Let a project turn a globally-enabled Claude Code setting back off

The six boolean settings were plain `bool`s merged with
`if p.x { true } else { g.x }`, so a project could only ever add to the
global set. There was no project value that produced `false` — turning a
switch off at project level simply fell through to the global value and
the control did nothing.

Widen them to `Option<bool>`. `None` means "not set at this level":
inherit the global on a project, leave Claude Code's own default alone
globally. `Some(false)` is a deliberate off and wins outright.

The fingerprint now formats with `{:?}` rather than `{}` — `None` and
`Some(false)` mean different things, and conflating them would leave the
container un-recreated when a project switched from inherit to off.

The project editor grows a third "Global" state per switch; the global
editor has nothing to inherit from, so it stays a plain toggle and keeps
collapsing to null at the default. Its three existing tests passed
unchanged and caught a first attempt that rendered unset as off, which
would have told every user their session recap was disabled.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GBq2rGum6GX7xXgsas1fDc

app/src-tauri/src/docker/container.rs

@@ -631,8 +631,14 @@ fn compute_ports_fingerprint(port_mappings: &[PortMapping]) -> String {
     sha256_hex(&joined)
 }
 
-/// Merge global and per-project ClaudeCodeSettings.
-/// Per-project fields override global fields when set (non-default).
+/// Merge global and per-project `ClaudeCodeSettings`.
+///
+/// A project field that is `Some` wins outright — **including `Some(false)`**.
+/// That is the point of the widening: these used to be plain `bool`s ORed
+/// together (`if p.x { true } else { g.x }`), so a project could only ever add
+/// to the global set and never turn a globally-enabled setting off. `None` at
+/// project level means "inherit", which is now a state the project can
+/// actually be in rather than the only state an off switch could produce.
 fn merge_claude_code_settings(
     global: Option<&ClaudeCodeSettings>,
     project: Option<&ClaudeCodeSettings>,
@@ -642,16 +648,15 @@ fn merge_claude_code_settings(
         (Some(g), None) => Some(g.clone()),
         (None, Some(p)) => Some(p.clone()),
         (Some(g), Some(p)) => {
-            // Project overrides global for each field when the project value is non-default
             Some(ClaudeCodeSettings {
                 tui_mode: p.tui_mode.clone().or_else(|| g.tui_mode.clone()),
                 effort: p.effort.clone().or_else(|| g.effort.clone()),
-                auto_scroll_disabled: if p.auto_scroll_disabled { true } else { g.auto_scroll_disabled },
-                focus_mode: if p.focus_mode { true } else { g.focus_mode },
-                show_thinking_summaries: if p.show_thinking_summaries { true } else { g.show_thinking_summaries },
-                session_recap_disabled: if p.session_recap_disabled { true } else { g.session_recap_disabled },
-                env_scrub: if p.env_scrub { true } else { g.env_scrub },
-                prompt_caching_1h: if p.prompt_caching_1h { true } else { g.prompt_caching_1h },
+                auto_scroll_disabled: p.auto_scroll_disabled.or(g.auto_scroll_disabled),
+                focus_mode: p.focus_mode.or(g.focus_mode),
+                show_thinking_summaries: p.show_thinking_summaries.or(g.show_thinking_summaries),
+                session_recap_disabled: p.session_recap_disabled.or(g.session_recap_disabled),
+                env_scrub: p.env_scrub.or(g.env_scrub),
+                prompt_caching_1h: p.prompt_caching_1h.or(g.prompt_caching_1h),
             })
         }
     }
@@ -673,12 +678,16 @@ fn compute_claude_code_settings_fingerprint(
             let parts = vec![
                 s.tui_mode.as_deref().unwrap_or("").to_string(),
                 s.effort.as_deref().unwrap_or("").to_string(),
-                format!("{}", s.auto_scroll_disabled),
-                format!("{}", s.focus_mode),
-                format!("{}", s.show_thinking_summaries),
-                format!("{}", s.session_recap_disabled),
-                format!("{}", s.env_scrub),
-                format!("{}", s.prompt_caching_1h),
+                // `{:?}` rather than `{}` so `None` and `Some(false)` produce
+                // different text. They mean different things — inherit versus a
+                // deliberate off — and a fingerprint that conflated them would
+                // leave the container un-recreated on a real change.
+                format!("{:?}", s.auto_scroll_disabled),
+                format!("{:?}", s.focus_mode),
+                format!("{:?}", s.show_thinking_summaries),
+                format!("{:?}", s.session_recap_disabled),
+                format!("{:?}", s.env_scrub),
+                format!("{:?}", s.prompt_caching_1h),
             ];
             sha256_hex(&parts.join("|"))
         }
@@ -738,15 +747,15 @@ fn claude_code_env_vars(settings: Option<&ClaudeCodeSettings>) -> Vec<String> {
         ),
         format!(
             "CLAUDE_CODE_ENABLE_AWAY_SUMMARY={}",
-            if s.session_recap_disabled { "0" } else { "" }
+            if s.session_recap_disabled.unwrap_or(false) { "0" } else { "" }
         ),
         format!(
             "CLAUDE_CODE_SUBPROCESS_ENV_SCRUB={}",
-            if s.env_scrub { "1" } else { "0" }
+            if s.env_scrub.unwrap_or(false) { "1" } else { "0" }
         ),
         format!(
             "ENABLE_PROMPT_CACHING_1H={}",
-            if s.prompt_caching_1h { "1" } else { "0" }
+            if s.prompt_caching_1h.unwrap_or(false) { "1" } else { "0" }
         ),
     ]
 }
@@ -817,12 +826,12 @@ fn build_claude_code_settings_json(
     // Documented default `true`, so the neutral value is a value.
     map.insert(
         "autoScrollEnabled".to_string(),
-        serde_json::json!(!s.auto_scroll_disabled),
+        serde_json::json!(!s.auto_scroll_disabled.unwrap_or(false)),
     );
     // Documented default `false`.
     map.insert(
         "showThinkingSummaries".to_string(),
-        serde_json::json!(s.show_thinking_summaries),
+        serde_json::json!(s.show_thinking_summaries.unwrap_or(false)),
     );
     // `viewMode: "focus"` is the real setting behind what the UI calls focus
     // mode — "collapses tool output to one-line summaries" is that key's
@@ -830,7 +839,7 @@ fn build_claude_code_settings_json(
     // did nothing.
     map.insert(
         "viewMode".to_string(),
-        if s.focus_mode {
+        if s.focus_mode.unwrap_or(false) {
             serde_json::json!("focus")
         } else {
             serde_json::Value::Null
@@ -842,7 +851,7 @@ fn build_claude_code_settings_json(
     // is here so the container's settings.json does not contradict it.
     map.insert(
         "awaySummaryEnabled".to_string(),
-        if s.session_recap_disabled {
+        if s.session_recap_disabled.unwrap_or(false) {
             serde_json::json!(false)
         } else {
             serde_json::Value::Null
@@ -3675,6 +3684,52 @@ mod tests {
         "sandbox",
     ];
 
+    #[test]
+    fn a_project_can_turn_a_globally_enabled_setting_back_off() {
+        // The whole reason the booleans are `Option<bool>`. Under the old
+        // `if p.x { true } else { g.x }` merge there was no project value that
+        // could produce `false` here.
+        let global = ClaudeCodeSettings {
+            focus_mode: Some(true),
+            env_scrub: Some(true),
+            prompt_caching_1h: Some(true),
+            ..Default::default()
+        };
+        let project = ClaudeCodeSettings {
+            focus_mode: Some(false),
+            ..Default::default()
+        };
+
+        let merged = merge_claude_code_settings(Some(&global), Some(&project)).unwrap();
+
+        assert_eq!(merged.focus_mode, Some(false), "project off must win");
+        // Untouched project fields still inherit.
+        assert_eq!(merged.env_scrub, Some(true));
+        assert_eq!(merged.prompt_caching_1h, Some(true));
+
+        // And it has to survive into what the container actually receives.
+        let payload = build_claude_code_settings_json(Some(&merged), false);
+        let v: serde_json::Value = serde_json::from_str(&payload).unwrap();
+        assert!(
+            v.get("viewMode").is_some_and(|m| m.is_null()),
+            "viewMode should be cleared, got {:?}",
+            v.get("viewMode")
+        );
+    }
+
+    #[test]
+    fn inherit_and_deliberate_off_fingerprint_differently() {
+        // If these collided, switching a project from "inherit" to an explicit
+        // "off" would not recreate the container and the change would silently
+        // not apply.
+        let inherit = ClaudeCodeSettings { focus_mode: None, ..Default::default() };
+        let off = ClaudeCodeSettings { focus_mode: Some(false), ..Default::default() };
+        assert_ne!(
+            compute_claude_code_settings_fingerprint(Some(&inherit), false),
+            compute_claude_code_settings_fingerprint(Some(&off), false),
+        );
+    }
+
     #[test]
     fn split_payload_never_emits_a_null_to_an_older_entrypoint() {
         // An existing project recreates from its own snapshot, which carries
@@ -3713,7 +3768,7 @@ mod tests {
         // managed key would silently stop being asserted.
         let settings = ClaudeCodeSettings {
             tui_mode: Some("fullscreen".to_string()),
-            focus_mode: true,
+            focus_mode: Some(true),
             ..Default::default()
         };
         let payload = build_claude_code_settings_json(Some(&settings), true);
@@ -3752,10 +3807,10 @@ mod tests {
         let on = ClaudeCodeSettings {
             tui_mode: Some("fullscreen".to_string()),
             effort: Some("xhigh".to_string()),
-            auto_scroll_disabled: true,
-            focus_mode: true,
-            show_thinking_summaries: true,
-            session_recap_disabled: true,
+            auto_scroll_disabled: Some(true),
+            focus_mode: Some(true),
+            show_thinking_summaries: Some(true),
+            session_recap_disabled: Some(true),
             ..Default::default()
         };
         let hot = settings_json(Some(&on), true);
@@ -3801,7 +3856,7 @@ mod tests {
     fn the_settings_payload_uses_the_key_names_claude_code_actually_reads() {
         let s = ClaudeCodeSettings {
             effort: Some("high".to_string()),
-            focus_mode: true,
+            focus_mode: Some(true),
             ..Default::default()
         };
         let json = settings_json(Some(&s), false);
@@ -3835,7 +3890,7 @@ mod tests {
         // has to be "don't interfere". Getting this backwards would have
         // silently disabled recaps for every existing project.
         let untouched = ClaudeCodeSettings::default();
-        assert!(!untouched.session_recap_disabled);
+        assert_eq!(untouched.session_recap_disabled, None);
         assert_eq!(
             settings_json(Some(&untouched), false)["awaySummaryEnabled"],
             serde_json::Value::Null
@@ -3847,7 +3902,7 @@ mod tests {
         // `container_needs_recreation` is label-based and never diffs env, so
         // the settings only reach a container if the fingerprint moves.
         let on = ClaudeCodeSettings {
-            focus_mode: true,
+            focus_mode: Some(true),
             ..Default::default()
         };
         let off = ClaudeCodeSettings::default();
@@ -3856,7 +3911,7 @@ mod tests {
             compute_claude_code_settings_fingerprint(Some(&off), false),
         );
         let recap_off = ClaudeCodeSettings {
-            session_recap_disabled: true,
+            session_recap_disabled: Some(true),
             ..Default::default()
         };
         assert_ne!(
@@ -3917,7 +3972,7 @@ mod tests {
         // The whole point of B3: `=1` when enabled was a no-op against a
         // feature that was already on, and there was no off path at all.
         let off = ClaudeCodeSettings {
-            session_recap_disabled: true,
+            session_recap_disabled: Some(true),
             ..Default::default()
         };
         assert!(claude_code_env_vars(Some(&off))

app/src-tauri/src/models/project.rs

@@ -85,6 +85,14 @@ impl PermissionMode {
 /// Settings for Claude Code CLI behavior inside the container.
 /// These map to Claude Code env vars and ~/.claude/settings.json entries.
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default)]
+/// Every field is three-state, and the third state is load-bearing.
+///
+/// `None` means "not set at this level". For a *project* that is "inherit
+/// whatever the global settings say"; for the *global* settings it is "leave
+/// Claude Code's own default alone". `Some(false)` is a deliberate off, which
+/// is what lets a project turn a globally-enabled setting back off — with a
+/// plain `bool` there is no value that can express that, which is why these
+/// were widened from `bool`.
 pub struct ClaudeCodeSettings {
     /// TUI renderer. `None` leaves settings.json's `tui` key unset, which is
     /// what lets Claude Code pick the renderer itself; `Some("default")` pins
@@ -101,14 +109,14 @@ pub struct ClaudeCodeSettings {
     /// because Claude Code's `autoScrollEnabled` defaults to `true`, so the
     /// zero value of this field has to mean "leave it on".
     #[serde(default)]
-    pub auto_scroll_disabled: bool,
+    pub auto_scroll_disabled: Option<bool>,
     /// Collapse tool output to one-line summaries. Written to settings.json as
     /// `viewMode: "focus"`; there is no `focusMode` key in Claude Code.
     #[serde(default)]
-    pub focus_mode: bool,
+    pub focus_mode: Option<bool>,
     /// Show thinking summaries in responses
     #[serde(default)]
-    pub show_thinking_summaries: bool,
+    pub show_thinking_summaries: Option<bool>,
     /// Turn the session recap **off**.
     ///
     /// Held in the disabled sense for the same reason as `auto_scroll_disabled`,
@@ -121,13 +129,13 @@ pub struct ClaudeCodeSettings {
     /// silently disabled it for all of them. A new name lets the old key be
     /// ignored, which lands every existing project on the correct default.
     #[serde(default)]
-    pub session_recap_disabled: bool,
+    pub session_recap_disabled: Option<bool>,
     /// Strip credentials from subprocess environments
     #[serde(default)]
-    pub env_scrub: bool,
+    pub env_scrub: Option<bool>,
     /// Enable 1-hour prompt cache TTL (vs default 5-minute)
     #[serde(default)]
-    pub prompt_caching_1h: bool,
+    pub prompt_caching_1h: Option<bool>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]

app/src/components/projects/ClaudeCodeSettingsEditor.test.tsx

@@ -3,10 +3,18 @@ import { render, screen, fireEvent } from "@testing-library/react";
 import ClaudeCodeSettingsEditor, { CLAUDE_CODE_DEFAULTS } from "./ClaudeCodeSettingsEditor";
 import type { ClaudeCodeSettings } from "../../lib/types";
 
-function renderEditor(settings: ClaudeCodeSettings | null) {
+function renderEditor(
+  settings: ClaudeCodeSettings | null,
+  scope: "global" | "project" = "global",
+) {
   const onSave = vi.fn().mockResolvedValue(undefined);
   render(
-    <ClaudeCodeSettingsEditor settings={settings} disabled={false} onSave={onSave} />,
+    <ClaudeCodeSettingsEditor
+      scope={scope}
+      settings={settings}
+      disabled={false}
+      onSave={onSave}
+    />,
   );
   return onSave;
 }
@@ -59,4 +67,57 @@ describe("ClaudeCodeSettingsEditor", () => {
       ).map((o) => o.getAttribute("value")),
     ).toEqual(["", "low", "medium", "high", "xhigh"]);
   });
+
+  describe("project scope", () => {
+    it("offers Global as a third state so a project can decline to have an opinion", () => {
+      renderEditor(null, "project");
+      const focus = screen.getByLabelText("Focus mode");
+      expect(
+        Array.from(focus.querySelectorAll("option")).map((o) => o.getAttribute("value")),
+      ).toEqual(["global", "off", "on"]);
+      expect((focus as HTMLSelectElement).value).toBe("global");
+    });
+
+    it("stores a deliberate false so the project can turn a global On back off", () => {
+      // The reason the field widened from boolean to boolean|null. Under the
+      // old merge there was no project value that could produce this.
+      const onSave = renderEditor(null, "project");
+      fireEvent.change(screen.getByLabelText("Focus mode"), { target: { value: "off" } });
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({ focus_mode: false }),
+      );
+    });
+
+    it("does not collapse a deliberate off to null", () => {
+      // `null` means inherit. Collapsing here would silently hand the setting
+      // straight back to the global value the user just overrode.
+      const onSave = renderEditor(null, "project");
+      fireEvent.change(screen.getByLabelText("Focus mode"), { target: { value: "off" } });
+      expect(onSave).not.toHaveBeenCalledWith(null);
+    });
+
+    it("round-trips the inverted fields through the disabled sense", () => {
+      // Session recap stores `session_recap_disabled`, so choosing "off" has to
+      // store `true` and choosing "on" has to store `false`.
+      const onSave = renderEditor(null, "project");
+      const recap = screen.getByLabelText("Session recap");
+
+      fireEvent.change(recap, { target: { value: "off" } });
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({ session_recap_disabled: true }),
+      );
+
+      fireEvent.change(recap, { target: { value: "on" } });
+      expect(onSave).toHaveBeenCalledWith(
+        expect.objectContaining({ session_recap_disabled: false }),
+      );
+    });
+
+    it("shows a stored override rather than the inherited state", () => {
+      renderEditor({ ...CLAUDE_CODE_DEFAULTS, session_recap_disabled: true }, "project");
+      expect((screen.getByLabelText("Session recap") as HTMLSelectElement).value).toBe(
+        "off",
+      );
+    });
+  });
 });

app/src/components/projects/ClaudeCodeSettingsEditor.tsx

@@ -8,29 +8,44 @@ interface Props {
   disabled: boolean;
   disabledReason?: string;
   onSave: (settings: ClaudeCodeSettings | null) => Promise<unknown>;
+  /**
+   * `"project"` adds a third "Global" state to every switch, because a project
+   * has somewhere to inherit *from*. The global editor has no such fallback —
+   * unset there just means Claude Code's own default — so it stays a plain
+   * on/off and never renders the extra choice.
+   */
+  scope?: "global" | "project";
 }
 
 export const CLAUDE_CODE_DEFAULTS: ClaudeCodeSettings = {
   tui_mode: null,
   effort: null,
-  auto_scroll_disabled: false,
-  focus_mode: false,
-  show_thinking_summaries: false,
-  session_recap_disabled: false,
-  env_scrub: false,
-  prompt_caching_1h: false,
+  auto_scroll_disabled: null,
+  focus_mode: null,
+  show_thinking_summaries: null,
+  session_recap_disabled: null,
+  env_scrub: null,
+  prompt_caching_1h: null,
 };
 
+/**
+ * "Nothing is set at this level", which is saved as `null` rather than as a
+ * struct of nulls so that a project with no opinion is indistinguishable from
+ * one that never opened this editor.
+ *
+ * Note `false` is *not* a default any more: it is a deliberate off that
+ * overrides a global on, so a settings object holding one has to be persisted.
+ */
 function isAllDefaults(s: ClaudeCodeSettings): boolean {
   return (
     s.tui_mode === null &&
     s.effort === null &&
-    s.auto_scroll_disabled === false &&
-    s.focus_mode === false &&
-    s.show_thinking_summaries === false &&
-    s.session_recap_disabled === false &&
-    s.env_scrub === false &&
-    s.prompt_caching_1h === false
+    s.auto_scroll_disabled === null &&
+    s.focus_mode === null &&
+    s.show_thinking_summaries === null &&
+    s.session_recap_disabled === null &&
+    s.env_scrub === null &&
+    s.prompt_caching_1h === null
   );
 }
 
@@ -83,6 +98,7 @@ export default function ClaudeCodeSettingsEditor({
   disabled,
   disabledReason,
   onSave,
+  scope = "global",
 }: Props) {
   const [local, setLocal] = useState<ClaudeCodeSettings>(
     settings ?? { ...CLAUDE_CODE_DEFAULTS },
@@ -151,7 +167,16 @@ export default function ClaudeCodeSettingsEditor({
         }
       />
 
-      {BOOLEAN_FIELDS.map(({ key, label, hint, invert }) => (
+      {BOOLEAN_FIELDS.map(({ key, label, hint, invert }) => {
+        const stored = local[key];
+
+        if (scope === "global") {
+          // No level above this one to inherit from, so "unset" and "off" are
+          // the same instruction here and a plain switch is the honest control.
+          // Unset therefore has to *display* as Claude Code's own default —
+          // which for the two inverted fields is on, not off.
+          const checked = invert ? stored !== true : stored === true;
+          return (
             <SwitchRow
               key={key}
               label={label}
@@ -159,15 +184,54 @@ export default function ClaudeCodeSettingsEditor({
               control={
                 <Toggle
                   label={label}
-              checked={invert ? !local[key] : local[key]}
+                  checked={checked}
                   disabled={disabled}
-              onChange={(v) =>
-                apply({ [key]: invert ? !v : v } as Partial<ClaudeCodeSettings>)
-              }
+                  onChange={(v) => {
+                    // Collapse back to null at the default rather than storing
+                    // a redundant `false`, so an untouched global stays
+                    // indistinguishable from one that was never opened.
+                    const atDefault = invert ? v : !v;
+                    apply({
+                      [key]: atDefault ? null : invert ? !v : v,
+                    } as Partial<ClaudeCodeSettings>);
+                  }}
                 />
               }
             />
-      ))}
+          );
+        }
+
+        // `stored` holds the deviation from Claude Code's default, so an
+        // inverted field reads back the other way round — see BOOLEAN_FIELDS.
+        const selected =
+          stored === null ? "global" : (invert ? !stored : stored) ? "on" : "off";
+
+        return (
+          <SwitchRow
+            key={key}
+            label={label}
+            hint={hint}
+            control={
+              <select
+                value={selected}
+                aria-label={label}
+                disabled={disabled}
+                onChange={(e) => {
+                  const choice = e.target.value;
+                  const next =
+                    choice === "global" ? null : invert ? choice === "off" : choice === "on";
+                  apply({ [key]: next } as Partial<ClaudeCodeSettings>);
+                }}
+                className={selectClass}
+              >
+                <option value="global">Global</option>
+                <option value="off">Off</option>
+                <option value="on">On</option>
+              </select>
+            }
+          />
+        );
+      })}
     </div>
   );
 }

app/src/components/projects/home/config/RuntimeSection.tsx

@@ -109,9 +109,10 @@ export default function RuntimeSection({
 
       <ConfigGroup
         title="Claude Code settings"
-        description="Per-project CLI behaviour. These override the global defaults in Settings."
+        description="Per-project CLI behaviour. Anything left on Global follows Settings; Off overrides a global On."
       >
         <ClaudeCodeSettingsEditor
+          scope="project"
           settings={project.claude_code_settings}
           disabled={disabled}
           disabledReason={disabledReason}

app/src/lib/types.ts

@@ -133,22 +133,28 @@ export interface OpenAiCompatibleConfig {
   haiku_model_id: string | null;
 }
 
+/**
+ * Every field is three-state. `null` means "not set at this level": on a
+ * project that is "inherit the global value", and on the global settings it is
+ * "leave Claude Code's own default alone". `false` is a deliberate off, which
+ * is what lets a project turn a globally-enabled setting back off.
+ */
 export interface ClaudeCodeSettings {
   /** `null` = let Claude Code choose the renderer; `"default"` = classic, `"fullscreen"` = alt-screen. */
   tui_mode: string | null;
   /** `null` = unset, else `"low" | "medium" | "high" | "xhigh"`. Written as `effortLevel`. */
   effort: string | null;
-  auto_scroll_disabled: boolean;
+  auto_scroll_disabled: boolean | null;
   /** Written as `viewMode: "focus"`. */
-  focus_mode: boolean;
-  show_thinking_summaries: boolean;
+  focus_mode: boolean | null;
+  show_thinking_summaries: boolean | null;
   /**
    * Turns the session recap **off**. Held in the disabled sense because Claude
    * Code's recap is on by default — see the Rust doc on `ClaudeCodeSettings`.
    */
-  session_recap_disabled: boolean;
-  env_scrub: boolean;
-  prompt_caching_1h: boolean;
+  session_recap_disabled: boolean | null;
+  env_scrub: boolean | null;
+  prompt_caching_1h: boolean | null;
 }
 
 export interface ContainerInfo {