diff --git a/ui/src/components/AgentConfigForm.render.test.tsx b/ui/src/components/AgentConfigForm.render.test.tsx
index 760012f0666..6d6969bd393 100644
--- a/ui/src/components/AgentConfigForm.render.test.tsx
+++ b/ui/src/components/AgentConfigForm.render.test.tsx
@@ -201,6 +201,8 @@ async function renderForm(
     showAdapterTestEnvironmentButton?: boolean;
     configurationShell?: boolean;
     visibleConfigurationSections?: ReadonlySet<string>;
+    onDirtyChange?: (dirty: boolean) => void;
+    onDirtyDetailsChange?: (details: { count: number; sections: string[] }) => void;
   } = {},
 ) {
   mockEnvironmentsApi.list.mockResolvedValue(environments);
@@ -229,6 +231,8 @@ async function renderForm(
             configurationShell={options.configurationShell}
             visibleConfigurationSections={options.visibleConfigurationSections}
             sectionLayout={options.configurationShell ? "cards" : undefined}
+            onDirtyChange={options.onDirtyChange}
+            onDirtyDetailsChange={options.onDirtyDetailsChange}
           />
         </TooltipProvider>
       </QueryClientProvider>,
@@ -623,6 +627,38 @@ describe("AgentConfigForm environment selector", () => {
     }
   });
 
+  it("reports editor-local environment drafts as unsaved configuration", async () => {
+    const onDirtyChange = vi.fn();
+    const onDirtyDetailsChange = vi.fn();
+    const result = await renderForm([
+      makeEnvironment({ id: "local-1", name: "Local", driver: "local" }),
+    ], {
+      adapterConfig: {
+        env: { API_TOKEN: { type: "plain", value: "old-token" } },
+      },
+    }, {
+      configurationShell: true,
+      visibleConfigurationSections: new Set(["environment"]),
+      onDirtyChange,
+      onDirtyDetailsChange,
+    });
+    roots.push(result.root);
+
+    const valueInput = result.container.querySelector<HTMLInputElement>('input[aria-label="Variable value"]');
+    expect(valueInput).toBeTruthy();
+
+    await act(async () => {
+      setInputValue(valueInput!, "draft-token");
+    });
+    await flushReact();
+
+    expect(onDirtyChange).toHaveBeenLastCalledWith(true);
+    expect(onDirtyDetailsChange).toHaveBeenLastCalledWith({
+      count: 1,
+      sections: ["environment"],
+    });
+  });
+
   it("surfaces request failures instead of converting them into model test checks", async () => {
     mockAgentsApi.testEnvironment.mockRejectedValueOnce(new Error("Network unavailable"));
 
diff --git a/ui/src/components/AgentConfigForm.tsx b/ui/src/components/AgentConfigForm.tsx
index d08adf6ef12..fc6dec88364 100644
--- a/ui/src/components/AgentConfigForm.tsx
+++ b/ui/src/components/AgentConfigForm.tsx
@@ -338,6 +338,7 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
 
   // ---- Edit mode: overlay for dirty tracking ----
   const [overlay, setOverlay] = useState<AgentConfigOverlay>(emptyOverlay);
+  const [environmentDraftDirty, setEnvironmentDraftDirty] = useState(false);
   const agentRef = useRef<Agent | null>(null);
 
   // Clear overlay when agent data refreshes (after save)
@@ -350,8 +351,18 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
     }
   }, [isCreate, !isCreate ? props.agent : undefined]); // eslint-disable-line react-hooks/exhaustive-deps
 
-  const isDirty = !isCreate && isOverlayDirty(overlay);
-  const dirtyDetails = useMemo(() => getAgentConfigDirtyDetails(overlay), [overlay]);
+  const overlayDirty = !isCreate && isOverlayDirty(overlay);
+  const isDirty = overlayDirty || environmentDraftDirty;
+  const dirtyDetails = useMemo(() => {
+    const details = getAgentConfigDirtyDetails(overlay);
+    if (!environmentDraftDirty || "env" in overlay.adapterConfig) return details;
+    return {
+      count: details.count + 1,
+      sections: details.sections.includes("environment")
+        ? details.sections
+        : [...details.sections, "environment"],
+    };
+  }, [environmentDraftDirty, overlay]);
   const changes = useMemo(
     () => isCreate ? [] : buildAgentConfigChanges(props.agent, overlay),
     [isCreate, overlay, !isCreate ? props.agent : undefined], // eslint-disable-line react-hooks/exhaustive-deps
@@ -406,6 +417,8 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
 
   /** Build accumulated patch and send to parent */
   const handleCancel = useCallback(() => {
+    environmentVariablesEditorRef.current?.discardPendingDraft();
+    setEnvironmentDraftDirty(false);
     setOverlay({ ...emptyOverlay });
   }, []);
 
@@ -1446,6 +1459,7 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
                       ? set!({ envBindings: env ?? {}, envVars: "" })
                       : mark("adapterConfig", "env", env)
                   }
+                  onDirtyChange={isCreate ? undefined : setEnvironmentDraftDirty}
                 />
               </Field>}
 
@@ -1631,6 +1645,7 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
                     ? set!({ envBindings: env ?? {}, envVars: "" })
                     : mark("adapterConfig", "env", env)
                 }
+                onDirtyChange={isCreate ? undefined : setEnvironmentDraftDirty}
               />
               {!isCreate && (
                 <Field label="Secret access" hint={help.secretAccess}>
diff --git a/ui/src/components/environment-variables-editor/index.tsx b/ui/src/components/environment-variables-editor/index.tsx
index d29f59c9303..39cf57807f3 100644
--- a/ui/src/components/environment-variables-editor/index.tsx
+++ b/ui/src/components/environment-variables-editor/index.tsx
@@ -143,6 +143,8 @@ export interface EnvironmentVariablesEditorHandle {
    * action reads parent state. Returns the promoted value when a draft existed.
    */
   flushPendingDraft: () => Record<string, EnvBinding> | null;
+  /** Discard the editor-local draft and restore the controlled value. */
+  discardPendingDraft: () => void;
 }
 
 export const EnvironmentVariablesEditor = forwardRef<EnvironmentVariablesEditorHandle, EnvironmentVariablesEditorProps>(function EnvironmentVariablesEditor({
@@ -288,7 +290,20 @@ export const EnvironmentVariablesEditor = forwardRef<EnvironmentVariablesEditorH
     return draftValue ?? {};
   }, [disabled, draftValue, draftValueKey, hasUnsavedChanges, onChange]);
 
-  useImperativeHandle(ref, () => ({ flushPendingDraft }), [flushPendingDraft]);
+  const discardPendingDraft = useCallback(() => {
+    if (disabled || !hasUnsavedChanges) return;
+    pendingSaveValueKeyRef.current = null;
+    const nextRows = rowsFromValue(value);
+    setRows(nextRows);
+    touchCommittedNames(nextRows);
+    markCommitted(normalizedEnvKey(value), nextRows);
+  }, [disabled, hasUnsavedChanges, value]);
+
+  useImperativeHandle(
+    ref,
+    () => ({ flushPendingDraft, discardPendingDraft }),
+    [discardPendingDraft, flushPendingDraft],
+  );
 
   useEffect(() => {
     const form = editorRootRef.current?.closest("form");