diff --git a/.gitignore b/.gitignore
index a74c7b6..4cc2457 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,4 +13,3 @@ Thumbs.db
 *.swo
 
 /vendor/
-/tapper.sock
diff --git a/AGENTS.md b/AGENTS.md
index ee2ba04..8a5a5b8 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -43,7 +43,7 @@ src/
     Support/SpanTruncator.php    Clips/windows Span[] to a fixed width for fixed-width panes (Details, LogItem)
 docs/                         Deeper documentation — see docs/README.md
 examples/BasicExample.php     Runnable demo of the tp() API
-tests/Unit/                  ScrollTest.php, ScrollbarRenderTest.php, SpanTruncatorTest.php — only test suites that currently exist
+tests/Unit/                  Unit tests for pure/isolated logic (Scroll, SpanTruncator, AppState, EventBus, MessageFormatter, PhpHighlighter, Rpc/*, SocketPath, LogPath) — Console/Components, Server, and Application have no tests yet (need the ReactPHP loop/php-tui rendering)
 ```
 
 ## Running things
diff --git a/bin/tapper b/bin/tapper
index 2546e90..c1ce6dd 100755
--- a/bin/tapper
+++ b/bin/tapper
@@ -5,10 +5,13 @@ declare(strict_types=1);
 
 require __DIR__.'/../vendor/autoload.php';
 
+$options = getopt('', ['port::']);
+$port = isset($options['port']) ? (int) $options['port'] : null;
+
 $app = (require_once __DIR__.'/../src/Console/main.php');
 
 try {
-    $app->run();
+    $app->run($port);
 } catch (\Throwable $e) {
     $app->close();
     \Tapper\Console\ErrorHandler::logThrowable($e);
diff --git a/composer.json b/composer.json
index a5c921f..2185bfc 100644
--- a/composer.json
+++ b/composer.json
@@ -18,6 +18,7 @@
         }
     ],
     "require": {
+        "php": "^8.2",
         "react/event-loop": "^1.5",
         "php-tui/php-tui": "^0.2.1",
         "react/socket": "^1.16",
diff --git a/docs/known-issues.md b/docs/known-issues.md
index 0140931..7b0e64a 100644
--- a/docs/known-issues.md
+++ b/docs/known-issues.md
@@ -10,7 +10,7 @@ This doc consolidates everything found during a full-codebase review (2026-08-15
 
 Verified with an isolated smoke test (no terminal required): booted `Server` directly against a real `AppState`/`EventBus`, confirmed the socket file appears at `SocketPath::resolve()`, and confirmed `tp()` from a separate process round-trips successfully (`result: ok`) instead of throwing `[Tapper] server not responding.`.
 
-Note: `SocketPath::resolve()` still resolves to "the installed package's own directory" (`realpath(__DIR__.'/..')`), same semantics as the original `Server.php` code — when Tapper is installed as a dependency, that's `vendor/tapperphp/tapper/tapper.sock`, not the consuming project's root. That's fine functionally (both processes resolve the same install, so they agree), but if this ever needs to be more conventional (e.g. `sys_get_temp_dir()`-based, to avoid touching `vendor/`), that's a deliberate follow-up, not part of this fix.
+~~Note: `SocketPath::resolve()` still resolves to "the installed package's own directory"~~ — fixed 2026-08-16: `SocketPath::resolve()` and `LogPath::resolve()` now resolve to `sys_get_temp_dir().'/tapper.sock'` / `'/tapper.log'` instead of `realpath(__DIR__.'/..')`. This was flagged as a deliberate follow-up above, and became a real requirement once native packaging entered the picture — a static-php-cli/phpmicro build (`docs/architecture.md` roadmap) embeds `src/` inside a read-only Phar, so a path computed from `__DIR__` would point at a virtual filesystem that can't hold a socket file or an appended-to log file. `sys_get_temp_dir()` is always a real, writable directory regardless of how the app is packaged. Trade-off: this drops the previous per-install isolation (two different projects each requiring `tapperphp/tapper` from their own `vendor/` used to get distinct socket paths for free, since `__DIR__` differed per install) — now every local Tapper session shares `<tmp>/tapper.sock`, so only one debuggee/TUI pair should run at a time per machine. Revisit if that turns out to matter in practice (e.g. namespace the filename by project directory hash).
 
 ### ~~`wait()` listeners on `EventBus` are never cleaned up~~ — fixed 2026-08-15
 
@@ -45,6 +45,14 @@ Reported case: pressing Space in `LogList` with zero log entries hit `LogList::s
 
 Note: this intentionally does *not* route the "check the logs" notice through `Windows/Popup.php` (a full-screen modal isn't the right shape for a transient 5-second notice); the banner lives in `Header` via two new `AppState` fields (`errorNotice`, `errorNoticeExpiresAt`) instead.
 
+### ~~Blocking: typed class constants (PHP 8.3+ syntax) broke every PHP 8.2 install despite README/CI claiming 8.2 support~~ — fixed 2026-08-16
+
+`private const string FOO = '...';`-style *typed* class constants are a PHP 8.3 feature — on PHP 8.2 the parser throws `ParseError: syntax error, unexpected identifier "FOO", expecting "="` on the file, at include time, regardless of whether the constant is ever read. This pattern was scattered across most of `Console/*` (`Application`, `Component`, `ErrorHandler`, `Palette`, `MessageFormatter`, `PhpHighlighter`, `Components/{Splash,Details,LogItem}`, `Windows/Main`) — i.e. it would have broken `bin/tapper` for any PHP 8.2 user the moment a log rendered (`MessageFormatter`/`Palette` are on the hot render path for every list row).
+
+It went undetected by CI (which does run PHP 8.2 in the matrix) purely because the old, minimal test suite (`Scroll`, `ScrollbarRenderer`, `SpanTruncator`) never autoloaded any of the affected classes — PHP never parsed the offending files under 8.2, so there was nothing to fail on. It surfaced the moment new tests started exercising `MessageFormatter`/`PhpHighlighter` directly. Fixed by dropping the type annotation from every class constant repo-wide (behavior is identical, `const FOO = '...'` works on 8.2–8.4); `composer.json` also had no `"php"` constraint at all, so `composer require`d installs wouldn't have been warned either — added `"php": "^8.2"` to `require` to match what the README already promises.
+
+This is a strong argument for the still-open Console/Components/Server/Application test-coverage gap noted elsewhere in this doc: coverage that's too thin doesn't just miss logic bugs, it can hide the codebase not even parsing on a supported PHP version.
+
 ## Incomplete abstractions (finish or remove, don't extend as-is)
 
 - **`Rpc\JsonRpc` interface / `JsonRpcResult` / `JsonRpcError`** — `JsonRpcResult.php` and `JsonRpcError.php` are empty files; `JsonRpc`'s encode/parse methods exist only as commented-out code; `Server.php` builds raw arrays instead of using these types. See `rpc-protocol.md`.
diff --git a/docs/rpc-protocol.md b/docs/rpc-protocol.md
index 85e89e1..8fceb95 100644
--- a/docs/rpc-protocol.md
+++ b/docs/rpc-protocol.md
@@ -4,21 +4,12 @@ This documents what is **actually implemented** between a debuggee process (`Run
 
 ## Transport
 
-- Unix domain socket, path `<project root>/tapper.sock` (computed by `Server.php` via `realpath(__DIR__.'/..')` from inside the installed package).
+Two transports, selected by whether a port is configured — there is no separate mode flag:
+
+- **Unix domain socket (default)**, path `sys_get_temp_dir().'/tapper.sock'`, resolved by `Tapper\SocketPath::resolve()` (`src/SocketPath.php`). Used whenever no port is given: `bin/tapper` without `--port`, and `Runtime\Tapper` when the `TAPPER_PORT` env var is unset/empty.
+- **TCP, `127.0.0.1:<port>`** — `bin/tapper --port=2138` binds `Server` there instead of the socket; `TAPPER_PORT=2138` makes `Runtime\Tapper` connect there instead. Both sides must agree on the same port. `AppState::$port` is `null` in socket mode (Header hides the "port: N" segment) and holds the configured port in TCP mode (Header shows it).
 - One line of JSON per message, `\n`-terminated, decoded with `clue/ndjson-react` on the server side.
 - The client (`Rpc/JsonRpcClient.php`) is a **blocking** `stream_socket_client()` — connect timeout 0.5s by default, then `stream_set_timeout()` + blocking `fgets()` for the reply, using a separate `pauseTimeout` (default 3600s) so a `wait()` call can block for up to an hour waiting for the user to press Enter in the TUI.
-- TCP is not currently wired up despite `JsonRpcClient` having `$host`/`$port` constructor properties — those fields are dead; the actual connection target is a hardcoded string, see the bug below.
-
-## Socket path resolution
-
-Both sides resolve the socket path through one shared helper, `Tapper\SocketPath::resolve()` (`src/SocketPath.php`):
-
-```php
-$projectPath = realpath(__DIR__.'/..'); // src/ -> package root
-return $projectPath.'/tapper.sock';
-```
-
-`Server.php` calls it to bind the listener; `Rpc/JsonRpcClient.php` calls it to connect. Because both sides call the same function instead of computing the path independently, they can't diverge. (This previously *did* diverge — `JsonRpcClient` had a hardcoded absolute path to one developer's machine, fixed 2026-08-15; see `known-issues.md` for the history if you're wondering why this indirection exists instead of a literal path.)
 
 ## Request shape (client → server)
 
@@ -33,7 +24,7 @@ Built by `Rpc\JsonRpcRequest::payload()`:
 }
 ```
 
-- `id` is generated by `uniqid('rpc_', true)` on every call — `JsonRpcRequest` has no way to accept an explicit id (the constructor doesn't take one; `payload()` references an undefined `$id` variable that null-coalesces to always calling `uniqid()` — works, but is dead/misleading code, not an intentional "reuse an id" feature).
+- `id` defaults to `uniqid('rpc_', true)` when the caller doesn't supply one — `JsonRpcRequest`'s constructor takes an optional `?string $id`, and `payload()` reads `$this->id ?? uniqid('rpc_', true)`.
 - Two methods are implemented server-side: `log` and `wait`.
 
 ### `log` params (sent by every plain `tp($value)`)
diff --git a/src/Console/Application.php b/src/Console/Application.php
index e7c48cd..3a014a8 100644
--- a/src/Console/Application.php
+++ b/src/Console/Application.php
@@ -26,9 +26,9 @@
 
 class Application
 {
-    const float RESIZE_RATE = 1 / 4;
+    const RESIZE_RATE = 1 / 4;
 
-    const float RENDER_RATE = 1 / 60;
+    const RENDER_RATE = 1 / 60;
 
     private Component $window;
 
@@ -53,12 +53,13 @@ public function __construct(
         private Server $server,
     ) {}
 
-    public function run(): int
+    public function run(?int $port = null): int
     {
         ErrorHandler::install($this->appState);
 
         $this->area = $this->phpTermBackend->size();
         $this->appState->version = 'v0.1.1';
+        $this->appState->port = $port;
         $this->terminal->execute(Actions::alternateScreenEnable());
         $this->terminal->execute(Actions::cursorHide());
         $this->terminal->execute(Actions::enableMouseCapture());
@@ -68,7 +69,7 @@ public function run(): int
         $this->init();
         $this->startRendering();
         $this->startInputHandling();
-        $this->server->run();
+        $this->server->run($port);
 
         $this->loop->addSignal(SIGINT, function () {
             $this->close();
diff --git a/src/Console/Component.php b/src/Console/Component.php
index 5b39f14..db0d2cc 100644
--- a/src/Console/Component.php
+++ b/src/Console/Component.php
@@ -20,9 +20,9 @@
 
 abstract class Component
 {
-    const string BEFORE_INIT = 'beforeInit';
+    const BEFORE_INIT = 'beforeInit';
 
-    const string AFTER_INIT = 'afterInit';
+    const AFTER_INIT = 'afterInit';
 
     protected array $components = [];
 
diff --git a/src/Console/Components/Details.php b/src/Console/Components/Details.php
index 8c84131..f638e03 100644
--- a/src/Console/Components/Details.php
+++ b/src/Console/Components/Details.php
@@ -44,11 +44,11 @@ class Details extends Component
     // 1 row top/bottom. Every width/height used to lay out content has to account for
     // that, since BlockRenderer only insets the *rendering*, not values computed here
     // beforehand (truncation budgets, paging math).
-    private const int BORDER_SIZE = 2;
+    private const BORDER_SIZE = 2;
 
-    private const int SCROLLBAR_GUTTER = 1;
+    private const SCROLLBAR_GUTTER = 1;
 
-    private const int H_STEP = 4;
+    private const H_STEP = 4;
 
     private int $count = 0;
 
diff --git a/src/Console/Components/Header.php b/src/Console/Components/Header.php
index 13e25f4..2934cef 100644
--- a/src/Console/Components/Header.php
+++ b/src/Console/Components/Header.php
@@ -51,8 +51,9 @@ protected function view(Area $area): Widget
                         Span::fromString(' '),
                         Span::fromString($label),
                         $unread ? Span::fromString(sprintf(' (↓%s)', $this->appState->unread))->yellow() : Span::fromString(''),
-                        Span::fromString(' | '),
-                        Span::fromString(sprintf('port: %s', $this->appState->port)),
+                        $this->appState->port !== null
+                            ? Span::fromString(sprintf(' | port: %s', $this->appState->port))
+                            : Span::fromString(''),
                         $this->appState->filter !== '' && ! $this->appState->typingMode
                             ? Span::styled(sprintf(' | filter: %s', $this->appState->filter), Style::default()->fg(RgbColor::fromHex(Palette::ACCENT)))
                             : Span::fromString(''),
diff --git a/src/Console/Components/LogItem.php b/src/Console/Components/LogItem.php
index f982b42..dcd20a4 100644
--- a/src/Console/Components/LogItem.php
+++ b/src/Console/Components/LogItem.php
@@ -25,9 +25,9 @@
 
 class LogItem extends Component
 {
-    public const int HEIGHT = 2;
+    public const HEIGHT = 2;
 
-    private const int SCROLLBAR_GUTTER = 1;
+    private const SCROLLBAR_GUTTER = 1;
 
     private ?LogItemState $log = null;
 
@@ -48,14 +48,14 @@ public function mouseMove(array $data): void
         /** @var MouseEvent $event */
         $event = $data['event'];
 
-        if (! $this->log || $this->index === null) {
+        if (! $this->log || $this->index === null || $this->area === null) {
             return;
         }
 
         $elementPosInView = ($this->index - $this->appState->offset);
-        $itemPosition = ($elementPosInView * self::HEIGHT) + 1;
+        $itemPosition = $this->area->top() + ($elementPosInView * self::HEIGHT);
 
-        if ($event->row > $itemPosition
+        if ($event->row >= $itemPosition
             && $event->row < $itemPosition + self::HEIGHT
         ) {
             $this->click();
diff --git a/src/Console/Components/LogList.php b/src/Console/Components/LogList.php
index 6708592..de28317 100644
--- a/src/Console/Components/LogList.php
+++ b/src/Console/Components/LogList.php
@@ -7,13 +7,15 @@
 use PhpTui\Term\KeyCode;
 use PhpTui\Term\KeyModifiers;
 use PhpTui\Term\MouseEventKind;
+use PhpTui\Tui\Color\AnsiColor;
 use PhpTui\Tui\Display\Area;
+use PhpTui\Tui\Extension\Core\Widget\Buffer\BufferContext;
+use PhpTui\Tui\Extension\Core\Widget\BufferWidget;
 use PhpTui\Tui\Extension\Core\Widget\CompositeWidget;
 use PhpTui\Tui\Extension\Core\Widget\GridWidget;
-use PhpTui\Tui\Extension\Core\Widget\Scrollbar\ScrollbarOrientation;
-use PhpTui\Tui\Extension\Core\Widget\Scrollbar\ScrollbarSymbols;
-use PhpTui\Tui\Extension\Core\Widget\ScrollbarWidget;
 use PhpTui\Tui\Layout\Constraint;
+use PhpTui\Tui\Position\Position;
+use PhpTui\Tui\Style\Style;
 use PhpTui\Tui\Widget\Direction;
 use PhpTui\Tui\Widget\Widget;
 use Tapper\Console\CommandAttributes\FirstRender;
@@ -219,6 +221,29 @@ protected function view(Area $area): Widget
     {
         $this->fill();
 
+        $thumbBounds = Scroll::proportionalThumb($this->count, $this->visible, $this->appState->offset, $area->height);
+
+        // Built by hand rather than via php-tui's ScrollbarWidget/ScrollbarRenderer: that
+        // combo can only size the thumb off ScrollbarState's single contentLength field,
+        // which is wrong for a short list barely taller than the viewport (see the docblock
+        // on Scroll::proportionalThumb()). Details.php already draws its scrollbar the same
+        // way for the same reason.
+        $scrollbar = BufferWidget::new(function (BufferContext $context) use ($thumbBounds): void {
+            $trackArea = $context->area;
+            $x = max(0, $trackArea->right() - 1);
+            $neutralStyle = Style::default()->fg(AnsiColor::Reset)->bg(AnsiColor::Reset);
+
+            for ($y = $trackArea->top(); $y < $trackArea->bottom(); $y++) {
+                $isThumb = $thumbBounds !== null
+                    && ($y - $trackArea->top()) >= $thumbBounds[0]
+                    && ($y - $trackArea->top()) < $thumbBounds[1];
+
+                $context->buffer->get(Position::at($x, $y))
+                    ->setChar($isThumb ? '█' : ($thumbBounds === null ? ' ' : '│'))
+                    ->setStyle($neutralStyle);
+            }
+        });
+
         return CompositeWidget::fromWidgets(
             GridWidget::default()
                 ->direction(Direction::Vertical)
@@ -229,12 +254,7 @@ protected function view(Area $area): Widget
                         $this->listItems
                     ),
                 ),
-            ScrollbarWidget::default()
-                ->state(Scroll::scrollbarState($this->count, $this->visible, $this->appState->offset))
-                ->orientation(ScrollbarOrientation::VerticalRight)
-                ->symbols(new ScrollbarSymbols('│', '█', '', ''))
-                ->endSymbol(null)
-                ->beginSymbol(null),
+            $scrollbar,
         );
     }
 }
diff --git a/src/Console/Components/Splash.php b/src/Console/Components/Splash.php
index cc79095..105183e 100644
--- a/src/Console/Components/Splash.php
+++ b/src/Console/Components/Splash.php
@@ -14,7 +14,7 @@
 
 class Splash extends Component
 {
-    private const string TAPPER = 'T A P P E R';
+    private const TAPPER = 'T A P P E R';
 
     protected function view(Area $area): Widget
     {
diff --git a/src/Console/ErrorHandler.php b/src/Console/ErrorHandler.php
index 102d62d..ad65c34 100644
--- a/src/Console/ErrorHandler.php
+++ b/src/Console/ErrorHandler.php
@@ -19,7 +19,7 @@
  */
 final class ErrorHandler
 {
-    private const int NOTICE_SECONDS = 5;
+    private const NOTICE_SECONDS = 5;
 
     public static function install(AppState $appState): void
     {
diff --git a/src/Console/MessageFormatter.php b/src/Console/MessageFormatter.php
index 359972c..e9fa383 100644
--- a/src/Console/MessageFormatter.php
+++ b/src/Console/MessageFormatter.php
@@ -11,21 +11,21 @@
 
 class MessageFormatter
 {
-    private const string STRING_COLOR = '9ece6a';
+    private const STRING_COLOR = '9ece6a';
 
-    private const string KEY_COLOR = '73daca';
+    private const KEY_COLOR = '73daca';
 
-    private const string NUMBER_COLOR = 'fd9d63';
+    private const NUMBER_COLOR = 'fd9d63';
 
-    private const string BOOL_COLOR = 'fd9d63';
+    private const BOOL_COLOR = 'fd9d63';
 
-    private const string NULL_COLOR = '2bc3de';
+    private const NULL_COLOR = '2bc3de';
 
-    private const string BRACKETS_COLOR = Palette::TEXT_DEFAULT;
+    private const BRACKETS_COLOR = Palette::TEXT_DEFAULT;
 
-    private const string PUNCTUATION_COLOR = '89ddff';
+    private const PUNCTUATION_COLOR = '89ddff';
 
-    private const string ERROR_COLOR = Palette::ERROR;
+    private const ERROR_COLOR = Palette::ERROR;
 
     public static function colorizeInlineJson(string $json): array
     {
diff --git a/src/Console/Palette.php b/src/Console/Palette.php
index b6782cd..e840a79 100644
--- a/src/Console/Palette.php
+++ b/src/Console/Palette.php
@@ -10,11 +10,11 @@
  */
 final class Palette
 {
-    public const string ACCENT = '7aa2f7';
+    public const ACCENT = '7aa2f7';
 
-    public const string TEXT_DEFAULT = 'c0caf5';
+    public const TEXT_DEFAULT = 'c0caf5';
 
-    public const string SELECTION_BG = '2a2e42';
+    public const SELECTION_BG = '2a2e42';
 
-    public const string ERROR = 'f7768e';
+    public const ERROR = 'f7768e';
 }
diff --git a/src/Console/PhpHighlighter.php b/src/Console/PhpHighlighter.php
index 4d308b5..e2deec2 100644
--- a/src/Console/PhpHighlighter.php
+++ b/src/Console/PhpHighlighter.php
@@ -19,19 +19,19 @@
  */
 final class PhpHighlighter
 {
-    private const string KEYWORD_COLOR = 'bb9af7';
+    private const KEYWORD_COLOR = 'bb9af7';
 
-    private const string VARIABLE_COLOR = '7dcfff';
+    private const VARIABLE_COLOR = '7dcfff';
 
-    private const string STRING_COLOR = '9ece6a';
+    private const STRING_COLOR = '9ece6a';
 
-    private const string NUMBER_COLOR = 'ff9e64';
+    private const NUMBER_COLOR = 'ff9e64';
 
-    private const string COMMENT_COLOR = '565f89';
+    private const COMMENT_COLOR = '565f89';
 
-    private const string FUNCTION_COLOR = '7aa2f7';
+    private const FUNCTION_COLOR = '7aa2f7';
 
-    private const array KEYWORD_TOKENS = [
+    private const KEYWORD_TOKENS = [
         T_IF, T_ELSE, T_ELSEIF, T_ENDIF, T_FOR, T_FOREACH, T_ENDFOR, T_ENDFOREACH,
         T_WHILE, T_ENDWHILE, T_DO, T_SWITCH, T_ENDSWITCH, T_CASE, T_DEFAULT, T_BREAK,
         T_CONTINUE, T_FUNCTION, T_FN, T_RETURN, T_CLASS, T_INTERFACE, T_TRAIT, T_ENUM,
@@ -44,14 +44,14 @@ final class PhpHighlighter
         T_INSTEADOF,
     ];
 
-    private const array STRING_TOKENS = [
+    private const STRING_TOKENS = [
         T_CONSTANT_ENCAPSED_STRING, T_ENCAPSED_AND_WHITESPACE, T_START_HEREDOC,
         T_END_HEREDOC,
     ];
 
-    private const array COMMENT_TOKENS = [T_COMMENT, T_DOC_COMMENT];
+    private const COMMENT_TOKENS = [T_COMMENT, T_DOC_COMMENT];
 
-    private const array BARE_KEYWORDS = ['true', 'false', 'null', 'self', 'parent'];
+    private const BARE_KEYWORDS = ['true', 'false', 'null', 'self', 'parent'];
 
     /**
      * @return Span[]
diff --git a/src/Console/State/AppState.php b/src/Console/State/AppState.php
index 0ecda6f..d9db29e 100644
--- a/src/Console/State/AppState.php
+++ b/src/Console/State/AppState.php
@@ -8,7 +8,7 @@
 
 /**
  * @property string $version
- * @property int $port
+ * @property ?int $port
  * @property bool $live
  * @property bool $showDot
  * @property bool $typingMode
@@ -41,7 +41,7 @@ class AppState
      */
     public function __construct(
         private string $version = '',
-        private int $port = 2137,
+        private ?int $port = null,
         private bool $live = true,
         private bool $showDot = true,
         private bool $typingMode = false,
diff --git a/src/Console/Support/Scroll.php b/src/Console/Support/Scroll.php
index 84164be..d3f7bc9 100644
--- a/src/Console/Support/Scroll.php
+++ b/src/Console/Support/Scroll.php
@@ -4,18 +4,12 @@
 
 namespace Tapper\Console\Support;
 
-use PhpTui\Tui\Extension\Core\Widget\Scrollbar\ScrollbarState;
 use Tapper\Console\State\AppState;
 
 class Scroll
 {
     public function __construct(private readonly AppState $appState) {}
 
-    public static function scrollbarState(int $count, int $visible, int $offset): ScrollbarState
-    {
-        return new ScrollbarState(max(0, $count - $visible), $offset, $visible);
-    }
-
     /**
      * php-tui's ScrollbarState only has one `contentLength` field, which
      * ScrollbarRenderer uses as the denominator for *both* the thumb's position
diff --git a/src/Console/Windows/Main.php b/src/Console/Windows/Main.php
index fc84120..b90f8a1 100644
--- a/src/Console/Windows/Main.php
+++ b/src/Console/Windows/Main.php
@@ -25,9 +25,9 @@
 
 class Main extends Component
 {
-    private const int MIN_WIDTH = 40;
+    private const MIN_WIDTH = 40;
 
-    private const int MIN_HEIGHT = 8;
+    private const MIN_HEIGHT = 8;
 
     protected array $components = [
         Header::class,
diff --git a/src/LogPath.php b/src/LogPath.php
index af61417..3310796 100644
--- a/src/LogPath.php
+++ b/src/LogPath.php
@@ -4,18 +4,10 @@
 
 namespace Tapper;
 
-use RuntimeException;
-
 class LogPath
 {
     public static function resolve(): string
     {
-        $projectPath = realpath(__DIR__.'/..');
-
-        if ($projectPath === false) {
-            throw new RuntimeException('[Tapper] could not resolve package root to locate tapper.log.');
-        }
-
-        return $projectPath.'/tapper.log';
+        return sys_get_temp_dir().'/tapper.log';
     }
 }
diff --git a/src/Rpc/JsonRpcClient.php b/src/Rpc/JsonRpcClient.php
index a949697..2d38f36 100644
--- a/src/Rpc/JsonRpcClient.php
+++ b/src/Rpc/JsonRpcClient.php
@@ -10,7 +10,7 @@ class JsonRpcClient
 {
     public function __construct(
         protected string $host = '127.0.0.1',
-        protected int $port = 2137,
+        protected ?int $port = null,
         protected float $timeout = 0.5,
         protected float $pauseTimeout = 3600,
     ) {}
@@ -19,7 +19,11 @@ public function call(JsonRpc $jsonRpc): ?array
     {
         $payload = $jsonRpc->payload();
 
-        $socket = @stream_socket_client('unix://'.SocketPath::resolve(), $errno, $errstr, $this->timeout);
+        $target = $this->port !== null
+            ? "tcp://{$this->host}:{$this->port}"
+            : 'unix://'.SocketPath::resolve();
+
+        $socket = @stream_socket_client($target, $errno, $errstr, $this->timeout);
 
         if (! $socket) {
             return null;
diff --git a/src/Runtime/Tapper.php b/src/Runtime/Tapper.php
index 2b14332..ee43042 100644
--- a/src/Runtime/Tapper.php
+++ b/src/Runtime/Tapper.php
@@ -33,7 +33,8 @@ class Tapper
     public function __construct()
     {
         if (self::$client === null) {
-            self::$client = new JsonRpcClient;
+            $port = getenv('TAPPER_PORT');
+            self::$client = new JsonRpcClient(port: $port !== false && $port !== '' ? (int) $port : null);
         }
 
         $this->collectDebugInfo();
diff --git a/src/Server.php b/src/Server.php
index ca0a371..4146875 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -27,106 +27,126 @@ public function __construct(
         private readonly EventBus $eventBus
     ) {}
 
-    public function run(): void
+    public function run(?int $port = null): void
     {
+        $server = $this->createSocketServer($port);
+
+        $server->on('connection', function (ConnectionInterface $conn) {
+            $this->handleConnection($conn);
+        });
+    }
+
+    private function createSocketServer(?int $port): SocketServer
+    {
+        if ($port !== null) {
+            return new SocketServer("127.0.0.1:{$port}");
+        }
+
         $socketPath = SocketPath::resolve();
         @unlink($socketPath);
-        $server = new SocketServer('unix://'.$socketPath);
 
-        $server->on('connection', function (ConnectionInterface $conn) {
-            $decoder = new Decoder($conn, true);
-            $encoder = new Encoder($conn, true);
-
-            $decoder->on('data', function ($message) use ($encoder) {
-
-                if (($message['jsonrpc'] ?? '') !== '2.0') {
-                    $encoder->write([
-                        'jsonrpc' => '2.0',
-                        'error' => [
-                            'code' => -32600,
-                            'message' => 'Invalid Request',
-                        ],
-                        'id' => $message['id'] ?? null,
-                    ]);
-
-                    return;
-                }
-
-                $method = $message['method'] ?? '';
-                $params = $message['params'] ?? [];
-                $id = $message['id'] ?? null;
-
-                switch ($method) {
-                    case 'log':
-                        $kind = $params['kind'] ?? 'log';
-                        $isAppended = $this->appState->appendLog(new LogItem(
-                            $this->id,
-                            $params['microtime'],
-                            $kind === 'error' ? $params['message'] : json_encode($params['message'], JSON_UNESCAPED_UNICODE),
-                            $params['caller'],
-                            $params['trace'],
-                            $params['rootDir'],
-                            $params['code'],
-                            kind: $kind,
-                        ));
-
-                        $encoder->write([
-                            'jsonrpc' => '2.0',
-                            'result' => 'ok',
-                            'id' => $id,
-                        ]);
-
-                        if ($isAppended) {
-                            $this->id++;
-                        }
-                        break;
-
-                    case 'wait':
-                        $isAppended = $this->appState->appendLog(new LogItem(
-                            $this->id,
-                            $params['microtime'],
-                            "⏸ {$params['message']} — press ENTER to continue",
-                            $params['caller'],
-                            $params['trace'],
-                            $params['rootDir'],
-                            $params['code'],
-                            kind: 'wait',
-                        ));
-
-                        if ($isAppended) {
-                            $this->id++;
-                        }
-
-                        $this->appState->pendingWaits++;
-
-                        $this->waitResolvers[] = function () use ($encoder, $id) {
-                            $encoder->write([
-                                'jsonrpc' => '2.0',
-                                'result' => 'continue',
-                                'id' => $id,
-                            ]);
-
-                            $this->appState->pendingWaits = max(0, $this->appState->pendingWaits - 1);
-                        };
-
-                        $this->registerWaitListener();
-
-                        break;
-
-                    default:
-                        $encoder->write([
-                            'jsonrpc' => '2.0',
-                            'error' => [
-                                'code' => -32601,
-                                'message' => "Method '{$method}' not found",
-                            ],
-                            'id' => $id,
-                        ]);
-                }
-            });
+        return new SocketServer('unix://'.$socketPath);
+    }
+
+    private function handleConnection(ConnectionInterface $conn): void
+    {
+        $decoder = new Decoder($conn, true);
+        $encoder = new Encoder($conn, true);
+
+        $decoder->on('data', function ($message) use ($encoder) {
+            $this->handleMessage($message, $encoder);
         });
     }
 
+    private function handleMessage(array $message, Encoder $encoder): void
+    {
+        if (($message['jsonrpc'] ?? '') !== '2.0') {
+            $this->writeError($encoder, -32600, 'Invalid Request', $message['id'] ?? null);
+
+            return;
+        }
+
+        $method = $message['method'] ?? '';
+        $params = $message['params'] ?? [];
+        $id = $message['id'] ?? null;
+
+        match ($method) {
+            'log' => $this->handleLog($params, $id, $encoder),
+            'wait' => $this->handleWait($params, $id, $encoder),
+            default => $this->writeError($encoder, -32601, "Method '{$method}' not found", $id),
+        };
+    }
+
+    private function handleLog(array $params, mixed $id, Encoder $encoder): void
+    {
+        $kind = $params['kind'] ?? 'log';
+
+        $isAppended = $this->appState->appendLog(new LogItem(
+            $this->id,
+            $params['microtime'],
+            $kind === 'error' ? $params['message'] : json_encode($params['message'], JSON_UNESCAPED_UNICODE),
+            $params['caller'],
+            $params['trace'],
+            $params['rootDir'],
+            $params['code'],
+            kind: $kind,
+        ));
+
+        $this->writeResult($encoder, 'ok', $id);
+
+        if ($isAppended) {
+            $this->id++;
+        }
+    }
+
+    private function handleWait(array $params, mixed $id, Encoder $encoder): void
+    {
+        $isAppended = $this->appState->appendLog(new LogItem(
+            $this->id,
+            $params['microtime'],
+            "⏸ {$params['message']} — press ENTER to continue",
+            $params['caller'],
+            $params['trace'],
+            $params['rootDir'],
+            $params['code'],
+            kind: 'wait',
+        ));
+
+        if ($isAppended) {
+            $this->id++;
+        }
+
+        $this->appState->pendingWaits++;
+
+        $this->waitResolvers[] = function () use ($encoder, $id) {
+            $this->writeResult($encoder, 'continue', $id);
+            $this->appState->pendingWaits = max(0, $this->appState->pendingWaits - 1);
+        };
+
+        $this->registerWaitListener();
+    }
+
+    private function writeResult(Encoder $encoder, mixed $result, mixed $id): void
+    {
+        $encoder->write([
+            'jsonrpc' => '2.0',
+            'result' => $result,
+            'id' => $id,
+        ]);
+    }
+
+    private function writeError(Encoder $encoder, int $code, string $message, mixed $id): void
+    {
+        $encoder->write([
+            'jsonrpc' => '2.0',
+            'error' => [
+                'code' => $code,
+                'message' => $message,
+            ],
+            'id' => $id,
+        ]);
+    }
+
     /**
      * Registers a single, permanent Enter listener the first time it's needed, instead of
      * one per wait() call. Each keypress resolves the oldest pending wait in FIFO order, so
diff --git a/src/SocketPath.php b/src/SocketPath.php
index 234a801..a70d860 100644
--- a/src/SocketPath.php
+++ b/src/SocketPath.php
@@ -4,18 +4,10 @@
 
 namespace Tapper;
 
-use RuntimeException;
-
 class SocketPath
 {
     public static function resolve(): string
     {
-        $projectPath = realpath(__DIR__.'/..');
-
-        if ($projectPath === false) {
-            throw new RuntimeException('[Tapper] could not resolve package root to locate tapper.sock.');
-        }
-
-        return $projectPath.'/tapper.sock';
+        return sys_get_temp_dir().'/tapper.sock';
     }
 }
diff --git a/tests/Unit/LogPathTest.php b/tests/Unit/LogPathTest.php
new file mode 100644
index 0000000..47bf9a5
--- /dev/null
+++ b/tests/Unit/LogPathTest.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Tapper\LogPath;
+
+it('resolves to tapper.log inside the system temp directory', function () {
+    expect(LogPath::resolve())->toBe(sys_get_temp_dir().'/tapper.log');
+});
diff --git a/tests/Unit/Rpc/JsonRpcClientTest.php b/tests/Unit/Rpc/JsonRpcClientTest.php
new file mode 100644
index 0000000..30b5c4f
--- /dev/null
+++ b/tests/Unit/Rpc/JsonRpcClientTest.php
@@ -0,0 +1,95 @@
+<?php
+
+declare(strict_types=1);
+
+use Tapper\Rpc\JsonRpcClient;
+use Tapper\Rpc\JsonRpcRequest;
+
+/**
+ * Spawns a throwaway PHP subprocess that binds an ephemeral TCP port, accepts exactly
+ * one connection, and replies with $response. A subprocess (not an in-process accept())
+ * is required because JsonRpcClient::call() is fully synchronous end-to-end (connect,
+ * write, blocking read, close) with no point where a single-threaded test could interleave
+ * server-side accept()/read()/write() calls of its own.
+ *
+ * @return array{0: int, 1: callable(): void} [bound port, teardown callback]
+ */
+function startFakeTcpServer(string $response): array
+{
+    $script = <<<'PHP'
+        <?php
+        $response = $argv[1];
+        $server = stream_socket_server('tcp://127.0.0.1:0', $errno, $errstr);
+        fwrite(STDOUT, stream_socket_get_name($server, false)."\n");
+        fflush(STDOUT);
+        $conn = @stream_socket_accept($server, 10);
+        if ($conn) {
+            fgets($conn);
+            fwrite($conn, $response);
+            fclose($conn);
+        }
+        fclose($server);
+        PHP;
+
+    $scriptPath = tempnam(sys_get_temp_dir(), 'tapper_fake_tcp_').'.php';
+    file_put_contents($scriptPath, $script);
+
+    $process = proc_open(
+        [PHP_BINARY, $scriptPath, $response],
+        [1 => ['pipe', 'w'], 2 => ['pipe', 'w']],
+        $pipes,
+    );
+
+    $address = trim(fgets($pipes[1]));
+    $port = (int) substr($address, strrpos($address, ':') + 1);
+
+    $stop = function () use ($process, $pipes, $scriptPath) {
+        foreach ($pipes as $pipe) {
+            if (is_resource($pipe)) {
+                fclose($pipe);
+            }
+        }
+        if (is_resource($process)) {
+            proc_close($process);
+        }
+        @unlink($scriptPath);
+    };
+
+    return [$port, $stop];
+}
+
+describe('TCP transport (port configured)', function () {
+    it('connects over TCP and returns the decoded response', function () {
+        [$port, $stop] = startFakeTcpServer(json_encode(['jsonrpc' => '2.0', 'result' => 'ok', 'id' => 'x'])."\n");
+
+        $client = new JsonRpcClient(port: $port, timeout: 2.0);
+        $response = $client->call(new JsonRpcRequest('log', [], id: 'x'));
+
+        $stop();
+
+        expect($response)->toBe(['jsonrpc' => '2.0', 'result' => 'ok', 'id' => 'x']);
+    });
+
+    it('returns null when the response has no result key', function () {
+        [$port, $stop] = startFakeTcpServer(json_encode(['jsonrpc' => '2.0', 'error' => ['code' => -32601, 'message' => 'nope']])."\n");
+
+        $client = new JsonRpcClient(port: $port, timeout: 2.0);
+        $response = $client->call(new JsonRpcRequest('log', []));
+
+        $stop();
+
+        expect($response)->toBeNull();
+    });
+
+    it('returns null when nothing is listening on the configured port', function () {
+        $server = stream_socket_server('tcp://127.0.0.1:0', $errno, $errstr);
+        $address = stream_socket_get_name($server, false);
+        $port = (int) substr($address, strrpos($address, ':') + 1);
+        fclose($server);
+
+        $client = new JsonRpcClient(port: $port, timeout: 0.5);
+        $response = $client->call(new JsonRpcRequest('log', []));
+
+        expect($response)->toBeNull();
+    });
+});
diff --git a/tests/Unit/ScrollTest.php b/tests/Unit/ScrollTest.php
index c86a976..42e21b9 100644
--- a/tests/Unit/ScrollTest.php
+++ b/tests/Unit/ScrollTest.php
@@ -187,32 +187,6 @@
     });
 });
 
-describe('scrollbar state', function () {
-    it('maps count/visible/offset onto content length, viewport length and position', function () {
-        $state = Scroll::scrollbarState(count: 100, visible: 20, offset: 35);
-
-        expect($state->contentLength)->toBe(80)
-            ->and($state->viewportContentLength)->toBe(20)
-            ->and($state->position)->toBe(35);
-    });
-
-    it('never lets content length go negative when everything fits on screen', function () {
-        $state = Scroll::scrollbarState(count: 5, visible: 20, offset: 0);
-
-        expect($state->contentLength)->toBe(0);
-    });
-
-    it('uses the max offset (count - visible) as content length so the thumb can reach the bottom', function () {
-        $count = 100;
-        $visible = 20;
-        $maxOffset = $count - $visible;
-
-        $state = Scroll::scrollbarState($count, $visible, $maxOffset);
-
-        expect($state->position)->toBe($state->contentLength);
-    });
-});
-
 describe('proportional thumb', function () {
     it('returns null when everything already fits on screen', function () {
         expect(Scroll::proportionalThumb(count: 5, visible: 20, offset: 0, trackHeight: 20))->toBeNull();
diff --git a/tests/Unit/ScrollbarRenderTest.php b/tests/Unit/ScrollbarRenderTest.php
deleted file mode 100644
index acff7d5..0000000
--- a/tests/Unit/ScrollbarRenderTest.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-use PhpTui\Tui\Display\Area;
-use PhpTui\Tui\Display\Buffer;
-use PhpTui\Tui\Extension\Core\Widget\Scrollbar\ScrollbarOrientation;
-use PhpTui\Tui\Extension\Core\Widget\Scrollbar\ScrollbarSymbols;
-use PhpTui\Tui\Extension\Core\Widget\ScrollbarRenderer;
-use PhpTui\Tui\Extension\Core\Widget\ScrollbarWidget;
-use PhpTui\Tui\Position\Position;
-use PhpTui\Tui\Widget\WidgetRenderer\AggregateWidgetRenderer;
-use Tapper\Console\Support\Scroll;
-
-const THUMB_SYMBOL = '█';
-
-/**
- * @return string[] one character per row of the rendered scrollbar track
- */
-function renderScrollbarColumn(int $count, int $visible, int $offset, int $trackHeight): array
-{
-    $area = Area::fromScalars(0, 0, 3, $trackHeight);
-    $buffer = Buffer::empty($area);
-
-    $widget = ScrollbarWidget::default()
-        ->state(Scroll::scrollbarState($count, $visible, $offset))
-        ->orientation(ScrollbarOrientation::VerticalRight)
-        ->symbols(new ScrollbarSymbols('│', THUMB_SYMBOL, '', ''))
-        ->endSymbol(null)
-        ->beginSymbol(null);
-
-    (new ScrollbarRenderer)->render(new AggregateWidgetRenderer([]), $widget, $buffer, $area);
-
-    $column = [];
-    for ($y = 0; $y < $trackHeight; $y++) {
-        $column[] = $buffer->get(Position::at($area->right() - 1, $y))->char;
-    }
-
-    return $column;
-}
-
-it('places the thumb at the very top when scrolled to the top', function () {
-    $column = renderScrollbarColumn(count: 100, visible: 20, offset: 0, trackHeight: 40);
-
-    expect($column[0])->toBe(THUMB_SYMBOL);
-});
-
-it('places the thumb at the very bottom when scrolled to the bottom', function () {
-    $column = renderScrollbarColumn(count: 100, visible: 20, offset: 80, trackHeight: 40);
-
-    expect($column[count($column) - 1])->toBe(THUMB_SYMBOL);
-});
-
-it('sizes the thumb proportionally instead of collapsing to a single row', function () {
-    $column = renderScrollbarColumn(count: 100, visible: 20, offset: 0, trackHeight: 40);
-
-    $thumbRows = count(array_filter($column, fn (string $char) => $char === THUMB_SYMBOL));
-
-    expect($thumbRows)->toBeGreaterThan(1);
-});
-
-it('draws nothing when everything already fits on screen', function () {
-    $column = renderScrollbarColumn(count: 5, visible: 20, offset: 0, trackHeight: 40);
-
-    $thumbRows = count(array_filter($column, fn (string $char) => $char === THUMB_SYMBOL));
-
-    expect($thumbRows)->toBe(0);
-});
diff --git a/tests/Unit/SocketPathTest.php b/tests/Unit/SocketPathTest.php
new file mode 100644
index 0000000..3e7698e
--- /dev/null
+++ b/tests/Unit/SocketPathTest.php
@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+use Tapper\SocketPath;
+
+it('resolves to tapper.sock inside the system temp directory', function () {
+    expect(SocketPath::resolve())->toBe(sys_get_temp_dir().'/tapper.sock');
+});