Add isEditable metadata key to disable editing in the editor

App/Sources/App/ContentViewModel.swift

@@ -30,6 +30,7 @@ final class ContentViewModel {
         .metadata(\.displayName, "Float Array Example")
     let intArrayVariable = ConfigVariable(key: "int_array", defaultValue: [1, 2, 4, 8, 16, 32])
         .metadata(\.displayName, "Int Array Example")
+        .metadata(\.isEditable, false)
     let stringArrayVariable = ConfigVariable(
         key: "string_array",
         defaultValue: ["Thom", "Jonny", "Ed", "Colin", "Phil"]

Sources/DevConfiguration/Editor/Config Variable Detail/ConfigVariableDetailViewModel.swift

@@ -49,7 +49,7 @@ final class ConfigVariableDetailViewModel: ConfigVariableDetailViewModeling {
         self.variableTypeName = registeredVariable.destinationTypeName
         self.metadataEntries = registeredVariable.metadata.displayTextEntries
         self.isSecret = registeredVariable.isSecret
-        self.editorControl = registeredVariable.editorControl
+        self.editorControl = registeredVariable.isEditable ? registeredVariable.editorControl : nil
 
         if let content = document.override(forKey: registeredVariable.key) {
             self.overrideText = content.editableString

Sources/DevConfiguration/Metadata/IsEditableMetadataKey.swift

@@ -0,0 +1,25 @@
+//
+//  IsEditableMetadataKey.swift
+//  DevConfiguration
+//
+//  Created by Prachi Gauriar on 3/17/2026.
+//
+
+import Foundation
+
+/// The metadata key indicating whether a variable is editable in the variable editor.
+private struct IsEditableMetadataKey: ConfigVariableMetadataKey {
+    static let defaultValue = true
+    static let keyDisplayText = localizedString("isEditableMetadata.keyDisplayText")
+}
+
+
+extension ConfigVariableMetadata {
+    /// Whether the configuration variable is editable in the variable editor.
+    ///
+    /// When `false`, the editor UI hides the override controls for this variable. Defaults to `true`.
+    public var isEditable: Bool {
+        get { self[IsEditableMetadataKey.self] }
+        set { self[IsEditableMetadataKey.self] = newValue }
+    }
+}

Sources/DevConfiguration/Resources/Localizable.xcstrings

@@ -361,6 +361,16 @@
         }
       }
     },
+    "isEditableMetadata.keyDisplayText" : {
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Is Editable"
+          }
+        }
+      }
+    },
     "requiresRelaunchMetadata.keyDisplayText" : {
       "localizations" : {
         "en" : {

Tests/DevConfigurationTests/Unit Tests/Editor/Config Variable Detail/ConfigVariableDetailViewModelTests.swift

@@ -86,6 +86,27 @@ struct ConfigVariableDetailViewModelTests: RandomValueGenerating {
     }
 
 
+    @Test
+    mutating func initSetsEditorControlToNilWhenNotEditable() {
+        // set up with isEditable = false
+        var metadata = ConfigVariableMetadata()
+        metadata.isEditable = false
+
+        let variable = randomRegisteredVariable(
+            metadata: metadata,
+            editorControl: .textField
+        )
+
+        let document = makeDocument(registeredVariables: [variable])
+
+        // exercise
+        let viewModel = makeViewModel(document: document, registeredVariable: variable)
+
+        // expect editorControl is nil because the variable is not editable
+        #expect(viewModel.editorControl == nil)
+    }
+
+
     @Test
     mutating func initUsesKeyDescriptionWhenDisplayNameIsNil() {
         // set up with no display name metadata

Tests/DevConfigurationTests/Unit Tests/Metadata/IsEditableMetadataKeyTests.swift

@@ -0,0 +1,42 @@
+//
+//  IsEditableMetadataKeyTests.swift
+//  DevConfiguration
+//
+//  Created by Prachi Gauriar on 3/17/2026.
+//
+
+import Testing
+
+@testable import DevConfiguration
+
+struct IsEditableMetadataKeyTests {
+    @Test
+    func isEditableDefaultsToTrueAndStoresAndRetrievesValue() {
+        // set up
+        var metadata = ConfigVariableMetadata()
+
+        // expect that unset isEditable returns true
+        #expect(metadata.isEditable)
+
+        // exercise
+        metadata.isEditable = false
+
+        // expect that the value is stored and retrieved correctly
+        #expect(!metadata.isEditable)
+    }
+
+
+    @Test
+    func isEditableDisplayTextShowsValue() throws {
+        // set up
+        var metadata = ConfigVariableMetadata()
+
+        // exercise
+        metadata.isEditable = false
+
+        // expect that displayTextEntries contains the is editable entry with a localized key
+        let entries = metadata.displayTextEntries
+        let entry = try #require(entries.first { $0.value == "false" })
+        #expect(entry.key != "isEditableMetadata.keyDisplayText")
+    }
+}