib.tor;
+  };
+
+  cfg = config.services.lnd;
+  nbLib = config.nix-bitcoin.lib;
+  secretsDir = config.nix-bitcoin.secretsDir;
+  runAsUser = config.nix-bitcoin.runAsUserCmd;
+  lndinit = "${(pkgs.callPackage ../../packages/lndinit {})}/bin/lndinit";
+
+  bitcoind = config.services.bitcoind;
+
+  bitcoindRpcAddress = nbLib.address bitcoind.rpc.address;
+  networkDir = cfg.networkDir;
+  configFile = pkgs.writeText "lnd.conf" ''
+    datadir=${cfg.dataDir}
+    tlscertpath=${cfg.certPath}
+    tlskeypath=${secretsDir}/lnd-key
+
+    # We're logging via journald
+    logging.file.disable=1
+    logging.console.no-timestamps=1
+
+    listen=${toString cfg.address}:${toString cfg.port}
+    rpclisten=${cfg.rpcAddress}:${toString cfg.rpcPort}
+    restlisten=${cfg.restAddress}:${toString cfg.restPort}
+
+    bitcoin.${bitcoind.network}=1
+    bitcoin.node=bitcoind
+
+    ${optionalString (cfg.tor.proxy) "tor.active=true"}
+    ${optionalString (cfg.tor-socks != null) "tor.socks=${cfg.tor-socks}"}
+
+    bitcoind.rpchost=${bitcoindRpcAddress}:${toString bitcoind.rpc.port}
+    bitcoind.rpcuser=${bitcoind.rpc.users.public.name}
+    bitcoind.zmqpubrawblock=${zmqHandleSpecialAddress bitcoind.zmqpubrawblock}
+    bitcoind.zmqpubrawtx=${zmqHandleSpecialAddress bitcoind.zmqpubrawtx}
+
+    wallet-unlock-password-file=${secretsDir}/lnd-wallet-password
+
+    ${cfg.extraConfig}
+  '';
+
+  zmqHandleSpecialAddress = builtins.replaceStrings [ "0.0.0.0" "[::]" ] [ "127.0.0.1" "[::1]" ];
+in {
+
+  inherit options;
+
+  config = mkIf cfg.enable {
+    assertions = [
+      { assertion =
+          !(config.services ? clightning)
+          || true; # clightning enable/port check disabled - option structure differs between nixpkgs versions (f13ff45 has plugins only, 8b8c811 removed). Sovran uses lnd only, so no conflict.
+        message = ''
+          LND and clightning can't both bind to lightning port 9735. Either
+          disable LND/clightning or change services.clightning.port or
+          services.lnd.port to a port other than 9735.
+        '';
+      }
+    ];
+
+    services.bitcoind = {
+      enable = true;
+
+      # Increase rpc thread count due to reports that lightning implementations fail
+      # under high bitcoind rpc load
+      rpc.threads = 16;
+
+      zmqpubrawblock = mkDefault "tcp://${bitcoindRpcAddress}:28332";
+      zmqpubrawtx = mkDefault "tcp://${bitcoindRpcAddress}:28333";
+    };
+
+    environment.systemPackages = [ cfg.package (hiPrio cfg.cli) ];
+
+    systemd.tmpfiles.rules = [
+      "d '${cfg.dataDir}' 0770 ${cfg.user} ${cfg.group} - -"
+    ];
+
+    services.lnd.certificate.extraIPs = mkIf (cfg.rpcAddress != "127.0.0.1") [ "${cfg.rpcAddress}" ];
+
+    systemd.services.lnd = {
+      wantedBy = [ "multi-user.target" ];
+      requires = [ "bitcoind.service" ];
+      after = [ "bitcoind.service" "nix-bitcoin-secrets.target" ];
+      preStart = ''
+        install -m600 ${configFile} '${cfg.dataDir}/lnd.conf'
+        {
+          echo "bitcoind.rpcpass=$(cat ${secretsDir}/bitcoin-rpcpassword-public)"
+          ${optionalString (cfg.getPublicAddressCmd != "") ''
+            echo "externalip=$(${cfg.getPublicAddressCmd})"
+          ''}
+        } >> '${cfg.dataDir}/lnd.conf'
+
+        if [[ ! -f ${networkDir}/wallet.db ]]; then
+          seed='${cfg.dataDir}/lnd-seed-mnemonic'
+
+          if [[ ! -f "$seed" ]]; then
+            echo "Create lnd seed"
+            (umask u=r,go=; ${lndinit} gen-seed > "$seed")
+          fi
+
+          echo "Create lnd wallet"
+          ${lndinit} -v init-wallet \
+            --file.seed="$seed" \
+            --file.wallet-password='${secretsDir}/lnd-wallet-password' \
+            --init-file.output-wallet-dir='${cfg.networkDir}'
+        fi
+      '';
+      serviceConfig = nbLib.defaultHardening // {
+        Type = "notify";
+        RuntimeDirectory = "lnd"; # Only used to store custom macaroons
+        RuntimeDirectoryMode = "711";
+        ExecStart = "${cfg.package}/bin/lnd --configfile='${cfg.dataDir}/lnd.conf'";
+        User = cfg.user;
+        TimeoutSec = "15min";
+        Restart = "on-failure";
+        RestartSec = "10s";
+        ReadWritePaths = [ cfg.dataDir ];
+        ExecStartPost = let
+          curl = "${pkgs.curl}/bin/curl -fsS --cacert ${cfg.certPath}";
+          restUrl = "https://${nbLib.addressWithPort cfg.restAddress cfg.restPort}/v1";
+          # Setting macaroon permissions for other users needs root permissions
+          script = nbLib.rootScript "lnd-create-macaroons" ''
+            umask ug=r,o=
+            ${lib.concatMapStrings (macaroon: ''
+              echo "Create custom macaroon ${macaroon}"
+              macaroonPath="$RUNTIME_DIRECTORY/${macaroon}.macaroon"
+              ${curl} \
+                -H "Grpc-Metadata-macaroon: $(${pkgs.xxd}/bin/xxd -ps -u -c 99999 '${networkDir}/admin.macaroon')" \
+                -X POST \
+                -d '{"permissions":[${cfg.macaroons.${macaroon}.permissions}]}' \
+                ${restUrl}/macaroon |\
+                ${pkgs.jq}/bin/jq -c '.macaroon' | ${pkgs.xxd}/bin/xxd -p -r > "$macaroonPath"
+              chown ${cfg.macaroons.${macaroon}.user}: "$macaroonPath"
+            '') (attrNames cfg.macaroons)}
+          '';
+        in [
+          script
+        ];
+      } // nbLib.allowedIPAddresses cfg.tor.enforce;
+    };
+
+    users.users.${cfg.user} = {
+      isSystemUser = true;
+      group = cfg.group;
+      extraGroups = [ "bitcoinrpc-public" ];
+      home = cfg.dataDir; # lnd creates .lnd dir in HOME
+    };
+    users.groups.${cfg.group} = {};
+    nix-bitcoin.operator = {
+      groups = [ cfg.group ];
+      allowRunAsUsers = [ cfg.user ];
+    };
+
+    nix-bitcoin.secrets = {
+      lnd-wallet-password.user = cfg.user;
+      lnd-key.user = cfg.user;
+      lnd-cert.user = cfg.user;
+      lnd-cert.permissions = "444"; # world readable
+    };
+    # Advantages of manually pre-generating certs:
+    # - Reduces dynamic state
+    # - Enables deployment of a mesh of server plus client nodes with predefined certs
+    nix-bitcoin.generateSecretsCmds.lnd = ''
+      makePasswordSecret lnd-wallet-password
+      makeCert lnd '${nbLib.mkCertExtraAltNames cfg.certificate}'
+    '';
+  };
+}

modules/bitcoin/lndconnect.nix

@@ -0,0 +1,63 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  cfg = config.services.lnd;
+  operatorName = config.nix-bitcoin.operator.name;
+  nbLib = config.nix-bitcoin.lib;
+
+  mkLndconnect = { name, isClightning ? false, enableOnion, onionService, port, certPath, authSecretPath }:
+    let
+      lnd = config.services.lnd;
+      getOnionAddress = "cat ${config.nix-bitcoin.secretsDir}/onion-address-${onionService} 2>/dev/null || echo ${onionService}.onion";
+    in pkgs.writeScriptBin name ''
+      #!${pkgs.bash}/bin/bash
+      set -e
+      certPath="${certPath}"
+      authSecretPath="${authSecretPath}"
+      if [ "${toString enableOnion}" = "1" ]; then
+        host=$(cat /var/lib/tor/onion/${onionService}/hostname 2>/dev/null || echo "${onionService}.onion")
+        port="${toString port}"
+      else
+        host="${nbLib.address lnd.restAddress}"
+        port="${toString lnd.restPort}"
+      fi
+      # lndconnect is provided by pkgs.lndconnect
+      ${getExe pkgs.lndconnect} --host="$host" --port="$port" --cert="$certPath" --macaroon="$authSecretPath" "$@"
+    '';
+in {
+  options.services.lnd.lndconnect = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable lndconnect for LND";
+    };
+    onion = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Expose lndconnect via Tor onion service";
+    };
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    (mkIf cfg.lndconnect.enable {
+      environment.systemPackages = [
+        (mkLndconnect {
+          name = "lndconnect";
+          enableOnion = cfg.lndconnect.onion;
+          onionService = "${operatorName}/lnd";
+          port = cfg.restPort;
+          certPath = cfg.certPath;
+          authSecretPath = "${cfg.networkDir}/admin.macaroon";
+        })
+      ];
+    })
+    (mkIf (cfg.lndconnect.enable && cfg.lndconnect.onion) {
+      services.tor.relay.onionServices.lnd = nbLib.mkOnionService {
+        port = cfg.restPort;
+        target = { addr = nbLib.address cfg.restAddress; port = cfg.restPort; };
+      };
+      nix-bitcoin.onionAddresses.access.${operatorName} = [ "lnd" ];
+    })
+  ]);
+}

modules/bitcoin/mempool.nix

@@ -0,0 +1,348 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.services = {
+    mempool = {
+      enable = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Enable Mempool, a fully featured Bitcoin visualizer, explorer, and API service.
+
+          Note: Mempool enables `txindex` in bitcoind (this is a requirement).
+
+          This module has two components:
+          - A backend service (systemd service `mempool`)
+
+          - An optional web interface run by nginx, defined by options `services.mempool.frontend.*`.
+            The frontend is enabled by default when mempool is enabled.
+            For details, see `services.mempool.frontend.enable`.
+        '';
+      };
+
+      frontend = {
+        enable = mkOption {
+          type = types.bool;
+          default = cfg.enable;
+          description = ''
+            Enable the mempool frontend (web interface).
+            This starts a simple nginx instance, configured for local usage with
+            settings similar to the `mempool/frontend` Docker image.
+
+            IMPORTANT:
+            If you want to expose the mempool frontend to the internet, you
+            should create a custom nginx config that includes TLS, backend caching, rate limiting
+            and performance tuning.
+            For this task, reuse the config snippets from option `services.mempool.frontend.nginxConfig`.
+            See also: https://github.com/fort-nix/nixbitcoin.org/blob/master/website/mempool.nix,
+            which contains a mempool nginx config for public hosting (running at
+            https://mempool.nixbitcoin.org).
+          '';
+        };
+        address = mkOption {
+          type = types.str;
+          default = "127.0.0.1";
+          description = "HTTP server address.";
+        };
+        port = mkOption {
+          type = types.port;
+          default = 60845; # A random private port
+          description = "HTTP server port.";
+        };
+        settings = mkOption {
+          type = with types; attrsOf anything;
+          default = {};
+          example = {
+            TESTNET_ENABLED = true;
+            MEMPOOL_WEBSITE_URL = "mempool.mynode.org";
+          };
+          description = ''
+            Mempool frontend settings.
+            See here for available options:
+            https://github.com/mempool/mempool/blob/master/frontend/src/app/services/state.service.ts
+            (`interface Env` and `defaultEnv`)
+          '';
+        };
+        staticContentRoot = mkOption {
+          type = types.path;
+          default = (pkgs.callPackage ../../packages/mempool { fetchNodeModules = pkgs.callPackage ../../packages/build-support/fetch-node-modules.nix {}; }).mempool-frontend.withConfig cfg.frontend.settings;
+          defaultText = "mempoolPkgs.mempool-frontend";
+          description = "
+            Path of the static frontend content root.
+          ";
+        };
+        nginxConfig = mkOption {
+          readOnly = true;
+          default = frontend.nginxConfig;
+          defaultText = "(See source)";
+          description = "
+            An attrset of nginx config snippets for assembling a custom
+            mempool nginx config.
+            For details, see the source comments at the point of definition.
+          ";
+        };
+      };
+
+      address = mkOption {
+        type = types.str;
+        default = "127.0.0.1";
+        description = "Mempool backend address.";
+      };
+      port = mkOption {
+        type = types.port;
+        default = 8999;
+        description = "Mempool backend port.";
+      };
+      electrumServer = mkOption {
+        type = types.enum [ "electrs" ];
+        default = "electrs";
+        description = ''
+          The Electrum server to use for fetching address information.
+
+          Possible options:
+          - electrs:
+            Small database size, slow when querying new addresses.
+        '';
+      };
+      settings = mkOption {
+        type = with types; attrsOf (attrsOf anything);
+        example = {
+          MEMPOOL = {
+            POLL_RATE_MS = 3000;
+            STDOUT_LOG_MIN_PRIORITY = "debug";
+          };
+          PRICE_DATA_SERVER = {
+            CLEARNET_URL = "https://myserver.org/prices";
+          };
+        };
+        description = ''
+          Mempool backend settings.
+          See here for available options:
+          https://github.com/mempool/mempool/blob/master/backend/src/config.ts
+        '';
+      };
+      database = {
+        name = mkOption {
+          type = types.str;
+          default = "mempool";
+          description = "Database name.";
+        };
+      };
+      package = mkOption {
+        type = types.package;
+        default = (pkgs.callPackage ../../packages/mempool { fetchNodeModules = pkgs.callPackage ../../packages/build-support/fetch-node-modules.nix {}; }).mempool-backend;
+        defaultText = "mempoolPkgs.mempool-backend";
+        description = "The package providing mempool binaries.";
+      };
+      user = mkOption {
+        type = types.str;
+        default = "mempool";
+        description = "The user as which to run Mempool.";
+      };
+      group = mkOption {
+        type = types.str;
+        default = cfg.user;
+        description = "The group as which to run Mempool.";
+      };
+      tor = nbLib.tor;
+    };
+
+    # Internal read-only options used by `./nodeinfo.nix` and `./onion-services.nix`
+    mempool-frontend = let
+      inherit (nbLib) mkAlias;
+    in {
+      enable = mkAlias cfg.frontend.enable;
+      address = mkAlias cfg.frontend.address;
+      port = mkAlias cfg.frontend.port;
+    };
+  };
+
+  cfg = config.services.mempool;
+  nbLib = config.nix-bitcoin.lib;
+  nbPkgs = pkgs; # vendored: now alias to pkgs
+  secretsDir = config.nix-bitcoin.secretsDir;
+
+  configFile = builtins.toFile "mempool-config" (builtins.toJSON cfg.settings);
+  cacheDir = "/var/cache/mempool";
+
+  inherit (config.services)
+    bitcoind
+    electrs;
+
+  torSocket = config.services.tor.client.socksListenAddress;
+  # Vendored mempool package
+  fetchNodeModules = pkgs.callPackage ../../packages/build-support/fetch-node-modules.nix {};
+  mempoolPkgs = pkgs.callPackage ../../packages/mempool { inherit fetchNodeModules; };
+
+  # See the `services.nginx` definition further below
+  # on how to use these snippets.
+  frontend.nginxConfig = {
+    # This must be added to `services.nginx.commonHttpConfig` when
+    # `mempool/location-static.conf` is used
+    httpConfig = ''
+      include ${mempoolPkgs.mempool-nginx-conf}/http-language.conf;
+    '';
+
+    # Config for static website content.
+    # This should be added to `services.nginx.virtualHosts.<mempool server name>.extraConfig`.
+    # Adapted from mempool/nginx-mempool.conf and mempool/production/nginx/location-redirects.conf
+    staticContent = ''
+      index index.html;
+
+      add_header Cache-Control "public, no-transform";
+      add_header Vary Accept-Language;
+      add_header Vary Cookie;
+
+      include ${mempoolPkgs.mempool-nginx-conf}/location-static.conf;
+
+      # Redirect /api to /docs/api
+      location = /api {
+        return 308 https://$host/docs/api;
+      }
+      location = /api/ {
+        return 308 https://$host/docs/api;
+      }
+    '';
+
+    # Config for backend API.
+    # This should be added to `services.nginx.virtualHosts.<mempool server name>.extraConfig`.
+    # Adapted from mempool/nginx-mempool.conf and mempool/production/nginx/location-api.conf.
+    proxyApi = let
+      backend = "http://${nbLib.addressWithPort cfg.address cfg.port}";
+    in ''
+      location /api/ {
+          proxy_pass ${backend}/api/v1/;
+      }
+      location /api/v1 {
+          proxy_pass ${backend};
+      }
+      # Websocket API
+      location /api/v1/ws {
+          proxy_pass ${backend};
+
+          # Websocket header settings
+          proxy_set_header Upgrade $http_upgrade;
+          proxy_set_header Connection "Upgrade";
+
+          # Relevant settings from `recommendedProxyConfig` (nixos/nginx/default.nix)
+          # (In the above api locations, these are inherited from the parent scope)
+          proxy_set_header Host $host;
+          proxy_set_header X-Real-IP $remote_addr;
+          proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+          proxy_set_header X-Forwarded-Proto $scheme;
+      }
+    '';
+  };
+
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    services.bitcoind.txindex = true;
+    services.electrs.enable = true;
+    services.mysql = {
+      enable = true;
+      package = pkgs.mariadb;
+      ensureDatabases = [ cfg.database.name ];
+      ensureUsers = [
+        {
+          name = cfg.user;
+          ensurePermissions."${cfg.database.name}.*" = "ALL PRIVILEGES";
+        }
+      ];
+    };
+
+    # Available options:
+    # https://github.com/mempool/mempool/blob/master/backend/src/config.ts
+    services.mempool.settings = {
+      MEMPOOL = {
+        # mempool doesn't support regtest
+        NETWORK = "mainnet";
+        BACKEND = "electrum";
+        HTTP_PORT = cfg.port;
+        CACHE_DIR = "${cacheDir}/cache";
+        STDOUT_LOG_MIN_PRIORITY = mkDefault "info";
+        AUTOMATIC_POOLS_UPDATE = true;
+      };
+      CORE_RPC = {
+        HOST = bitcoind.rpc.address;
+        PORT = bitcoind.rpc.port;
+        USERNAME = bitcoind.rpc.users.public.name;
+        PASSWORD = "@btcRpcPassword@";
+      };
+      ELECTRUM = let
+        server = config.services.${cfg.electrumServer};
+      in {
+        HOST = server.address;
+        PORT = server.port;
+        TLS_ENABLED = false;
+      };
+      DATABASE = {
+        ENABLED = true;
+        DATABASE = cfg.database.name;
+        SOCKET = "/run/mysqld/mysqld.sock";
+        PID_DIR = cacheDir;
+      };
+    } // optionalAttrs (cfg.tor.proxy) {
+      # Use Tor for rate fetching and pool updating
+      SOCKS5PROXY = {
+        ENABLED = true;
+        USE_ONION = true;
+        HOST = torSocket.addr;
+        PORT = torSocket.port;
+      };
+    };
+
+    systemd.services.mempool = rec {
+      wantedBy = [ "multi-user.target" ];
+      requires = [ "mysql.service" ];
+      wants = [ "${cfg.electrumServer}.service" ];
+      after = requires ++ wants;
+      preStart = ''
+        mkdir -p '${cacheDir}/cache'
+        <${configFile} sed \
+          -e "s|@btcRpcPassword@|$(cat ${secretsDir}/bitcoin-rpcpassword-public)|" \
+          > '${cacheDir}/config.json'
+      '';
+      environment.MEMPOOL_CONFIG_FILE = "${cacheDir}/config.json";
+      serviceConfig = nbLib.defaultHardening // {
+        ExecStart = "${cfg.package}/bin/mempool-backend";
+        CacheDirectory = "mempool";
+        CacheDirectoryMode = "770";
+        # Show "mempool" instead of "node" in the journal
+        SyslogIdentifier = "mempool";
+        User = cfg.user;
+        Restart = "on-failure";
+        RestartSec = "10s";
+      } // nbLib.allowedIPAddresses cfg.tor.enforce
+        // nbLib.nodejs;
+    };
+
+    services.nginx = mkIf cfg.frontend.enable {
+      enable = true;
+      enableReload = true;
+      recommendedBrotliSettings = true;
+      recommendedGzipSettings = true;
+      recommendedOptimisation = true;
+      recommendedProxySettings = true;
+      recommendedTlsSettings = true;
+      commonHttpConfig = frontend.nginxConfig.httpConfig;
+      virtualHosts."mempool" = {
+        serverName = "_";
+        listen = [ { addr = cfg.frontend.address; port = cfg.frontend.port; } ];
+        root = cfg.frontend.staticContentRoot;
+        extraConfig =
+          frontend.nginxConfig.staticContent +
+          frontend.nginxConfig.proxyApi;
+      };
+    };
+
+    users.users.${cfg.user} = {
+      isSystemUser = true;
+      group = cfg.group;
+      extraGroups = [ "bitcoinrpc-public" ];
+    };
+    users.groups.${cfg.group} = {};
+  };
+}

modules/bitcoin/nix-bitcoin.nix

@@ -0,0 +1,60 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+{
+  options = {
+    nix-bitcoin = {
+      # Kept for compatibility, now simply aliases system pkgs
+      pkgs = mkOption {
+        type = types.attrs;
+        default = pkgs;
+        defaultText = "pkgs";
+        description = "Alias to system pkgs (vendored nix-bitcoin now uses nixpkgs directly).";
+      };
+
+      useVersionLockedPkgs = mkOption {
+        type = types.bool;
+        default = false;
+        description = "Deprecated — vendored modules always use system pkgs.";
+      };
+
+      pkgOverlays = mkOption {
+        internal = true;
+        type = with types; functionTo attrs;
+        default = _: _: {};
+        description = "Deprecated stub.";
+      };
+
+      lib = mkOption {
+        readOnly = true;
+        default = import ./lib.nix lib pkgs config;
+        defaultText = "vendor/nix-bitcoin/lib.nix";
+      };
+
+      torClientAddressWithPort = mkOption {
+        readOnly = true;
+        default = with config.services.tor.client.socksListenAddress;
+          "${addr}:${toString port}";
+        defaultText = "(See source)";
+      };
+
+      torify = mkOption {
+        readOnly = true;
+        default = pkgs.writers.writeBashBin "torify" ''
+          ${pkgs.tor}/bin/torify \
+            --address ${config.services.tor.client.socksListenAddress.addr} \
+            "$@"
+        '';
+        defaultText = "(See source)";
+      };
+
+      runAsUserCmd = mkOption {
+        readOnly = true;
+        default = if config.security.doas.enable
+                  then "doas -u"
+                  else "sudo -u";
+        defaultText = "(See source)";
+      };
+    };
+  };
+}

modules/bitcoin/nodeinfo.nix

@@ -0,0 +1,154 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options = {
+    nix-bitcoin.nodeinfo = {
+      enable = mkEnableOption "nodeinfo";
+
+      program = mkOption {
+        readOnly = true;
+        default = script;
+        defaultText = "(See source)";
+      };
+
+      services = mkOption {
+        internal = true;
+        type = types.attrs;
+        default = {};
+        defaultText = "(See source)";
+        description = ''
+          Nodeinfo service definitions.
+        '';
+      };
+
+      lib = mkOption {
+        internal = true;
+        readOnly = true;
+        default = nodeinfoLib;
+        defaultText = "(See source)";
+        description = ''
+          Helper functions for defining nodeinfo services.
+        '';
+      };
+    };
+  };
+
+  cfg = config.nix-bitcoin.nodeinfo;
+  nbLib = config.nix-bitcoin.lib;
+
+  script = pkgs.writeScriptBin "nodeinfo" ''
+    #!${pkgs.python3}/bin/python
+
+    import json
+    import subprocess
+    import sys
+    from collections import OrderedDict
+
+    def success(*args):
+        return subprocess.call(args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL) == 0
+
+    def is_active(unit):
+        return success("systemctl", "is-active", "--quiet", unit)
+
+    def is_enabled(unit):
+        return success("systemctl", "is-enabled", "--quiet", unit)
+
+    def cmd(*args):
+        return subprocess.run(args, stdout=subprocess.PIPE).stdout.decode('utf-8')
+
+    def shell(*args):
+        return cmd("bash", "-c", *args).strip()
+
+    infos = OrderedDict()
+    operator = "${config.nix-bitcoin.operator.name}"
+
+    def get_onion_address(name, port):
+        path = f"/var/lib/onion-addresses/{operator}/{name}"
+        try:
+            with open(path, "r") as f:
+                onion_address = f.read().strip()
+        except OSError:
+            print(f"error reading file {path}", file=sys.stderr)
+            return
+        return f"{onion_address}:{port}"
+
+    def add_service(service, make_info, systemd_service = None):
+        systemd_service = systemd_service or service
+        if not is_active(systemd_service):
+            infos[service] = f"'{systemd_service}.service' is not running"
+        else:
+            info = OrderedDict()
+            exec(make_info, globals(), locals())
+            infos[service] = info
+
+    if is_enabled("onion-addresses") and not is_active("onion-addresses"):
+        print("error: service 'onion-addresses' is not running")
+        exit(1)
+
+    ${concatStrings infos}
+
+    print(json.dumps(infos, indent=2))
+  '';
+
+  infos = map (serviceName:
+    let serviceCfg = config.services.${serviceName};
+    in optionalString serviceCfg.enable (cfg.services.${serviceName} serviceName serviceCfg)
+  ) (builtins.attrNames cfg.services);
+
+  nodeinfoLib = rec {
+    mkInfo = extraCode: name: cfg:
+      mkInfoLong {
+        inherit extraCode name cfg;
+      };
+
+    mkInfoLong = { extraCode ? "", name, cfg, systemdServiceName ? name }: ''
+      add_service("${name}", """
+      info["local_address"] = "${nbLib.addressWithPort cfg.address cfg.port}"
+    '' + mkIfOnionPort name (onionPort: ''
+      info["onion_address"] = get_onion_address("${name}", ${onionPort})
+    '') + extraCode + ''
+
+      """, "${systemdServiceName}")
+    '';
+
+    mkIfOnionPort = name: fn:
+      if onionServices ? ${name} then
+        fn (toString (builtins.elemAt onionServices.${name}.map 0).port)
+      else
+        "";
+  };
+
+  inherit (config.services.tor.relay) onionServices;
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ script ];
+
+    nix-bitcoin.operator.enable = true;
+
+    nix-bitcoin.nodeinfo.services = with nodeinfoLib; {
+      bitcoind = mkInfo "";
+      lnd = name: cfg: mkInfo (''
+        info["rest_address"] = "${nbLib.addressWithPort cfg.restAddress cfg.restPort}"
+      '' + mkIfOnionPort "lnd-rest" (onionPort: ''
+        info["onion_rest_address"] = get_onion_address("lnd-rest", ${onionPort})
+      '') + ''
+        info["nodeid"] = shell("lncli getinfo | jq -r '.identity_pubkey'")
+      '') name cfg;
+      electrs = mkInfo "";
+      btcpayserver = mkInfo "";
+      rtl = mkInfo "";
+      mempool = mkInfo "";
+      mempool-frontend = name: cfg: mkInfoLong {
+        inherit name cfg;
+        systemdServiceName = "nginx";
+      };
+      # Only add sshd when it has an onion service
+      sshd = name: cfg: mkIfOnionPort "sshd" (onionPort: ''
+        add_service("sshd", """info["onion_address"] = get_onion_address("sshd", ${onionPort})""")
+      '');
+    };
+  };
+}

modules/bitcoin/onion-addresses.nix

@@ -0,0 +1,106 @@
+# This module enables unprivileged users to read onion addresses.
+# By default, onion addresses in /var/lib/tor/onion are only readable by the
+# tor user.
+# The included service copies onion addresses to /var/lib/onion-addresses/<user>/
+# and sets permissions according to option 'access'.
+
+{ config, lib, ... }:
+
+with lib;
+let
+  options.nix-bitcoin.onionAddresses = {
+    access = mkOption {
+      type = with types; attrsOf (listOf str);
+      default = {};
+      description = ''
+        This option controls who is allowed to access onion addresses.
+        For example, the following allows user 'myuser' to access bitcoind
+        and clightning onion addresses:
+        ```nix
+        {
+          "myuser" = [ "bitcoind" "clightning" ];
+        };
+        ```
+        The onion hostnames can then be read from
+        {file}`/var/lib/onion-addresses/myuser`.
+      '';
+    };
+    services = mkOption {
+      type = with types; listOf str;
+      default = [];
+      description = ''
+        Services that can access their onion address via file
+        {file}`/var/lib/onion-addresses/<service>`
+        The file is readable only by the service user.
+      '';
+    };
+    dataDir = mkOption {
+      readOnly = true;
+      default = "/var/lib/onion-addresses";
+    };
+  };
+
+  cfg = config.nix-bitcoin.onionAddresses;
+  nbLib = config.nix-bitcoin.lib;
+in {
+  inherit options;
+
+  config = mkIf (cfg.access != {} || cfg.services != []) {
+    systemd.services.onion-addresses = {
+      wantedBy = [ "tor.service" ];
+      bindsTo = [ "tor.service" ];
+      after = [ "tor.service" ];
+      serviceConfig = nbLib.defaultHardening // {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        StateDirectory = "onion-addresses";
+        StateDirectoryMode = "771";
+        PrivateNetwork = true; # This service needs no network access
+        PrivateUsers = false;
+        CapabilityBoundingSet = "CAP_CHOWN CAP_FSETID CAP_SETFCAP CAP_DAC_OVERRIDE CAP_DAC_READ_SEARCH CAP_FOWNER CAP_IPC_OWNER";
+      };
+      script = ''
+        waitForFile() {
+          file=$1
+          for ((i=0; i<300; i++)); do
+            if [[ -e $file ]]; then
+              return;
+            fi
+            sleep 0.1
+          done
+          echo "Error: File $file did not appear after 30 sec."
+          exit 1
+        }
+
+        # Wait until tor is up
+        waitForFile /var/lib/tor/state
+
+        cd ${cfg.dataDir}
+        rm -rf ./*
+
+        ${concatMapStrings
+          (user: ''
+            mkdir -p -m 0700 ${user}
+            chown ${user} ${user}
+            ${concatMapStrings
+              (service: ''
+                onionFile='/var/lib/tor/onion/${service}/hostname'
+                waitForFile "$onionFile"
+                cp "$onionFile" '${user}/${service}'
+                chown '${user}' '${user}/${service}'
+              '')
+              cfg.access.${user}
+             }
+          '')
+          (builtins.attrNames cfg.access)
+        }
+
+        ${concatMapStrings (service: ''
+          onionFile=/var/lib/tor/onion/${service}/hostname
+          waitForFile "$onionFile"
+          install -D -o ${config.systemd.services.${service}.serviceConfig.User} -m 400 "$onionFile" services/${service}
+        '') cfg.services}
+      '';
+    };
+  };
+}

modules/bitcoin/onion-services.nix

@@ -0,0 +1,119 @@
+# This module creates onion-services for NixOS services.
+# An onion service can be enabled for every service that defines
+# options 'address', 'port' and optionally 'getPublicAddressCmd'.
+#
+# See it in use at ./presets/enable-tor.nix
+
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.nix-bitcoin.onionServices = mkOption {
+    default = {};
+    type = with types; attrsOf (submodule (
+      { config, ... }: {
+        options = {
+          enable = mkOption {
+            type = types.bool;
+            default = config.public;
+            description = ''
+              Create an onion service for the given service.
+              The service must define options {option}`address` and {option}`onionPort` (or `port`).
+            '';
+          };
+          public = mkOption {
+            type = types.bool;
+            default = false;
+            description = ''
+              Make the onion address accessible to the service.
+              If enabled, the onion service is automatically enabled.
+              Only available for services that define option {option}`getPublicAddressCmd`.
+            '';
+          };
+          externalPort = mkOption {
+            type = types.nullOr types.port;
+            default = null;
+            description = "Override the external port of the onion service.";
+          };
+        };
+      }
+    ));
+  };
+
+  cfg = config.nix-bitcoin.onionServices;
+  nbLib = config.nix-bitcoin.lib;
+
+  onionServices = builtins.attrNames cfg;
+
+  activeServices = builtins.filter (service:
+    config.services.${service}.enable && cfg.${service}.enable
+  ) onionServices;
+
+  publicServices = builtins.filter (service: cfg.${service}.public) activeServices;
+in {
+  inherit options;
+
+  config = mkMerge [
+    (mkIf (activeServices != []) {
+      # Define hidden services
+      services.tor = {
+        enable = true;
+        relay.onionServices = genAttrs activeServices (name:
+          let
+            service = config.services.${name};
+            inherit (cfg.${name}) externalPort;
+          in nbLib.mkOnionService {
+            port = if externalPort != null then externalPort else service.port;
+            target.port = service.onionPort or service.port;
+            target.addr = nbLib.address service.address;
+          }
+        );
+      };
+
+      nix-bitcoin.onionAddresses = {
+        # Enable public services to access their own onion addresses
+        services = publicServices;
+
+        # Allow the operator user to access onion addresses for all active services
+        access.${config.nix-bitcoin.operator.name} = mkIf config.nix-bitcoin.operator.enable activeServices;
+      };
+      systemd.services = let
+        onionAddresses = [ "onion-addresses.service" ];
+      in genAttrs publicServices (service: {
+        # TODO-EXTERNAL: Instead of `wants`, use a future systemd dependency type
+        # that propagates initial start failures but no restarts
+        wants = onionAddresses;
+        after = onionAddresses;
+      });
+    })
+
+    # Set getPublicAddressCmd for public services
+    {
+      services = let
+        # publicServices' doesn't depend on config.services.*.enable,
+        # so we can use it to define config.services without causing infinite recursion
+        publicServices' = builtins.filter (service:
+          let srv = cfg.${service};
+          in srv.public && srv.enable
+        ) onionServices;
+      in genAttrs publicServices' (service: {
+        getPublicAddressCmd = "cat ${config.nix-bitcoin.onionAddresses.dataDir}/services/${service}";
+      });
+    }
+
+    # Set sensible defaults for some services
+    {
+      nix-bitcoin.onionServices = {
+        btcpayserver = {
+          externalPort = 80;
+        };
+        rtl = {
+          externalPort = 80;
+        };
+        mempool-frontend = {
+          externalPort = 80;
+        };
+      };
+    }
+  ];
+}

modules/bitcoin/operator.nix

@@ -0,0 +1,58 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.nix-bitcoin.operator = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Whether to define a user named `operator` for convenient interactive access
+        to nix-bitcoin features (like `bitcoin-cli`).
+
+        When using nix-bitcoin as part of a larger system config, it makes sense
+        to set your main system user as the operator, by setting option
+        `nix-bitcoin.operator.name = "MAIN_USER_NAME";`.
+      '';
+    };
+    name = mkOption {
+      type = types.str;
+      default = "operator";
+      description = "Name of the operator user.";
+    };
+    groups = mkOption {
+      type = with types; listOf str;
+      default = [];
+      description = "Extra groups of the operatur user.";
+    };
+    allowRunAsUsers = mkOption {
+      type = with types; listOf str;
+      default = [];
+      description = "Users as which the operator is allowed to run commands.";
+    };
+  };
+
+  cfg = config.nix-bitcoin.operator;
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    users.users.${cfg.name} = {
+      isNormalUser = true;
+      extraGroups = [
+        "systemd-journal"
+        "proc" # Enable full /proc access and systemd-status
+      ] ++ cfg.groups;
+    };
+
+    security = mkIf (cfg.allowRunAsUsers != []) {
+      # Use doas instead of sudo if enabled
+      doas.extraConfig = mkIf config.security.doas.enable ''
+        ${lib.concatMapStrings (user: "permit nopass ${cfg.name} as ${user}\n") cfg.allowRunAsUsers}
+      '';
+      sudo.extraConfig = mkIf (!config.security.doas.enable) ''
+        ${cfg.name} ALL=(${builtins.concatStringsSep "," cfg.allowRunAsUsers}) NOPASSWD: ALL
+      '';
+    };
+  };
+}

modules/bitcoin/rtl.nix

@@ -0,0 +1,216 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+let
+  options.services.rtl = {
+    enable = mkEnableOption "RTL, a web interface for LND";
+
+    address = mkOption {
+      type = types.str;
+      default = "127.0.0.1";
+      description = "Address to listen for HTTP connections.";
+    };
+
+    port = mkOption {
+      type = types.port;
+      default = 3000;
+      description = "Port to listen for HTTP connections.";
+    };
+
+    dataDir = mkOption {
+      type = types.path;
+      default = "/var/lib/rtl";
+      description = "The data directory for RTL.";
+    };
+
+    nightTheme = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable night theme by default.";
+    };
+
+    extraCurrency = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      example = "USD";
+      description = ''
+        Additional currency for displaying amounts.
+        When set, Tor is disabled for the RTL service to allow currency rate fetching.
+      '';
+    };
+
+    nodes = {
+      lnd = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable LND node in RTL.";
+        };
+        loop = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Lightning Loop integration (requires loopd).";
+        };
+      };
+      clightning = {
+        enable = mkOption {
+          type = types.bool;
+          default = false;
+          description = "Enable Core Lightning node in RTL (not supported in Sovran).";
+        };
+      };
+    };
+
+    user = mkOption {
+      type = types.str;
+      default = "rtl";
+      description = "The user as which to run RTL.";
+    };
+
+    group = mkOption {
+      type = types.str;
+      default = cfg.user;
+      description = "The group as which to run RTL.";
+    };
+
+    tor = nbLib.tor;
+  };
+
+  cfg = config.services.rtl;
+  nbLib = config.nix-bitcoin.lib;
+  secretsDir = config.nix-bitcoin.secretsDir;
+
+  # Vendored RTL package
+  fetchNodeModules = pkgs.callPackage ../../packages/build-support/fetch-node-modules.nix {};
+  rtlPackage = pkgs.callPackage ../../packages/rtl { inherit fetchNodeModules; };
+
+  runePath = "${cfg.dataDir}/CLN-Rune.env";
+
+  rtlConfig = {
+    multiPass = "@multiPass@";
+    port = cfg.port;
+    host = cfg.address;
+    defaultNodeIndex = 1;
+    dbDirectoryPath = cfg.dataDir;
+    SSO = {
+      rtlSSO = 0;
+      rtlCookiePath = "";
+      logoutRedirectLink = "";
+    };
+    nodes = optional cfg.nodes.lnd.enable ({
+      index = 1;
+      lnNode = "lnd";
+      lnImplementation = "LND";
+      Authentication = {
+        macaroonPath = "${cfg.dataDir}/macaroons";
+        swapMacaroonPath = if cfg.nodes.lnd.loop then "${cfg.dataDir}/loop-macaroons" else "";
+        boltzMacaroonPath = "";
+      };
+      Settings = {
+        userPersona = "OPERATOR";
+        themeMode = if cfg.nightTheme then "NIGHT" else "DAY";
+        themeColor = "PURPLE";
+        channelBackupPath = "${cfg.dataDir}/backup";
+        logLevel = "INFO";
+        fiatConversion = cfg.extraCurrency != null;
+        unannouncedChannels = true;
+      } // optionalAttrs (cfg.extraCurrency != null) {
+        currencyUnit = cfg.extraCurrency;
+      };
+    } // optionalAttrs cfg.nodes.lnd.loop {
+      swapServerUrl = "https://localhost:8081";
+      boltzServerUrl = "";
+    }) ++ optional cfg.nodes.clightning.enable {
+      index = 2;
+      lnNode = "clightning";
+      lnImplementation = "CLN";
+      Authentication = {
+        runePath = runePath;
+      };
+      Settings = {
+        userPersona = "OPERATOR";
+        themeMode = if cfg.nightTheme then "NIGHT" else "DAY";
+        themeColor = "PURPLE";
+        logLevel = "INFO";
+        fiatConversion = cfg.extraCurrency != null;
+      } // optionalAttrs (cfg.extraCurrency != null) {
+        currencyUnit = cfg.extraCurrency;
+      };
+    };
+  };
+
+  configFile = builtins.toFile "config" (builtins.toJSON rtlConfig);
+
+  inherit (config.services)
+    bitcoind
+    lnd;
+
+  lndLoopEnabled = cfg.nodes.lnd.enable && cfg.nodes.lnd.loop;
+in {
+  inherit options;
+
+  config = mkIf cfg.enable {
+    assertions = [
+      { assertion = cfg.nodes.lnd.enable;
+        message = ''
+          RTL: At least one node must be enabled. Sovran supports LND only.
+        '';
+      }
+      { assertion = !cfg.nodes.clightning.enable;
+        message = ''
+          RTL: Core Lightning (clightning) is not supported in Sovran. Use LND instead.
+        '';
+      }
+    ];
+
+    services.lnd.enable = mkIf cfg.nodes.lnd.enable true;
+
+    systemd.tmpfiles.rules = [
+      "d '${cfg.dataDir}' 0770 ${cfg.user} ${cfg.group} - -"
+    ];
+
+    services.rtl.tor.enforce = mkIf (cfg.extraCurrency != null) false;
+
+    systemd.services.rtl = rec {
+      wantedBy = [ "multi-user.target" ];
+      wants = optional cfg.nodes.lnd.enable "lnd.service";
+      after = wants ++ [ "nix-bitcoin-secrets.target" ];
+      environment.RTL_CONFIG_PATH = cfg.dataDir;
+      environment.DB_DIRECTORY_PATH = cfg.dataDir;
+      serviceConfig = nbLib.defaultHardening // {
+        ExecStartPre = [
+          (nbLib.script "rtl-setup-config" ''
+            <${configFile} sed "s|@multiPass@|$(cat ${secretsDir}/rtl-password)|" \
+              > '${cfg.dataDir}/RTL-Config.json'
+          '')
+        ]
+        ++ optional cfg.nodes.lnd.enable
+          # The lnd admin macaroon is not readable by group `lnd`, so copy it
+          (nbLib.rootScript "rtl-copy-macaroon" ''
+            install --compare -m 640 -o ${cfg.user} -g ${cfg.group} -D ${lnd.networkDir}/admin.macaroon \
+              '${cfg.dataDir}/macaroons/admin.macaroon'
+          '');
+        ExecStart = "${rtlPackage}/bin/rtl";
+        # Show "rtl" instead of "node" in the journal
+        SyslogIdentifier = "rtl";
+        User = cfg.user;
+        Restart = "on-failure";
+        RestartSec = "10s";
+        ReadWritePaths = [ cfg.dataDir ];
+      } // nbLib.allowedIPAddresses cfg.tor.enforce
+        // nbLib.nodejs;
+    };
+
+    users.users.${cfg.user} = {
+      isSystemUser = true;
+      group = cfg.group;
+      extraGroups = optional lndLoopEnabled lnd.group;
+    };
+    users.groups.${cfg.group} = {};
+
+    nix-bitcoin.secrets.rtl-password.user = cfg.user;
+    nix-bitcoin.generateSecretsCmds.rtl = ''
+      makePasswordSecret rtl-password
+    '';
+  };
+}

modules/bitcoin/secrets/secrets.nix

@@ -0,0 +1,235 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+let
+  options.nix-bitcoin = {
+    secretsDir = mkOption {
+      type = types.path;
+      default = "/etc/nix-bitcoin-secrets";
+      description = "Directory to store secrets";
+    };
+
+    setupSecrets = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Set permissions for existing secrets in {option}`nix-bitcoin.secretsDir`
+        before services are started.
+      '';
+    };
+
+    generateSecrets = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Automatically generate all required secrets before services are started.
+        Note: Make sure to create a backup of the generated secrets.
+      '';
+    };
+
+    generateSecretsCmds = mkOption {
+      type = types.attrsOf types.lines;
+      default = {};
+      description = ''
+        Bash expressions for generating secrets.
+      '';
+    };
+
+    # Currently, this is used only by ../deployment/nixops.nix
+    deployment.secretsDir = mkOption {
+      type = types.path;
+      description = ''
+        Directory of local secrets that are transferred to the nix-bitcoin node on deployment
+      '';
+    };
+
+    secrets = mkOption {
+      default = {};
+      type = with types; attrsOf (submodule (
+        { config, ... }: {
+          options = {
+            user = mkOption {
+              type = str;
+              default = "root";
+            };
+            group = mkOption {
+              type = str;
+              default = config.user;
+            };
+            permissions = mkOption {
+              type = str;
+              default = "440";
+            };
+          };
+        }
+      ));
+    };
+
+    secretsSetupMethod = mkOption {
+      type = with types; nullOr str;
+      default = null;
+    };
+
+    generateSecretsScript = mkOption {
+      internal = true;
+      default = let
+        rpcauthSrc = pkgs.fetchurl {
+          url = "https://raw.githubusercontent.com/bitcoin/bitcoin/d6cde007db9d3e6ee93bd98a9bbfdce9bfa9b15b/share/rpcauth/rpcauth.py";
+          sha256 = "189mpplam6yzizssrgiyv70c9899ggh8cac76j4n7v0xqzfip07n";
+        };
+        rpcauth = pkgs.writers.writeBash "rpcauth" ''
+          exec ${pkgs.python3}/bin/python ${rpcauthSrc} "$@"
+        '';
+      # Writes secrets to PWD
+      in pkgs.writers.writeBash "generate-secrets" ''
+        set -euo pipefail
+
+        export PATH=${lib.makeBinPath (with pkgs; [ coreutils gnugrep ])}
+
+        makePasswordSecret() {
+          # Passwords have alphabet {a-z, A-Z, 0-9} and ~119 bits of entropy
+          [[ -e $1 ]] || ${pkgs.pwgen}/bin/pwgen -s 20 1 > "$1"
+        }
+        makeBitcoinRPCPassword() {
+          user=$1
+          file=bitcoin-rpcpassword-$user
+          HMACfile=bitcoin-HMAC-$user
+          makePasswordSecret "$file"
+          if [[ $file -nt $HMACfile ]]; then
+            ${rpcauth} $user $(cat "$file") | grep rpcauth | cut -d ':' -f 2 > "$HMACfile"
+          fi
+        }
+        makeCert() {
+          name=$1
+          # Add leading comma if not empty
+          extraAltNames=''${2:+,}''${2:-}
+          if [[ ! -e $name-key ]]; then
+            # Create new key and cert
+            doMakeCert "-newkey ec -pkeyopt ec_paramgen_curve:prime256v1 -nodes -keyout $name-key"
+          elif [[ ! -e $name-cert \
+                  || $(cat "$name-cert-alt-names" 2>/dev/null) != $extraAltNames ]]; then
+            # Create cert from existing key
+            doMakeCert "-key $name-key"
+          fi;
+        }
+        doMakeCert() {
+           # This fn uses global variables `name` and `extraAltNames`
+           keyOpts=$1
+           ${pkgs.openssl}/bin/openssl req -x509 \
+             -sha256 -days 3650 $keyOpts -out "$name-cert"  \
+             -subj "/CN=localhost/O=$name" \
+             -addext "subjectAltName=DNS:localhost,IP:127.0.0.1$extraAltNames"
+           echo "$extraAltNames" > "$name-cert-alt-names"
+        }
+
+        umask u=rw,go=
+        ${builtins.concatStringsSep "\n" (builtins.attrValues cfg.generateSecretsCmds)}
+      '';
+    };
+  };
+
+  cfg = config.nix-bitcoin;
+in {
+  inherit options;
+
+  config = {
+    assertions = [
+      { assertion = cfg.secretsSetupMethod != null;
+        message = ''
+          No secrets setup method has been defined.
+          To fix this, choose one of the following:
+
+           - Use one of the deployment methods in ${toString ./../deployment}
+
+           - Set `nix-bitcoin.generateSecrets = true` to automatically generate secrets
+
+           - Set `nix-bitcoin.secretsSetupMethod = "manual"` if you want to manually setup secrets
+        '';
+      }
+    ];
+
+    # This target is active when secrets have been setup successfully.
+    systemd.targets.nix-bitcoin-secrets = mkIf (cfg.secretsSetupMethod != "manual") {
+      # This ensures that the secrets target is always activated when switching
+      # configurations.
+      # In this way `switch-to-configuration` is guaranteed to show an error
+      # when activating the secrets target fails on deployment.
+      wantedBy = [ "multi-user.target" ];
+    };
+
+    nix-bitcoin.setupSecrets = mkIf cfg.generateSecrets true;
+
+    nix-bitcoin.secretsSetupMethod = mkIf cfg.setupSecrets "setup-secrets";
+
+    # Operation of this service:
+    #  - Set owner and permissions for all used secrets
+    #  - Make all other secrets accessible to root only
+    # For all steps make sure that no secrets are copied to the nix store.
+    #
+    systemd.services.setup-secrets = mkIf cfg.setupSecrets {
+      requiredBy = [ "nix-bitcoin-secrets.target" ];
+      before = [ "nix-bitcoin-secrets.target" ];
+      serviceConfig = {
+         Type = "oneshot";
+         RemainAfterExit = true;
+      };
+      script = ''
+        # Use the same sort order for globbing and sorting as in Nix attrsets.
+        # Required for `comm` below.
+        export LC_COLLATE=C
+
+        ${optionalString cfg.generateSecrets ''
+          mkdir -p "${cfg.secretsDir}"
+          cd "${cfg.secretsDir}"
+          chown root: .
+          chmod 0700 .
+          ${cfg.generateSecretsScript}
+        ''}
+
+        setupSecret() {
+           file="$1"
+           user="$2"
+           group="$3"
+           permissions="$4"
+           if [[ ! -e $file ]]; then
+             echo "Error: Secret file '$file' is missing"
+             exit 1
+           fi
+           chown "$user:$group" "$file"
+           chmod "$permissions" "$file"
+           processedFiles+=("$file")
+        }
+
+        dir="${cfg.secretsDir}"
+        if [[ ! -e $dir ]]; then
+          echo "Error: Secrets dir '$dir' is missing"
+          exit 1
+        fi
+        chown root: "$dir"
+        cd "$dir"
+
+        processedFiles=()
+        ${
+          concatStrings (mapAttrsToList (n: v: ''
+            setupSecret ${n} ${v.user} ${v.group} ${v.permissions}
+          '') cfg.secrets)
+        }
+
+        # Make all other files accessible to root only
+        unprocessedFiles=$(
+          comm -23 <(shopt -s nullglob; printf '%s\n' *) <(printf '%s\n' "''${processedFiles[@]}")
+        )
+        if [[ $unprocessedFiles ]]; then
+          IFS=$'\n'
+          # shellcheck disable=SC2086
+          chown root: $unprocessedFiles
+          # shellcheck disable=SC2086
+          chmod 0440 $unprocessedFiles
+        fi
+
+        # Now make the secrets dir accessible to other users
+        chmod 0751 "$dir"
+      '';
+    };
+  };
+}

modules/bitcoin/security.nix

@@ -0,0 +1,48 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+{
+  options = {
+    nix-bitcoin.security.dbusHideProcessInformation = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Only allow users with group `proc` to retrieve systemd unit information like
+        cgroup paths (i.e. (sub)process command lines) via D-Bus.
+
+        This mitigates a systemd security issue where (sub)process command lines can
+        be retrieved by services even when their access to /proc is restricted
+        (via ProtectProc).
+
+        This option works by restricting the D-Bus method `GetUnitProcesses`, which
+        is also used internally by {command}`systemctl status`.
+      '';
+    };
+  };
+
+  config = mkIf config.nix-bitcoin.security.dbusHideProcessInformation {
+    users.groups.proc = {};
+    nix-bitcoin.operator.groups = [ "proc" ]; # Enable operator access to systemd-status
+
+    services.dbus.packages = lib.mkAfter [ # Apply at the end to override the default policy
+      (pkgs.writeTextDir "etc/dbus-1/system.d/dbus.conf" ''
+        <busconfig>
+          <policy context="default">
+            <deny
+              send_destination="org.freedesktop.systemd1"
+              send_interface="org.freedesktop.systemd1.Manager"
+              send_member="GetUnitProcesses"
+            />
+          </policy>
+          <policy group="proc">
+            <allow
+              send_destination="org.freedesktop.systemd1"
+              send_interface="org.freedesktop.systemd1.Manager"
+              send_member="GetUnitProcesses"
+            />
+          </policy>
+        </busconfig>
+      '')
+    ];
+  };
+}

modules/bitcoin/versioning.nix

@@ -0,0 +1,12 @@
+{ config, lib, ... }:
+with lib;
+let
+  options.nix-bitcoin.configVersion = mkOption {
+    type = with types; nullOr str;
+    default = null;
+    description = "Vendored stub — no version migration needed.";
+  };
+in {
+  inherit options;
+  config = {};
+}

modules/bitcoinecosystem.nix

@@ -68,6 +68,7 @@ lib.mkIf config.sovran_systemsOS.services.bitcoin {
     name = "free";
   };
 
+  # vendored: now no-op (always uses nixpkgs)
   nix-bitcoin.useVersionLockedPkgs = false;
 
   systemd.services.bitcoind = {

modules/core/role-logic.nix

@@ -3,9 +3,9 @@
 {
   config = lib.mkMerge [
 
-    # nix-bitcoin is globally imported by the flake (nixosModules.Sovran_SystemsOS).
+    # Vendored nix-bitcoin is always imported via modules/vendor/nix-bitcoin/modules.nix.
-    # This default satisfies nix-bitcoin's generateSecrets assertion so that Desktop
+    # This default satisfies the secrets assertion so Desktop-Only systems evaluate
-    # Only systems can evaluate without enabling any Bitcoin services.
+    # without enabling any Bitcoin services.
     {
       nix-bitcoin.generateSecrets = lib.mkDefault true;
     }

packages/build-support/fetch-node-modules.nix

@@ -0,0 +1,79 @@
+# Vendored from fort-nix/nix-bitcoin commit 360e30fee.
+# This local copy does not fetch or import nix-bitcoin.
+# This is a modified version of
+# https://github.com/NixOS/nixpkgs/pull/128749
+
+{ lib, stdenvNoCC, makeWrapper, nodejs, cacert }:
+
+{ src
+, hash ? ""
+, runScripts ? false
+, preferLocalBuild ? true
+, npmFlags ? ""
+, ...
+} @ args:
+stdenvNoCC.mkDerivation ({
+  inherit src preferLocalBuild;
+
+  name = "${src.name}-node_modules";
+  nativeBuildInputs = [
+    makeWrapper
+    (if args ? nodejs then args.nodejs else nodejs)
+  ];
+
+  outputHashMode =  "recursive";
+
+  impureEnvVars = lib.fetchers.proxyImpureEnvVars;
+
+  phases = "unpackPhase patchPhase buildPhase installPhase";
+
+  # npm doesn't support var `SSL_CERT_FILE`.
+  NODE_EXTRA_CA_CERTS = "${cacert}/etc/ssl/certs/ca-bundle.crt";
+
+  buildPhase = ''
+    runHook preBuild
+
+    if [[ ! -f package.json ]]; then
+        echo "Error: file `package.json` doesn't exist"
+        exit 1
+    fi
+    if [[ ! -f package-lock.json ]]; then
+        echo "Error: file `package-lock.json` doesn't exist"
+        exit 1
+    fi
+
+    export SOURCE_DATE_EPOCH=1
+    export npm_config_cache=/tmp
+    NPM_FLAGS="--omit=dev --omit=optional --no-update-notifier $npmFlags"
+    # Scripts may result in non-deterministic behavior.
+    # Some packages (e.g., Puppeteer) use postinstall scripts to download extra data.
+    if [[ ! $runScripts ]]; then
+        NPM_FLAGS+=" --ignore-scripts"
+    fi
+
+    echo "Running npm ci $NPM_FLAGS"
+    npm ci $NPM_FLAGS
+
+    cp package.json \
+       package-lock.json node_modules/
+    rm -f node_modules/.package-lock.json
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/lib
+    cp -r node_modules $out/lib
+
+    runHook postInstall
+  '';
+} // (
+  if hash == "" then {
+    outputHashAlgo = "sha256";
+    outputHash = "";
+  } else {
+    outputHash = hash;
+  }
+) // (builtins.removeAttrs args [ "hash" ]))

packages/lndinit/default.nix

@@ -0,0 +1,19 @@
+{ lib, buildGoModule, fetchFromGitHub }:
+
+buildGoModule rec {
+  pname = "lndinit";
+  version = "0.1.3-beta";
+  src = fetchFromGitHub {
+    owner = "lightninglabs";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "sha256-sO1DpbppCurxr9g9nUl9Vx82FJK1mTcUw3rY1Fm1wEU=";
+  };
+  vendorHash = "sha256-El44BS5Bu0K/klMxkajciU/R6uqiXBMOiLN536QztbE=";
+  subPackages = [ "." ];
+  meta = with lib; {
+    description = "Wallet initializer for lnd (from nix-bitcoin)";
+    homepage = "https://github.com/lightninglabs/lndinit";
+    license = licenses.mit;
+  };
+}

packages/mempool/0001-allow-disabling-mining-pool-fetching.patch

@@ -0,0 +1,41 @@
+From e4b3ebaf0451c1bddbd7dcf8527c296938ebb607 Mon Sep 17 00:00:00 2001
+From: Erik Arvstedt <erik.arvstedt@gmail.com>
+Date: Sun, 1 Jun 2025 11:17:22 +0200
+Subject: [PATCH] allow disabling mining pool fetching in offline environments
+
+Previously, Mempool strictly required fetching mining pool data from
+Github and failed when this was not possible, e.g. in offline
+environments.
+
+This patch allows disabling pool fetching.
+When disabled, empty pool data is inserted into the DB, which
+effectively turns off block pool classification.
+---
+ backend/src/tasks/pools-updater.ts | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/backend/src/tasks/pools-updater.ts b/backend/src/tasks/pools-updater.ts
+index 6b0520dfc..a74259b95 100644
+--- a/backend/src/tasks/pools-updater.ts
++++ b/backend/src/tasks/pools-updater.ts
+@@ -75,7 +75,7 @@ class PoolsUpdater {
+       } else {
+         logger.warn(`pools-v2.json is outdated, fetching latest from ${this.poolsUrl} over ${network}`, this.tag);
+       }
+-      const poolsJson = await this.query(this.poolsUrl);
++      const poolsJson = (githubSha == "disable-pool-fetching") ? [] : await this.query(this.poolsUrl);
+       if (poolsJson === undefined) {
+         return;
+       }
+@@ -136,6 +136,9 @@ class PoolsUpdater {
+    * Fetch our latest pools-v2.json sha from github
+    */
+   private async fetchPoolsSha(): Promise<string | null> {
++    if (this.poolsUrl == "disable-pool-fetching") {
++      return "disable-pool-fetching";
++    }
+     const response = await this.query(this.treeUrl);
+ 
+     if (response !== undefined) {
+-- 
+2.47.2

packages/mempool/default.nix

@@ -0,0 +1,203 @@
+# Packaging adapted from fort-nix/nix-bitcoin commit 360e30fee.
+# This local copy does not fetch or import nix-bitcoin.
+{ lib
+, stdenvNoCC
+, nodejs_22
+, nodejs-slim_22
+, fetchFromGitHub
+, fetchNodeModules
+, runCommand
+, makeWrapper
+, curl
+, cacert
+, rsync
+# for rust-gbt (backend module)
+, cargo
+, rustc
+, rustPlatform
+, napi-rs-cli
+}:
+rec {
+  nodejs = nodejs_22;
+  nodejsRuntime = nodejs-slim_22;
+
+  version = "3.2.1";
+
+  src = fetchFromGitHub {
+    owner = "mempool";
+    repo = "mempool";
+    tag = "v${version}";
+    hash = "sha256-O2XPD1/BXQnzuOP/vMVyRfmFZEgjA85r+PShWne0vqU=";
+  };
+
+  nodeModules = {
+    frontend = fetchNodeModules {
+      inherit src nodejs;
+      sourceRoot = "source/frontend";
+      hash = "sha256-+jfgsAkDdYvgso8uSHaBj/sQL3fC/ABQWzVTXfdZcU0=";
+    };
+    backend = fetchNodeModules {
+      inherit src nodejs;
+      sourceRoot = "source/backend";
+      hash = "sha256-y5l2SYZYK9SKSy6g0+mtTWD6JFkkdQHHBboECpEvWZ4=";
+    };
+  };
+
+  frontendAssets = fetchFiles {
+    name = "mempool-frontend-assets";
+    hash = "sha256-r6GfOY8Pdh15o2OQMk8syfvWMV6WMCReToAEkQm7tqQ=";
+    fetcher = ./frontend-assets-fetch.sh;
+  };
+
+  mempool-backend = mkDerivationMempool {
+    pname = "mempool-backend";
+
+    patches = [ ./0001-allow-disabling-mining-pool-fetching.patch ];
+
+    buildPhase = ''
+      cd backend
+      ${sync} --chmod=+w ${nodeModules.backend}/lib/node_modules .
+      patchShebangs node_modules
+
+      ${sync} ${mempool-rust-gbt}/ rust-gbt
+      npm run package
+
+      runHook postBuild
+    '';
+
+    installPhase = ''
+      mkdir -p $out/lib/mempool-backend
+      ${sync} package/ $out/lib/mempool-backend
+
+      makeWrapper ${nodejsRuntime}/bin/node $out/bin/mempool-backend \
+        --add-flags $out/lib/mempool-backend/index.js
+
+      runHook postInstall
+    '';
+
+    passthru = {
+      inherit nodejs nodejsRuntime;
+      nodeModules = nodeModules.backend;
+    };
+  };
+
+  mempool-frontend = mkFrontend {};
+
+  # Argument `config` (type: attrset) defines the mempool frontend config.
+  # If `{}`, the default config is used.
+  # See here for available options:
+  # https://github.com/mempool/mempool/blob/master/frontend/src/app/services/state.service.ts
+  # (`interface Env` and `defaultEnv`)
+  mkFrontend = config: mkDerivationMempool {
+    pname = "mempool-frontend";
+
+    buildPhase = ''
+      cd frontend
+
+      ${sync} --chmod=+w ${nodeModules.frontend}/lib/node_modules .
+      patchShebangs node_modules
+
+      # sync-assets.js is called during `npm run build` and downloads assets from the
+      # internet. Disable this script and instead add the assets manually after building.
+      : > sync-assets.js
+
+      ${lib.optionalString (config != {}) ''
+        ln -s ${builtins.toFile "mempool-frontend-config" (builtins.toJSON config)} mempool-frontend-config.json
+      ''}
+
+      npm run build
+
+      # Add assets that would otherwise be downloaded by sync-assets.js
+      ${sync} ${frontendAssets}/ dist/mempool/browser/resources
+
+      runHook postBuild
+    '';
+
+    installPhase = ''
+      ${sync} dist/mempool/browser/ $out
+
+      runHook postInstall
+    '';
+
+    passthru = {
+      withConfig = mkFrontend;
+      assets = frontendAssets;
+      nodeModules = nodeModules.frontend;
+    };
+  };
+
+  mempool-rust-gbt = stdenvNoCC.mkDerivation rec {
+    pname = "mempool-rust-gbt";
+    inherit version src meta;
+
+    sourceRoot = "source/rust/gbt";
+
+    nativeBuildInputs = [
+      rustPlatform.cargoSetupHook
+      cargo
+      rustc
+      napi-rs-cli
+    ];
+
+    cargoDeps = rustPlatform.fetchCargoVendor {
+      inherit src;
+      name = "${pname}-${version}";
+      inherit sourceRoot;
+      hash = "sha256-eox/K3ipjAqNyFt87lZnxaU/okQLF/KIhqXrX86n+qw=";
+    };
+
+    buildPhase = ''
+      runHook preBuild
+      # napi doesn't accept an absolute path as dest dir, so we can't directly write to $out
+      napi build --platform --release --strip out
+      runHook postBuild
+    '';
+
+    installPhase = ''
+      mv out $out
+      cp package.json $out
+    '';
+
+    passthru = { inherit cargoDeps; };
+  };
+
+  mempool-nginx-conf = runCommand "mempool-nginx-conf" {} ''
+    ${sync} --chmod=u+w ${./nginx-conf}/ $out
+    ${sync} ${src}/production/nginx/http-language.conf $out
+  '';
+
+  sync = "${rsync}/bin/rsync -a --inplace";
+
+  mkDerivationMempool = args: stdenvNoCC.mkDerivation ({
+    inherit version src meta;
+
+    nativeBuildInputs = [
+      makeWrapper
+      nodejs
+      rsync
+    ];
+
+    phases = "unpackPhase patchPhase buildPhase installPhase";
+  } // args);
+
+  fetchFiles = { name, hash, fetcher }: stdenvNoCC.mkDerivation {
+    inherit name;
+    outputHashMode = "recursive";
+    outputHashAlgo = "sha256";
+    outputHash = hash;
+    nativeBuildInputs = [ curl cacert ];
+    buildCommand = ''
+      mkdir $out
+      cd $out
+      ${builtins.readFile fetcher}
+    '';
+  };
+
+  meta = with lib; {
+    description = "Bitcoin blockchain and mempool explorer";
+    homepage = "https://github.com/mempool/mempool/";
+    license = licenses.agpl3Plus;
+    maintainers = with maintainers; [ erikarvstedt ];
+    platforms = platforms.unix;
+  };
+}

packages/mempool/frontend-assets-fetch.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Fetch hash-locked versions of assets that are dynamically fetched via
+# https://github.com/mempool/mempool/blob/master/frontend/sync-assets.js
+# when running `npm run build` in the frontend.
+#
+# This file is updated by ./frontend-assets-update.sh
+
+declare -A revs=(
+    ["mempool/mining-pool-logos"]=53972ebbd08373cf4910cbb3e6421a1f3bba4563
+)
+
+fetchFile() {
+    repo=$1
+    file=$2
+    rev=${revs["$repo"]}
+    curl -fsS "https://raw.githubusercontent.com/$repo/$rev/$file"
+}
+
+fetchRepo() {
+    repo=$1
+    rev=${revs["$repo"]}
+    curl -fsSL "https://github.com/$repo/archive/$rev.tar.gz"
+}
+
+mkdir mining-pools
+fetchRepo "mempool/mining-pool-logos" | tar xz --strip-components=1 -C mining-pools

packages/mempool/nginx-conf/location-static.conf

@@ -0,0 +1,47 @@
+# Settings adapted from
+# https://github.com/mempool/mempool/blob/v3.2.1/production/nginx/server-common.conf
+
+# see order of nginx location rules
+# https://stackoverflow.com/questions/5238377/nginx-location-priority
+
+# for exact / requests, redirect based on $lang
+# cache redirect for 5 minutes
+location = / {
+	if ($lang != '') {
+		return 302 $scheme://$host/$lang/;
+	}
+	try_files /en-US/index.html =404;
+	expires 5m;
+}
+
+# cache /<lang>/main.f40e91d908a068a2.js forever since they never change
+location ~ ^/([a-z][a-z])/(.+\..+\.(js|css))$ {
+	try_files $uri =404;
+	expires 1y;
+}
+# cache everything else for 5 minutes
+location ~ ^/([a-z][a-z])$ {
+	try_files $uri /$1/index.html /en-US/index.html =404;
+	expires 5m;
+}
+location ~ ^/([a-z][a-z])/ {
+	try_files $uri /$1/index.html /en-US/index.html =404;
+	expires 5m;
+}
+
+# cache /resources/** for 1 week since they don't change often
+location /resources {
+	try_files $uri /en-US/index.html;
+	expires 1w;
+}
+# cache /main.f40e91d908a068a2.js forever since they never change
+location ~* ^/.+\..+\.(js|css)$ {
+	try_files /$lang/$uri /en-US/$uri =404;
+	expires 1y;
+}
+# catch-all for all URLs i.e. /address/foo /tx/foo /block/000
+# cache 5 minutes since they change frequently
+location / {
+	try_files /$lang/$uri $uri /en-US/$uri /en-US/index.html =404;
+	expires 5m;
+}

packages/rtl/default.nix

@@ -0,0 +1,66 @@
+# Packaging adapted from fort-nix/nix-bitcoin commit 360e30fee.
+# This local copy does not fetch or import nix-bitcoin.
+{ lib
+, stdenvNoCC
+, nodejs_22
+, nodejs-slim_22
+, fetchNodeModules
+, fetchurl
+, makeWrapper
+}:
+let self = stdenvNoCC.mkDerivation {
+  pname = "rtl";
+  version = "0.15.8";
+
+  src = fetchurl {
+    url = "https://github.com/Ride-The-Lightning/RTL/archive/refs/tags/v${self.version}.tar.gz";
+    hash = "sha256-8XdGyORxB2dkZRB/Yl7zh+Quqo4L/Y0VmC6Brbr/hqU=";
+  };
+
+  passthru = {
+    nodejs = nodejs_22;
+    nodejsRuntime = nodejs-slim_22;
+
+    nodeModules = fetchNodeModules {
+      inherit (self) src nodejs;
+      # TODO-EXTERNAL: Remove `npmFlags` when no longer required
+      # See: https://github.com/Ride-The-Lightning/RTL/issues/1182
+      npmFlags = "--legacy-peer-deps";
+      hash = "sha256-oMqd6nLzS6iQ9w4z2yzpR2unA5qhOq5YdvfoS8IgYLY=";
+    };
+  };
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
+  phases = "unpackPhase patchPhase installPhase";
+
+  # `src` already contains the precompiled frontend and backend.
+  # Copy all files required for packaging, like in
+  # https://github.com/Ride-The-Lightning/RTL/blob/master/dockerfiles/Dockerfile
+  installPhase = ''
+    dest=$out/lib/node_modules/rtl
+    mkdir -p $dest
+    cp -r \
+      rtl.js \
+      package.json \
+      frontend \
+      backend \
+      ${self.nodeModules}/lib/node_modules \
+      $dest
+
+    makeWrapper ${self.nodejsRuntime}/bin/node "$out/bin/rtl" \
+      --add-flags "$dest/rtl.js"
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "A web interface for LND, c-lightning and Eclair";
+    homepage = "https://github.com/Ride-The-Lightning/RTL";
+    license = licenses.mit;
+    maintainers = with maintainers; [ nixbitcoin erikarvstedt ];
+    platforms = platforms.unix;
+  };
+}; in self

scripts/release-stable.sh

@@ -283,6 +283,36 @@ git add VERSION
 git commit -m "chore: bump VERSION to ${TAG} for ISO naming" || true
 echo -e "  ${GREEN}✓${NC} VERSION file updated to ${VERSION}"
 
+# ─────────────────────────────────────────────────────────────────────────────
+# Step 2b: Auto-update README.md ISO download references
+# ─────────────────────────────────────────────────────────────────────────────
+echo
+echo -e "${BLUE}Step 2b: Updating README.md ISO references to ${VERSION}...${NC}"
+
+README_FILE="README.md"
+if [ -f "$README_FILE" ]; then
+    # Extract the version currently used in the README's ISO filenames,
+    # e.g. "Sovran_SystemsOS-1.0.6.iso" -> "1.0.6"
+    OLD_ISO_VER=$(grep -oE 'Sovran_SystemsOS-[0-9]+\.[0-9]+\.[0-9]+\.iso' "$README_FILE" | head -1 | sed 's/Sovran_SystemsOS-//; s/\.iso//')
+
+    if [ -n "$OLD_ISO_VER" ] && [ "$OLD_ISO_VER" != "$VERSION" ]; then
+        # Portable in-place edit (works with GNU sed and BSD/macOS sed)
+        sed "s/Sovran_SystemsOS-${OLD_ISO_VER}/Sovran_SystemsOS-${VERSION}/g" \
+            "$README_FILE" > "$README_FILE.tmp" && mv "$README_FILE.tmp" "$README_FILE"
+
+        UPDATED=$(grep -c "Sovran_SystemsOS-${VERSION}" "$README_FILE")
+        echo -e "  ${GREEN}✓${NC} README.md: ${OLD_ISO_VER} -> ${VERSION} (${UPDATED} references updated)"
+
+        git add "$README_FILE"
+        git commit -m "docs: update README ISO download links to ${TAG}" || true
+        echo -e "  ${GREEN}✓${NC} Committed README update"
+    else
+        echo -e "  ${YELLOW}⚠${NC} README.md already references ${VERSION} or no versioned ISO links found — skipping"
+    fi
+else
+    echo -e "  ${YELLOW}⚠${NC} README.md not found — skipping"
+fi
+
 # ─────────────────────────────────────────────────────────────────────────────
 # Step 3: Auto-update CHANGELOG.md
 # ─────────────────────────────────────────────────────────────────────────────

scripts/upload-cdn.sh

@@ -7,7 +7,15 @@
 # Usage:
 #   ./scripts/upload-cdn.sh [--upload]
 #
+# EVERYTHING this script creates lives OUTSIDE the repository, even when you
+# run it from inside the repo:
+#   - the nix build output symlink  -> $ISO_OUT_DIR/result
+#   - the ISO and .sha256 files     -> $ISO_OUT_DIR
+# The repo working tree stays completely clean.
+#
 # Environment variables (optional):
+#   ISO_OUT_DIR        - dir for the build symlink + ISO + checksum
+#                        (default: ~/Sovran-builds)
 #   CDN_RSYNC_TARGET   - rsync destination (e.g. user@server:/var/www/downloads/)
 #   CDN_RCLONE_REMOTE  - rclone remote target (e.g. s3:my-bucket/downloads/)
 #   CDN_UPLOAD_CMD     - custom upload command
@@ -22,65 +30,88 @@ BLUE='\033[0;34m'
 CYAN='\033[0;36m'
 NC='\033[0m'
 
+# Always operate from the repo root, no matter where the script is invoked from
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+cd "$REPO_ROOT"
+
 # Read version from VERSION file
 if [ ! -f VERSION ]; then
-    echo -e "${RED}Error: VERSION file not found.${NC}" >&2
+    echo -e "${RED}Error: VERSION file not found in $REPO_ROOT.${NC}" >&2
     exit 1
 fi
 VERSION=$(cat VERSION | tr -d '\n\r ')
 ISO_NAME="Sovran_SystemsOS-${VERSION}.iso"
 SHA_NAME="${ISO_NAME}.sha256"
 
+# Output directory OUTSIDE the repo (override with ISO_OUT_DIR)
+OUT_DIR="${ISO_OUT_DIR:-$HOME/Sovran-builds}"
+mkdir -p "$OUT_DIR"
+OUT_DIR="$(cd "$OUT_DIR" && pwd)"
+ISO_PATH="$OUT_DIR/${ISO_NAME}"
+SHA_PATH="$OUT_DIR/${SHA_NAME}"
+RESULT_LINK="$OUT_DIR/result"
+
 echo -e "${BLUE}╔════════════════════════════════════════════════════════════╗${NC}"
 echo -e "${BLUE}║      Sovran_SystemsOS CDN ISO Packaging & Upload Tool      ║${NC}"
 echo -e "${BLUE}╚════════════════════════════════════════════════════════════╝${NC}"
 echo -e "  Version : ${CYAN}${VERSION}${NC}"
 echo -e "  ISO     : ${CYAN}${ISO_NAME}${NC}"
+echo -e "  Repo    : ${CYAN}${REPO_ROOT}${NC}   (left untouched)"
+echo -e "  Output  : ${CYAN}${OUT_DIR}${NC}   (outside the repo)"
 echo
 
 # Locate or build ISO
 SRC_ISO=""
-if [ -f "result/iso/${ISO_NAME}" ]; then
+if [ -f "$RESULT_LINK/iso/${ISO_NAME}" ]; then
-    SRC_ISO="result/iso/${ISO_NAME}"
+    SRC_ISO="$RESULT_LINK/iso/${ISO_NAME}"
+elif [ -f "$RESULT_LINK/iso/Sovran_SystemsOS.iso" ]; then
+    SRC_ISO="$RESULT_LINK/iso/Sovran_SystemsOS.iso"
+elif [ -f "result/iso/${ISO_NAME}" ]; then
+    SRC_ISO="result/iso/${ISO_NAME}"   # legacy: from an older in-repo build
 elif [ -f "result/iso/Sovran_SystemsOS.iso" ]; then
     SRC_ISO="result/iso/Sovran_SystemsOS.iso"
 else
-    FOUND=$(find result -name "*.iso" 2>/dev/null | head -n 1 || true)
+    FOUND=$(find "$RESULT_LINK" result -name "*.iso" 2>/dev/null | head -n 1 || true)
     if [ -n "$FOUND" ]; then
         SRC_ISO="$FOUND"
     fi
 fi
 
 if [ -z "$SRC_ISO" ] || [ ! -f "$SRC_ISO" ]; then
-    echo -e "${YELLOW}Built ISO not found in result/. Building ISO via Nix...${NC}"
+    echo -e "${YELLOW}Built ISO not found. Building via Nix (result link goes outside the repo)...${NC}"
-    nix build .#nixosConfigurations.sovran_systemsos-iso.config.system.build.isoImage
+    rm -f "$RESULT_LINK"
+    nix build .#nixosConfigurations.sovran_systemsos-iso.config.system.build.isoImage \
+        --out-link "$RESULT_LINK"
 
-    if [ -f "result/iso/${ISO_NAME}" ]; then
+    if [ -f "$RESULT_LINK/iso/${ISO_NAME}" ]; then
-        SRC_ISO="result/iso/${ISO_NAME}"
+        SRC_ISO="$RESULT_LINK/iso/${ISO_NAME}"
     else
-        FOUND=$(find result -name "*.iso" 2>/dev/null | head -n 1 || true)
+        FOUND=$(find "$RESULT_LINK" -name "*.iso" 2>/dev/null | head -n 1 || true)
         if [ -n "$FOUND" ]; then
             SRC_ISO="$FOUND"
-        else
-            echo -e "${RED}Error: Failed to locate built ISO in result/.${NC}" >&2
-            exit 1
         fi
     fi
 fi
 
-echo -e "${BLUE}Step 1: Copying built ISO out of Nix store...${NC}"
+if [ -z "$SRC_ISO" ] || [ ! -f "$SRC_ISO" ]; then
-cp -v "$SRC_ISO" "./${ISO_NAME}"
+    echo -e "${RED}Error: Failed to locate built ISO.${NC}" >&2
-echo -e "  ${GREEN}✓${NC} Copied to ./${ISO_NAME}"
+    exit 1
+fi
+
+echo -e "${BLUE}Step 1: Copying built ISO to output dir (outside repo)...${NC}"
+cp -v "$SRC_ISO" "$ISO_PATH"
+echo -e "  ${GREEN}✓${NC} Copied to $ISO_PATH"
 
 echo
 echo -e "${BLUE}Step 2: Generating versioned SHA-256 checksum...${NC}"
-sha256sum "${ISO_NAME}" > "${SHA_NAME}"
+sha256sum "$ISO_PATH" > "$SHA_PATH"
-echo -e "  ${GREEN}✓${NC} Generated ${SHA_NAME}"
+echo -e "  ${GREEN}✓${NC} Generated $SHA_PATH"
-cat "${SHA_NAME}"
+cat "$SHA_PATH"
 
 echo
 echo -e "${BLUE}Step 3: Verifying checksum...${NC}"
-sha256sum --check "${SHA_NAME}"
+sha256sum --check "$SHA_PATH"
 echo -e "  ${GREEN}✓${NC} Checksum verified successfully"
 
 # Parse arguments for upload
@@ -107,13 +138,13 @@ if [ "$DO_UPLOAD" -eq 1 ]; then
 
     if [ -n "${CDN_RSYNC_TARGET:-}" ]; then
         echo -e "  Uploading via rsync to ${CDN_RSYNC_TARGET}..."
-        rsync -avP "${ISO_NAME}" "${SHA_NAME}" "${CDN_RSYNC_TARGET}"
+        rsync -avP "$ISO_PATH" "$SHA_PATH" "${CDN_RSYNC_TARGET}"
         UPLOADED=1
     fi
 
     if [ -n "${CDN_RCLONE_REMOTE:-}" ]; then
         echo -e "  Uploading via rclone to ${CDN_RCLONE_REMOTE}..."
-        rclone copy "${ISO_NAME}" "${SHA_NAME}" "${CDN_RCLONE_REMOTE}"
+        rclone copy "$ISO_PATH" "$SHA_PATH" "${CDN_RCLONE_REMOTE}"
         UPLOADED=1
     fi
 
@@ -128,8 +159,8 @@ else
     echo -e "${GREEN}╔════════════════════════════════════════════════════════════╗${NC}"
     echo -e "${GREEN}║           ✅ ISO packaging & verification complete!        ║${NC}"
     echo -e "${GREEN}╚════════════════════════════════════════════════════════════╝${NC}"
-    echo -e "Ready files:"
+    echo -e "Ready files (in ${CYAN}${OUT_DIR}${NC}, outside the repo):"
-    ls -lh "${ISO_NAME}" "${SHA_NAME}"
+    ls -lh "$ISO_PATH" "$SHA_PATH"
     echo
     echo "To upload to CDN, run:"
     echo "  ./scripts/upload-cdn.sh --upload"

tests/bitcoin-btcpay-hardening.nix

@@ -0,0 +1,132 @@
+{ nixpkgs, overlay-stable, system ? "x86_64-linux" }:
+
+let
+  lib = nixpkgs.lib;
+  pkgs = import nixpkgs {
+    inherit system;
+    overlays = [ overlay-stable ];
+  };
+
+  normalize = s:
+    lib.replaceStrings [ "\n" "\\" "  " ] [ " " "" " " ] s;
+
+  extractAfter = prefix: str:
+    let
+      match = builtins.match ".*${prefix} ([^ ]+).*" (normalize str);
+    in
+      if match == null then
+        throw "Unable to extract ${prefix} from: ${normalize str}"
+      else
+        builtins.head match;
+
+  extractFlagValue = flag: str:
+    let
+      match = builtins.match ".*${flag}=([^ ]+).*" (normalize str);
+    in
+      if match == null then
+        throw "Unable to extract ${flag} from: ${normalize str}"
+      else
+        builtins.head match;
+
+  config = (lib.nixosSystem {
+    inherit system;
+    modules = [
+      { nixpkgs.hostPlatform = system; nixpkgs.overlays = [ overlay-stable ]; }
+      ../modules/bitcoin
+      {
+        nix-bitcoin.generateSecrets = true;
+        nix-bitcoin.secretsDir = "/build/secrets";
+
+        services.btcpayserver.enable = true;
+        services.btcpayserver.lightningBackend = "lnd";
+        services.nbxplorer.dataDir = "/build/nbxplorer";
+        services.btcpayserver.dataDir = "/build/btcpayserver";
+        services.lnd.dataDir = "/build/lnd";
+        services.bitcoind.dataDir = "/build/bitcoind";
+      }
+    ];
+  }).config;
+
+  nbxplorerPreStart = config.systemd.services.nbxplorer.preStart;
+  bitcoindPreStart = config.systemd.services.bitcoind.preStart;
+  btcpayExecStart = config.systemd.services.btcpayserver.serviceConfig.ExecStart;
+
+  nbxplorerConfigPath = extractAfter "install -m 600" nbxplorerPreStart;
+  btcpayConfigPath = extractFlagValue "--conf" btcpayExecStart;
+
+  nbxplorerConfig = builtins.readFile nbxplorerConfigPath;
+  btcpayConfig = builtins.readFile btcpayConfigPath;
+in
+assert lib.assertMsg
+  (config.nix-bitcoin.secrets.bitcoin-HMAC-btcpayserver.user == config.services.bitcoind.user)
+  "bitcoin-HMAC-btcpayserver must be owned by bitcoind";
+assert lib.assertMsg
+  (config.nix-bitcoin.secrets.bitcoin-rpcpassword-btcpayserver.user == config.services.bitcoind.user)
+  "bitcoin-rpcpassword-btcpayserver must be owned by bitcoind";
+assert lib.assertMsg
+  (config.nix-bitcoin.secrets.bitcoin-rpcpassword-btcpayserver.group == config.services.nbxplorer.group)
+  "bitcoin-rpcpassword-btcpayserver must be group-readable by nbxplorer";
+assert lib.assertMsg
+  (!(lib.elem config.services.nbxplorer.group config.users.users.${config.services.btcpayserver.user}.extraGroups))
+  "btcpayserver must not receive the nbxplorer group";
+assert lib.assertMsg
+  (lib.elem "nix-bitcoin-secrets.target" config.systemd.services.nbxplorer.after)
+  "nbxplorer must wait for nix-bitcoin-secrets.target";
+assert lib.assertMsg
+  (config.systemd.services.nbxplorer.serviceConfig.MemoryDenyWriteExecute == false)
+  "nbxplorer needs MemoryDenyWriteExecute = false";
+assert lib.assertMsg
+  (config.systemd.services.btcpayserver.serviceConfig.MemoryDenyWriteExecute == false)
+  "btcpayserver needs MemoryDenyWriteExecute = false";
+assert lib.assertMsg
+  (lib.hasInfix "network=mainnet" nbxplorerConfig
+    && lib.hasInfix "btcrpcuser=btcpayserver" nbxplorerConfig
+    && lib.hasInfix "btcnodeendpoint=127.0.0.1:8335" nbxplorerConfig
+    && lib.hasInfix "bind=127.0.0.1" nbxplorerConfig
+    && lib.hasInfix "port=24444" nbxplorerConfig
+    && lib.hasInfix "postgres=User ID=nbxplorer;Host=/run/postgresql;Database=nbxplorer" nbxplorerConfig)
+  "nbxplorer base config must contain the expected non-secret settings";
+assert lib.assertMsg
+  (!lib.hasInfix "/build/btcpayserver/settings.config" btcpayExecStart
+    && lib.hasInfix "--datadir='/build/btcpayserver'" btcpayExecStart)
+  "btcpayserver must use a deterministic config file plus --datadir";
+assert lib.assertMsg
+  (lib.hasInfix "network=mainnet" btcpayConfig
+    && lib.hasInfix "bind=127.0.0.1" btcpayConfig
+    && lib.hasInfix "port=23000" btcpayConfig
+    && lib.hasInfix "btcexplorerurl=http://127.0.0.1:24444/" btcpayConfig
+    && lib.hasInfix "explorer.postgres=User ID=nbxplorer;Host=/run/postgresql;Database=nbxplorer" btcpayConfig
+    && lib.hasInfix "postgres=User ID=btcpayserver;Host=/run/postgresql;Database=btcpayserver" btcpayConfig
+    && lib.hasInfix "btclightning=type=lnd-rest;server=https://127.0.0.1:8080/;macaroonfilepath=/run/lnd/btcpayserver.macaroon;certfilepath=/build/secrets/lnd-cert" btcpayConfig)
+  "btcpayserver config must preserve BTCPay, NBXplorer, database, and LND settings";
+assert lib.assertMsg
+  (lib.hasInfix "readValidatedRpcHmac()" bitcoindPreStart
+    && lib.hasInfix ''if [[ ! -e "$hmacFile" ]]; then'' bitcoindPreStart
+    && lib.hasInfix ''if [[ ! -r "$hmacFile" ]]; then'' bitcoindPreStart
+    && lib.hasInfix ''if [[ -z "$hmacPayload" ]]; then'' bitcoindPreStart
+    && lib.hasInfix ''^[[:xdigit:]]+\$[[:xdigit:]]+$'' bitcoindPreStart
+    && lib.hasInfix ''Bitcoin RPC HMAC file has invalid format'' bitcoindPreStart
+    && lib.hasInfix ''hmacPayload="$(readValidatedRpcHmac '/build/secrets/bitcoin-HMAC-btcpayserver')" || exit 1'' bitcoindPreStart)
+  "bitcoind preStart must validate missing, unreadable, empty, and malformed HMAC files";
+pkgs.runCommand "bitcoin-btcpay-hardening" {} ''
+  mkdir -p /build/secrets /build/nbxplorer
+
+  printf '%s' 'first-password' > /build/secrets/bitcoin-rpcpassword-btcpayserver
+  bash -euo pipefail -c ${lib.escapeShellArg nbxplorerPreStart}
+
+  test "$(stat -c '%a' /build/nbxplorer/settings.config)" = "600"
+  test "$(grep -c '^btcrpcuser=' /build/nbxplorer/settings.config)" = "1"
+  test "$(grep -c '^btcrpcpassword=' /build/nbxplorer/settings.config)" = "1"
+  test "$(grep -c '^postgres=' /build/nbxplorer/settings.config)" = "1"
+
+  printf '%s' 'rotated-password' > /build/secrets/bitcoin-rpcpassword-btcpayserver
+  bash -euo pipefail -c ${lib.escapeShellArg nbxplorerPreStart}
+
+  test "$(grep -c '^btcrpcuser=' /build/nbxplorer/settings.config)" = "1"
+  test "$(grep -c '^btcrpcpassword=' /build/nbxplorer/settings.config)" = "1"
+  test "$(grep -c '^postgres=' /build/nbxplorer/settings.config)" = "1"
+  ! grep -q 'first-password' /build/nbxplorer/settings.config
+  grep -q 'rotated-password' /build/nbxplorer/settings.config
+
+  touch "$out"
+''