Expose model selection for provider-locked runtimes (#2071)

Signed-off-by: Wes <wesbillman@users.noreply.github.com>
Co-authored-by: Pinky <44b8e82baa6e0e254e0208d68f335c283c94e7b78dd1fa10d5a49d3f13dd0435@sprout-oss.stage.blox.sqprod.co>

desktop/src/features/agents/ui/AgentAiConfigurationMode.tsx

@@ -3,11 +3,28 @@ import type { AgentAiConfigurationMode } from "./agentAiConfigurationPolicy";
 
 export type { AgentAiConfigurationMode } from "./agentAiConfigurationPolicy";
 
+export function HarnessModelDefaultNotice({
+  model,
+}: {
+  model?: string | null;
+}) {
+  return (
+    <div className="text-sm" data-testid="agent-harness-defaults-notice">
+      <span className="text-muted-foreground">Model</span>{" "}
+      <span className="text-foreground">
+        {model?.trim() || "Harness default"}
+      </span>
+    </div>
+  );
+}
+
 export function AgentAiConfigurationModeField({
   mode,
+  needsProviderSelection = true,
   onModeChange,
 }: {
   mode: AgentAiConfigurationMode;
+  needsProviderSelection?: boolean;
   onModeChange: (mode: AgentAiConfigurationMode) => void;
 }) {
   return (
@@ -20,13 +37,19 @@ export function AgentAiConfigurationModeField({
         value={mode}
       >
         <TabsList>
-          <TabsTrigger value="defaults">Use agent defaults</TabsTrigger>
+          <TabsTrigger value="defaults">
+            {needsProviderSelection
+              ? "Use agent defaults"
+              : "Use harness defaults"}
+          </TabsTrigger>
           <TabsTrigger value="custom">Customize for this agent</TabsTrigger>
         </TabsList>
       </Tabs>
       {mode === "custom" ? (
         <p className="text-xs text-muted-foreground">
-          Provider and model changes apply only to this agent.
+          {needsProviderSelection
+            ? "Provider and model changes apply only to this agent."
+            : "Model changes apply only to this agent."}
         </p>
       ) : null}
     </div>

desktop/src/features/agents/ui/AgentDefinitionDialog.tsx

@@ -73,6 +73,7 @@ import { AgentAiDefaultsNotice } from "./AgentAiDefaults";
 import { AgentAiDefaultsDialog } from "./AgentAiDefaultsDialog";
 import {
   AgentAiConfigurationModeField,
+  HarnessModelDefaultNotice,
   type AgentAiConfigurationMode,
 } from "./AgentAiConfigurationMode";
 import {
@@ -346,11 +347,14 @@ export function AgentDefinitionDialog({
     setIsCustomModelEditing(false);
     const nextPair = agentAiConfigurationPairForMode({
       current: { provider, model },
-      inherited: {
-        provider: inheritedProviderDefault.value,
-        model: inheritedModelDefault.value,
-      },
+      inherited: runtimeCanChooseLlmProvider
+        ? {
+            provider: inheritedProviderDefault.value,
+            model: inheritedModelDefault.value,
+          }
+        : { provider: "", model: runtimeFileConfig?.model?.trim() ?? "" },
       mode: nextMode,
+      needsProviderSelection: runtimeCanChooseLlmProvider,
     });
     setProvider(nextPair.provider);
     setModel(nextPair.model);
@@ -428,8 +432,6 @@ export function AgentDefinitionDialog({
     aiConfigurationMode === "custom" && runtimeCanChooseLlmProvider;
   const modelFieldVisible =
     runtime.trim().length > 0 || blankRuntimeModelProviderEditable;
-  // Customize pins a complete provider/model pair. Shared compute's concrete
-  // automatic-routing value is the only valid non-model-id choice.
   const isExplicitModelRequired = aiConfigurationMode === "custom";
   // Gate the provider requirement on the field's actual visibility, not the raw
   // runtime capability. Codex/Claude hide the provider picker (they drive their
@@ -852,9 +854,10 @@ export function AgentDefinitionDialog({
               {runtimeWarning}
             </div>
 
-            {llmProviderFieldVisible ? (
+            {modelFieldVisible ? (
               <AgentAiConfigurationModeField
                 mode={aiConfigurationMode}
+                needsProviderSelection={runtimeCanChooseLlmProvider}
                 onModeChange={handleAiConfigurationModeChange}
               />
             ) : null}
@@ -950,19 +953,23 @@ export function AgentDefinitionDialog({
             </AnimatePresence>
 
             {aiConfigurationMode === "defaults" ? (
-              <AgentAiDefaultsNotice
-                onEditDefaults={() => setAiDefaultsOpen(true)}
-                triggerRef={aiDefaultsTriggerRef}
-                explicitModel=""
-                explicitProvider=""
-                inheritedModel={inheritedModelDefault}
-                inheritedProvider={inheritedProviderDefault}
-              />
+              runtimeCanChooseLlmProvider ? (
+                <AgentAiDefaultsNotice
+                  onEditDefaults={() => setAiDefaultsOpen(true)}
+                  triggerRef={aiDefaultsTriggerRef}
+                  explicitModel=""
+                  explicitProvider=""
+                  inheritedModel={inheritedModelDefault}
+                  inheritedProvider={inheritedProviderDefault}
+                />
+              ) : (
+                <HarnessModelDefaultNotice model={runtimeFileConfig?.model} />
+              )
             ) : null}
 
             <AgentAiDefaultsDialog
               onOpenChange={setAiDefaultsOpen}
-              open={aiDefaultsOpen}
+              open={runtimeCanChooseLlmProvider && aiDefaultsOpen}
               returnFocusRef={aiDefaultsTriggerRef}
             />
 

desktop/src/features/agents/ui/agentAiConfigurationPolicy.test.mjs

@@ -126,6 +126,20 @@ test("Defaults clears provider and model together", () => {
   );
 });
 
+test("entering Customize pins only the harness model without a provider picker", () => {
+  for (const model of ["claude-opus", "gpt-5.2-codex"]) {
+    assert.deepEqual(
+      agentAiConfigurationPairForMode({
+        current: { provider: "", model: "" },
+        inherited: { provider: "databricks_v2", model },
+        mode: "custom",
+        needsProviderSelection: false,
+      }),
+      { provider: "", model },
+    );
+  }
+});
+
 test("entering Customize pins unresolved fields from the inherited pair", () => {
   assert.deepEqual(
     agentAiConfigurationPairForMode({

desktop/src/features/agents/ui/agentAiConfigurationPolicy.ts

@@ -15,17 +15,21 @@ export function agentAiConfigurationPairForMode({
   current,
   inherited,
   mode,
+  needsProviderSelection = true,
 }: {
   current: AgentAiConfigurationPair;
   inherited: AgentAiConfigurationPair;
   mode: AgentAiConfigurationMode;
+  needsProviderSelection?: boolean;
 }): AgentAiConfigurationPair {
   if (mode === "defaults") {
     return { provider: "", model: "" };
   }
 
   return {
-    provider: current.provider.trim() || inherited.provider,
+    provider: needsProviderSelection
+      ? current.provider.trim() || inherited.provider
+      : "",
     model: current.model.trim() || inherited.model,
   };
 }

desktop/src/features/agents/ui/personaSubmitBlock.test.mjs

@@ -129,6 +129,8 @@ test("Customize on Codex/Claude asks only for a model, never a provider", () =>
   );
   assert.match(reason, /Select a model/);
   assert.doesNotMatch(reason, /provider/);
+  assert.match(reason, /Use harness defaults/);
+  assert.doesNotMatch(reason, /Use AI defaults/);
 });
 
 test("precedence: a missing name outranks incomplete AI defaults", () => {

desktop/src/features/agents/ui/personaSubmitBlock.ts

@@ -128,7 +128,10 @@ export function personaSubmitBlock(
     if (input.customModelEmpty) pieces.push("a model");
     const what =
       pieces.length > 0 ? joinWithAnd(pieces) : "the AI configuration";
-    return `Select ${what} for this agent, or switch to Use AI defaults.`;
+    const defaultsLabel = input.runtimeNeedsProviderSelection
+      ? "Use AI defaults"
+      : "Use harness defaults";
+    return `Select ${what} for this agent, or switch to ${defaultsLabel}.`;
   }
 
   return null;

desktop/tests/e2e/agent-provider-dropdowns.spec.ts

@@ -197,4 +197,46 @@ test.describe("agent provider dropdown screenshots", () => {
       path: `${SHOTS}/03-builtin-edit-runtime-seeded.png`,
     });
   });
+
+  test("04-codex-definition-exposes-model-without-global-provider-defaults", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      globalAgentConfig: {
+        provider: "databricks_v2",
+        model: "global-databricks-model",
+        env_vars: {},
+      },
+      personas: [
+        {
+          displayName: "Codex Definition",
+          systemPrompt: "A Codex-backed definition.",
+          runtime: "codex",
+        },
+      ],
+    });
+
+    await page.goto("/");
+    await page.getByTestId("open-agents-view").click();
+    await page
+      .getByRole("button", { name: "Open actions for Codex Definition" })
+      .click();
+    await page.getByRole("menuitem", { name: "Edit" }).click();
+
+    const dialog = page.getByTestId("persona-dialog");
+    await expect(dialog).toBeVisible({ timeout: 10_000 });
+    await expect(
+      dialog.getByRole("tab", { name: "Customize for this agent" }),
+    ).toBeVisible();
+    await expect(
+      dialog.getByText("Harness default", { exact: true }),
+    ).toBeVisible();
+    await expect(dialog.getByText(/Databricks/i)).toHaveCount(0);
+
+    await dialog.getByRole("tab", { name: "Customize for this agent" }).click();
+    await expect(
+      dialog.getByRole("combobox", { name: /model/i }),
+    ).toBeVisible();
+    await expect(dialog.getByText("Model changes apply only")).toBeVisible();
+  });
 });