diff --git a/pkgs/by-name/si/signal-desktop-source/libsignal-node.nix b/pkgs/by-name/si/signal-desktop-source/libsignal-node.nix
new file mode 100644
index 000000000000..5f07a3457af6
--- /dev/null
+++ b/pkgs/by-name/si/signal-desktop-source/libsignal-node.nix
@@ -0,0 +1,87 @@
+{
+  stdenv,
+  rustPlatform,
+  fetchNpmDeps,
+  npmHooks,
+  protobuf,
+  clang,
+  gitMinimal,
+  cmake,
+  boringssl,
+  runCommand,
+  fetchFromGitHub,
+  python3,
+  nodejs,
+
+}:
+let
+  # boring-sys expects the static libraries in build/ instead of lib/
+  boringssl-wrapper = runCommand "boringssl-wrapper" { } ''
+    mkdir $out
+    cd $out
+    ln -s ${boringssl.out}/lib build
+    ln -s ${boringssl.dev}/include include
+  '';
+in
+rustPlatform.buildRustPackage (finalAttrs: {
+  pname = "libsignal-node";
+  version = "0.67.0";
+
+  src = fetchFromGitHub {
+    owner = "signalapp";
+    repo = "libsignal";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-Cwra5o9g2+M3dboQUuBikRWyaydL/CGwOfJbImsFRoI=";
+  };
+  useFetchCargoVendor = true;
+  cargoHash = "sha256-KVt4ESHaHDtD+pcaMMG/DMMznYGpWleEf7uTZB45Ud0=";
+
+  npmRoot = "node";
+  npmDeps = fetchNpmDeps {
+    name = "${finalAttrs.pname}-npm-deps";
+    inherit (finalAttrs) version src;
+    sourceRoot = "${finalAttrs.src.name}/${finalAttrs.npmRoot}";
+    hash = "sha256-TXRZFfdl86PLJ1FWOkTcXjbx8aZV7gEvs22Pu8b5uFU=";
+  };
+
+  nativeBuildInputs = [
+    python3
+    protobuf
+    nodejs
+    clang
+    gitMinimal
+    cmake
+    npmHooks.npmConfigHook
+    rustPlatform.bindgenHook
+  ];
+  env.BORING_BSSL_PATH = "${boringssl-wrapper}";
+  env.NIX_LDFLAGS = if stdenv.hostPlatform.isDarwin then "-lc++" else "-lstdc++";
+
+  patchPhase = ''
+    runHook prePatch
+
+    substituteInPlace node/binding.gyp \
+      --replace-fail "'--out-dir', '<(PRODUCT_DIR)/'," \
+                     "'--out-dir', '$out/lib/<(NODE_OS_NAME)-<(target_arch)/'," \
+      --replace-fail "'target_name': 'libsignal_client_<(NODE_OS_NAME)_<(target_arch).node'," \
+                     "'target_name': '@signalapp+libsignal-client',"
+
+    substituteInPlace node/build_node_bridge.py \
+      --replace-fail "dst_base = 'libsignal_client_%s_%s' % (node_os_name, node_arch)" \
+                     "dst_base = '@signalapp+libsignal-client'"
+
+    runHook postPatch
+  '';
+
+  buildPhase = ''
+    runHook preBuild
+
+    pushd node
+    npx node-gyp rebuild
+    popd
+
+    runHook postBuild
+  '';
+
+  dontCargoInstall = true;
+})
diff --git a/pkgs/by-name/si/signal-desktop-source/package.nix b/pkgs/by-name/si/signal-desktop-source/package.nix
new file mode 100644
index 000000000000..a085ec0fe610
--- /dev/null
+++ b/pkgs/by-name/si/signal-desktop-source/package.nix
@@ -0,0 +1,228 @@
+{
+  stdenv,
+  lib,
+  nodejs_20,
+  pnpm_10,
+  electron_34,
+  python3,
+  makeWrapper,
+  callPackage,
+  libpulseaudio,
+  fetchFromGitHub,
+  runCommand,
+  fetchzip,
+  autoPatchelfHook,
+  makeDesktopItem,
+  copyDesktopItems,
+  replaceVars,
+  noto-fonts-color-emoji,
+  nixosTests,
+  withAppleEmojis ? false,
+}:
+let
+  nodejs = nodejs_20;
+  pnpm = pnpm_10;
+  electron = electron_34;
+
+  electron-headers = runCommand "electron-headers" { } ''
+    mkdir -p $out
+    tar -C $out --strip-components=1 -xvf ${electron.headers}
+  '';
+
+  sqlcipher-signal-extension = callPackage ./sqlcipher-signal-extension.nix { };
+  libsignal-node = callPackage ./libsignal-node.nix { inherit nodejs; };
+
+  ringrtc = stdenv.mkDerivation (finalAttrs: {
+    pname = "ringrtc-bin";
+    version = "2.50.1";
+    src = fetchzip {
+      url = "https://build-artifacts.signal.org/libraries/ringrtc-desktop-build-v${finalAttrs.version}.tar.gz";
+      hash = "sha256-KHNTw5ScBdYAAyKFdJ6PTmFr+7GYHqgnb4mmNUJZvzM=";
+    };
+
+    installPhase = ''
+      cp -r . $out
+    '';
+
+    nativeBuildInputs = [ autoPatchelfHook ];
+    buildInputs = [ libpulseaudio ];
+    meta = {
+      homepage = "https://github.com/signalapp/ringrtc";
+      license = lib.licenses.agpl3Only;
+      sourceProvenance = with lib.sourceTypes; [ binaryNativeCode ];
+    };
+  });
+
+  # Noto Color Emoji PNG files for emoji replacement; see below.
+  noto-fonts-color-emoji-png = noto-fonts-color-emoji.overrideAttrs (prevAttrs: {
+    pname = "noto-fonts-color-emoji-png";
+
+    # The build produces 136×128 PNGs by default for arcane font
+    # reasons, but we want square PNGs.
+    buildFlags = prevAttrs.buildFlags or [ ] ++ [ "BODY_DIMENSIONS=128x128" ];
+
+    makeTargets = [ "compressed" ];
+
+    installPhase = ''
+      runHook preInstall
+
+      mkdir -p $out/share
+      mv build/compressed_pngs $out/share/noto-fonts-color-emoji-png
+      python3 add_aliases.py --srcdir=$out/share/noto-fonts-color-emoji-png
+
+      runHook postInstall
+    '';
+  });
+
+in
+stdenv.mkDerivation (finalAttrs: {
+  pname = "signal-desktop-source";
+  version = "7.46.0";
+
+  src = fetchFromGitHub {
+    owner = "signalapp";
+    repo = "Signal-Desktop";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-pV28jcIQcPjyZL8q+gisnlfAGf0SOKDQ7OxacTM3B0M=";
+  };
+
+  nativeBuildInputs = [
+    nodejs
+    (pnpm.override { inherit nodejs; }).configHook
+    makeWrapper
+    copyDesktopItems
+    python3
+  ];
+  buildInputs = (lib.optional (!withAppleEmojis) noto-fonts-color-emoji-png);
+
+  patches = lib.optional (!withAppleEmojis) (
+    replaceVars ./replace-apple-emoji-with-noto-emoji.patch {
+      noto-emoji-pngs = "${noto-fonts-color-emoji-png}/share/noto-fonts-color-emoji-png";
+    }
+  );
+
+  pnpmDeps = pnpm.fetchDeps {
+    inherit (finalAttrs)
+      pname
+      version
+      src
+      patches
+      ;
+    hash =
+      if withAppleEmojis then
+        "sha256-keG+ymMD4ma0dt6N4Fai9u0+rh9VzkQD6tClPKoQXkM="
+      else
+        "sha256-qImY0s8UQmuKGf8dvgO3YrJlrqqdoZtvbtLgvgMVnnE=";
+  };
+
+  env = {
+    ELECTRON_SKIP_BINARY_DOWNLOAD = "1";
+    SIGNAL_ENV = "production";
+    SOURCE_DATE_EPOCH = 1741810629;
+  };
+
+  preBuild = ''
+    cp ${sqlcipher-signal-extension}/share/sqlite3.gyp node_modules/@signalapp/better-sqlite3/deps/sqlite3.gyp
+
+    cp -r ${ringrtc} node_modules/@signalapp/ringrtc/build
+
+    rm -fr node_modules/@signalapp/libsignal-client/prebuilds
+    cp -r ${libsignal-node}/lib node_modules/@signalapp/libsignal-client/prebuilds
+  '';
+
+  buildPhase = ''
+    runHook preBuild
+
+    export npm_config_nodedir=${electron-headers}
+    cp -r ${electron.dist} electron-dist
+    chmod -R u+w electron-dist
+
+    pnpm run generate
+    pnpm exec electron-builder \
+      --dir \
+      --config.extraMetadata.environment=$SIGNAL_ENV \
+      -c.electronDist=electron-dist \
+      -c.electronVersion=${electron.version}
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/share/
+    cp -r dist/*-unpacked/resources $out/share/signal-desktop
+
+    for icon in build/icons/png/*
+    do
+      install -Dm644 $icon $out/share/icons/hicolor/`basename ''${icon%.png}`/apps/signal-desktop.png
+    done
+
+    makeWrapper '${lib.getExe electron}' "$out/bin/signal-desktop" \
+      --add-flags "$out/share/signal-desktop/app.asar" \
+      --set-default ELECTRON_FORCE_IS_PACKAGED 1 \
+      --add-flags "\''${NIXOS_OZONE_WL:+\''${WAYLAND_DISPLAY:+--ozone-platform-hint=auto --enable-features=WaylandWindowDecorations --enable-wayland-ime=true}}"
+
+    runHook postInstall
+  '';
+
+  desktopItems = [
+    (makeDesktopItem {
+      name = finalAttrs.pname;
+      desktopName = "Signal";
+      exec = "${finalAttrs.meta.mainProgram} %U";
+      type = "Application";
+      terminal = false;
+      icon = "signal-desktop";
+      comment = "Private messaging from your desktop";
+      startupWMClass = "signal";
+      mimeTypes = [
+        "x-scheme-handler/sgnl"
+        "x-scheme-handler/signalcaptcha"
+      ];
+      categories = [
+        "Network"
+        "InstantMessaging"
+        "Chat"
+      ];
+    })
+  ];
+
+  passthru = {
+    inherit sqlcipher-signal-extension libsignal-node;
+    tests.application-launch = nixosTests.signal-desktop;
+  };
+
+  meta = {
+    description = "Private, simple, and secure messenger (nixpkgs build)";
+    longDescription = ''
+      Signal Desktop is an Electron application that links with your
+      "Signal Android" or "Signal iOS" app.
+    '';
+    homepage = "https://signal.org/";
+    changelog = "https://github.com/signalapp/Signal-Desktop/releases/tag/v${finalAttrs.version}";
+    license =
+      with lib.licenses;
+      [
+        agpl3Only
+
+        # Various npm packages
+        free
+      ]
+      ++ lib.optional withAppleEmojis unfree;
+    maintainers = with lib.maintainers; [
+      marcin-serwin
+    ];
+    mainProgram = "signal-desktop";
+    platforms = [
+      "x86_64-linux"
+      "aarch64-linux"
+    ];
+    sourceProvenance = with lib.sourceTypes; [
+      fromSource
+
+      # ringrtc
+      binaryNativeCode
+    ];
+  };
+})
diff --git a/pkgs/by-name/si/signal-desktop-source/replace-apple-emoji-with-noto-emoji.patch b/pkgs/by-name/si/signal-desktop-source/replace-apple-emoji-with-noto-emoji.patch
new file mode 100644
index 000000000000..3779f5859b23
--- /dev/null
+++ b/pkgs/by-name/si/signal-desktop-source/replace-apple-emoji-with-noto-emoji.patch
@@ -0,0 +1,129 @@
+diff --git a/ACKNOWLEDGMENTS.md b/ACKNOWLEDGMENTS.md
+index aed1048..e4c1f50 100644
+--- a/ACKNOWLEDGMENTS.md
++++ b/ACKNOWLEDGMENTS.md
+@@ -745,30 +745,6 @@ Signal Desktop makes use of the following open source projects.
+     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+     SOFTWARE.
+ 
+-## emoji-datasource-apple
+-
+-    The MIT License (MIT)
+-
+-    Copyright (c) 2013 Cal Henderson
+-
+-    Permission is hereby granted, free of charge, to any person obtaining a copy
+-    of this software and associated documentation files (the "Software"), to deal
+-    in the Software without restriction, including without limitation the rights
+-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+-    copies of the Software, and to permit persons to whom the Software is
+-    furnished to do so, subject to the following conditions:
+-
+-    The above copyright notice and this permission notice shall be included in all
+-    copies or substantial portions of the Software.
+-
+-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+-    SOFTWARE.
+-
+ ## emoji-regex
+ 
+     Copyright Mathias Bynens <https://mathiasbynens.be/>
+diff --git a/app/protocol_filter.ts b/app/protocol_filter.ts
+index 68dceea..4b35bb1 100644
+--- a/app/protocol_filter.ts
++++ b/app/protocol_filter.ts
+@@ -59,6 +59,7 @@ function _createFileHandler({
+   const allowedRoots = [
+     userDataPath,
+     installPath,
++    "@noto-emoji-pngs@",
+     getAvatarsPath(userDataPath),
+     getBadgesPath(userDataPath),
+     getDraftPath(userDataPath),
+diff --git a/package.json b/package.json
+index 3a6ac26..40cdb25 100644
+--- a/package.json
++++ b/package.json
+@@ -130,7 +130,6 @@
+     "dashdash": "2.0.0",
+     "direction": "1.0.4",
+     "emoji-datasource": "15.1.2",
+-    "emoji-datasource-apple": "15.1.2",
+     "emoji-regex": "10.4.0",
+     "encoding": "0.1.13",
+     "fabric": "4.6.0",
+diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
+index ba2f205..705e454 100644
+--- a/pnpm-lock.yaml
++++ b/pnpm-lock.yaml
+@@ -169,9 +169,6 @@ importers:
+       emoji-datasource:
+         specifier: 15.1.2
+         version: 15.1.2
+-      emoji-datasource-apple:
+-        specifier: 15.1.2
+-        version: 15.1.2
+       emoji-regex:
+         specifier: 10.4.0
+         version: 10.4.0
+@@ -4790,9 +4787,6 @@ packages:
+     resolution: {integrity: sha512-DeWwawk6r5yR9jFgnDKYt4sLS0LmHJJi3ZOnb5/JdbYwj3nW+FxQnHIjhBKz8YLC7oRNPVM9NQ47I3CVx34eqQ==}
+     engines: {node: '>=12'}
+ 
+-  emoji-datasource-apple@15.1.2:
+-    resolution: {integrity: sha512-32UZTK36x4DlvgD1smkmBlKmmJH7qUr5Qut4U/on2uQLGqNXGbZiheq6/LEA8xRQEUrmNrGEy25wpEI6wvYmTg==}
+-
+   emoji-datasource@15.1.2:
+     resolution: {integrity: sha512-tXAqGsrDVhgCRpFePtaD9P4Z8Ro2SUQSL/4MIJBG0SxqQJaMslEbin8J53OaFwEBu6e7JxFaIF6s4mw9+8acAQ==}
+ 
+@@ -14929,8 +14923,6 @@ snapshots:
+ 
+   emittery@0.13.1: {}
+ 
+-  emoji-datasource-apple@15.1.2: {}
+-
+   emoji-datasource@15.1.2: {}
+ 
+   emoji-regex@10.4.0: {}
+diff --git a/ts/components/conversation/Emojify.tsx b/ts/components/conversation/Emojify.tsx
+index f0b1115..7613230 100644
+--- a/ts/components/conversation/Emojify.tsx
++++ b/ts/components/conversation/Emojify.tsx
+@@ -35,8 +35,15 @@ function getImageTag({
+   }
+ 
+   let srcSet: string | undefined;
++  const emojiToNotoName = (emoji: string): string =>
++    `emoji_u${
++      [...emoji]
++        .filter(c => c != "\ufe0f")
++        .map(c => c.codePointAt(0)?.toString(16).padStart(4, "0"))
++        .join("_")
++    }.png`;
+   if (sizeClass != null && JUMBO_SIZES.has(sizeClass)) {
+-    srcSet = `emoji://jumbo?emoji=${encodeURIComponent(match)} 2x, ${img}`;
++    srcSet = `file://@noto-emoji-pngs@/${emojiToNotoName(match)} 2x, ${img}`;
+   }
+ 
+   return (
+diff --git a/ts/components/emoji/lib.ts b/ts/components/emoji/lib.ts
+index 9753017..cf51d3d 100644
+--- a/ts/components/emoji/lib.ts
++++ b/ts/components/emoji/lib.ts
+@@ -102,7 +102,10 @@ const ROOT_PATH = get(
+ );
+ 
+ const makeImagePath = (src: string) => {
+-  return `${ROOT_PATH}node_modules/emoji-datasource-apple/img/apple/64/${src}`;
++  const datasourceToNoto = (name: string): string =>
++    `emoji_u${name.slice(0,-4).split("-").filter(c => c != "fe0f").join("_")}.png`;
++
++  return `@noto-emoji-pngs@/${datasourceToNoto(src)}`;
+ };
+ 
+ const imageQueue = new PQueue({
diff --git a/pkgs/by-name/si/signal-desktop-source/sqlcipher-signal-extension.nix b/pkgs/by-name/si/signal-desktop-source/sqlcipher-signal-extension.nix
new file mode 100644
index 000000000000..e53a3e63eb0a
--- /dev/null
+++ b/pkgs/by-name/si/signal-desktop-source/sqlcipher-signal-extension.nix
@@ -0,0 +1,105 @@
+{
+  rustPlatform,
+  lib,
+  fetchFromGitHub,
+  sqlcipher,
+  fetchpatch,
+  stdenv,
+  openssl,
+  tcl,
+  buildEnv,
+  rust-cbindgen,
+}:
+let
+  signal-sqlcipher-extension = rustPlatform.buildRustPackage (finalAttrs: {
+    pname = "signal-sqlcipher-extension";
+    version = "0.2.1";
+
+    src = fetchFromGitHub {
+      owner = "signalapp";
+      repo = "Signal-Sqlcipher-Extension";
+      tag = "v${finalAttrs.version}";
+      hash = "sha256-INSkm7ZuetPASuIqezzzG/bXoEHClUb9XpxWbxLVXRc=";
+    };
+    useFetchCargoVendor = true;
+    cargoHash = "sha256-qT4HM/FRL8qugKKNlMYM/0zgUsC6cDOa9fgd1d4VIrc=";
+
+    meta = {
+      description = "SQLite extension used by Signal Desktop";
+      homepage = "https://github.com/signalapp/Signal-Sqlcipher-Extension";
+      license = lib.licenses.agpl3Only;
+      maintainers = with lib.maintainers; [ marcin-serwin ];
+      platforms = lib.platforms.all;
+    };
+  });
+
+  sqlcipher-amalgamation = stdenv.mkDerivation {
+    pname = "sqlcipher-with-signal-extension";
+
+    inherit (sqlcipher) version src meta;
+
+    patches = [
+      (fetchpatch {
+        # https://github.com/sqlcipher/sqlcipher/pull/529
+        name = "custom-crypto-provider.patch";
+        url = "https://github.com/sqlcipher/sqlcipher/commit/0e3b20c155df8a2943b62a9f3cc0f4d3dba9e152.patch";
+        hash = "sha256-OKh6qCGHBQWZyzXfyEveAs71wrNwlWLuG9jNqDeKNG4=";
+      })
+    ];
+
+    nativeBuildInputs = [ tcl ];
+
+    buildInputs = [ openssl ];
+
+    CFLAGS = [ "-DSQLITE_ENABLE_UPDATE_DELETE_LIMIT=1" ];
+
+    makeFlags = [ "sqlite3.c" ];
+
+    installPhase = ''
+      install -Dm644 sqlite3.c $out/src/sqlite3.c
+      install -Dm644 sqlite3.h $out/include/sqlite3.h
+      install -Dm644 sqlite3ext.h $out/include/sqlite3ext.h
+    '';
+  };
+
+  signal-tokenizer-headers = rustPlatform.buildRustPackage (finalAttrs: {
+    pname = "Signal-FTS5-Extension";
+    version = "0.2.1";
+
+    src = fetchFromGitHub {
+      owner = "signalapp";
+      repo = "Signal-FTS5-Extension";
+      tag = "v${finalAttrs.version}";
+      hash = "sha256-MzgdRuRsfL3yhlVU0RAAUtAaOukMpqSSa42nRYhpmh0=";
+    };
+    useFetchCargoVendor = true;
+    cargoHash = "sha256-0DDX3ciXk5/3MqsHzxV8s4qEhqYmrwGg7cSbrkFRZbw=";
+
+    nativeBuildInputs = [ rust-cbindgen ];
+
+    buildPhase = ''
+      cbindgen --profile release . -o signal-tokenizer.h
+    '';
+    installPhase = ''
+      install -Dm644 signal-tokenizer.h $out/include/signal-tokenizer.h
+    '';
+    doCheck = false;
+  });
+
+in
+buildEnv {
+  name = "sqlcipher-signal";
+
+  paths = [
+    sqlcipher-amalgamation
+    signal-tokenizer-headers
+    signal-sqlcipher-extension
+  ];
+
+  postBuild = ''
+    install -Dm644 ${./sqlite3.gyp} $out/share/sqlite3.gyp
+    substituteInPlace $out/share/sqlite3.gyp \
+      --replace-fail "@extension@" "$out" \
+      --replace-fail "@static_lib_ext@" "${stdenv.hostPlatform.extensions.staticLibrary}"
+  '';
+}
diff --git a/pkgs/by-name/si/signal-desktop-source/sqlite3.gyp b/pkgs/by-name/si/signal-desktop-source/sqlite3.gyp
new file mode 100644
index 000000000000..2c73ab250b61
--- /dev/null
+++ b/pkgs/by-name/si/signal-desktop-source/sqlite3.gyp
@@ -0,0 +1,40 @@
+{
+  'includes': ['common.gypi'],
+  'targets': [
+    {
+      'target_name': 'locate_sqlite3',
+      'type': 'none',
+      'copies': [{
+        'files': [
+          '@extension@/src/sqlite3.c',
+        ],
+        'destination': '<(SHARED_INTERMEDIATE_DIR)/sqlite3',
+      }],
+    },
+    {
+      'target_name': 'sqlite3',
+      'type': 'static_library',
+      'dependencies': ['locate_sqlite3'],
+      'sources': ['<(SHARED_INTERMEDIATE_DIR)/sqlite3/sqlite3.c'],
+      'include_dirs': [
+        '<(SHARED_INTERMEDIATE_DIR)/sqlite3/',
+      ],
+      'direct_dependent_settings': {
+        'include_dirs': [
+          '@extension@/include',
+        ],
+      },
+      'cflags': ['-std=c99', '-w'],
+      'xcode_settings': {
+        'OTHER_CFLAGS': ['-std=c99'],
+        'WARNING_CFLAGS': ['-w'],
+      },
+      'includes': ['defines.gypi'],
+      'link_settings': {
+        'libraries': [
+          '@extension@/lib/libsignal_sqlcipher_extension@static_lib_ext@',
+        ]
+      }
+    },
+  ],
+}