diff --git a/Sources/CodexBarClaudeWebProbe/main.swift b/Sources/CodexBarClaudeWebProbe/main.swift
index 63d9ce867..81aab4a16 100644
--- a/Sources/CodexBarClaudeWebProbe/main.swift
+++ b/Sources/CodexBarClaudeWebProbe/main.swift
@@ -1,7 +1,6 @@
 import CodexBarCore
 import Foundation
 
-@main
 enum CodexBarClaudeWebProbe {
     private static let defaultEndpoints: [String] = [
         "https://claude.ai/api/organizations",
@@ -19,7 +18,7 @@ enum CodexBarClaudeWebProbe {
         "https://claude.ai/settings/usage",
     ]
 
-    static func main() async {
+    static func run() async {
         let args = CommandLine.arguments.dropFirst()
         let endpoints = args.isEmpty ? Self.defaultEndpoints : Array(args)
         let includePreview = ProcessInfo.processInfo.environment["CLAUDE_WEB_PROBE_PREVIEW"] == "1"
@@ -61,3 +60,5 @@ enum CodexBarClaudeWebProbe {
         print("")
     }
 }
+await CodexBarClaudeWebProbe.run()
+
diff --git a/Sources/CodexBarCore/PathEnvironment.swift b/Sources/CodexBarCore/PathEnvironment.swift
index ece93eda2..7f3797d32 100644
--- a/Sources/CodexBarCore/PathEnvironment.swift
+++ b/Sources/CodexBarCore/PathEnvironment.swift
@@ -52,6 +52,7 @@ public enum BinaryLocator {
             loginPATH: loginPATH,
             commandV: commandV,
             aliasResolver: aliasResolver,
+            useShellCache: true,
             fileManager: fileManager,
             home: home)
     }
@@ -72,6 +73,7 @@ public enum BinaryLocator {
             loginPATH: loginPATH,
             commandV: commandV,
             aliasResolver: aliasResolver,
+            useShellCache: true,
             fileManager: fileManager,
             home: home)
     }
@@ -92,6 +94,7 @@ public enum BinaryLocator {
             loginPATH: loginPATH,
             commandV: commandV,
             aliasResolver: aliasResolver,
+            useShellCache: true,
             fileManager: fileManager,
             home: home)
     }
@@ -112,6 +115,7 @@ public enum BinaryLocator {
             loginPATH: loginPATH,
             commandV: commandV,
             aliasResolver: aliasResolver,
+            useShellCache: true,
             fileManager: fileManager,
             home: home)
     }
@@ -124,6 +128,7 @@ public enum BinaryLocator {
         loginPATH: [String]?,
         commandV: (String, String?, TimeInterval, FileManager) -> String?,
         aliasResolver: (String, String?, TimeInterval, FileManager, String) -> String?,
+        useShellCache: Bool,
         fileManager: FileManager,
         home: String) -> String?
     {
@@ -150,18 +155,48 @@ public enum BinaryLocator {
             return pathHit
         }
 
-        // 4) Interactive login shell lookup (captures nvm/fnm/mise paths from .zshrc/.bashrc)
-        if let shellHit = commandV(name, env["SHELL"], 2.0, fileManager),
-           fileManager.isExecutableFile(atPath: shellHit)
-        {
-            return shellHit
-        }
-
-        // 4b) Alias fallback (login shell); only attempt after all standard lookups fail.
-        if let aliasHit = aliasResolver(name, env["SHELL"], 2.0, fileManager, home),
-           fileManager.isExecutableFile(atPath: aliasHit)
-        {
-            return aliasHit
+        // 4) Interactive login shell lookup — use cache to avoid repeated shell spawns
+        //    (shell auto-start hooks like zellij create new daemon instances on each invocation).
+        //    Cache is bypassed when custom commandV/aliasResolver closures are injected (e.g. tests)
+        //    to prevent a cached result from one call context affecting another.
+        if useShellCache {
+            let cached = BinaryResolutionCache.shared.cachedResult(for: name)
+            if let cached {
+                if let path = cached.path {
+                    if fileManager.isExecutableFile(atPath: path) {
+                        return path
+                    }
+                    // Cached path is no longer executable (e.g. CLI uninstalled/moved) — retry
+                    BinaryResolutionCache.shared.invalidate(name)
+                } else {
+                    // Cached nil = confirmed not found; skip shell spawns
+                    return nil
+                }
+            }
+            // Not yet cached (or just invalidated) — run the shell lookups once and cache the result
+            var resolved: String? = nil
+            if let shellHit = commandV(name, env["SHELL"], 2.0, fileManager),
+               fileManager.isExecutableFile(atPath: shellHit)
+            {
+                resolved = shellHit
+            } else if let aliasHit = aliasResolver(name, env["SHELL"], 2.0, fileManager, home),
+                      fileManager.isExecutableFile(atPath: aliasHit)
+            {
+                resolved = aliasHit
+            }
+            BinaryResolutionCache.shared.store(path: resolved, for: name)
+            if let resolved { return resolved }
+        } else {
+            if let shellHit = commandV(name, env["SHELL"], 2.0, fileManager),
+               fileManager.isExecutableFile(atPath: shellHit)
+            {
+                return shellHit
+            }
+            if let aliasHit = aliasResolver(name, env["SHELL"], 2.0, fileManager, home),
+               fileManager.isExecutableFile(atPath: aliasHit)
+            {
+                return aliasHit
+            }
         }
 
         // 5) Minimal fallback
@@ -440,6 +475,44 @@ enum LoginShellPathCapturer {
     }
 }
 
+/// Caches the results of interactive-shell binary lookups (steps 4/4b of resolveBinary).
+/// Prevents repeated login-shell spawns — which can trigger auto-start hooks like zellij —
+/// on every refresh cycle when a binary is not found on the standard PATH.
+final class BinaryResolutionCache: @unchecked Sendable {
+    static let shared = BinaryResolutionCache()
+
+    private let lock = NSLock()
+    // nil value = binary confirmed not found; missing key = not yet looked up
+    private var cache: [String: String?] = [:]
+
+    func cachedResult(for name: String) -> (found: Bool, path: String?)? {
+        lock.lock()
+        defer { lock.unlock() }
+        guard cache.keys.contains(name) else { return nil }
+        return (found: cache[name] != nil, path: cache[name] ?? nil)
+    }
+
+    func store(path: String?, for name: String) {
+        lock.lock()
+        defer { lock.unlock() }
+        cache[name] = path
+    }
+
+    /// Resets a single entry (e.g., when a binary is installed/uninstalled at runtime).
+    func invalidate(_ name: String) {
+        lock.lock()
+        defer { lock.unlock() }
+        cache.removeValue(forKey: name)
+    }
+
+    /// Resets all cached entries.
+    func invalidateAll() {
+        lock.lock()
+        defer { lock.unlock() }
+        cache.removeAll()
+    }
+}
+
 public final class LoginShellPathCache: @unchecked Sendable {
     public static let shared = LoginShellPathCache()