diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
new file mode 100644
index 0000000..c374e64
--- /dev/null
+++ b/.github/workflows/e2e.yml
@@ -0,0 +1,28 @@
+name: "End-to-end tests"
+
+on:
+    push:
+        branches: ["main"]
+    pull_request:
+    workflow_dispatch:
+
+jobs:
+    e2e:
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v6
+              with:
+                  submodules: recursive
+
+            - name: Lix GHA Installer Action
+              uses: samueldr/lix-gha-installer-action@v2026-02-22
+              with:
+                  extra_nix_config: experimental-features = nix-command flakes flake-self-attrs
+
+            - name: Generate code
+              run: nix develop --command bash -c "flutter pub get && dart scripts/generate.dart && flutter pub run build_runner build"
+
+            - name: Run end-to-end tests
+              run: nix run .#e2e-headless
diff --git a/flake.lock b/flake.lock
index db5f957..be46f01 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,5 +1,99 @@
 {
   "nodes": {
+    "advisory-db": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1793979272,
+        "narHash": "sha256-oUcBtPbtS7PlEMuSrgTAN4wv49cXYbwKbQqhH2pah5w=",
+        "owner": "rustsec",
+        "repo": "advisory-db",
+        "rev": "309392b18f6b17022f82c701f300433126901068",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rustsec",
+        "repo": "advisory-db",
+        "type": "github"
+      }
+    },
+    "continuwuity": {
+      "inputs": {
+        "advisory-db": "advisory-db",
+        "crane": "crane",
+        "fenix": "fenix",
+        "flake-compat": "flake-compat",
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs",
+        "treefmt-nix": "treefmt-nix"
+      },
+      "locked": {
+        "lastModified": 1794250216,
+        "narHash": "sha256-IQcTJbLuxL9BxtTp9tjhC5NM8YvSfODbEP4wKXzc9gM=",
+        "ref": "refs/heads/quad/nexus",
+        "rev": "62b78e20b0f28a7a3c847cc4baa6223eeeed53f1",
+        "revCount": 8090,
+        "type": "git",
+        "url": "file:///home/quadradical/Documents/Code/continuwuity"
+      },
+      "original": {
+        "type": "git",
+        "url": "file:///home/quadradical/Documents/Code/continuwuity"
+      }
+    },
+    "crane": {
+      "locked": {
+        "lastModified": 1793836618,
+        "narHash": "sha256-TREenflwEjxOSq292FYwbc3kEm7TDRtXCZRNWEdjBmg=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "79fd63528501446749c09f08cad486a58c7d173e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "fenix": {
+      "inputs": {
+        "nixpkgs": [
+          "continuwuity",
+          "nixpkgs"
+        ],
+        "rust-analyzer-src": "rust-analyzer-src"
+      },
+      "locked": {
+        "lastModified": 1794142885,
+        "narHash": "sha256-xWFSr7q8IerDAVRk4W7/CgTmi05hMy2qjZ0z3VYpOVk=",
+        "owner": "nix-community",
+        "repo": "fenix",
+        "rev": "f7d416b5073152c7f2e4de1a28d1a4330dd30a26",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "fenix",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1767039857,
+        "narHash": "sha256-vNpUSpF5Nuw8xvDLj2KCwwksIbjua2LZCqhV1LNRDns=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "5edf11c44bc78a0d334f6334cdaf7d60d732daab",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "ref": "master",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib"
@@ -18,6 +112,24 @@
         "type": "github"
       }
     },
+    "flake-parts_2": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib_2"
+      },
+      "locked": {
+        "lastModified": 1793576659,
+        "narHash": "sha256-V1h85lUaJBQoHFrB2vpXZOE0Ju1MYSnIpsehoVZYlDo=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "ea2630b7470978622c7689a1ff75d2b389175399",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "inputs": {
         "systems": "systems"
@@ -39,7 +151,7 @@
     "nix2flatpak": {
       "inputs": {
         "flake-utils": "flake-utils",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs_2"
       },
       "locked": {
         "lastModified": 1791751882,
@@ -57,11 +169,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1773389992,
-        "narHash": "sha256-wvfdLLWJ2I9oEpDd9PfMA8osfIZicoQ5MT1jIwNs9Tk=",
+        "lastModified": 1794042290,
+        "narHash": "sha256-ziZn2PvCJE5JEEpqTdxXwJpPB+L3YqoCpTAMCzyaP3U=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "c06b4ae3d6599a672a6210b7021d699c351eebda",
+        "rev": "f4a03c008967841f2a0b3cb7c436fc6fc31671f6",
         "type": "github"
       },
       "original": {
@@ -86,7 +198,38 @@
         "type": "github"
       }
     },
+    "nixpkgs-lib_2": {
+      "locked": {
+        "lastModified": 1793504054,
+        "narHash": "sha256-ThkfL3D/FhCiZFc9+3BtxwuMmpuK+/bGtXCSo1+yVew=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "7851ba61fd862b277cb6a9cef37394bc18bb94e4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
     "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1773389992,
+        "narHash": "sha256-wvfdLLWJ2I9oEpDd9PfMA8osfIZicoQ5MT1jIwNs9Tk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "c06b4ae3d6599a672a6210b7021d699c351eebda",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_3": {
       "locked": {
         "lastModified": 1793540411,
         "narHash": "sha256-fiPJ88izTVucjeo2EQ3jk4aWmLg03I1D4vxnX2QjEgE=",
@@ -104,9 +247,27 @@
     },
     "root": {
       "inputs": {
-        "flake-parts": "flake-parts",
+        "continuwuity": "continuwuity",
+        "flake-parts": "flake-parts_2",
         "nix2flatpak": "nix2flatpak",
-        "nixpkgs": "nixpkgs_2"
+        "nixpkgs": "nixpkgs_3"
+      }
+    },
+    "rust-analyzer-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1794096810,
+        "narHash": "sha256-dWC+YtMX+cwH3e9ndiFB77ijTsKtO5I2OxfcvUY4j3k=",
+        "owner": "rust-lang",
+        "repo": "rust-analyzer",
+        "rev": "03ae6be57aa063bb373f69eead3b8e15168a45d2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rust-lang",
+        "ref": "nightly",
+        "repo": "rust-analyzer",
+        "type": "github"
       }
     },
     "systems": {
@@ -123,6 +284,27 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "continuwuity",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1791885023,
+        "narHash": "sha256-C3alQ2MEt0zVrUSho5NUDo3jmhbff72++bfwoqT9Omo=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "0d6d739a833ba9a9c93034862e4a7b061a062a1c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index e4cae8a..2074aa6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,6 +6,8 @@
     nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
     flake-parts.url = "github:hercules-ci/flake-parts";
     nix2flatpak.url = "github:neobrain/nix2flatpak";
+    # TEMPORARY: the e2e tests against a local Continuwuity checkout
+    continuwuity.url = "git+file:///home/quadradical/Documents/Code/continuwuity";
   };
 
   outputs =
diff --git a/integration_test/helpers/fakes.dart b/integration_test/helpers/fakes.dart
new file mode 100644
index 0000000..050eb99
--- /dev/null
+++ b/integration_test/helpers/fakes.dart
@@ -0,0 +1,47 @@
+import "dart:async";
+
+import "package:app_links_platform_interface/app_links_platform_interface.dart";
+import "package:url_launcher_platform_interface/link.dart";
+import "package:url_launcher_platform_interface/url_launcher_platform_interface.dart";
+
+/// Delivers links to the app as if the OS had opened them.
+class FakeAppLinks extends AppLinksPlatform {
+  final _links = StreamController<Uri>.broadcast();
+
+  void open(Uri uri) => _links.add(uri);
+
+  @override
+  Future<Uri?> getInitialLink() async => null;
+
+  @override
+  Future<String?> getInitialLinkString() async => null;
+
+  @override
+  Future<Uri?> getLatestLink() async => null;
+
+  @override
+  Future<String?> getLatestLinkString() async => null;
+
+  @override
+  Stream<Uri> get uriLinkStream => _links.stream;
+
+  @override
+  Stream<String> get stringLinkStream =>
+      _links.stream.map((uri) => uri.toString());
+}
+
+/// Hands launched URLs to [onLaunch] instead of opening a browser.
+class FakeUrlLauncher(final void Function(Uri url) onLaunch)
+    extends UrlLauncherPlatform {
+  @override
+  LinkDelegate? get linkDelegate => null;
+
+  @override
+  Future<bool> canLaunch(String url) async => true;
+
+  @override
+  Future<bool> launchUrl(String url, LaunchOptions options) async {
+    onLaunch(.parse(url));
+    return true;
+  }
+}
diff --git a/integration_test/helpers/matrix_user.dart b/integration_test/helpers/matrix_user.dart
new file mode 100644
index 0000000..bd2692c
--- /dev/null
+++ b/integration_test/helpers/matrix_user.dart
@@ -0,0 +1,174 @@
+import "dart:convert";
+
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:http/http.dart" as http;
+
+const homeserver = String.fromEnvironment("NEXUS_E2E_HOMESERVER");
+
+/// A user acting over the client-server API directly, as a control for the
+/// tests: it doesn't go through gomuks or any other Nexus code, so it sets
+/// things up and checks the server's side independently of what's being
+/// tested. That includes Nexus' models, so the JSON it sends is written out
+/// here rather than built the way Nexus builds it.
+class const MatrixUser(final String userId, final String accessToken) {
+  static Future<MatrixUser> login(String username, String password) async {
+    final json = await request(
+      "POST",
+      "/_matrix/client/v3/login",
+      body: {
+        "type": "m.login.password",
+        "identifier": {"type": "m.id.user", "user": username},
+        "password": password,
+      },
+    );
+    return MatrixUser(json["user_id"], json["access_token"]);
+  }
+
+  static Future<Map<String, dynamic>> request(
+    String method,
+    String path, {
+    String? accessToken,
+    Object? body,
+  }) async {
+    final httpRequest =
+        http.Request(method, Uri.parse(homeserver).resolve(path))
+          ..headers.addAll({
+            "Content-Type": "application/json",
+            if (accessToken != null) "Authorization": "Bearer $accessToken",
+          });
+    if (method != "GET") httpRequest.body = jsonEncode(body ?? {});
+    final response = await http.Response.fromStream(await httpRequest.send());
+
+    if (response.statusCode == 429) {
+      final retryAfter = jsonDecode(response.body)["retry_after_ms"] ?? 1000;
+      await Future.delayed(.new(milliseconds: retryAfter));
+      return request(method, path, accessToken: accessToken, body: body);
+    }
+    if (response.statusCode >= 300) {
+      throw StateError(
+        "$method $path failed with ${response.statusCode}: ${response.body}",
+      );
+    }
+    return jsonDecode(response.body);
+  }
+
+  Future<String> createRoom(String name) async => (await request(
+    "POST",
+    "/_matrix/client/v3/createRoom",
+    accessToken: accessToken,
+    body: {"name": name, "preset": "private_chat"},
+  ))["room_id"];
+
+  Future<void> invite(String roomId, String userId) => request(
+    "POST",
+    "/_matrix/client/v3/rooms/${Uri.encodeComponent(roomId)}/invite",
+    accessToken: accessToken,
+    body: {"user_id": userId},
+  );
+
+  Future<void> join(String roomId) => request(
+    "POST",
+    "/_matrix/client/v3/join/${Uri.encodeComponent(roomId)}",
+    accessToken: accessToken,
+  );
+
+  Future<void> logout() =>
+      request("POST", "/_matrix/client/v3/logout", accessToken: accessToken);
+
+  Future<String> sendEvent(
+    String roomId,
+    String type,
+    Map<String, Object> content,
+  ) async => (await request(
+    "PUT",
+    "/_matrix/client/v3/rooms/${Uri.encodeComponent(roomId)}/send/$type/"
+        "${DateTime.now().microsecondsSinceEpoch}",
+    accessToken: accessToken,
+    body: content,
+  ))["event_id"];
+
+  /// Sends a text message. With [threadRoot] it's a reply in that thread, and
+  /// otherwise with [replyTo] it's a reply to that event.
+  Future<String> send(
+    String roomId,
+    String body, {
+    String? threadRoot,
+    String? replyTo,
+  }) => sendEvent(roomId, "m.room.message", {
+    "msgtype": "m.text",
+    "body": body,
+    "m.relates_to": ?switch ((threadRoot, replyTo)) {
+      (final threadRoot?, _) => {
+        "rel_type": "m.thread",
+        "event_id": threadRoot,
+        "is_falling_back": true,
+        "m.in_reply_to": {"event_id": threadRoot},
+      },
+      (null, final replyTo?) => {
+        "m.in_reply_to": {"event_id": replyTo},
+      },
+      (null, null) => null,
+    },
+  });
+
+  /// Sends [rootBody], then [replies] in a thread from it, oldest first.
+  Future<({String rootId, IList<String> replyIds})> sendThread(
+    String roomId,
+    String rootBody,
+    IList<String> replies,
+  ) async {
+    final rootId = await send(roomId, rootBody);
+    // One at a time, so they're in order (oops earlier tests weren't reproducable)
+    final replyIds = await Stream.fromIterable(replies)
+        .asyncMap((body) => send(roomId, body, threadRoot: rootId))
+        .toList();
+    return (rootId: rootId, replyIds: replyIds.toIList());
+  }
+
+  /// Edits the text message [eventId] to say [body].
+  Future<String> edit(String roomId, String eventId, String body) =>
+      sendEvent(roomId, "m.room.message", {
+        "msgtype": "m.text",
+        "body": "* $body",
+        "m.new_content": {"msgtype": "m.text", "body": body},
+        "m.relates_to": {"rel_type": "m.replace", "event_id": eventId},
+      });
+
+  Future<void> redact(String roomId, String eventId) => request(
+    "PUT",
+    "/_matrix/client/v3/rooms/${Uri.encodeComponent(roomId)}/redact/"
+        "${Uri.encodeComponent(eventId)}/${DateTime.now().microsecondsSinceEpoch}",
+    accessToken: accessToken,
+  );
+
+  /// The bodies of the replies in the thread from [threadRoot], oldest first.
+  Future<IList<String>> threadReplies(String roomId, String threadRoot) async {
+    final json = await request(
+      "GET",
+      "/_matrix/client/v1/rooms/${Uri.encodeComponent(roomId)}/relations/"
+          "${Uri.encodeComponent(threadRoot)}/m.thread?dir=f&limit=100",
+      accessToken: accessToken,
+    );
+    return (json["chunk"] as List)
+        .map((event) => event["content"]["body"] as String)
+        .toIList();
+  }
+
+  Future<IList<String>> threadRepliesIncluding(
+    String roomId,
+    String threadRoot,
+    String body, {
+    int attempts = 20,
+  }) async {
+    final replies = await threadReplies(roomId, threadRoot);
+    if (replies.contains(body) || attempts <= 1) return replies;
+
+    await Future.delayed(const .new(milliseconds: 500));
+    return threadRepliesIncluding(
+      roomId,
+      threadRoot,
+      body,
+      attempts: attempts - 1,
+    );
+  }
+}
diff --git a/integration_test/helpers/oauth.dart b/integration_test/helpers/oauth.dart
new file mode 100644
index 0000000..be652d7
--- /dev/null
+++ b/integration_test/helpers/oauth.dart
@@ -0,0 +1,68 @@
+import "package:http/http.dart" as http;
+
+import "fakes.dart";
+
+/// Fake platforms that do the browser's part of OAuth on Continuwuity, logging
+/// in as [username], then hand the redirect back to Nexus.
+class OAuthFakes(final String username, final String password) {
+  final links = FakeAppLinks();
+  late final launcher = FakeUrlLauncher(onLaunch);
+
+  Future<void> onLaunch(Uri url) async {
+    if (!url.queryParameters.containsKey("code_challenge")) return;
+
+    final redirect = await authorize(url);
+    // Nexus listens for the redirect after the launch returns
+    await Future.delayed(const .new(milliseconds: 500));
+    links.open(redirect);
+  }
+
+  /// Logs in on [authorizationUrl], then confirms the grant, returning the URI
+  /// Continuwuity redirects back to the app with.
+  Future<Uri> authorize(Uri authorizationUrl) async {
+    final client = http.Client();
+    String? cookie;
+
+    Future<Uri> followRedirect(
+      String method,
+      Uri url, [
+      Map<String, String>? form,
+    ]) async {
+      final request = http.Request(method, url)
+        ..followRedirects = false
+        ..headers.addAll({
+          // Continuwuity only accepts its forms from top-level navigations
+          "Sec-Fetch-Site": "same-origin",
+          "Sec-Fetch-Mode": "navigate",
+          "Sec-Fetch-Dest": "document",
+          "Cookie": ?cookie,
+        });
+      if (form != null) request.bodyFields = form;
+
+      final response = await http.Response.fromStream(
+        await client.send(request),
+      );
+      if (response.headers["set-cookie"] case final setCookie?) {
+        cookie = setCookie.split(";").first;
+      }
+
+      return switch ((response.statusCode, response.headers["location"])) {
+        (302 || 303 || 307, final location?) => url.resolve(location),
+        (final status, _) => throw StateError(
+          "Expected $method $url to redirect, got $status: ${response.body}",
+        ),
+      };
+    }
+
+    try {
+      final loginUrl = await followRedirect("GET", authorizationUrl);
+      final grantUrl = await followRedirect("POST", loginUrl, {
+        "identifier": username,
+        "password": password,
+      });
+      return await followRedirect("POST", grantUrl, {"stage": "confirm"});
+    } finally {
+      client.close();
+    }
+  }
+}
diff --git a/integration_test/helpers/pump_until.dart b/integration_test/helpers/pump_until.dart
new file mode 100644
index 0000000..5f278f4
--- /dev/null
+++ b/integration_test/helpers/pump_until.dart
@@ -0,0 +1,56 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/widgets/error_dialog.dart";
+
+// Custom because `patrol_finder` gives me jQuery vibes, and that's Not GoodTM
+extension PumpUntil on WidgetTester {
+  /// Pumps until [finder] finds something, failing if it doesn't within 30
+  /// seconds, or if the app shows an error.
+  Future<void> pumpUntil(Finder finder) async {
+    const timeout = Duration(seconds: 30);
+
+    String textsIn(Finder finder) => widgetList<Text>(
+      find.descendant(of: finder, matching: find.byType(Text)),
+    ).map((text) => text.data).nonNulls.join("\n");
+
+    final stopwatch = Stopwatch()..start();
+    while (stopwatch.elapsed < timeout) {
+      await pump(const .new(milliseconds: 100));
+
+      if (finder.evaluate().isNotEmpty) return;
+
+      final errorDialog = find.byType(ErrorDialog);
+      if (errorDialog.evaluate().isNotEmpty) {
+        fail(
+          "The app showed an error while waiting for $finder:\n"
+          "${textsIn(errorDialog)}",
+        );
+      }
+    }
+
+    final snackBar = find.byType(SnackBar);
+    final shown = find
+        .byType(RichText)
+        .hitTestable()
+        .evaluate()
+        .map((element) => (element.widget as RichText).text.toPlainText())
+        .where((text) => text.trim().isNotEmpty)
+        .toIList()
+        .removeDuplicates()
+        .join(" | ");
+    fail(
+      "Timed out after $timeout waiting for $finder"
+      "${snackBar.evaluate().isEmpty ? "" : "\nSnack bar: ${textsIn(snackBar)}"}"
+      "\nShown: $shown",
+    );
+  }
+
+  /// Taps [finder] once it can be tapped, like after animating in.
+  Future<void> tapWhenShown(Finder finder) async {
+    final tappable = finder.hitTestable();
+    await pumpUntil(tappable);
+    await tap(tappable.first);
+    await pump();
+  }
+}
diff --git a/integration_test/helpers/test_app.dart b/integration_test/helpers/test_app.dart
new file mode 100644
index 0000000..d6724c0
--- /dev/null
+++ b/integration_test/helpers/test_app.dart
@@ -0,0 +1,115 @@
+import "package:app_links_platform_interface/app_links_platform_interface.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:material_ui/material_ui.dart";
+import "package:media_kit/media_kit.dart";
+import "package:nexus/controllers/active_account.dart";
+import "package:nexus/main.dart" as nexus;
+import "package:nexus/widgets/account_scope.dart";
+import "package:nexus/widgets/pages/chat.dart";
+import "package:nexus/widgets/pages/select_server.dart";
+import "package:nexus/widgets/pages/verify.dart";
+import "package:nexus/widgets/room_chat/room_chat.dart";
+import "package:url_launcher_platform_interface/url_launcher_platform_interface.dart";
+
+import "matrix_user.dart";
+import "oauth.dart";
+import "pump_until.dart";
+
+/// Nexus, run as the account [username], which is set up through the UI the
+/// first time it's opened.
+class TestApp(final String username, final String password) {
+  late final fakes = OAuthFakes(username, password);
+
+  void setUp() {
+    nexus.isInBackground = false;
+    MediaKit.ensureInitialized();
+    AppLinksPlatform.instance = fakes.links;
+    UrlLauncherPlatform.instance = fakes.launcher;
+
+    // A tap that misses would otherwise only warn
+    WidgetController.hitTestWarningShouldBeFatal = true;
+  }
+
+  Future<void> join(MatrixUser inviter, String roomId) async {
+    final user = await MatrixUser.login(username, password);
+    await inviter.invite(roomId, user.userId);
+    await user.join(roomId);
+    await user.logout();
+  }
+
+  /// Starts Nexus like [open], then opens [roomName].
+  Future<void> openRoom(WidgetTester tester, String roomName) async {
+    await open(tester);
+    await selectRoom(tester, roomName);
+  }
+
+  /// Taps [roomName] in the room list, opening the drawer it's in first when
+  /// the window is narrow enough for the mobile layout.
+  Future<void> selectRoom(WidgetTester tester, String roomName) async {
+    // Shown once the first sync is done, as is the drawer button on mobile
+    await tester.pumpUntil(find.byType(RoomChat));
+
+    final drawerButton = find
+        .byTooltip(const DefaultMaterialLocalizations().openAppDrawerTooltip)
+        .hitTestable();
+    if (drawerButton.evaluate().isNotEmpty) await tester.tap(drawerButton);
+    await tester.tapWhenShown(find.text(roomName));
+  }
+
+  /// Starts Nexus, logged in and verified, logging in and setting up
+  /// encryption through the UI first if it isn't.
+  Future<void> open(WidgetTester tester) async {
+    await tester.pumpWidget(
+      AccountScope(
+        initialAccountId: await ActiveAccountController.stored(),
+        retry: (_, _) => null,
+        child: nexus.App(),
+      ),
+    );
+
+    await tester.pumpUntil(
+      find.byWidgetPredicate(
+        (widget) =>
+            widget is SelectServerPage ||
+            widget is VerifyPage ||
+            widget is ChatPage,
+      ),
+    );
+    if (find.byType(SelectServerPage).evaluate().isNotEmpty) {
+      await logIn(tester);
+    }
+    if (find.byType(VerifyPage).evaluate().isNotEmpty) {
+      await setUpEncryption(tester);
+    }
+    await tester.pumpUntil(find.byType(ChatPage));
+  }
+
+  Future<void> logIn(WidgetTester tester) async {
+    final homeserverField = find.widgetWithText(TextField, "Homeserver URL");
+    await tester.pumpUntil(homeserverField);
+    await tester.enterText(homeserverField, homeserver);
+    await tester.testTextInput.receiveAction(.done);
+
+    // Discovery only uses HTTPS, which the test homeserver doesn't serve, so
+    // Nexus offers to log in with the URL as typed
+    await tester.tapWhenShown(find.text("Attempt log in anyways"));
+
+    // Nexus opens the authorization page, which fakes authorizes
+    await tester.pumpUntil(
+      find.byWidgetPredicate(
+        (widget) => widget is VerifyPage || widget is ChatPage,
+      ),
+    );
+  }
+
+  /// Sets up encryption from the verify page, for an account without it.
+  Future<void> setUpEncryption(WidgetTester tester) async {
+    await tester.pumpUntil(find.text("Set Up Encryption"));
+    await tester.tapWhenShown(find.widgetWithText(TextButton, "Set Up"));
+
+    await tester.tapWhenShown(find.text("I've saved my recovery key"));
+    await tester.tapWhenShown(find.widgetWithText(TextButton, "Set Up"));
+
+    await tester.tapWhenShown(find.widgetWithText(TextButton, "Done"));
+  }
+}
diff --git a/integration_test/helpers/threads.dart b/integration_test/helpers/threads.dart
new file mode 100644
index 0000000..d2eee0d
--- /dev/null
+++ b/integration_test/helpers/threads.dart
@@ -0,0 +1,34 @@
+import "package:flutter_test/flutter_test.dart";
+import "package:material_ui/material_ui.dart";
+
+import "pump_until.dart";
+
+extension MessageFinders on CommonFinders {
+  Finder message(String body) => textContaining(body, findRichText: true);
+}
+
+extension RelativeFinders on Finder {
+  Finder inside(Type type) =>
+      find.descendant(of: find.byType(type), matching: this);
+
+  /// The [InkWell] ancestor around what this finds
+  Finder get inkWell => find.ancestor(of: this, matching: find.byType(InkWell));
+}
+
+extension ReplyCounts on WidgetTester {
+  /// Waits for a reply count in widgets of [type], then checks it, so a wrong
+  /// count fails straight away with what was shown.
+  Future<void> expectReplyCount(Type type, int expected) async {
+    final repliesLabel = RegExp(r"^(\d+) repl(?:y|ies)$");
+    final labels = find.textContaining(repliesLabel).inside(type);
+    await pumpUntil(labels);
+
+    final shown = widgetList<Text>(labels)
+        .map((label) => label.data)
+        .nonNulls
+        .map(repliesLabel.firstMatch)
+        .nonNulls
+        .map((match) => int.parse(match[1]!));
+    expect(shown, everyElement(expected), reason: "Reply count in $type");
+  }
+}
diff --git a/integration_test/links_test.dart b/integration_test/links_test.dart
new file mode 100644
index 0000000..7690cd7
--- /dev/null
+++ b/integration_test/links_test.dart
@@ -0,0 +1,56 @@
+import "package:flutter_test/flutter_test.dart";
+import "package:integration_test/integration_test.dart";
+import "package:nexus/widgets/room_chat/room_chat.dart";
+import "package:nexus/widgets/room_summary_sheet.dart";
+import "package:nexus/widgets/user_bottom_sheet.dart";
+
+import "helpers/matrix_user.dart";
+import "helpers/test_app.dart";
+import "helpers/pump_until.dart";
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  final app = TestApp("dave", "davepass");
+  setUpAll(app.setUp);
+  final run = DateTime.now().millisecondsSinceEpoch;
+  Future<MatrixUser> bob() => MatrixUser.login("bob", "bobpass");
+
+  Future<void> openLink(WidgetTester tester, String link) async {
+    await app.open(tester);
+    app.fakes.links.open(.parse(link));
+  }
+
+  group("a link opened by the OS", () {
+    testWidgets("to a user opens their popover", (tester) async {
+      await openLink(tester, "matrix:u/bob:localhost");
+
+      await tester.pumpUntil(find.byType(UserBottomSheet));
+    });
+
+    testWidgets("to a joined room opens it", (tester) async {
+      final inviter = await bob();
+      final roomId = await inviter.createRoom("Linked $run");
+      // Joined before Nexus starts, so the room is there once it syncs
+      await app.join(inviter, roomId);
+
+      await openLink(tester, "matrix:roomid/${roomId.substring(1)}");
+
+      await tester.pumpUntil(
+        find.byWidgetPredicate(
+          (widget) => widget is RoomChat && widget.roomId == roomId,
+        ),
+      );
+    });
+
+    testWidgets("to a room that isn't joined shows its summary", (
+      tester,
+    ) async {
+      final roomId = await (await bob()).createRoom("Unjoined $run");
+
+      await openLink(tester, "matrix:roomid/${roomId.substring(1)}");
+
+      await tester.pumpUntil(find.byType(RoomSummarySheet));
+    });
+  });
+}
diff --git a/integration_test/long_thread_test.dart b/integration_test/long_thread_test.dart
new file mode 100644
index 0000000..b292c12
--- /dev/null
+++ b/integration_test/long_thread_test.dart
@@ -0,0 +1,115 @@
+import "package:fast_immutable_collections/fast_immutable_collections.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:integration_test/integration_test.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/widgets/room_chat/room_chat.dart";
+import "package:nexus/widgets/thread_drawer.dart";
+import "package:nexus/widgets/threads_drawer.dart";
+
+import "helpers/matrix_user.dart";
+import "helpers/test_app.dart";
+import "helpers/pump_until.dart";
+import "helpers/threads.dart";
+
+/// A thread longer than gomuks' initial sync, which gets the latest 100
+/// events, so its start only reaches Nexus through `/relations`. That needs
+/// an account whose first sync is after the thread exists, so it's not the one
+/// other tests use.
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  final app = TestApp("carol", "carolpass");
+  setUpAll(app.setUp);
+  final run = DateTime.now().millisecondsSinceEpoch;
+  final roomName = "Long thread $run";
+  final rootBody = "Long thread root $run";
+  const replyCount = 120;
+  // Among the first replies, which aren't synced
+  const jumpedTo = 10;
+  // Padded, so no reply's text contains another's (oops those failures were confusing when I didn't do that)
+  String reply(int number) => "Long reply ${number.toString().padLeft(3, "0")}";
+
+  setUpAll(() async {
+    final bob = await MatrixUser.login("bob", "bobpass");
+    final roomId = await bob.createRoom(roomName);
+    await app.join(bob, roomId);
+
+    final thread = await bob.sendThread(
+      roomId,
+      rootBody,
+      Iterable.generate(replyCount, (index) => reply(index + 1)).toIList(),
+    );
+    // In the room's timeline, so there's something to jump from, to a reply
+    // with others on both sides that aren't synced either
+    await bob.send(
+      roomId,
+      "Quoting an old reply",
+      replyTo: thread.replyIds[jumpedTo - 1],
+    );
+  });
+
+  /// Drags the open thread by [offset] until [finder] is shown in it, loading
+  /// more replies as it goes, for up to 30 seconds.
+  Future<void> scrollThread(
+    WidgetTester tester,
+    Finder finder,
+    Offset offset,
+  ) => tester.dragUntilVisible(
+    finder.inside(ThreadDrawer),
+    find.byType(CustomScrollView).inside(ThreadDrawer).first,
+    offset,
+    maxIteration: 60,
+    duration: const .new(milliseconds: 500),
+  );
+
+  Future<void> openThreadsDrawer(WidgetTester tester) async {
+    await app.openRoom(tester, roomName);
+    await tester.tapWhenShown(find.byTooltip("Open threads"));
+    await tester.pumpUntil(find.message(rootBody).inside(ThreadsDrawer));
+  }
+
+  testWidgets("lists the thread with all of its replies", (tester) async {
+    await openThreadsDrawer(tester);
+
+    await tester.expectReplyCount(ThreadsDrawer, replyCount);
+  });
+
+  // Before the whole thread is loaded by scrolling through it below
+  testWidgets("jumps to a reply in the thread that isn't loaded", (
+    tester,
+  ) async {
+    await app.openRoom(tester, roomName);
+
+    // The quote of the reply is fetched on its own, then tapped
+    await tester.tapWhenShown(
+      find.message(reply(jumpedTo)).inside(RoomChat).inkWell,
+    );
+
+    // The thread opens around the reply, with replies on both sides
+    await tester.pumpUntil(
+      find.message(reply(jumpedTo)).inside(ThreadDrawer).hitTestable(),
+    );
+    await tester.pumpUntil(
+      find.message(reply(jumpedTo - 1)).inside(ThreadDrawer),
+    );
+    await tester.pumpUntil(
+      find.message(reply(jumpedTo + 1)).inside(ThreadDrawer),
+    );
+
+    await scrollThread(tester, find.message(reply(60)), const .new(0, -400));
+  });
+
+  testWidgets("loads older replies back to the root", (tester) async {
+    await openThreadsDrawer(tester);
+    await tester.tapWhenShown(
+      find.message(rootBody).inside(ThreadsDrawer).inkWell,
+    );
+    await tester.pumpUntil(
+      find.message(reply(replyCount)).inside(ThreadDrawer),
+    );
+
+    // Dragging down scrolls up the reversed timeline, to older replies
+    await scrollThread(tester, find.message(rootBody), const .new(0, 400));
+    expect(find.message(reply(1)).inside(ThreadDrawer), findsWidgets);
+  });
+}
diff --git a/integration_test/threads_test.dart b/integration_test/threads_test.dart
new file mode 100644
index 0000000..6eba136
--- /dev/null
+++ b/integration_test/threads_test.dart
@@ -0,0 +1,258 @@
+import "package:flutter_test/flutter_test.dart";
+import "package:integration_test/integration_test.dart";
+import "package:material_ui/material_ui.dart";
+import "package:nexus/widgets/composer/composer.dart";
+import "package:nexus/widgets/room_chat/room_chat.dart";
+import "package:nexus/widgets/thread_drawer.dart";
+import "package:nexus/widgets/thread_summary.dart";
+import "package:nexus/widgets/threads_drawer.dart";
+
+import "helpers/matrix_user.dart";
+import "helpers/test_app.dart";
+import "helpers/pump_until.dart";
+import "helpers/threads.dart";
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  final app = TestApp("alice", "alicepass");
+  setUpAll(app.setUp);
+  final run = DateTime.now().millisecondsSinceEpoch;
+  late MatrixUser bob;
+
+  setUpAll(() async => bob = await MatrixUser.login("bob", "bobpass"));
+
+  /// Opens [roomName], waiting for the thread from [rootBody] in its timeline.
+  Future<void> openRoom(
+    WidgetTester tester,
+    String roomName,
+    String rootBody,
+  ) async {
+    await app.openRoom(tester, roomName);
+    await tester.pumpUntil(
+      find.message(rootBody).inside(RoomChat).hitTestable(),
+    );
+  }
+
+  /// Opens the thread from the room's summary, waiting for [reply] in it.
+  Future<void> openThread(WidgetTester tester, String reply) async {
+    await tester.tapWhenShown(find.byType(ThreadSummary));
+    await tester.pumpUntil(find.message(reply).inside(ThreadDrawer));
+  }
+
+  group("a thread", () {
+    final roomName = "Threads $run";
+    final rootBody = "Thread root $run";
+    const firstReply = "First reply";
+    const secondReply = "Second reply";
+
+    late String roomId;
+    late String rootId;
+
+    setUpAll(() async {
+      roomId = await bob.createRoom(roomName);
+      // Joined before Nexus logs in, so the room is there once it does
+      await app.join(bob, roomId);
+
+      rootId = (await bob.sendThread(
+        roomId,
+        rootBody,
+        .new([firstReply, secondReply]),
+      )).rootId;
+    });
+
+    Future<int> replyCount() async =>
+        (await bob.threadReplies(roomId, rootId)).length;
+
+    testWidgets("logs in with OAuth and sets up encryption", (tester) async {
+      await app.open(tester);
+
+      await app.selectRoom(tester, roomName);
+    });
+
+    testWidgets("summarises the thread under its root", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+
+      await tester.expectReplyCount(ThreadSummary, 2);
+      expect(find.message(secondReply).inside(ThreadSummary), findsWidgets);
+      // Replies are in the thread, not the room's timeline
+      expect(find.message(firstReply), findsNothing);
+    });
+
+    testWidgets("lists the thread in the threads drawer", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+      await tester.tapWhenShown(find.byTooltip("Open threads"));
+
+      await tester.pumpUntil(find.message(rootBody).inside(ThreadsDrawer));
+      await tester.expectReplyCount(ThreadsDrawer, 2);
+      expect(find.text("Last active:").inside(ThreadsDrawer), findsOneWidget);
+    });
+
+    testWidgets("opens the thread from the threads drawer", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+      await tester.tapWhenShown(find.byTooltip("Open threads"));
+      await tester.tapWhenShown(
+        find.message(rootBody).inside(ThreadsDrawer).inkWell,
+      );
+
+      await tester.pumpUntil(find.message(secondReply).inside(ThreadDrawer));
+    });
+
+    testWidgets("shows the root and its replies, oldest first", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+      await openThread(tester, secondReply);
+
+      final root = find.message(rootBody).inside(ThreadDrawer).first;
+      final first = find.message(firstReply).inside(ThreadDrawer).first;
+      final second = find.message(secondReply).inside(ThreadDrawer).first;
+      expect(root, findsOneWidget);
+      expect(first, findsOneWidget);
+      expect(
+        tester.getTopLeft(root).dy,
+        lessThan(tester.getTopLeft(first).dy),
+        reason: "The root should be above the replies",
+      );
+      expect(
+        tester.getTopLeft(first).dy,
+        lessThan(tester.getTopLeft(second).dy),
+        reason: "Older replies should be above newer ones",
+      );
+    });
+
+    testWidgets("sends replies to the thread", (tester) async {
+      final body = "Reply from Nexus $run";
+      final before = await replyCount();
+      await openRoom(tester, roomName, rootBody);
+      await openThread(tester, secondReply);
+
+      final composer = find
+          .widgetWithText(TextField, "Your message here...")
+          .inside(ThreadDrawer);
+      await tester.pumpUntil(composer);
+      await tester.enterText(composer, body);
+      await tester.tapWhenShown(
+        find.byTooltip("Send message").inside(ThreadDrawer),
+      );
+      await tester.pumpUntil(find.message(body).inside(ThreadDrawer));
+
+      // It's in the thread for other clients too
+      final replies = await bob.threadRepliesIncluding(roomId, rootId, body);
+      expect(replies.last, body);
+
+      // Shown as the latest reply once the summary has caught up
+      await tester.pumpUntil(find.message(body).inside(ThreadSummary));
+      await tester.expectReplyCount(ThreadSummary, before + 1);
+      expect(
+        find.text(body).inside(Composer),
+        findsNothing,
+        reason: "The composer should be cleared once sent",
+      );
+    });
+
+    testWidgets("shows replies from others as they arrive", (tester) async {
+      final body = "Live reply $run";
+      await openRoom(tester, roomName, rootBody);
+      await openThread(tester, secondReply);
+
+      final before = await replyCount();
+      await bob.send(roomId, body, threadRoot: rootId);
+
+      await tester.pumpUntil(find.message(body).inside(ThreadDrawer));
+      await tester.pumpUntil(find.message(body).inside(ThreadSummary));
+      await tester.expectReplyCount(ThreadSummary, before + 1);
+    });
+  });
+
+  group("redactions", () {
+    final roomName = "Redactions $run";
+    final rootBody = "Redaction root $run";
+    const keptReply = "Kept reply";
+    const redactedReply = "Redacted reply";
+
+    late String roomId;
+    late String rootId;
+    late String redactedId;
+
+    setUpAll(() async {
+      roomId = await bob.createRoom(roomName);
+      await app.join(bob, roomId);
+
+      final thread = await bob.sendThread(
+        roomId,
+        rootBody,
+        .new([keptReply, redactedReply]),
+      );
+      rootId = thread.rootId;
+      redactedId = thread.replyIds.last;
+    });
+
+    testWidgets("drops a redacted reply from its thread", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+      await tester.expectReplyCount(ThreadSummary, 2);
+
+      await bob.redact(roomId, redactedId);
+
+      // The reply before it becomes the latest
+      await tester.pumpUntil(find.message(keptReply).inside(ThreadSummary));
+      await tester.expectReplyCount(ThreadSummary, 1);
+
+      await openThread(tester, keptReply);
+      expect(find.message(redactedReply).inside(ThreadDrawer), findsNothing);
+    });
+
+    testWidgets("still opens the thread of a redacted root", (tester) async {
+      await bob.redact(roomId, rootId);
+      await app.openRoom(tester, roomName);
+      await tester.tapWhenShown(find.byTooltip("Open threads"));
+
+      // The root's preview is redacted, so the card is found by its count
+      await tester.tapWhenShown(
+        find.text("1 reply").inside(ThreadsDrawer).inkWell,
+      );
+
+      final root = find.text("Redacted event").inside(ThreadDrawer);
+      final reply = find.message(keptReply).inside(ThreadDrawer);
+      await tester.pumpUntil(root);
+      await tester.pumpUntil(reply);
+      expect(
+        tester.getTopLeft(root.first).dy,
+        lessThan(tester.getTopLeft(reply.first).dy),
+        reason: "The redacted root should still be above the replies",
+      );
+    });
+  });
+
+  group("edits", () {
+    final roomName = "Edits $run";
+    final rootBody = "Edit root $run";
+    const originalReply = "Reply before editing";
+    const editedReply = "Reply after editing";
+
+    late String roomId;
+    late String replyId;
+
+    setUpAll(() async {
+      roomId = await bob.createRoom(roomName);
+      await app.join(bob, roomId);
+
+      final thread = await bob.sendThread(
+        roomId,
+        rootBody,
+        .new([originalReply]),
+      );
+      replyId = thread.replyIds.single;
+    });
+
+    testWidgets("shows an edited reply's new text", (tester) async {
+      await openRoom(tester, roomName, rootBody);
+      await tester.pumpUntil(find.message(originalReply).inside(ThreadSummary));
+
+      await bob.edit(roomId, replyId, editedReply);
+
+      await tester.pumpUntil(find.message(editedReply).inside(ThreadSummary));
+      await openThread(tester, editedReply);
+      expect(find.message(originalReply).inside(ThreadDrawer), findsNothing);
+      expect(find.text("(edited)").inside(ThreadDrawer), findsOneWidget);
+    });
+  });
+}
diff --git a/linux/nix/build_env.nix b/linux/nix/build_env.nix
new file mode 100644
index 0000000..cac5fbd
--- /dev/null
+++ b/linux/nix/build_env.nix
@@ -0,0 +1,30 @@
+{ pkgs, lib }:
+# What building Nexus needs, shared by the dev shell and the e2e tests
+{
+  packages =
+    with pkgs;
+    [
+      stdenv.cc
+      go
+      git
+
+      libGL
+      (flutter.override {
+        extraPkgConfigPackages = [
+          mpv-unwrapped
+          libass
+        ];
+      })
+    ]
+    ++ lib.optionals pkgs.stdenv.isLinux [
+      wayland
+      # nativeapi includes XInput2.h, which needs these, but xi.pc only lists them privately
+      libxext
+      libxfixes
+      (callPackage ./pkg/hook_pkg_config.nix { })
+    ];
+
+  env = lib.optionalAttrs pkgs.stdenv.isLinux {
+    LD_LIBRARY_PATH = "./build/native_assets/linux:${lib.makeLibraryPath [ pkgs.zlib ]}";
+  };
+}
diff --git a/linux/nix/default.nix b/linux/nix/default.nix
index 3c0a301..3d3b395 100644
--- a/linux/nix/default.nix
+++ b/linux/nix/default.nix
@@ -54,6 +54,52 @@
         };
 
       devShells.default = pkgs.callPackage ./devshell.nix { };
+
+      apps =
+        let
+          buildEnv = import ./build_env.nix { inherit pkgs lib; };
+          e2e = pkgs.writeShellApplication {
+            name = "nexus-e2e";
+            runtimeInputs =
+              buildEnv.packages
+              ++ (with pkgs; [
+                # TEMPORARY: matrix-continuwuity, once the local fixes are released
+                inputs.continuwuity.packages.${system}.default
+                curl
+                dbus
+              ]);
+            runtimeEnv = buildEnv.env;
+            text = builtins.readFile ./e2e.sh;
+          };
+        in
+        {
+          e2e = {
+            type = "app";
+            program = lib.getExe e2e;
+          };
+
+          e2e-headless = {
+            type = "app";
+            program = lib.getExe (
+              pkgs.writeShellApplication {
+                name = "nexus-e2e-headless";
+                runtimeInputs = [ pkgs.cage ];
+                runtimeEnv = {
+                  WLR_BACKENDS = "headless";
+                  __EGL_VENDOR_LIBRARY_FILENAMES = "${pkgs.mesa}/share/glvnd/egl_vendor.d/50_mesa.json";
+                };
+                text = ''
+                  unset DISPLAY WAYLAND_DISPLAY
+                  # Wayland needs one, which CI may not have
+                  XDG_RUNTIME_DIR="''${XDG_RUNTIME_DIR:-$(mktemp -d)}"
+                  export XDG_RUNTIME_DIR
+
+                  exec cage -- ${lib.getExe e2e} "$@"
+                '';
+              }
+            );
+          };
+        };
     };
 
   flake.nixosModules.default = import ./module.nix self;
diff --git a/linux/nix/devshell.nix b/linux/nix/devshell.nix
index f4bf1c6..cc2223e 100644
--- a/linux/nix/devshell.nix
+++ b/linux/nix/devshell.nix
@@ -20,41 +20,20 @@ let
     includeNDK = true;
     ndkVersions = [ "28.2.13676358" ];
   };
+  buildEnv = import ./build_env.nix { inherit pkgs lib; };
 in
 pkgs.mkShell {
-  packages =
-    with pkgs;
-    [
-      go
-      git
+  packages = buildEnv.packages ++ [ android.platform-tools ];
 
-      libGL
-      (flutter.override {
-        extraPkgConfigPackages = [
-          mpv-unwrapped
-          libass
-        ];
-      })
-      android.platform-tools
-    ]
-    ++ lib.optionals pkgs.stdenv.isLinux [
-      wayland
-      # nativeapi includes XInput2.h, which needs these, but xi.pc only lists them privately
-      libxext
-      libxfixes
-      (callPackage ./pkg/hook_pkg_config.nix { })
-    ];
+  env =
+    rec {
+      LIBCLANG_PATH = lib.makeLibraryPath [ pkgs.libclang ];
 
-  env = rec {
-    LIBCLANG_PATH = lib.makeLibraryPath [ pkgs.libclang ];
+      ANDROID_HOME = "${android.androidsdk}/libexec/android-sdk";
+      ANDROID_SDK_ROOT = ANDROID_HOME;
+      JAVA_HOME = pkgs.jdk21;
 
-    ANDROID_HOME = "${android.androidsdk}/libexec/android-sdk";
-    ANDROID_SDK_ROOT = ANDROID_HOME;
-    JAVA_HOME = pkgs.jdk21;
-
-    GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${ANDROID_HOME}/build-tools/36.0.0/aapt2";
-  }
-  // lib.optionalAttrs pkgs.stdenv.isLinux {
-    LD_LIBRARY_PATH = "./build/native_assets/linux:${lib.makeLibraryPath [ pkgs.zlib ]}";
-  };
+      GRADLE_OPTS = "-Dorg.gradle.project.android.aapt2FromMavenOverride=${ANDROID_HOME}/build-tools/36.0.0/aapt2";
+    }
+    // buildEnv.env;
 }
diff --git a/linux/nix/e2e.sh b/linux/nix/e2e.sh
new file mode 100755
index 0000000..6cc9f09
--- /dev/null
+++ b/linux/nix/e2e.sh
@@ -0,0 +1,77 @@
+# shellcheck shell=bash
+
+files=()
+flutter_args=()
+for arg in "$@"; do
+    if [[ "$arg" == *.dart ]]; then files+=("$arg"); else flutter_args+=("$arg"); fi
+done
+if [[ ${#files[@]} -eq 0 ]]; then files=(integration_test/*_test.dart); fi
+
+homeserver="http://localhost:8448"
+
+if curl -s -o /dev/null "$homeserver"; then
+    echo "Something is already using port 8448, like another e2e run." >&2
+    exit 1
+fi
+
+work="$(mktemp -d)"
+# shellcheck disable=SC2329 # Run by the trap
+cleanup() {
+    [[ -n "${server_pid:-}" ]] && kill "$server_pid" 2>/dev/null && wait "$server_pid" 2>/dev/null
+    rm -rf "$work"
+}
+trap cleanup EXIT
+
+mkdir -p "$work/db"
+cat > "$work/continuwuity.toml" <<EOF
+[global]
+server_name = "localhost"
+database_path = "$work/db"
+address = ["127.0.0.1", "::1"]
+port = 8448
+
+[global.well_known]
+client = "$homeserver"
+EOF
+
+users=(alice bob carol dave)
+create_users=()
+for user in "${users[@]}"; do
+    create_users+=(--execute "users create-user $user ${user}pass")
+done
+
+echo "Starting Continuwuity (log: $work/continuwuity.log)..."
+conduwuit -c "$work/continuwuity.toml" "${create_users[@]}" \
+    > "$work/continuwuity.log" 2>&1 &
+server_pid=$!
+
+all_can_log_in() {
+    for user in "${users[@]}"; do
+        curl -sf -XPOST "$homeserver/_matrix/client/v3/login" \
+            -d "{\"type\":\"m.login.password\",\"identifier\":{\"type\":\"m.id.user\",\"user\":\"$user\"},\"password\":\"${user}pass\"}" \
+            > /dev/null || return 1
+    done
+}
+
+# Wait until login succeeds, otherwise you might try to log in before the account is created
+attempts=60
+until all_can_log_in; do
+    kill -0 "$server_pid" 2>/dev/null || { cat "$work/continuwuity.log"; exit 1; }
+    (( --attempts )) || { echo "Test users weren't created" >&2; exit 1; }
+    sleep 0.5
+done
+
+GOCACHE="$(go env GOCACHE)"
+export GOCACHE
+
+status=0
+for file in "${files[@]}"; do
+    name="$(basename "$file" .dart)"
+    mkdir -p "$work/$name/data" "$work/$name/cache"
+    XDG_DATA_HOME="$work/$name/data" XDG_CACHE_HOME="$work/$name/cache" \
+        dbus-run-session -- \
+        flutter test "$file" -d linux \
+        --dart-define="NEXUS_E2E_HOMESERVER=$homeserver" "${flutter_args[@]}" ||
+        status=$?
+done
+exit "$status"
diff --git a/pubspec.lock b/pubspec.lock
index 9ea2664..c4ccd9b 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -58,7 +58,7 @@ packages:
     source: hosted
     version: "1.0.4"
   app_links_platform_interface:
-    dependency: transitive
+    dependency: "direct dev"
     description:
       name: app_links_platform_interface
       sha256: "7546f09a6e93f4a2df2fe2bd40a5c6c64310ac461b036d82b43033be7a59f809"
@@ -471,6 +471,11 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.9.1"
+  flutter_driver:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
   flutter_file_dialog:
     dependency: "direct main"
     description:
@@ -581,7 +586,7 @@ packages:
     source: hosted
     version: "2.3.2"
   flutter_test:
-    dependency: transitive
+    dependency: "direct dev"
     description: flutter
     source: sdk
     version: "0.0.0"
@@ -623,6 +628,11 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.0"
+  fuchsia_remote_debug_protocol:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
   geoclue:
     dependency: transitive
     description:
@@ -839,6 +849,11 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.2.2"
+  integration_test:
+    dependency: "direct dev"
+    description: flutter
+    source: sdk
+    version: "0.0.0"
   intl:
     dependency: "direct main"
     description:
@@ -1552,6 +1567,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.4.1"
+  sync_http:
+    dependency: transitive
+    description:
+      name: sync_http
+      sha256: "7f0cd72eca000d2e026bcd6f990b81d0ca06022ef4e32fb257b30d3d1014a961"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.1"
   synchronized:
     dependency: transitive
     description:
@@ -1715,7 +1738,7 @@ packages:
     source: hosted
     version: "3.2.6"
   url_launcher_platform_interface:
-    dependency: transitive
+    dependency: "direct dev"
     description:
       name: url_launcher_platform_interface
       sha256: "552f8a1e663569be95a8190206a38187b531910283c3e982193e4f2733f01029"
@@ -1843,6 +1866,14 @@ packages:
       url: "https://github.com/DavidClaudeAI/webcrypto.dart"
     source: git
     version: "0.6.2-wip"
+  webdriver:
+    dependency: transitive
+    description:
+      name: webdriver
+      sha256: "28b82ec894fed45dd71c23ba62d1af973ed97dd59a4f5790a4d38b0b13e5657e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.0"
   webpush_encryption:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index a1dbdf5..145a55c 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -122,6 +122,12 @@ dependencies:
     latlong2: 0.10.1
     geolocator: 14.1.2
 dev_dependencies:
+    flutter_test:
+        sdk: flutter
+    integration_test:
+        sdk: flutter
+    app_links_platform_interface: 2.0.4
+    url_launcher_platform_interface: 2.3.2
     build_runner: 2.17.1
     flutter_lints: 6.0.0
     freezed: 4.0.3