feat: Add blacklist mode for browser host filtering

Resources/Localizable.xcstrings

@@ -58362,6 +58362,108 @@
         }
       }
     },
+    "settings.browser.hostBlacklist": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Hosts to Block from Embedded Browser"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "内蔵ブラウザからブロックするホスト"
+          }
+        }
+      }
+    },
+    "settings.browser.hostBlacklist.subtitle": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Applies to terminal link clicks and intercepted `open https://...` calls. These hosts always open in your default browser. All other hosts open in cmux. One host or wildcard per line (for example: example.com, *.internal.example). Leave empty to open all hosts in cmux."
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "ターミナルのリンククリックおよびインターセプトされた`open https://...`呼び出しに適用されます。これらのホストは常にデフォルトブラウザで開きます。その他のホストはcmuxで開きます。1行に1つのホストまたはワイルドカード（例: example.com, *.internal.example）。空欄にするとすべてのホストをcmuxで開きます。"
+          }
+        }
+      }
+    },
+    "settings.browser.hostListMode": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Host List Mode"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "ホストリストモード"
+          }
+        }
+      }
+    },
+    "settings.browser.hostListMode.blacklist": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Blacklist"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "ブラックリスト"
+          }
+        }
+      }
+    },
+    "settings.browser.hostListMode.subtitle": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Whitelist: only listed hosts open in cmux. Blacklist: listed hosts always open in your default browser."
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "ホワイトリスト：リストのホストのみcmuxで開きます。ブラックリスト：リストのホストは常にデフォルトブラウザで開きます。"
+          }
+        }
+      }
+    },
+    "settings.browser.hostListMode.whitelist": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Whitelist"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "needs_review",
+            "value": "ホワイトリスト"
+          }
+        }
+      }
+    },
     "settings.browser.hostWhitelist": {
       "extractionState": "manual",
       "localizations": {

Resources/bin/open

@@ -27,8 +27,9 @@ elif command -v python3 >/dev/null 2>&1; then
 fi
 
 settings_domain="${CMUX_BUNDLE_ID:-}"
-whitelist_raw=""
-whitelist_patterns=()
+host_list_raw=""
+host_list_patterns=()
+host_list_mode="whitelist"
 
 system_open() {
     exec "$SYSTEM_OPEN_BIN" "$@"
@@ -338,29 +339,49 @@ host_matches_pattern() {
     [[ "$host" == "$pattern" ]]
 }
 
-host_matches_whitelist() {
+host_matches_list_pattern() {
     local url="$1"
-    if [[ ${#whitelist_patterns[@]} -eq 0 ]]; then
+    if [[ ${#host_list_patterns[@]} -eq 0 ]]; then
         return 0
     fi
 
     local host
     host="$(normalize_host "$url")" || return 1
-    for pattern in "${whitelist_patterns[@]}"; do
+    for pattern in "${host_list_patterns[@]}"; do
         if host_matches_pattern "$host" "$pattern"; then
             return 0
         fi
     done
     return 1
 }
 
-load_whitelist_patterns() {
+# Determine whether a URL's host should open in cmux, respecting the
+# configured host-list mode (whitelist or blacklist).
+should_open_in_cmux() {
+    local url="$1"
+    if [[ ${#host_list_patterns[@]} -eq 0 ]]; then
+        return 0
+    fi
+
+    if [[ "$host_list_mode" == "blacklist" ]]; then
+        # Blacklist mode: if the host matches a pattern, it should NOT open in cmux.
+        if host_matches_list_pattern "$url"; then
+            return 1
+        fi
+        return 0
+    fi
+
+    # Whitelist mode (default): delegate directly.
+    host_matches_list_pattern "$url"
+}
+
+load_host_list_patterns() {
     local raw="$1"
     local line
     while IFS= read -r line || [[ -n "$line" ]]; do
         local normalized
         normalized="$(normalize_whitelist_pattern "$line")" || continue
-        whitelist_patterns+=("$normalized")
+        host_list_patterns+=("$normalized")
     done <<< "$raw"
 }
 
@@ -433,9 +454,14 @@ if [[ -n "$settings_domain" ]]; then
         system_open "$@"
     fi
 
-    whitelist_raw="$("$DEFAULTS_BIN" read "$settings_domain" browserHostWhitelist 2>/dev/null || true)"
-    if [[ -n "$whitelist_raw" ]]; then
-        load_whitelist_patterns "$whitelist_raw"
+    host_list_raw="$("$DEFAULTS_BIN" read "$settings_domain" browserHostWhitelist 2>/dev/null || true)"
+    if [[ -n "$host_list_raw" ]]; then
+        load_host_list_patterns "$host_list_raw"
+    fi
+
+    host_list_mode_raw="$("$DEFAULTS_BIN" read "$settings_domain" browserHostListMode 2>/dev/null || true)"
+    if [[ "$host_list_mode_raw" == "blacklist" ]]; then
+        host_list_mode="blacklist"
     fi
 
 fi
@@ -453,7 +479,7 @@ fi
 # terminal link clicks and intercepted `open` commands share one regex dialect.
 failed_urls=()
 for url in "${cmux_targets[@]}"; do
-    if is_http_url "$url" && ! host_matches_whitelist "$url"; then
+    if is_http_url "$url" && ! should_open_in_cmux "$url"; then
         failed_urls+=("$url")
         continue
     fi

Sources/ContentView.swift

@@ -8672,9 +8672,18 @@ struct ContentView: View {
         var openedCount = 0
         if openSidebarPullRequestLinksInCmuxBrowser {
             for pullRequest in pullRequests {
-                if tabManager.openBrowser(url: pullRequest.url, insertAtEnd: true) != nil {
+                let url = pullRequest.url
+                // Respect external-open patterns and host whitelist/blacklist settings.
+                let shouldOpenExternally = BrowserLinkOpenSettings.shouldOpenExternally(url)
+                    || {
+                        guard let host = BrowserInsecureHTTPSettings.normalizeHost(url.host ?? "") else { return false }
+                        return !BrowserLinkOpenSettings.shouldOpenInCmuxBrowser(host: host)
+                    }()
+                if shouldOpenExternally {
+                    if NSWorkspace.shared.open(url) { openedCount += 1 }
+                } else if tabManager.openBrowser(url: url, insertAtEnd: true) != nil {
                     openedCount += 1
-                } else if NSWorkspace.shared.open(pullRequest.url) {
+                } else if NSWorkspace.shared.open(url) {
                     openedCount += 1
                 }
             }
@@ -13793,6 +13802,16 @@ private struct TabItemView: View, Equatable {
     private func openPullRequestLink(_ url: URL) {
         updateSelection()
         if openSidebarPullRequestLinksInCmuxBrowser {
+            // Respect external-open patterns and host whitelist/blacklist settings.
+            if BrowserLinkOpenSettings.shouldOpenExternally(url) {
+                NSWorkspace.shared.open(url)
+                return
+            }
+            if let host = BrowserInsecureHTTPSettings.normalizeHost(url.host ?? ""),
+               !BrowserLinkOpenSettings.shouldOpenInCmuxBrowser(host: host) {
+                NSWorkspace.shared.open(url)
+                return
+            }
             if tabManager.openBrowser(
                 inWorkspace: tab.id,
                 url: url,

Sources/GhosttyTerminalView.swift

@@ -3123,10 +3123,11 @@ class GhosttyApp {
                     }
                 }
 
-                // If a host whitelist is configured and this host isn't in it, open externally.
-                if !BrowserLinkOpenSettings.hostMatchesWhitelist(host) {
+                // If the host-list rules (whitelist or blacklist mode) say this host should not
+                // open in cmux, open externally.
+                if !BrowserLinkOpenSettings.shouldOpenInCmuxBrowser(host: host) {
                     #if DEBUG
-                    dlog("link.openURL target=embedded but hostWhitelist miss host=\(host) url=\(url)")
+                    dlog("link.openURL target=embedded but hostList miss host=\(host) url=\(url)")
                     #endif
                     return performOnMain {
                         NSWorkspace.shared.open(url)

Sources/KeyboardShortcutSettingsFileStore.swift

@@ -80,6 +80,7 @@ final class CmuxSettingsFileStore {
         "browser.theme",
         "browser.openTerminalLinksInCmuxBrowser",
         "browser.interceptTerminalOpenCommandInCmuxBrowser",
+        "browser.hostListMode",
         "browser.hostsToOpenInEmbeddedBrowser",
         "browser.urlsToAlwaysOpenExternally",
         "browser.insecureHttpHostsAllowedInEmbeddedBrowser",

Sources/Panels/BrowserPanel.swift

@@ -546,9 +546,26 @@ enum BrowserLinkOpenSettings {
 
     static let browserHostWhitelistKey = "browserHostWhitelist"
     static let defaultBrowserHostWhitelist: String = ""
+    static let browserHostListModeKey = "browserHostListMode"
+    static let defaultBrowserHostListMode: String = "whitelist"
     static let browserExternalOpenPatternsKey = "browserExternalOpenPatterns"
     static let defaultBrowserExternalOpenPatterns: String = ""
 
+    /// The two supported host-list modes.
+    /// - `whitelist`: only listed hosts open in cmux (empty list = allow all).
+    /// - `blacklist`: listed hosts always open externally (empty list = allow all in cmux).
+    enum HostListMode: String, CaseIterable, Identifiable {
+        case whitelist
+        case blacklist
+
+        var id: String { rawValue }
+    }
+
+    static func hostListMode(defaults: UserDefaults = .standard) -> HostListMode {
+        let raw = defaults.string(forKey: browserHostListModeKey) ?? defaultBrowserHostListMode
+        return HostListMode(rawValue: raw) ?? .whitelist
+    }
+
     static func openTerminalLinksInCmuxBrowser(defaults: UserDefaults = .standard) -> Bool {
         if defaults.object(forKey: openTerminalLinksInCmuxBrowserKey) == nil {
             return defaultOpenTerminalLinksInCmuxBrowser
@@ -627,12 +644,26 @@ enum BrowserLinkOpenSettings {
         return false
     }
 
-    /// Check whether a hostname matches the configured whitelist.
-    /// Empty whitelist means "allow all" (no filtering).
-    /// Supports exact match and wildcard prefix (`*.example.com`).
-    static func hostMatchesWhitelist(_ host: String, defaults: UserDefaults = .standard) -> Bool {
+    /// Determine whether a host should open in the cmux embedded browser,
+    /// respecting the configured host-list mode (whitelist or blacklist).
+    ///
+    /// - Whitelist mode (default): empty list = allow all; non-empty = only listed hosts open in cmux.
+    /// - Blacklist mode: empty list = allow all; non-empty = listed hosts open externally, everything else in cmux.
+    static func shouldOpenInCmuxBrowser(host: String, defaults: UserDefaults = .standard) -> Bool {
         let rawPatterns = hostWhitelist(defaults: defaults)
         if rawPatterns.isEmpty { return true }
+
+        let matchesEntry = hostMatchesEntry(host, rawPatterns: rawPatterns)
+        switch hostListMode(defaults: defaults) {
+        case .whitelist:
+            return matchesEntry
+        case .blacklist:
+            return !matchesEntry
+        }
+    }
+
+    /// Check whether a host matches any entry in the provided raw patterns list.
+    private static func hostMatchesEntry(_ host: String, rawPatterns: [String]) -> Bool {
         guard let normalizedHost = BrowserInsecureHTTPSettings.normalizeHost(host) else { return false }
         for rawPattern in rawPatterns {
             guard let pattern = normalizeWhitelistPattern(rawPattern) else { continue }