diff --git a/src/ctrace/BinaryLocator.ts b/src/ctrace/BinaryLocator.ts
index 48be29e..9f37ae0 100755
--- a/src/ctrace/BinaryLocator.ts
+++ b/src/ctrace/BinaryLocator.ts
@@ -23,6 +23,22 @@ export async function locateBinary(extensionPath: string): Promise<string | null
     return null;
 }
 
+/**
+ * Looks for a ctrace binary on PATH (e.g. built from source on macOS, where
+ * no prebuilt release exists). Returns the resolved path, or null.
+ */
+export async function locateBinaryOnPath(): Promise<string | null> {
+    for (const dir of (process.env.PATH || '').split(path.delimiter).filter(Boolean)) {
+        for (const name of ['ctrace', 'coretrace']) {
+            const candidate = path.join(dir, name);
+            if (await isExecutableFile(candidate)) {
+                return candidate;
+            }
+        }
+    }
+    return null;
+}
+
 async function isExecutableFile(filePath: string): Promise<boolean> {
     try {
         const stat = await fs.promises.stat(filePath);
diff --git a/src/ctrace/BinaryUpdater.ts b/src/ctrace/BinaryUpdater.ts
index c75e5b8..d504665 100755
--- a/src/ctrace/BinaryUpdater.ts
+++ b/src/ctrace/BinaryUpdater.ts
@@ -4,7 +4,7 @@ import * as path from 'path';
 import * as tar from 'tar';
 import { pipeline } from 'stream/promises';
 import { Readable, Transform } from 'stream';
-import { locateBinary } from './BinaryLocator';
+import { locateBinary, locateBinaryOnPath } from './BinaryLocator';
 
 const REPO_LATEST_RELEASE_URL = 'https://api.github.com/repos/CoreTrace/coretrace/releases/latest';
 
@@ -53,15 +53,17 @@ async function doEnsureBinary(context: vscode.ExtensionContext, output: vscode.O
     const FAILURE_BACKOFF = 60 * 1000;
 
     // If we have a cached binary and checked recently, avoid spamming the GitHub API.
-    if (downloadedBinaryPath && now - lastCheck < TWELVE_HOURS) {
-        return downloadedBinaryPath;
+    // A PATH binary counts too: platforms without a release asset (macOS) would otherwise hit the API on every scan.
+    const knownBinary = downloadedBinaryPath ?? await locateBinaryOnPath();
+    if (knownBinary && now - lastCheck < TWELVE_HOURS) {
+        return knownBinary;
     }
 
     // When there is no cached binary, keep retrying with a short backoff.
     // This avoids a 12-hour lockout if the very first download fails.
     if (!downloadedBinaryPath && now - lastFailedCheck < FAILURE_BACKOFF) {
         output.appendLine('Skipping update check due to recent failure backoff.');
-        return await locateBinary(context.extensionUri.fsPath);
+        return await locateBinaryOnPath();
     }
 
     try {
@@ -121,8 +123,8 @@ async function doEnsureBinary(context: vscode.ExtensionContext, output: vscode.O
     const cachedBin = await getExtractedBinaryPath(binDir);
     if (cachedBin) return cachedBin;
 
-    // Fallback to bundled
-    return await locateBinary(context.extensionUri.fsPath);
+    // Bundled was already checked at the top; last resort is a user-installed ctrace.
+    return await locateBinaryOnPath();
 }
 
 function getAssetForPlatform(assets: any[]): { name: string; url: string } | null {
diff --git a/src/ctrace/DependencyInstaller.ts b/src/ctrace/DependencyInstaller.ts
index 3ee5025..c4b91fc 100644
--- a/src/ctrace/DependencyInstaller.ts
+++ b/src/ctrace/DependencyInstaller.ts
@@ -235,6 +235,12 @@ elif command -v zypper >/dev/null 2>&1; then
 elif command -v apk >/dev/null 2>&1; then
     echo "Detected Alpine Linux (apk)."
     apk add --no-cache cppcheck flawfinder build-base git cmake python3 py3-pip curl || true
+elif command -v brew >/dev/null 2>&1; then
+    echo "Detected macOS (Homebrew)."
+    # Homebrew refuses to run as root, so install as the invoking user.
+    sudo -u "\${SUDO_USER:-$(id -un)}" brew install cppcheck flawfinder cmake python3 || true
+    # IKOS is only published through NASA's tap (builds LLVM deps, can take a while).
+    sudo -u "\${SUDO_USER:-$(id -un)}" brew install nasa-sw-vnv/core/ikos || true
 else
     echo "Warning: Unrecognized package manager. Please ensure git, g++, make, cmake, python3, and curl are installed."
 fi
@@ -242,7 +248,8 @@ fi
 echo "=== [2/5] Creating CoreTrace tools directory structure... ==="
 USER_HOME="$CORETRACE_USER_HOME"
 if [ -z "$USER_HOME" ] && [ -n "$SUDO_USER" ]; then
-    USER_HOME=$(getent passwd "$SUDO_USER" | cut -d: -f6)
+    # getent does not exist on macOS; tilde expansion works everywhere.
+    USER_HOME=$(eval echo "~$SUDO_USER")
 fi
 if [ -z "$USER_HOME" ]; then
     USER_HOME="$HOME"
@@ -344,7 +351,7 @@ fi
 # Ensure permissions
 TOOLS_OWNER="$CORETRACE_USER_NAME"
 if [ -z "$TOOLS_OWNER" ]; then TOOLS_OWNER="$SUDO_USER"; fi
-if [ -n "$TOOLS_OWNER" ]; then chown -R "$TOOLS_OWNER:$TOOLS_OWNER" "$TOOLS_DIR" 2>/dev/null || true; fi
+if [ -n "$TOOLS_OWNER" ]; then chown -R "$TOOLS_OWNER" "$TOOLS_DIR" 2>/dev/null || true; fi
 chmod -R 755 "$TOOLS_DIR" 2>/dev/null || true
 
 echo "=== All CoreTrace dependencies installed and verified successfully! ==="
diff --git a/src/extension.ts b/src/extension.ts
index 5103671..c141059 100755
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -72,8 +72,11 @@ export function activate(context: vscode.ExtensionContext) {
         if (!p) {
             const extPath = context.extensionUri.fsPath;
             const globalStorage = context.globalStorageUri.fsPath;
+            const hint = process.platform === 'darwin'
+                ? '\nCoreTrace publishes no prebuilt macOS binary: build it from https://github.com/CoreTrace/coretrace and put `ctrace` on your PATH.'
+                : '';
             vscode.window.showErrorMessage(
-                `Ctrace binary could not be found or downloaded. Checked: \n- ${globalStorage}/bin\n- ${extPath}\nSee the "Ctrace" Output channel for details.`
+                `Ctrace binary could not be found or downloaded. Checked: \n- ${globalStorage}/bin\n- ${extPath}\n- PATH${hint}\nSee the "Ctrace" Output channel for details.`
             );
         }
         return p;