Clarify agent harness defaults in create flow (#2601)

2026-08-18 06:50:31 +02:00 · 2026-07-24 01:23:31 +01:00
parent 3d17195ac8
commit 76aeae7036
33 changed files with 1489 additions and 855 deletions
@@ -79,6 +79,27 @@ with a TypeScript lookup table or an id comparison in a component.
   harnesses always keep the field. Gate: `defaults hides model when optional
   harness has empty discovery` (and the failed-discovery counterpart) in
   `onboarding-agent-defaults.spec.ts`.
+9. **The defaults modal is progressively disclosed.** An unset global config
+   starts on the Buzz Agent-first deployment fallback and carries that visible
+   harness into the next saved edit. The `progressive-defaults` disclosure
+   preset therefore begins at Provider for Buzz Agent, then reveals Model,
+   Effort, and Advanced only after a provider is configured. Harnesses whose
+   runtime metadata has no provider field skip that gate. Reveals animate their
+   height through Motion and become immediate when reduced motion is requested.
+   Once the Advanced toggle is visible, its expanded state is exclusively
+   user-controlled: provider, harness, and required-env changes must never
+   open it automatically in defaults, create, or edit flows. In Create mode,
+   the defaults summary follows preferred-harness changes saved while the
+   dialog is open, and its configured state includes required credentials as
+   well as provider/model values. If no available harness can resolve, Create
+   starts in Customize and lets unavailable catalog entries be selected only
+   to expose their setup guidance; submission remains blocked.
+   Advanced-only required credentials mark the collapsed Advanced toggle
+   without opening it in Global Defaults and Edit, and block incomplete saves.
+   Runtime-file credentials satisfy Global Defaults just as they do Create and
+   Edit. In Edit,
+   selecting Custom command keeps its required command field beside the harness
+   picker rather than hiding it in Advanced.

 ## The tests that enforce this

@@ -0,0 +1,26 @@
+import { hasMissingRequiredEnvKey } from "./personaRuntimeModel";
+
+export function AdvancedRequiredBadge({
+  envVars,
+  requiredEnvKeys,
+  show,
+  testId,
+}: {
+  envVars?: Record<string, string>;
+  requiredEnvKeys?: readonly string[];
+  show?: boolean;
+  testId: string;
+}) {
+  const visible =
+    show ?? hasMissingRequiredEnvKey(requiredEnvKeys ?? [], envVars ?? {});
+  if (!visible) return null;
+  return (
+    <span
+      aria-hidden="true"
+      className="rounded-full bg-destructive/10 px-2 py-0.5 text-xs text-destructive"
+      data-testid={testId}
+    >
+      Required
+    </span>
+  );
+}
@@ -1,20 +1,67 @@
+import type * as React from "react";
 import { Tabs, TabsList, TabsTrigger } from "@/shared/ui/tabs";
 import type { AgentAiConfigurationMode } from "./agentAiConfigurationPolicy";
+import { AgentAiDefaultsNotice } from "./AgentAiDefaults";
+import type { InheritedDefault } from "./bakedEnvHelpers";

 export type { AgentAiConfigurationMode } from "./agentAiConfigurationPolicy";

 export function HarnessModelDefaultNotice({
+  harness,
  model,
 }: {
+  harness: string;
  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">
+    <dl
+      className="grid grid-cols-[auto_minmax(0,1fr)] gap-x-3 text-sm"
+      data-testid="agent-harness-defaults-notice"
+    >
+      <dt className="text-muted-foreground">Harness</dt>
+      <dd className="truncate text-foreground">
+        {harness || "Not configured"}
+      </dd>
+      <dt className="text-muted-foreground">Model</dt>
+      <dd className="truncate text-foreground">
        {model?.trim() || "Harness default"}
-      </span>
-    </div>
+      </dd>
+    </dl>
+  );
+}
+
+export function AgentCreateAiDefaultsSummary({
+  canChooseProvider,
+  harness,
+  inheritedModel,
+  inheritedProvider,
+  isConfigured,
+  model,
+  onEditDefaults,
+  triggerRef,
+}: {
+  canChooseProvider: boolean;
+  harness: string;
+  inheritedModel: InheritedDefault;
+  inheritedProvider: InheritedDefault;
+  isConfigured: boolean;
+  model?: string | null;
+  onEditDefaults: () => void;
+  triggerRef?: React.Ref<HTMLButtonElement>;
+}) {
+  return canChooseProvider ? (
+    <AgentAiDefaultsNotice
+      isConfigured={isConfigured}
+      onEditDefaults={onEditDefaults}
+      triggerRef={triggerRef}
+      explicitModel=""
+      explicitProvider=""
+      harness={harness}
+      inheritedModel={inheritedModel}
+      inheritedProvider={inheritedProvider}
+    />
+  ) : (
+    <HarnessModelDefaultNotice harness={harness} model={model} />
  );
 }

@@ -36,22 +83,31 @@ export function AgentAiConfigurationModeField({
        }
        value={mode}
      >
-        <TabsList>
-          <TabsTrigger value="defaults">
+        <TabsList className="relative isolate grid h-9 w-full grid-cols-2 overflow-hidden rounded-lg bg-muted p-0.5">
+          <div
+            aria-hidden="true"
+            className="absolute bottom-0.5 left-0.5 top-0.5 z-0 rounded-md bg-background shadow-sm transition-transform duration-[250ms] ease-out"
+            style={{
+              transform: `translateX(${mode === "custom" ? 100 : 0}%)`,
+              width: "calc((100% - 4px) / 2)",
+            }}
+          />
+          <TabsTrigger
+            className="relative z-10 h-full rounded-md bg-transparent text-xs font-medium shadow-none transition-colors data-[state=active]:bg-transparent data-[state=active]:shadow-none"
+            value="defaults"
+          >
            {needsProviderSelection
              ? "Use agent defaults"
              : "Use harness defaults"}
          </TabsTrigger>
-          <TabsTrigger value="custom">Customize for this agent</TabsTrigger>
+          <TabsTrigger
+            className="relative z-10 h-full rounded-md bg-transparent text-xs font-medium shadow-none transition-colors data-[state=active]:bg-transparent data-[state=active]:shadow-none"
+            value="custom"
+          >
+            Customize for this agent
+          </TabsTrigger>
        </TabsList>
      </Tabs>
-      {mode === "custom" ? (
-        <p className="text-xs text-muted-foreground">
-          {needsProviderSelection
-            ? "Provider and model changes apply only to this agent."
-            : "Model changes apply only to this agent."}
-        </p>
-      ) : null}
    </div>
  );
 }
@@ -26,26 +26,62 @@ export function formatAiDefaultsSummary({
 }

 export function AgentAiDefaultsNotice({
+  isConfigured = true,
  onEditDefaults,
  triggerRef,
  explicitModel,
  explicitProvider,
+  harness,
  inheritedModel,
  inheritedProvider,
 }: {
+  isConfigured?: boolean;
  onEditDefaults: () => void;
  triggerRef?: React.Ref<HTMLButtonElement>;
  explicitModel: string;
  explicitProvider: string;
+  harness?: string;
  inheritedModel: InheritedDefault;
  inheritedProvider: InheritedDefault;
 }) {
  const provider = explicitProvider.trim() || inheritedProvider.value;
  const model = explicitModel.trim() || inheritedModel.value;

+  if (!isConfigured) {
+    return (
+      <div
+        className="flex items-center justify-between gap-3 rounded-xl border border-border/70 bg-muted/30 px-3 py-2.5"
+        data-testid="agent-ai-defaults-notice"
+      >
+        <p className="text-sm font-medium text-foreground">
+          Global defaults not set
+        </p>
+        <Button
+          className="shrink-0"
+          data-testid="set-ai-defaults"
+          onClick={onEditDefaults}
+          ref={triggerRef}
+          size="sm"
+          type="button"
+          variant="outline"
+        >
+          Set
+        </Button>
+      </div>
+    );
+  }
+
  return (
    <div className="space-y-1" data-testid="agent-ai-defaults-notice">
      <dl className="grid grid-cols-[auto_minmax(0,1fr)] gap-x-3 text-sm">
+        {harness !== undefined ? (
+          <>
+            <dt className="text-muted-foreground">Harness</dt>
+            <dd className="truncate text-foreground">
+              {harness || "Not configured"}
+            </dd>
+          </>
+        ) : null}
        <dt className="text-muted-foreground">Provider</dt>
        <dd className="truncate text-foreground">
          {provider ? providerLabel(provider) : "Not configured"}
@@ -7,8 +7,12 @@
 */
 import * as React from "react";
 import { ChevronDown } from "lucide-react";
+import { AnimatePresence, motion, useReducedMotion } from "motion/react";

-import type { BakedEnvEntry } from "@/shared/api/tauri";
+import type {
+  BakedEnvEntry,
+  RuntimeFileConfigSubset,
+} from "@/shared/api/tauri";
 import type {
  AcpRuntimeCatalogEntry,
  GlobalAgentConfig,
@@ -31,10 +35,10 @@ import {
  CUSTOM_PROVIDER_DROPDOWN_VALUE,
  getPersonaProviderOptions,
  getProviderApiKeyEnvVar,
-  requiredCredentialEnvKeys,
  runtimeSupportsLlmProviderSelection,
 } from "@/features/agents/ui/agentConfigOptions";
 import {
+  AgentConfigTextInput,
  AgentDropdownSelect,
  AgentModelField,
 } from "@/features/agents/ui/agentConfigControls";
@@ -48,10 +52,10 @@ import {
  EffortSelectField,
  useEffortAutoClear,
 } from "@/features/agents/ui/buzzAgentModelTuningFields";
-import { Input } from "@/shared/ui/input";
 import { SettingsOptionGroup } from "@/features/settings/ui/SettingsOptionGroup";
+import { AdvancedRequiredBadge } from "./AdvancedRequiredBadge";
+import { getGlobalAgentCredentialState } from "./globalAgentCredentialState";

-/** Sentinel value for an unconfigured global agent config. */
 export const EMPTY_GLOBAL_CONFIG: GlobalAgentConfig = {
  env_vars: {},
  provider: null,
@@ -66,6 +70,16 @@ const BAKED_STRUCTURED_KEYS = new Set([
  BUZZ_AGENT_THINKING_EFFORT,
 ]);

+const PROGRESSIVE_FIELDS_TRANSITION = {
+  duration: 0.22,
+  ease: [0.23, 1, 0.32, 1],
+} as const;
+
+type AgentConfigDisclosure =
+  | "full"
+  | "onboarding-essential"
+  | "progressive-defaults";
+
 // Canonical behaviors (PR 2 flag cleanup). These were per-surface props;
 // onboarding's values won every call and are now the only behavior:
 // - auto-select a valid model when the provider changes
@@ -92,12 +106,13 @@ export const CANONICAL_CONFIG_BEHAVIORS = {
 } as const;

 /**
- * Disclosure preset → the eight visibility decisions it owns. Effort is
- * shown in both presets (onboarding never hid it; the old prop existed but
- * was never flipped). Exported for the contract test.
+ * Disclosure preset → the eight visibility decisions it owns. Full and
+ * progressive defaults expose the same controls; the progressive preset
+ * changes only when those controls are revealed. Exported for the contract
+ * test.
 */
-export function resolveDisclosure(disclosure: "full" | "onboarding-essential") {
-  const full = disclosure === "full";
+export function resolveDisclosure(disclosure: AgentConfigDisclosure) {
+  const full = disclosure !== "onboarding-essential";
  return {
    showAdvancedFields: full,
    showCustomModelOption: full,
@@ -110,6 +125,22 @@ export function resolveDisclosure(disclosure: "full" | "onboarding-essential") {
  } as const;
 }

+export function shouldRevealDependentConfigFields({
+  disclosure,
+  providerFieldVisible,
+  providerValue,
+}: {
+  disclosure: AgentConfigDisclosure;
+  providerFieldVisible: boolean;
+  providerValue: string;
+}): boolean {
+  return (
+    disclosure !== "progressive-defaults" ||
+    !providerFieldVisible ||
+    providerValue.trim().length > 0
+  );
+}
+
 /**
 * Determines whether the status line beneath the Model field should render.
 *
@@ -170,6 +201,7 @@ export type AgentConfigFieldsProps = {
  onCustomModelEditingChange: (value: boolean) => void;
  onIsCustomProviderChange: (value: boolean) => void;
  onValidityChange?: (valid: boolean) => void;
+  runtimeFileConfig?: RuntimeFileConfigSubset | null;
  placeholderClassName?: string;
  selectClassName?: string;
  /**
@@ -182,11 +214,14 @@ export type AgentConfigFieldsProps = {
   *   valid forward choices. No advanced section, no custom escape hatches,
   *   no descriptions (the page copy does that job), no un-choosing via
   *   placeholder options, no greyed-out effort levels.
+   * - "progressive-defaults": the defaults modal's full controls, revealed in
+   *   order. Provider appears after harness selection; model, effort, and
+   *   Advanced appear after a provider is configured.
   * If a second surface wants the trimmed view, rename this value to plain
   * "essential" — and have the conversation about whether it should really
   * match onboarding.
   */
-  disclosure?: "full" | "onboarding-essential";
+  disclosure?: AgentConfigDisclosure;
  unstyled?: boolean;
  useCustomSelect?: boolean;
  useChevronSelectIcon?: boolean;
@@ -202,6 +237,7 @@ export function AgentConfigFields({
  onCustomModelEditingChange,
  onIsCustomProviderChange,
  onValidityChange,
+  runtimeFileConfig,
  placeholderClassName,
  selectClassName,
  disclosure = "full",
@@ -209,6 +245,7 @@ export function AgentConfigFields({
  useCustomSelect = false,
  useChevronSelectIcon = false,
 }: AgentConfigFieldsProps) {
+  const shouldReduceMotion = useReducedMotion();
  const {
    showAdvancedFields,
    showCustomModelOption,
@@ -260,9 +297,6 @@ export function AgentConfigFields({
    modelIsOptional ||
    (config.model?.trim().length ?? 0) > 0 ||
    fallbackModel !== null;
-  React.useEffect(() => {
-    onValidityChange?.(modelIsValid);
-  }, [modelIsValid, onValidityChange]);
  const bakedEffort = React.useMemo(
    () =>
      bakedEnv.find((e) => e.key === BUZZ_AGENT_THINKING_EFFORT)?.value ?? null,
@@ -278,10 +312,18 @@ export function AgentConfigFields({
    providerFieldVisible && !isCustomProvider
      ? providerValue || bakedProvider || ""
      : "";
+  const configuredProviderValue = isCustomProvider
+    ? providerValue
+    : providerForDiscovery;
  const dependentFieldsDisabled =
    providerFieldVisible &&
    requireProviderForModelAndEffort &&
-    providerForDiscovery.trim().length === 0;
+    configuredProviderValue.trim().length === 0;
+  const revealDependentFields = shouldRevealDependentConfigFields({
+    disclosure,
+    providerFieldVisible,
+    providerValue: configuredProviderValue,
+  });
  const credentialProvider =
    providerFieldVisible && !isCustomProvider ? effectiveProvider : "";
  const credentialRuntimeId = runtimeSupportsLlmProviderSelection(
@@ -289,24 +331,31 @@ export function AgentConfigFields({
  )
    ? selectedRuntimeId
    : "buzz-agent";
-  const requiredEnvKeys = requiredCredentialEnvKeys(
-    credentialRuntimeId,
-    credentialProvider,
-  );
-  const apiKeyEnvVar = getProviderApiKeyEnvVar(credentialProvider);
-  const advancedRequiredEnvKeys = requiredEnvKeys.filter(
-    (key) =>
-      key !== apiKeyEnvVar && !bakedEnv.some((entry) => entry.key === key),
-  );
-  const apiKeyValue = apiKeyEnvVar ? (config.env_vars[apiKeyEnvVar] ?? "") : "";
  const bakedEnvKeys = React.useMemo(
    () => bakedEnv.map((entry) => entry.key),
    [bakedEnv],
  );
-  const apiKeyInherited =
-    apiKeyEnvVar !== null &&
-    apiKeyValue.length === 0 &&
-    bakedEnvKeys.includes(apiKeyEnvVar);
+  const {
+    advancedCredentialMissing,
+    advancedFileSatisfiedEnvKeys,
+    advancedRequiredEnvKeys,
+    apiKeyEnvVar,
+    apiKeyFileSatisfied,
+    apiKeyInherited,
+    apiKeyValue,
+    credentialsValid,
+  } = getGlobalAgentCredentialState({
+    bakedEnvKeys,
+    envVars: config.env_vars,
+    provider: credentialProvider,
+    runtimeFileConfig,
+    runtimeId: credentialRuntimeId,
+  });
+  const configIsValid =
+    selectedRuntimeId.length > 0 && modelIsValid && credentialsValid;
+  React.useEffect(() => {
+    onValidityChange?.(configIsValid);
+  }, [configIsValid, onValidityChange]);

  const {
    discoveredModelOptions,
@@ -343,16 +392,9 @@ export function AgentConfigFields({
  const healOnMount =
    fieldModel.dependentValuePolicy.onCatalogMismatch === "onboardingCleanup";
  const userEditedProviderRef = React.useRef(false);
-  // Env vars live under a collapsed Advanced section (matching the create
-  // flow). Auto-open when a required key is missing so the field the user
-  // must fill is never hidden behind the toggle.
+  // Advanced visibility is user-controlled. Provider changes can add required
+  // rows, but must not open this section without an explicit toggle click.
  const [advancedOpen, setAdvancedOpen] = React.useState(false);
-  const requiredAdvancedKeyMissing = advancedRequiredEnvKeys.some(
-    (key) => !(config.env_vars[key] ?? "").trim(),
-  );
-  React.useEffect(() => {
-    if (requiredAdvancedKeyMissing) setAdvancedOpen(true);
-  }, [requiredAdvancedKeyMissing]);
  // Read inside effects via ref so biome's exhaustive-deps stays honest:
  // refs are stable, and healOnMount is captured at declaration.
  const mayMutateDependentFieldsRef = React.useRef(false);
@@ -598,9 +640,15 @@ export function AgentConfigFields({
    : "";
  const effortFieldVisible = showEffortField && effortField !== undefined;

-  const fieldClassName = unstyled ? "space-y-4" : "space-y-1.5 p-3";
+  const progressiveDefaults = disclosure === "progressive-defaults";
+  const fieldClassName = unstyled
+    ? progressiveDefaults
+      ? "space-y-1.5"
+      : "space-y-4"
+    : "space-y-1.5 p-3";
  const blockClassName = unstyled ? "" : "p-3";
-  const fieldLabelClassName = unstyled ? "pl-3" : undefined;
+  const fieldLabelClassName =
+    unstyled && !progressiveDefaults ? "pl-3" : undefined;
  const providerDropdownOptions = [
    ...providerOptions
      .filter(
@@ -661,44 +709,49 @@ export function AgentConfigFields({
    </select>
  );

-  const content = (
-    <>
-      {providerFieldVisible ? (
-        <div className={fieldClassName}>
-          <label
-            className={cn("text-sm font-medium", fieldLabelClassName)}
-            htmlFor="global-agent-provider"
-          >
-            Provider
-          </label>
-          {!useCustomSelect && useChevronSelectIcon ? (
-            <div className="relative">
-              {providerSelect}
-              <ChevronDown
-                aria-hidden="true"
-                className="pointer-events-none absolute right-4 top-1/2 h-4 w-4 -translate-y-1/2 text-foreground"
-              />
-            </div>
-          ) : (
-            providerSelect
-          )}
-          {isCustomProvider ? (
-            <Input
-              aria-label="Custom global provider ID"
-              autoCorrect="off"
-              onChange={(e) => handleCustomProviderInput(e.target.value)}
-              placeholder="Custom provider ID"
-              value={providerValue}
-            />
-          ) : null}
+  const providerContent = providerFieldVisible ? (
+    <div className={fieldClassName}>
+      <label
+        className={cn("text-sm font-medium", fieldLabelClassName)}
+        htmlFor="global-agent-provider"
+      >
+        Provider
+      </label>
+      {!useCustomSelect && useChevronSelectIcon ? (
+        <div className="relative">
+          {providerSelect}
+          <ChevronDown
+            aria-hidden="true"
+            className="pointer-events-none absolute right-4 top-1/2 h-4 w-4 -translate-y-1/2 text-foreground"
+          />
        </div>
+      ) : (
+        providerSelect
+      )}
+      {isCustomProvider ? (
+        <AgentConfigTextInput
+          aria-label="Custom global provider ID"
+          autoCorrect="off"
+          onChange={(e) => handleCustomProviderInput(e.target.value)}
+          placeholder="Custom provider ID"
+          usePersonaInputStyle={progressiveDefaults}
+          value={providerValue}
+        />
      ) : null}
+    </div>
+  ) : null;

+  const dependentContent = (
+    <>
      {providerFieldVisible && apiKeyEnvVar ? (
        <div className={blockClassName}>
          <PersonaProviderApiKeyField
            disabled={false}
-            inheritedLabel="Provided by this build"
+            inheritedLabel={
+              apiKeyFileSatisfied
+                ? "Set in runtime config"
+                : "Provided by this build"
+            }
            isInherited={apiKeyInherited}
            isRequired={!apiKeyInherited && apiKeyValue.length === 0}
            label={
@@ -763,6 +816,7 @@ export function AgentConfigFields({
            testId="global-agent-model"
            useCustomSelect={useCustomSelect}
            useChevronIcon={useChevronSelectIcon}
+            usePersonaInputStyle={progressiveDefaults}
          />
        </div>
      ) : null}
@@ -817,12 +871,19 @@ export function AgentConfigFields({
        <div className={cn(blockClassName, "space-y-3")}>
          <button
            aria-expanded={advancedOpen}
-            className="inline-flex h-9 items-center gap-1.5 text-sm font-medium text-foreground transition-colors hover:text-foreground/80 focus-visible:outline-hidden focus-visible:ring-2 focus-visible:ring-ring"
+            className={cn(
+              "inline-flex h-9 items-center gap-1.5 text-sm font-medium text-foreground transition-colors hover:text-foreground/80 focus-visible:outline-hidden focus-visible:ring-2 focus-visible:ring-ring",
+              unstyled && "ml-3",
+            )}
            data-testid="global-agent-advanced-toggle"
            onClick={() => setAdvancedOpen((current) => !current)}
            type="button"
          >
            <span>Advanced</span>
+            <AdvancedRequiredBadge
+              show={advancedCredentialMissing}
+              testId="global-agent-advanced-required-badge"
+            />
            <ChevronDown
              className={cn(
                "h-4 w-4 text-muted-foreground transition-transform duration-150 ease-out",
@@ -830,8 +891,42 @@ export function AgentConfigFields({
              )}
            />
          </button>
-          {advancedOpen ? (
+          {disclosure === "progressive-defaults" ? (
+            <AnimatePresence initial={false}>
+              {advancedOpen ? (
+                <motion.div
+                  animate={{ height: "auto", opacity: 1 }}
+                  className="overflow-hidden"
+                  data-testid="global-agent-advanced-fields-motion"
+                  exit={{ height: 0, opacity: 0 }}
+                  initial={{ height: 0, opacity: 0 }}
+                  key="global-agent-advanced-fields"
+                  transition={
+                    shouldReduceMotion
+                      ? { duration: 0 }
+                      : PROGRESSIVE_FIELDS_TRANSITION
+                  }
+                >
+                  <EnvVarsEditor
+                    fileSatisfiedKeys={advancedFileSatisfiedEnvKeys}
+                    hiddenKeys={apiKeyEnvVar ? [apiKeyEnvVar] : []}
+                    inheritedRows={bakedGenericRows}
+                    inheritedRowsLabel="build"
+                    label="Environment variables"
+                    onChange={handleEnvVarsChange}
+                    requiredKeys={advancedRequiredEnvKeys}
+                    value={Object.fromEntries(
+                      Object.entries(config.env_vars).filter(
+                        ([k]) => k !== BUZZ_AGENT_THINKING_EFFORT,
+                      ),
+                    )}
+                  />
+                </motion.div>
+              ) : null}
+            </AnimatePresence>
+          ) : advancedOpen ? (
            <EnvVarsEditor
+              fileSatisfiedKeys={advancedFileSatisfiedEnvKeys}
              hiddenKeys={apiKeyEnvVar ? [apiKeyEnvVar] : []}
              inheritedRows={bakedGenericRows}
              inheritedRowsLabel="build"
@@ -850,9 +945,52 @@ export function AgentConfigFields({
    </>
  );

+  const content = (
+    <>
+      {providerContent}
+      {disclosure === "progressive-defaults" ? (
+        <AnimatePresence initial={false}>
+          {revealDependentFields ? (
+            <motion.div
+              animate={{ height: "auto", opacity: 1 }}
+              className={cn(
+                "overflow-hidden",
+                unstyled && (progressiveDefaults ? "space-y-5" : "space-y-7"),
+              )}
+              data-testid="global-agent-dependent-fields-motion"
+              exit={{ height: 0, opacity: 0 }}
+              initial={{ height: 0, opacity: 0 }}
+              key="global-agent-dependent-fields"
+              transition={
+                shouldReduceMotion
+                  ? { duration: 0 }
+                  : PROGRESSIVE_FIELDS_TRANSITION
+              }
+            >
+              {dependentContent}
+            </motion.div>
+          ) : null}
+        </AnimatePresence>
+      ) : (
+        dependentContent
+      )}
+    </>
+  );
+
  if (unstyled) {
-    return <div className="space-y-7">{content}</div>;
+    return (
+      <div
+        className={progressiveDefaults ? "space-y-5" : "space-y-7"}
+        data-testid="global-agent-config-fields"
+      >
+        {content}
+      </div>
+    );
  }

-  return <SettingsOptionGroup>{content}</SettingsOptionGroup>;
+  return (
+    <SettingsOptionGroup data-testid="global-agent-config-fields">
+      {content}
+    </SettingsOptionGroup>
+  );
 }
@@ -94,6 +94,7 @@ export function AgentDefaultsDialog({
            </DialogDescription>
          </DialogHeader>
          <AgentDefaultsEditor
+            layout="flat"
            onDirtyChange={setDirty}
            onSaveSuccess={handleSaveSuccess}
            onSavingChange={setSaving}
@@ -8,6 +8,7 @@
 * Precedence: baked floor < GLOBAL (this card) < persona < per-agent.
 */
 import { AlertCircle, Check, Loader } from "lucide-react";
+import { AnimatePresence, motion, useReducedMotion } from "motion/react";
 import * as React from "react";

 import { useQueryClient } from "@tanstack/react-query";
@@ -19,10 +20,15 @@ import {
 import type { GlobalAgentConfig } from "@/shared/api/types";
 import { getBakedBuildEnv, type BakedEnvEntry } from "@/shared/api/tauri";
 import { globalAgentConfigQueryKey } from "@/features/agents/useGlobalAgentConfig";
-import { useAcpRuntimesQuery } from "@/features/agents/hooks";
+import {
+  useAcpRuntimesQuery,
+  useRuntimeFileConfigQuery,
+} from "@/features/agents/hooks";
 import {
  formatRuntimeOptionLabel,
  getDefaultPersonaRuntime,
+  PERSONA_FIELD_CONTROL_CLASS,
+  PERSONA_FIELD_SHELL_CLASS,
  resetConfigForHarnessChange,
  sortPersonaRuntimes,
 } from "@/features/agents/ui/agentConfigOptions";
@@ -31,15 +37,28 @@ import {
  AgentConfigFields,
  EMPTY_GLOBAL_CONFIG,
 } from "@/features/agents/ui/AgentConfigFields";
+import { cn } from "@/shared/lib/cn";
 import { Button } from "@/shared/ui/button";

 type SaveState = "idle" | "saving" | "saved" | "error";

+const PROGRESSIVE_FIELDS_TRANSITION = {
+  duration: 0.22,
+  ease: [0.23, 1, 0.32, 1],
+} as const;
+
+const PERSONA_SELECT_TRIGGER_CLASS = cn(
+  PERSONA_FIELD_CONTROL_CLASS,
+  PERSONA_FIELD_SHELL_CLASS,
+  "h-11 px-3 py-2 leading-6 hover:bg-muted/40 focus:bg-muted/40 [&>svg]:text-muted-foreground/60",
+);
+
 export type GlobalAgentConfigSaveResult = Awaited<
  ReturnType<typeof setGlobalAgentConfig>
 >;

 type AgentDefaultsEditorProps = {
+  layout?: "flat" | "grouped";
  onDirtyChange?: (dirty: boolean) => void;
  onSaveSuccess?: (result: GlobalAgentConfigSaveResult) => void;
  onSavingChange?: (saving: boolean) => void;
@@ -47,11 +66,14 @@ type AgentDefaultsEditorProps = {
 };

 export function AgentDefaultsEditor({
+  layout = "grouped",
  onDirtyChange,
  onSaveSuccess,
  onSavingChange,
  secondaryAction,
 }: AgentDefaultsEditorProps) {
+  const flatLayout = layout === "flat";
+  const shouldReduceMotion = useReducedMotion();
  const [config, setConfig] =
    React.useState<GlobalAgentConfig>(EMPTY_GLOBAL_CONFIG);
  const configRef = React.useRef(config);
@@ -117,17 +139,28 @@ export function AgentDefaultsEditor({
    () => sortPersonaRuntimes(runtimesQuery.data ?? []),
    [runtimesQuery.data],
  );
-  // A missing/stale preference displays the same effective fallback the backend
-  // would use; it is persisted only after the user edits and saves this form.
-  // Keep persona ordering here so this shared editor matches agent dialogs.
-  const selectedRuntime = React.useMemo(
-    () =>
-      sortedRuntimes.find(
-        (runtime) => runtime.id === config.preferred_runtime,
-      ) ??
+  // An unset preferred runtime uses the same Buzz Agent-first fallback as
+  // deployment. The rendered draft below carries that fallback forward so the
+  // next user edit persists the visible harness instead of saving null.
+  const selectedRuntime = React.useMemo(() => {
+    const configuredRuntime = sortedRuntimes.find(
+      (runtime) => runtime.id === config.preferred_runtime,
+    );
+    return (
+      configuredRuntime ??
      getDefaultPersonaRuntime(sortedRuntimes) ??
-      sortedRuntimes[0],
-    [config.preferred_runtime, sortedRuntimes],
+      sortedRuntimes[0]
+    );
+  }, [config.preferred_runtime, sortedRuntimes]);
+  const renderedConfig = React.useMemo(
+    () =>
+      config.preferred_runtime || !selectedRuntime
+        ? config
+        : { ...config, preferred_runtime: selectedRuntime.id },
+    [config, selectedRuntime],
+  );
+  const { data: runtimeFileConfig } = useRuntimeFileConfigQuery(
+    selectedRuntime?.id ?? "",
  );
  const harnessOptions = React.useMemo(
    () =>
@@ -141,7 +174,7 @@ export function AgentDefaultsEditor({
  const configSurfaceError =
    loadError ||
    runtimesQuery.isError ||
-    (!configSurfaceLoading && selectedRuntime === undefined);
+    (!configSurfaceLoading && sortedRuntimes.length === 0);

  function handleConfigChange(next: GlobalAgentConfig) {
    configRef.current = next;
@@ -153,6 +186,7 @@ export function AgentDefaultsEditor({

  function handleHarnessChange(runtimeId: string) {
    handleConfigChange(resetConfigForHarnessChange(config, runtimeId));
+    setConfigIsValid(false);
    setIsCustomModelEditing(false);
    setIsCustomProvider(false);
  }
@@ -202,8 +236,32 @@ export function AgentDefaultsEditor({
    }
  }

+  const configFields = selectedRuntime ? (
+    <AgentConfigFields
+      bakedEnv={bakedEnv}
+      selectedRuntime={selectedRuntime}
+      config={renderedConfig}
+      disclosure={flatLayout ? "progressive-defaults" : "full"}
+      isCustomModelEditing={isCustomModelEditing}
+      isCustomProvider={isCustomProvider}
+      onConfigChange={handleConfigChange}
+      onCustomModelEditingChange={setIsCustomModelEditing}
+      onIsCustomProviderChange={setIsCustomProvider}
+      onValidityChange={setConfigIsValid}
+      placeholderClassName={flatLayout ? "text-muted-foreground/55" : undefined}
+      runtimeFileConfig={runtimeFileConfig}
+      key={selectedRuntime.id}
+      selectClassName={flatLayout ? PERSONA_SELECT_TRIGGER_CLASS : undefined}
+      unstyled={flatLayout}
+      useCustomSelect
+    />
+  ) : null;
+  const progressiveFieldsTransition = shouldReduceMotion
+    ? { duration: 0 }
+    : PROGRESSIVE_FIELDS_TRANSITION;
+
  return (
-    <div className="min-w-0 space-y-4">
+    <div className={cn("min-w-0", flatLayout ? "space-y-7" : "space-y-4")}>
      {configSurfaceLoading ? (
        <div className="flex items-center gap-2 py-4 text-sm text-muted-foreground">
          <Loader className="size-4 animate-spin" />
@@ -224,26 +282,37 @@ export function AgentDefaultsEditor({
              Default harness
            </label>
            <AgentDropdownSelect
+              className={flatLayout ? PERSONA_SELECT_TRIGGER_CLASS : undefined}
              id="global-agent-default-harness"
              onValueChange={handleHarnessChange}
              options={harnessOptions}
              placeholder="Select a harness"
+              placeholderClassName={
+                flatLayout ? "text-muted-foreground/55" : undefined
+              }
              testId="global-agent-default-harness"
              value={selectedRuntime?.id ?? ""}
            />
          </div>
-          <AgentConfigFields
-            bakedEnv={bakedEnv}
-            selectedRuntime={selectedRuntime}
-            config={config}
-            isCustomModelEditing={isCustomModelEditing}
-            isCustomProvider={isCustomProvider}
-            onConfigChange={handleConfigChange}
-            onCustomModelEditingChange={setIsCustomModelEditing}
-            onIsCustomProviderChange={setIsCustomProvider}
-            onValidityChange={setConfigIsValid}
-            useCustomSelect
-          />
+          {flatLayout ? (
+            <AnimatePresence initial={false}>
+              {configFields ? (
+                <motion.div
+                  animate={{ height: "auto", opacity: 1 }}
+                  className="overflow-hidden"
+                  data-testid="global-agent-runtime-fields-motion"
+                  exit={{ height: 0, opacity: 0 }}
+                  initial={{ height: 0, opacity: 0 }}
+                  key={selectedRuntime?.id}
+                  transition={progressiveFieldsTransition}
+                >
+                  {configFields}
+                </motion.div>
+              ) : null}
+            </AnimatePresence>
+          ) : (
+            configFields
+          )}
        </>
      )}

@@ -269,7 +338,12 @@ export function AgentDefaultsEditor({
          <div className="ml-auto flex items-center gap-3">
            {secondaryAction}
            <Button
-              disabled={!dirty || !configIsValid || saveState === "saving"}
+              disabled={
+                !dirty ||
+                !configIsValid ||
+                selectedRuntime === undefined ||
+                saveState === "saving"
+              }
              onClick={() => void handleSave()}
              size="sm"
            >
@@ -31,7 +31,6 @@ import {
  emptyPersonaBehaviorDraft,
  personaBehaviorDraftValid,
 } from "./personaBehaviorDraft";
-import { personaSubmitBlock } from "./personaSubmitBlock";
 import {
  AUTO_MODEL_DROPDOWN_VALUE,
  AUTO_PROVIDER_DROPDOWN_VALUE,
@@ -69,11 +68,11 @@ import {
 } from "./usePersonaModelDiscovery";
 import { useBakedBuildEnvKeysQuery, useRuntimeFileConfigQuery } from "../hooks";
 import { useAgentDialogDefaults } from "./useAgentDialogDefaults";
-import { AgentAiDefaultsNotice } from "./AgentAiDefaults";
 import { AgentDefaultsDialog } from "./AgentDefaultsDialog";
+import { AgentHarnessField } from "./AgentHarnessField";
 import {
  AgentAiConfigurationModeField,
-  HarnessModelDefaultNotice,
+  AgentCreateAiDefaultsSummary,
  type AgentAiConfigurationMode,
 } from "./AgentAiConfigurationMode";
 import {
@@ -170,6 +169,7 @@ export function AgentDefinitionDialog({
    () => getDefaultPersonaRuntime(runtimes, globalConfig.preferred_runtime),
    [globalConfig.preferred_runtime, runtimes],
  );
+  const isCreateMode = Boolean(initialValues && !("id" in initialValues));
  const shouldReduceMotion = useReducedMotion();
  const initialModelProviderEditableWithoutRuntime = Boolean(
    initialValues &&
@@ -208,9 +208,7 @@ export function AgentDefinitionDialog({
    setBehaviorDraft(nextBehaviorDraft);
    setNamePoolText(nextNamePoolText);
    setEnvVars(nextEnvVars);
-    // Item 5: collapsed by default in edit mode — only expand if a non-default
-    // behavior value demands attention. Having env vars or a name pool is not
-    // sufficient reason to auto-open.
+    // Advanced always starts collapsed and only changes from its toggle.
    setShowAdvancedFields(false);
    setIsAvatarUploadPending(false);
    isRuntimeAutoSeededRef.current = false;
@@ -241,6 +239,46 @@ export function AgentDefinitionDialog({
    }
  }, [defaultRuntime, initialValues, open, runtime, runtimesLoading]);

+  // Keep an inherited Create runtime synced with defaults saved in-place.
+  React.useEffect(() => {
+    if (
+      !open ||
+      !initialValues ||
+      "id" in initialValues ||
+      initialValues.runtime?.trim() ||
+      aiConfigurationMode !== "defaults" ||
+      runtimesLoading ||
+      defaultRuntime === null ||
+      (runtime.trim().length > 0 && !isRuntimeAutoSeededRef.current)
+    ) {
+      return;
+    }
+
+    if (runtime !== defaultRuntime.id) setRuntime(defaultRuntime.id);
+    isRuntimeAutoSeededRef.current = true;
+    hasSeededForOpenRef.current = true;
+  }, [
+    aiConfigurationMode,
+    defaultRuntime,
+    initialValues,
+    open,
+    runtime,
+    runtimesLoading,
+  ]);
+
+  // Keep setup guidance reachable when no available runtime can be inherited.
+  React.useEffect(() => {
+    if (
+      open &&
+      isCreateMode &&
+      !runtimesLoading &&
+      defaultRuntime === null &&
+      runtime.trim().length === 0
+    ) {
+      setAiConfigurationMode("custom");
+    }
+  }, [defaultRuntime, isCreateMode, open, runtime, runtimesLoading]);
+
  function handleOpenChange(next: boolean) {
    if (!next) {
      setDisplayName("");
@@ -339,8 +377,9 @@ export function AgentDefinitionDialog({
  // locked rows in the env vars editor.
  // File-layer config for the selected runtime (e.g. goose config.yaml).
  // Used to silence requirements already satisfied there.
-  const { data: runtimeFileConfig, isLoading: fileConfigLoading } =
-    useRuntimeFileConfigQuery(runtime, { enabled: open });
+  const { data: runtimeFileConfig } = useRuntimeFileConfigQuery(runtime, {
+    enabled: open,
+  });
  function handleAiConfigurationModeChange(nextMode: AgentAiConfigurationMode) {
    setAiConfigurationMode(nextMode);
    setIsCustomProviderEditing(false);
@@ -359,9 +398,7 @@ export function AgentDefinitionDialog({
    setProvider(nextPair.provider);
    setModel(nextPair.model);
  }
-  const { data: bakedEnvKeys, isLoading: bakedLoading } =
-    useBakedBuildEnvKeysQuery({ enabled: open });
-  const credentialSettled = !fileConfigLoading && !bakedLoading;
+  const { data: bakedEnvKeys } = useBakedBuildEnvKeysQuery({ enabled: open });
  const localModeGate = React.useMemo(
    () =>
      computeLocalModeGate({
@@ -391,7 +428,6 @@ export function AgentDefinitionDialog({
  // requiredEnvKeys: the gate already handles baked-, global-, and file-
  // satisfied keys so no further filtering is needed.
  const { requiredEnvKeys } = localModeGate;
-  // D1: single boolean for both canSubmit and handleSubmit — never recompose.
  const localModeSatisfied = localModeGate.satisfied;
  // Effective provider: agent value → global fallback → file fallback.
  // Mirrors the chain inside computeLocalModeGate so model-option scoping and
@@ -399,18 +435,14 @@ export function AgentDefinitionDialog({
  const fileProvider = runtimeFileConfig?.provider?.trim() ?? "";
  const effectiveProvider =
    trimmedProvider || inheritedProviderDefault.value || fileProvider;
-  // D2: the top-level API key owns display while the full gate remains intact.
  const apiKeyFieldState = useProviderApiKeyFieldState({
    bakedEnvKeys,
    effectiveEnvVars: envVars,
    envVars,
    fileSatisfiedEnvKeys: localModeGate.fileSatisfiedEnvKeys,
    globalEnvVars: globalConfig.env_vars,
-    open,
    provider: effectiveProvider,
    requiredEnvKeys,
-    satisfactionSettled: credentialSettled,
-    setShowAdvancedFields,
  });
  const {
    advancedRequiredEnvKeys,
@@ -420,14 +452,6 @@ export function AgentDefinitionDialog({
    secretEnvVar: topLevelSecretEnvVar,
    value: apiKeyValue,
  } = apiKeyFieldState;
-  // Provider required-ness is a static property of the field's visibility — it
-  // does not change based on whether the field is currently filled. Using the
-  // dynamic missingNormalizedFields check would flip the asterisk off once a
-  // value is selected, which is incoherent (required means required, not
-  // "required until satisfied"). runtimeCanChooseLlmProvider is the authoritative
-  // gate: it tracks exactly when the provider picker is shown (Buzz Agent/Goose,
-  // plus runtime-less legacy/builtin definitions), so the required marker never
-  // drifts from whether Save actually needs a provider.
  const providerIsRequired =
    aiConfigurationMode === "custom" && runtimeCanChooseLlmProvider;
  const modelFieldVisible =
@@ -444,7 +468,6 @@ export function AgentDefinitionDialog({
    { provider, model },
    runtimeCanChooseLlmProvider,
  );
-  const isCreateMode = Boolean(initialValues && !("id" in initialValues));
  const selectedRuntimeIsAvailable =
    runtime.trim().length === 0 ||
    selectedRuntime?.availability === "available";
@@ -464,29 +487,6 @@ export function AgentDefinitionDialog({
    customAiPairSatisfied &&
    !isAvatarUploadPending;

-  // Derive the single, deterministic reason the action is disabled from the
-  // same gate outputs that feed canSubmit — no policy is recomputed here.
-  // Precedence mirrors canSubmit's term order, so the reason is `null` exactly
-  // when the form can be submitted (transient Saving/Uploading states aside).
-  const submitBlockReason = personaSubmitBlock({
-    isPending,
-    isAvatarUploadPending,
-    displayNameEmpty: displayName.trim().length === 0,
-    isCreateMode,
-    runtimeChosen: runtime.trim().length > 0,
-    runtimeAvailable: selectedRuntimeIsAvailable,
-    createBackendBlocked: createSubmitBlocked,
-    allowlistEmpty: !personaBehaviorDraftValid(behaviorDraft),
-    aiConfigurationMode,
-    localModeSatisfied,
-    localModeMissingFields: localModeGate.missingNormalizedFields,
-    localModeMissingEnvKeys: localModeGate.missingEnvKeys,
-    customAiPairSatisfied,
-    runtimeNeedsProviderSelection: runtimeCanChooseLlmProvider,
-    customProviderEmpty: provider.trim().length === 0,
-    customModelEmpty: model.trim().length === 0,
-  });
-
  // Merge global env as the base layer so credential keys satisfied via global
  // config are available to model discovery — same rationale as in AgentInstanceEditDialog.
  const envVarsForDiscovery = React.useMemo(
@@ -571,7 +571,10 @@ export function AgentDefinitionDialog({
        ]
      : []),
    ...sortedRuntimes.map((candidate) => ({
-      disabled: isCreateMode && candidate.availability !== "available",
+      disabled:
+        isCreateMode &&
+        defaultRuntime !== null &&
+        candidate.availability !== "available",
      label: `${formatRuntimeOptionLabel(candidate)}${
        isCreateMode && candidate.id === defaultRuntime?.id ? " (default)" : ""
      }`,
@@ -587,6 +590,9 @@ export function AgentDefinitionDialog({
      value: runtime.trim(),
    });
  }
+  const runtimeSummaryLabel = selectedRuntime
+    ? formatRuntimeOptionLabel(selectedRuntime)
+    : runtime.trim() || "Not configured";
  const providerDropdownOptions: PersonaDropdownOption[] = [
    ...providerOptions
      .filter((option) => option.id.trim().length > 0)
@@ -734,40 +740,27 @@ export function AgentDefinitionDialog({
        headerClassName="pb-2"
        title={title}
        footer={
-          <div className="flex w-full items-center justify-between gap-3">
-            <div className="flex min-h-9 items-center">
-              {submitBlockReason ? (
-                <p
-                  className="text-2xs text-muted-foreground"
-                  data-testid="persona-dialog-submit-reason"
-                >
-                  {submitBlockReason}
-                </p>
-              ) : null}
-            </div>
-
-            <div className="flex items-center gap-2">
-              <Button
-                disabled={isPending || isAvatarUploadPending}
-                onClick={() => handleOpenChange(false)}
-                type="button"
-                variant="outline"
-              >
-                Cancel
-              </Button>
-              <Button
-                data-testid="persona-dialog-submit"
-                disabled={!canSubmit}
-                form="persona-dialog-form"
-                type="submit"
-              >
-                {isPending
-                  ? "Saving..."
-                  : isAvatarUploadPending
-                    ? "Uploading..."
-                    : submitLabel}
-              </Button>
-            </div>
+          <div className="flex w-full items-center justify-end gap-2">
+            <Button
+              disabled={isPending || isAvatarUploadPending}
+              onClick={() => handleOpenChange(false)}
+              type="button"
+              variant="outline"
+            >
+              Cancel
+            </Button>
+            <Button
+              data-testid="persona-dialog-submit"
+              disabled={!canSubmit}
+              form="persona-dialog-form"
+              type="submit"
+            >
+              {isPending
+                ? "Saving..."
+                : isAvatarUploadPending
+                  ? "Uploading..."
+                  : submitLabel}
+            </Button>
          </div>
        }
      >
@@ -836,24 +829,6 @@ export function AgentDefinitionDialog({
              </div>
            </div>

-            <div className="space-y-1.5">
-              <label
-                className="text-sm font-medium text-foreground"
-                htmlFor="persona-runtime"
-              >
-                Agent harness
-              </label>
-              <PersonaDropdownField
-                disabled={isPending || runtimesLoading}
-                id="persona-runtime"
-                onValueChange={handleRuntimeDropdownChange}
-                options={runtimeDropdownOptions}
-                placeholder={blankRuntimeOptionLabel}
-                value={runtimeDropdownValue}
-              />
-              {runtimeWarning}
-            </div>
-
            {modelFieldVisible ? (
              <AgentAiConfigurationModeField
                mode={aiConfigurationMode}
@@ -862,110 +837,124 @@ export function AgentDefinitionDialog({
              />
            ) : null}

-            {llmProviderFieldVisible && aiConfigurationMode === "custom" ? (
-              <div className="space-y-1.5">
-                <RequiredFieldLabel
-                  htmlFor="persona-llm-provider"
-                  isRequired={providerIsRequired}
-                >
-                  LLM provider
-                  {!providerIsRequired ? (
-                    <span className={PERSONA_LABEL_OPTIONAL_CLASS}>
-                      Optional
-                    </span>
-                  ) : null}
-                </RequiredFieldLabel>
-                <PersonaDropdownField
-                  disabled={isPending}
-                  id="persona-llm-provider"
-                  onValueChange={handleProviderDropdownChange}
-                  options={providerDropdownOptions}
-                  placeholder="Choose a provider"
-                  value={providerSelectValue}
-                />
-                {showCustomProviderInput ? (
-                  <div
-                    className={cn(
-                      "mt-2 flex min-h-11 items-center px-3",
-                      PERSONA_FIELD_SHELL_CLASS,
-                    )}
-                  >
-                    <Input
-                      aria-label="Custom provider ID"
-                      autoCorrect="off"
-                      className={cn(
-                        "h-8 px-0 py-0 leading-6",
-                        PERSONA_FIELD_CONTROL_CLASS,
-                      )}
-                      disabled={isPending}
-                      id="persona-custom-provider"
-                      onChange={(event) => setProvider(event.target.value)}
-                      placeholder="Custom provider ID"
-                      value={provider}
-                    />
-                  </div>
-                ) : null}
-              </div>
-            ) : null}
-
-            {llmProviderFieldVisible &&
-            aiConfigurationMode === "custom" &&
-            topLevelSecretEnvVar ? (
-              <PersonaProviderApiKeyField
-                disabled={isPending}
-                isInherited={apiKeyIsInherited}
-                inheritedLabel={apiKeyInheritedLabel}
-                isRequired={apiKeyIsRequired}
-                label={
-                  effectiveProvider === "anthropic"
-                    ? "Anthropic API key"
-                    : "OpenAI API key"
-                }
-                onValueChange={(next) => {
-                  setEnvVars((prev) => ({
-                    ...prev,
-                    [topLevelSecretEnvVar]: next,
-                  }));
-                }}
-                value={apiKeyValue}
-              />
-            ) : null}
-
-            <AnimatePresence initial={false}>
-              {modelFieldVisible && aiConfigurationMode === "custom" ? (
-                <PersonaModelField
-                  disabled={isPending}
-                  isExplicitModelRequired={isExplicitModelRequired}
-                  model={model}
-                  modelDiscoveryStatus={modelDiscoveryStatus}
-                  modelDropdownOptions={modelDropdownOptions}
-                  modelSelectValue={modelSelectValue}
-                  onCustomModelChange={setModel}
-                  showSharedComputeAutoHint={
-                    isRelayMesh &&
-                    modelSelectValue === AUTO_MODEL_DROPDOWN_VALUE
-                  }
-                  onModelValueChange={handleModelDropdownChange}
-                  showCustomModelInput={showCustomModelInput}
-                  transition={advancedFieldsTransition}
+            <div
+              className="space-y-5"
+              data-testid={`agent-${aiConfigurationMode}-configuration-section`}
+            >
+              {aiConfigurationMode === "custom" ? (
+                <AgentHarnessField
+                  disabled={isPending || runtimesLoading}
+                  onValueChange={handleRuntimeDropdownChange}
+                  options={runtimeDropdownOptions}
+                  placeholder={blankRuntimeOptionLabel}
+                  value={runtimeDropdownValue}
+                  warning={runtimeWarning}
                />
              ) : null}
-            </AnimatePresence>

-            {aiConfigurationMode === "defaults" ? (
-              runtimeCanChooseLlmProvider ? (
-                <AgentAiDefaultsNotice
-                  onEditDefaults={() => setAiDefaultsOpen(true)}
-                  triggerRef={aiDefaultsTriggerRef}
-                  explicitModel=""
-                  explicitProvider=""
+              {llmProviderFieldVisible && aiConfigurationMode === "custom" ? (
+                <div className="space-y-1.5">
+                  <RequiredFieldLabel
+                    htmlFor="persona-llm-provider"
+                    isRequired={providerIsRequired}
+                  >
+                    LLM provider
+                    {!providerIsRequired ? (
+                      <span className={PERSONA_LABEL_OPTIONAL_CLASS}>
+                        Optional
+                      </span>
+                    ) : null}
+                  </RequiredFieldLabel>
+                  <PersonaDropdownField
+                    disabled={isPending}
+                    id="persona-llm-provider"
+                    onValueChange={handleProviderDropdownChange}
+                    options={providerDropdownOptions}
+                    placeholder="Choose a provider"
+                    value={providerSelectValue}
+                  />
+                  {showCustomProviderInput ? (
+                    <div
+                      className={cn(
+                        "mt-2 flex min-h-11 items-center px-3",
+                        PERSONA_FIELD_SHELL_CLASS,
+                      )}
+                    >
+                      <Input
+                        aria-label="Custom provider ID"
+                        autoCorrect="off"
+                        className={cn(
+                          "h-8 px-0 py-0 leading-6",
+                          PERSONA_FIELD_CONTROL_CLASS,
+                        )}
+                        disabled={isPending}
+                        id="persona-custom-provider"
+                        onChange={(event) => setProvider(event.target.value)}
+                        placeholder="Custom provider ID"
+                        value={provider}
+                      />
+                    </div>
+                  ) : null}
+                </div>
+              ) : null}
+
+              {llmProviderFieldVisible &&
+              aiConfigurationMode === "custom" &&
+              topLevelSecretEnvVar ? (
+                <PersonaProviderApiKeyField
+                  disabled={isPending}
+                  isInherited={apiKeyIsInherited}
+                  inheritedLabel={apiKeyInheritedLabel}
+                  isRequired={apiKeyIsRequired}
+                  label={
+                    effectiveProvider === "anthropic"
+                      ? "Anthropic API key"
+                      : "OpenAI API key"
+                  }
+                  onValueChange={(next) => {
+                    setEnvVars((prev) => ({
+                      ...prev,
+                      [topLevelSecretEnvVar]: next,
+                    }));
+                  }}
+                  value={apiKeyValue}
+                />
+              ) : null}
+
+              <AnimatePresence initial={false}>
+                {modelFieldVisible && aiConfigurationMode === "custom" ? (
+                  <PersonaModelField
+                    disabled={isPending}
+                    isExplicitModelRequired={isExplicitModelRequired}
+                    model={model}
+                    modelDiscoveryStatus={modelDiscoveryStatus}
+                    modelDropdownOptions={modelDropdownOptions}
+                    modelSelectValue={modelSelectValue}
+                    onCustomModelChange={setModel}
+                    showSharedComputeAutoHint={
+                      isRelayMesh &&
+                      modelSelectValue === AUTO_MODEL_DROPDOWN_VALUE
+                    }
+                    onModelValueChange={handleModelDropdownChange}
+                    showCustomModelInput={showCustomModelInput}
+                    transition={advancedFieldsTransition}
+                  />
+                ) : null}
+              </AnimatePresence>
+
+              {aiConfigurationMode === "defaults" ? (
+                <AgentCreateAiDefaultsSummary
+                  canChooseProvider={runtimeCanChooseLlmProvider}
+                  harness={runtimeSummaryLabel}
                  inheritedModel={inheritedModelDefault}
                  inheritedProvider={inheritedProviderDefault}
+                  isConfigured={localModeGate.satisfied}
+                  model={runtimeFileConfig?.model}
+                  onEditDefaults={() => setAiDefaultsOpen(true)}
+                  triggerRef={aiDefaultsTriggerRef}
                />
-              ) : (
-                <HarnessModelDefaultNotice model={runtimeFileConfig?.model} />
-              )
-            ) : null}
+              ) : null}
+            </div>

            <AgentDefaultsDialog
              onOpenChange={setAiDefaultsOpen}
@@ -983,6 +972,17 @@ export function AgentDefinitionDialog({
                type="button"
              >
                <span>Advanced</span>
+                {localModeGate.missingEnvKeys.some((key) =>
+                  advancedRequiredEnvKeys.includes(key),
+                ) ? (
+                  <span
+                    aria-hidden="true"
+                    className="rounded-full bg-destructive/10 px-2 py-0.5 text-xs text-destructive"
+                    data-testid="persona-advanced-required-badge"
+                  >
+                    Required
+                  </span>
+                ) : null}
                <ChevronDown
                  className={cn(
                    "h-4 w-4 text-muted-foreground transition-transform duration-150 ease-out",
@@ -0,0 +1,40 @@
+import type { ReactNode } from "react";
+
+import type { PersonaDropdownOption } from "./agentConfigOptions";
+import { PersonaDropdownField } from "./PersonaDropdownField";
+
+export function AgentHarnessField({
+  disabled,
+  onValueChange,
+  options,
+  placeholder,
+  value,
+  warning,
+}: {
+  disabled: boolean;
+  onValueChange: (value: string) => void;
+  options: PersonaDropdownOption[];
+  placeholder: string;
+  value: string;
+  warning?: ReactNode;
+}) {
+  return (
+    <div className="space-y-1.5">
+      <label
+        className="text-sm font-medium text-foreground"
+        htmlFor="persona-runtime"
+      >
+        Agent harness
+      </label>
+      <PersonaDropdownField
+        disabled={disabled}
+        id="persona-runtime"
+        onValueChange={onValueChange}
+        options={options}
+        placeholder={placeholder}
+        value={value}
+      />
+      {warning}
+    </div>
+  );
+}
@@ -81,6 +81,8 @@ import { useAgentDialogDefaults } from "./useAgentDialogDefaults";
 import { AgentAiDefaultsNotice } from "./AgentAiDefaults";
 import { AgentDefaultsDialog } from "./AgentDefaultsDialog";
 import { useProviderApiKeyFieldState } from "./providerApiKeyFieldState";
+import { resolveModelFieldStatusMessage } from "./agentConfigControls";
+import { AdvancedRequiredBadge } from "./AdvancedRequiredBadge";

 const ADVANCED_FIELDS_MOTION_TRANSITION = {
  duration: 0.18,
@@ -367,26 +369,21 @@ export function AgentInstanceEditDialog({
  } = useAgentDialogDefaults({ inheritedEnvVars, open });

  // Runtime/provider-required credential state, derived from the PROSPECTIVE
-  // post-submit runtime — see the hook for the inherit-transition and
-  // Advanced-auto-expand rationale.
+  // post-submit runtime — see the hook for the inherit-transition rationale.
  // Pass globalProvider so the hook uses it as a fallback when the per-agent
  // provider is empty (global-provider-only configs must surface required keys).
  // Pass globalEnvVars so keys satisfied by global config are excluded from
  // requiredEnvKeys and do not block Save (display and gate agree).
-  const {
-    requiredEnvKeys,
-    fileSatisfiedEnvKeys,
-    requiredEnvKeyMissing,
-    settled: credentialSettled,
-  } = useRequiredCredentialState({
-    open,
-    prospectiveRuntimeId,
-    provider: inheritedSubmission.provider ?? "",
-    globalProvider: inheritedProviderDefault.value,
-    envVars: inheritedSubmission.envVars,
-    globalEnvVars: globalConfig.env_vars,
-    personaEnvVars: inheritHarness ? inheritedEnvVars : undefined,
-  });
+  const { requiredEnvKeys, fileSatisfiedEnvKeys, requiredEnvKeyMissing } =
+    useRequiredCredentialState({
+      open,
+      prospectiveRuntimeId,
+      provider: inheritedSubmission.provider ?? "",
+      globalProvider: inheritedProviderDefault.value,
+      envVars: inheritedSubmission.envVars,
+      globalEnvVars: globalConfig.env_vars,
+      personaEnvVars: inheritHarness ? inheritedEnvVars : undefined,
+    });

  const { data: bakedEnvKeys } = useBakedBuildEnvKeysQuery({ enabled: open });

@@ -418,7 +415,7 @@ export function AgentInstanceEditDialog({
    selectedRuntime,
  });

-  // D2: derive advancedRequiredEnvKeys for EnvVarsEditor display + auto-open.
+  // D2: derive advancedRequiredEnvKeys for EnvVarsEditor display.
  // The full requiredEnvKeys/requiredEnvKeyMissing continue driving Save gating.
  // D2/D3: the top-level API key owns display, while the readiness gate keeps
  // the complete required-key list. The effective snapshot covers persona
@@ -434,12 +431,9 @@ export function AgentInstanceEditDialog({
    envVars,
    fileSatisfiedEnvKeys,
    globalEnvVars: globalConfig.env_vars,
-    open,
    personaSatisfied,
    provider: effectiveProvider,
    requiredEnvKeys,
-    satisfactionSettled: credentialSettled,
-    setShowAdvancedFields,
  });
  const {
    advancedRequiredEnvKeys,
@@ -449,7 +443,6 @@ export function AgentInstanceEditDialog({
    secretEnvVar: topLevelSecretEnvVar,
    value: apiKeyValue,
  } = apiKeyFieldState;
-
  // Clear model when provider scope changes and current model is no longer valid.
  React.useEffect(() => {
    if (
@@ -520,17 +513,6 @@ export function AgentInstanceEditDialog({
      setInheritHarness(false);
    }

-    // "Custom command" is the only selection whose command must be typed by
-    // the user, and that input lives inside the collapsed Advanced section.
-    // Auto-expand Advanced so the command field is visible — otherwise the
-    // user can Save without ever seeing it, leaving agentCommand equal to the
-    // original effective command (so the update is omitted) and the custom
-    // selection silently no-ops. See handleSubmit's customCommandPinned gate,
-    // which blocks Save when the revealed field is still empty.
-    if (isCustomCommand) {
-      setShowAdvancedFields(true);
-    }
-
    // When switching to a catalog-known runtime, update the agent command to
    // its resolved command so the command field stays consistent.
    if (nextRuntime?.command) {
@@ -788,6 +770,11 @@ export function AgentInstanceEditDialog({
    loadingValue: MODEL_DISCOVERY_LOADING_VALUE,
    options: effectiveModelOptions,
  });
+  const modelStatusMessage = resolveModelFieldStatusMessage({
+    discoveredModelOptions,
+    loading: modelDiscoveryLoading,
+    status: modelDiscoveryStatus,
+  });

  // Provider field derived state
  const trimmedProvider = provider.trim();
@@ -957,6 +944,35 @@ export function AgentInstanceEditDialog({
                </p>
              ) : null}
            </div>
+            {selectedRuntimeId === "custom" && !inheritHarness ? (
+              <div className="space-y-1.5">
+                <label
+                  className="text-sm font-medium text-foreground"
+                  htmlFor="edit-agent-command"
+                >
+                  Agent command
+                </label>
+                <div
+                  className={cn(
+                    "flex min-h-11 items-center px-3",
+                    PERSONA_FIELD_SHELL_CLASS,
+                  )}
+                >
+                  <Input
+                    autoCorrect="off"
+                    className={cn(
+                      "h-8 px-0 py-0 leading-6",
+                      PERSONA_FIELD_CONTROL_CLASS,
+                    )}
+                    disabled={updateMutation.isPending}
+                    id="edit-agent-command"
+                    onChange={(event) => setAgentCommand(event.target.value)}
+                    placeholder="Full path or shell command"
+                    value={agentCommand}
+                  />
+                </div>
+              </div>
+            ) : null}
            {/* LLM provider */}
            {llmProviderFieldVisible ? (
              <div className="space-y-1.5">
@@ -1074,15 +1090,11 @@ export function AgentInstanceEditDialog({
                  />
                </div>
              ) : null}
-              <p className="text-xs text-muted-foreground">
-                {modelDiscoveryLoading
-                  ? "Loading models..."
-                  : modelDiscoveryStatus !== null
-                    ? modelDiscoveryStatus.message
-                    : discoveredModelOptions !== null
-                      ? "Saved changes take effect on the next start."
-                      : "Select a provider above to see available models."}
-              </p>
+              {modelStatusMessage ? (
+                <p className="text-xs text-muted-foreground">
+                  {modelStatusMessage}
+                </p>
+              ) : null}
            </div>

            <AgentAiDefaultsNotice
@@ -1109,6 +1121,11 @@ export function AgentInstanceEditDialog({
                type="button"
              >
                <span>Advanced</span>
+                <AdvancedRequiredBadge
+                  envVars={inheritedSubmission.envVars}
+                  requiredEnvKeys={advancedRequiredEnvKeys}
+                  testId="edit-agent-advanced-required-badge"
+                />
                <ChevronDown
                  className={cn(
                    "h-4 w-4 text-muted-foreground transition-transform duration-150 ease-out",
@@ -1129,7 +1146,6 @@ export function AgentInstanceEditDialog({
                    <EditAgentAdvancedFields
                      acpCommand={acpCommand}
                      agentArgs={agentArgs}
-                      agentCommand={agentCommand}
                      autoRestartOnConfigChange={autoRestartOnConfigChange}
                      disabled={updateMutation.isPending}
                      envVars={envVars}
@@ -1150,11 +1166,9 @@ export function AgentInstanceEditDialog({
                      parallelism={parallelism}
                      provider={effectiveProvider}
                      requiredEnvKeys={advancedRequiredEnvKeys}
-                      selectedRuntimeId={selectedRuntimeId}
                      systemPrompt={systemPrompt}
                      onAcpCommandChange={setAcpCommand}
                      onAgentArgsChange={setAgentArgs}
-                      onAgentCommandChange={setAgentCommand}
                      onAutoRestartChange={setAutoRestartOnConfigChange}
                      onEnvVarsChange={setEnvVars}
                      onInheritHarnessChange={setInheritHarness}
@@ -136,6 +136,7 @@ export function AgentsView() {
                ) : null}
              </div>
            }
+            className="mx-auto w-full max-w-[996px]"
            description="Set up and manage your agents."
            title="Agents"
          />
@@ -14,7 +14,6 @@ import { isBuzzAgentRuntime } from "./buzzAgentConfig";
 export function EditAgentAdvancedFields({
  acpCommand,
  agentArgs,
-  agentCommand,
  autoRestartOnConfigChange,
  disabled,
  envVars,
@@ -29,11 +28,9 @@ export function EditAgentAdvancedFields({
  parallelism,
  provider,
  requiredEnvKeys,
-  selectedRuntimeId,
  systemPrompt,
  onAcpCommandChange,
  onAgentArgsChange,
-  onAgentCommandChange,
  onEnvVarsChange,
  onInheritHarnessChange,
  onParallelismChange,
@@ -42,7 +39,6 @@ export function EditAgentAdvancedFields({
 }: {
  acpCommand: string;
  agentArgs: string;
-  agentCommand: string;
  autoRestartOnConfigChange: boolean;
  disabled: boolean;
  envVars: EnvVarsValue;
@@ -65,11 +61,9 @@ export function EditAgentAdvancedFields({
  /** Active LLM provider id — forwarded to BuzzAgentModelTuningFields for effort filtering. */
  provider?: string;
  requiredEnvKeys: readonly string[];
-  selectedRuntimeId: string;
  systemPrompt: string;
  onAcpCommandChange: (value: string) => void;
  onAgentArgsChange: (value: string) => void;
-  onAgentCommandChange: (value: string) => void;
  onEnvVarsChange: (value: EnvVarsValue) => void;
  onInheritHarnessChange: (value: boolean) => void;
  onParallelismChange: (value: string) => void;
@@ -124,37 +118,6 @@ export function EditAgentAdvancedFields({
        </p>
      </div>

-      {/* Custom agent command (when custom runtime) */}
-      {selectedRuntimeId === "custom" && !inheritHarness ? (
-        <div className="space-y-1.5">
-          <label
-            className="text-sm font-medium text-foreground"
-            htmlFor="edit-agent-command"
-          >
-            Agent command
-          </label>
-          <div
-            className={cn(
-              "flex min-h-11 items-center px-3",
-              PERSONA_FIELD_SHELL_CLASS,
-            )}
-          >
-            <Input
-              autoCorrect="off"
-              className={cn(
-                "h-8 px-0 py-0 leading-6",
-                PERSONA_FIELD_CONTROL_CLASS,
-              )}
-              disabled={disabled}
-              id="edit-agent-command"
-              onChange={(event) => onAgentCommandChange(event.target.value)}
-              placeholder="Full path or shell command"
-              value={agentCommand}
-            />
-          </div>
-        </div>
-      ) : null}
-
      {/* Agent runtime args */}
      <div className="space-y-1.5">
        <label
@@ -23,7 +23,7 @@ import { CreateIdentityCard } from "./CreateIdentityCard";
 import { TeamIdentityCard } from "./TeamIdentityCard";

 const TEAM_CARD_COLUMN_CLASS = "w-full";
-const TEAM_CARD_GRID_CLASS = `${TEAM_CARD_COLUMN_CLASS} grid grid-cols-[repeat(auto-fill,minmax(220px,240px))] justify-start gap-3`;
+const TEAM_CARD_GRID_CLASS = `${TEAM_CARD_COLUMN_CLASS} mx-auto grid max-w-[996px] grid-cols-[repeat(auto-fill,minmax(220px,240px))] justify-center gap-3`;

 type TeamsSectionProps = {
  teams: AgentTeam[];
@@ -61,7 +61,7 @@ type UnifiedAgentsSectionProps = {
 };

 const AGENT_CARD_COLUMN_CLASS = "w-full";
-const AGENT_CARD_GRID_CLASS = `${AGENT_CARD_COLUMN_CLASS} grid grid-cols-[repeat(auto-fill,minmax(220px,240px))] justify-start gap-3`;
+const AGENT_CARD_GRID_CLASS = `${AGENT_CARD_COLUMN_CLASS} mx-auto grid max-w-[996px] grid-cols-[repeat(auto-fill,minmax(220px,240px))] justify-center gap-3`;

 export function UnifiedAgentsSection(props: UnifiedAgentsSectionProps) {
  const {
@@ -5,6 +5,7 @@ import {
  MODEL_NO_MODELS_VALUE,
  appendNoModelsSentinel,
  resolveDefaultModelLabel,
+  resolveModelFieldStatusMessage,
 } from "./agentConfigControls.tsx";

 test("uses the harness-discovered default model label for an unset model", () => {
@@ -66,3 +67,41 @@ test("appendNoModelsSentinel_nonEmptyOptionsDiscoveryFinished_doesNotAddRow", ()
  assert.equal(options.length, 1);
  assert.equal(options[0].label, "Default model");
 });
+
+test("model status omits provider selection guidance before discovery", () => {
+  assert.equal(
+    resolveModelFieldStatusMessage({
+      discoveredModelOptions: null,
+      loading: false,
+      status: null,
+    }),
+    null,
+  );
+});
+
+test("model status preserves loading, discovery, and saved-state messages", () => {
+  assert.equal(
+    resolveModelFieldStatusMessage({
+      discoveredModelOptions: null,
+      loading: true,
+      status: null,
+    }),
+    "Loading models...",
+  );
+  assert.equal(
+    resolveModelFieldStatusMessage({
+      discoveredModelOptions: null,
+      loading: false,
+      status: { message: "Couldn't load models", tone: "warning" },
+    }),
+    "Couldn't load models",
+  );
+  assert.equal(
+    resolveModelFieldStatusMessage({
+      discoveredModelOptions: [],
+      loading: false,
+      status: null,
+    }),
+    "Saved changes take effect on the next start.",
+  );
+});
@@ -20,6 +20,8 @@ import {
  getModelSelectValue,
  getPersonaProviderOptions,
  hasPersonaModelOption,
+  PERSONA_FIELD_CONTROL_CLASS,
+  PERSONA_FIELD_SHELL_CLASS,
  providerDisplayLabel,
  type PersonaModelOption,
 } from "./agentConfigOptions";
@@ -54,11 +56,59 @@ export function appendNoModelsSentinel(
  return options;
 }

+export function resolveModelFieldStatusMessage({
+  discoveredModelOptions,
+  loading,
+  status,
+}: {
+  discoveredModelOptions: readonly PersonaModelOption[] | null;
+  loading: boolean;
+  status: PersonaModelDiscoveryStatus | null;
+}): string | null {
+  if (loading) return "Loading models...";
+  if (status !== null) return status.message;
+  return discoveredModelOptions !== null
+    ? "Saved changes take effect on the next start."
+    : null;
+}
+
 function optionTestId(testId: string | undefined, value: string) {
  if (!testId) return undefined;
  return `${testId}-option-${value || "empty"}`;
 }

+export function AgentConfigTextInput({
+  className,
+  usePersonaInputStyle = false,
+  ...props
+}: React.ComponentProps<typeof Input> & {
+  usePersonaInputStyle?: boolean;
+}) {
+  const input = (
+    <Input
+      {...props}
+      className={cn(
+        usePersonaInputStyle && "h-8 px-0 py-0 leading-6",
+        usePersonaInputStyle && PERSONA_FIELD_CONTROL_CLASS,
+        className,
+      )}
+    />
+  );
+
+  return usePersonaInputStyle ? (
+    <div
+      className={cn(
+        "mt-2 flex min-h-11 items-center px-3",
+        PERSONA_FIELD_SHELL_CLASS,
+      )}
+    >
+      {input}
+    </div>
+  ) : (
+    input
+  );
+}
+
 export function AgentDropdownSelect({
  ariaRequired,
  className,
@@ -307,6 +357,7 @@ export function AgentModelField({
  showStatusMessage = true,
  showCustomModelOption = true,
  useChevronIcon = false,
+  usePersonaInputStyle = false,
 }: {
  disabled: boolean;
  discoveredModelOptions: readonly PersonaModelOption[] | null;
@@ -352,6 +403,8 @@ export function AgentModelField({
  showCustomModelOption?: boolean;
  /** Render a controlled chevron instead of the native select indicator. */
  useChevronIcon?: boolean;
+  /** Match custom agent text inputs when this field is shown in that flow. */
+  usePersonaInputStyle?: boolean;
 }) {
  const trimmedModel = model.trim();
  const isSharedCompute = provider?.trim() === "relay-mesh";
@@ -474,6 +527,11 @@ export function AgentModelField({
    !isCustomModelEditing
      ? "Loading models..."
      : placeholder;
+  const statusMessage = resolveModelFieldStatusMessage({
+    discoveredModelOptions,
+    loading: modelDiscoveryLoading,
+    status: modelDiscoveryStatus,
+  });

  const modelSelect = useCustomSelect ? (
    <AgentDropdownSelect
@@ -537,25 +595,18 @@ export function AgentModelField({
        modelSelect
      )}
      {showCustomModelInput ? (
-        <Input
+        <AgentConfigTextInput
          aria-label="Custom model ID"
          autoCorrect="off"
          disabled={disabled}
          onChange={(event) => onModelChange(event.target.value)}
          placeholder="Custom model ID"
+          usePersonaInputStyle={usePersonaInputStyle}
          value={model}
        />
      ) : null}
-      {showStatusMessage ? (
-        <p className="text-xs text-muted-foreground">
-          {modelDiscoveryLoading
-            ? "Loading models..."
-            : modelDiscoveryStatus !== null
-              ? modelDiscoveryStatus.message
-              : discoveredModelOptions !== null
-                ? "Saved changes take effect on the next start."
-                : "Select a provider above to see available models."}
-        </p>
+      {showStatusMessage && statusMessage ? (
+        <p className="text-xs text-muted-foreground">{statusMessage}</p>
      ) : null}
    </div>
  );
@@ -21,6 +21,7 @@ import test from "node:test";
 import {
  CANONICAL_CONFIG_BEHAVIORS,
  resolveDisclosure,
+  shouldRevealDependentConfigFields,
  shouldRenderModelControl,
  shouldShowModelStatusMessage,
 } from "./AgentConfigFields.tsx";
@@ -60,6 +61,48 @@ test("onboarding-essential hides power tools but never the effort field", () =>
  });
 });

+test("progressive defaults keep full disclosure", () => {
+  assert.deepEqual(
+    resolveDisclosure("progressive-defaults"),
+    resolveDisclosure("full"),
+  );
+});
+
+test("progressive defaults wait for a provider only when the harness needs one", () => {
+  assert.equal(
+    shouldRevealDependentConfigFields({
+      disclosure: "progressive-defaults",
+      providerFieldVisible: true,
+      providerValue: "",
+    }),
+    false,
+  );
+  assert.equal(
+    shouldRevealDependentConfigFields({
+      disclosure: "progressive-defaults",
+      providerFieldVisible: true,
+      providerValue: "anthropic",
+    }),
+    true,
+  );
+  assert.equal(
+    shouldRevealDependentConfigFields({
+      disclosure: "progressive-defaults",
+      providerFieldVisible: false,
+      providerValue: "",
+    }),
+    true,
+  );
+  assert.equal(
+    shouldRevealDependentConfigFields({
+      disclosure: "full",
+      providerFieldVisible: true,
+      providerValue: "",
+    }),
+    true,
+  );
+});
+
 // ── shouldShowModelStatusMessage ──────────────────────────────────────────────
 // The onboarding-essential preset sets showDescriptions=false.  Discovery
 // warnings must bypass the preset so first-run failures are never invisible.
@@ -542,86 +542,6 @@ test("editAgent_resolveAgentCommandUpdate_inheritSentinelOnlyWhenPinToClear", ()
  );
 });

-test("editAgent_customCommandSelected_autoExpandsAdvancedSection", () => {
-  // Selecting "Custom command" must reveal the Advanced command input, which is
-  // otherwise collapsed. Without this the user can Save without ever seeing the
-  // field, leaving agentCommand equal to the original effective command (so the
-  // update is omitted) and the custom selection silently no-ops.
-  let showAdvancedFields = false; // starts collapsed on open
-
-  const NO_RUNTIME_DROPDOWN_VALUE = "__none__";
-  const nextValue = "custom";
-  const nextRuntimeId =
-    nextValue === NO_RUNTIME_DROPDOWN_VALUE ? "" : nextValue;
-  const resolvedRuntimeId = nextRuntimeId || "custom";
-  const isCustomCommand = resolvedRuntimeId === "custom";
-
-  // Mirror the handler's auto-expand branch.
-  if (isCustomCommand) {
-    showAdvancedFields = true;
-  }
-
-  assert.equal(
-    showAdvancedFields,
-    true,
-    "selecting 'Custom command' must auto-expand Advanced so the command input is visible",
-  );
-});
-
-test("editAgent_missingRequiredEnvKey_autoExpandsAdvancedOnTransition", () => {
-  // Codex P2: when a provider change makes a credential newly required, the
-  // EnvVarsEditor lives inside the collapsed Advanced section, so the amber
-  // required row would stay unmounted (invisible) while Save is disabled. The
-  // effect auto-expands Advanced on the missing→present-requirement transition.
-  let showAdvancedFields = false; // collapsed by default on open
-  let previousMissing = false;
-
-  // Mirror the effect's transition guard.
-  function applyMissingEffect(requiredEnvKeyMissing) {
-    if (requiredEnvKeyMissing && !previousMissing) {
-      showAdvancedFields = true;
-    }
-    previousMissing = requiredEnvKeyMissing;
-  }
-
-  // Initial render: buzz-agent with no provider — nothing required yet.
-  applyMissingEffect(
-    hasMissingRequiredEnvKey(requiredCredentialEnvKeys("buzz-agent", ""), {}),
-  );
-  assert.equal(
-    showAdvancedFields,
-    false,
-    "Advanced stays collapsed while no credential is required",
-  );
-
-  // User picks anthropic → ANTHROPIC_API_KEY becomes required and is unset.
-  applyMissingEffect(
-    hasMissingRequiredEnvKey(
-      requiredCredentialEnvKeys("buzz-agent", "anthropic"),
-      {},
-    ),
-  );
-  assert.equal(
-    showAdvancedFields,
-    true,
-    "Advanced auto-expands when a required credential is newly missing",
-  );
-
-  // User fills the key, then collapses Advanced manually — no re-expand.
-  showAdvancedFields = false;
-  applyMissingEffect(
-    hasMissingRequiredEnvKey(
-      requiredCredentialEnvKeys("buzz-agent", "anthropic"),
-      { ANTHROPIC_API_KEY: "sk-ant-test" },
-    ),
-  );
-  assert.equal(
-    showAdvancedFields,
-    false,
-    "Advanced does not re-expand once the required credential is filled",
-  );
-});
-
 test("editAgent_missingRequiredEnvKey_blocksSaveViaValidity", () => {
  // The block-save gate is folded into computeEditAgentFormValidity so the
  // Save button disables when a runtime/provider-required credential is unset.
@@ -0,0 +1,60 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { getGlobalAgentCredentialState } from "./globalAgentCredentialState.ts";
+
+test("global defaults accept an advanced credential set in runtime config", () => {
+  const state = getGlobalAgentCredentialState({
+    bakedEnvKeys: [],
+    envVars: {},
+    provider: "databricks_v2",
+    runtimeFileConfig: {
+      provider: "databricks_v2",
+      model: "goose-claude-4-6-opus",
+      satisfiedEnvKeys: ["DATABRICKS_HOST"],
+    },
+    runtimeId: "goose",
+  });
+
+  assert.equal(state.advancedCredentialMissing, false);
+  assert.equal(state.credentialsValid, true);
+  assert.deepEqual(state.advancedRequiredEnvKeys, []);
+  assert.deepEqual(state.advancedFileSatisfiedEnvKeys, ["DATABRICKS_HOST"]);
+});
+
+test("an explicit empty global value shadows the runtime config", () => {
+  const state = getGlobalAgentCredentialState({
+    bakedEnvKeys: [],
+    envVars: { DATABRICKS_HOST: "" },
+    provider: "databricks_v2",
+    runtimeFileConfig: {
+      provider: "databricks_v2",
+      model: "goose-claude-4-6-opus",
+      satisfiedEnvKeys: ["DATABRICKS_HOST"],
+    },
+    runtimeId: "goose",
+  });
+
+  assert.equal(state.advancedCredentialMissing, true);
+  assert.equal(state.credentialsValid, false);
+  assert.deepEqual(state.advancedRequiredEnvKeys, ["DATABRICKS_HOST"]);
+  assert.deepEqual(state.advancedFileSatisfiedEnvKeys, []);
+});
+
+test("global defaults accept a provider key set in runtime config", () => {
+  const state = getGlobalAgentCredentialState({
+    bakedEnvKeys: [],
+    envVars: {},
+    provider: "openai",
+    runtimeFileConfig: {
+      provider: "openai",
+      model: "gpt-5.5",
+      satisfiedEnvKeys: ["OPENAI_COMPAT_API_KEY"],
+    },
+    runtimeId: "goose",
+  });
+
+  assert.equal(state.apiKeyFileSatisfied, true);
+  assert.equal(state.apiKeyInherited, true);
+  assert.equal(state.credentialsValid, true);
+});
@@ -0,0 +1,70 @@
+import type { RuntimeFileConfigSubset } from "@/shared/api/tauri";
+import {
+  getBakedSatisfiedEnvKeys,
+  getProviderApiKeyEnvVar,
+  requiredCredentialEnvKeys,
+} from "@/features/agents/ui/agentConfigOptions";
+
+export function getGlobalAgentCredentialState({
+  bakedEnvKeys,
+  envVars,
+  provider,
+  runtimeFileConfig,
+  runtimeId,
+}: {
+  bakedEnvKeys: readonly string[];
+  envVars: Record<string, string>;
+  provider: string;
+  runtimeFileConfig: RuntimeFileConfigSubset | null | undefined;
+  runtimeId: string;
+}) {
+  const requiredEnvKeys = requiredCredentialEnvKeys(runtimeId, provider);
+  const apiKeyEnvVar = getProviderApiKeyEnvVar(provider);
+  const bakedSatisfiedEnvKeys = getBakedSatisfiedEnvKeys(
+    requiredEnvKeys,
+    envVars,
+    bakedEnvKeys,
+  );
+  const fileSatisfiedEnvKeys = requiredEnvKeys.filter(
+    (key) =>
+      !(key in envVars) &&
+      !bakedSatisfiedEnvKeys.includes(key) &&
+      (runtimeFileConfig?.satisfiedEnvKeys.includes(key) ?? false),
+  );
+  const displayedRequiredEnvKeys = requiredEnvKeys.filter(
+    (key) =>
+      !bakedSatisfiedEnvKeys.includes(key) &&
+      !fileSatisfiedEnvKeys.includes(key),
+  );
+  const advancedRequiredEnvKeys = displayedRequiredEnvKeys.filter(
+    (key) => key !== apiKeyEnvVar,
+  );
+  const advancedFileSatisfiedEnvKeys = fileSatisfiedEnvKeys.filter(
+    (key) => key !== apiKeyEnvVar,
+  );
+  const apiKeyValue = apiKeyEnvVar ? (envVars[apiKeyEnvVar] ?? "") : "";
+  const apiKeyFileSatisfied =
+    apiKeyEnvVar !== null && fileSatisfiedEnvKeys.includes(apiKeyEnvVar);
+  const apiKeyInherited =
+    apiKeyEnvVar !== null &&
+    apiKeyValue.length === 0 &&
+    (bakedSatisfiedEnvKeys.includes(apiKeyEnvVar) || apiKeyFileSatisfied);
+  const advancedCredentialMissing = advancedRequiredEnvKeys.some(
+    (key) => (envVars[key] ?? "").trim().length === 0,
+  );
+  const apiKeyMissing =
+    apiKeyEnvVar !== null &&
+    !apiKeyInherited &&
+    apiKeyValue.trim().length === 0;
+
+  return {
+    advancedCredentialMissing,
+    advancedFileSatisfiedEnvKeys,
+    advancedRequiredEnvKeys,
+    apiKeyEnvVar,
+    apiKeyFileSatisfied,
+    apiKeyInherited,
+    apiKeyValue,
+    credentialsValid: !advancedCredentialMissing && !apiKeyMissing,
+  };
+}
@@ -100,7 +100,7 @@ export function resolveAgentCommandUpdate(input: {
 * config contribute no entries, so this never blocks on out-of-band auth.
 */
 export function hasMissingRequiredEnvKey(
-  requiredEnvKeys: string[],
+  requiredEnvKeys: readonly string[],
  envVars: Record<string, string>,
 ): boolean {
  return requiredEnvKeys.some((key) => (envVars[key] ?? "").length === 0);
@@ -1,160 +0,0 @@
-import assert from "node:assert/strict";
-import test from "node:test";
-
-import { personaSubmitBlock } from "./personaSubmitBlock.ts";
-
-/** A fully valid, submittable form: personaSubmitBlock returns null. */
-function submittable(overrides = {}) {
-  return {
-    isPending: false,
-    isAvatarUploadPending: false,
-    displayNameEmpty: false,
-    isCreateMode: true,
-    runtimeChosen: true,
-    runtimeAvailable: true,
-    createBackendBlocked: false,
-    allowlistEmpty: false,
-    aiConfigurationMode: "defaults",
-    localModeSatisfied: true,
-    localModeMissingFields: [],
-    localModeMissingEnvKeys: [],
-    customAiPairSatisfied: true,
-    runtimeNeedsProviderSelection: true,
-    customProviderEmpty: false,
-    customModelEmpty: false,
-    ...overrides,
-  };
-}
-
-test("a valid form has no disabled reason", () => {
-  assert.equal(personaSubmitBlock(submittable()), null);
-});
-
-test("missing name is reported first", () => {
-  assert.equal(
-    personaSubmitBlock(submittable({ displayNameEmpty: true })),
-    "Enter a name for this agent.",
-  );
-});
-
-test("Buzz Agent + Use AI defaults with no global provider/model names the fix", () => {
-  const reason = personaSubmitBlock(
-    submittable({
-      aiConfigurationMode: "defaults",
-      localModeSatisfied: false,
-      localModeMissingFields: ["provider", "model"],
-    }),
-  );
-  assert.match(reason, /global AI defaults are incomplete/);
-  assert.match(reason, /a provider and a model/);
-  assert.match(reason, /Settings → AI defaults/);
-});
-
-test("incomplete defaults also names missing credential keys", () => {
-  const reason = personaSubmitBlock(
-    submittable({
-      localModeSatisfied: false,
-      localModeMissingFields: [],
-      localModeMissingEnvKeys: ["ANTHROPIC_API_KEY"],
-    }),
-  );
-  assert.match(reason, /a value for ANTHROPIC_API_KEY/);
-});
-
-test("the reason disappears once the blocking input is corrected", () => {
-  const blocked = submittable({
-    localModeSatisfied: false,
-    localModeMissingFields: ["provider", "model"],
-  });
-  assert.notEqual(personaSubmitBlock(blocked), null);
-  // Correct the blocking input: defaults now resolve.
-  const corrected = {
-    ...blocked,
-    localModeSatisfied: true,
-    localModeMissingFields: [],
-  };
-  assert.equal(personaSubmitBlock(corrected), null);
-});
-
-test("create mode requires a chosen, available runtime", () => {
-  assert.equal(
-    personaSubmitBlock(submittable({ runtimeChosen: false })),
-    "Choose where this agent runs.",
-  );
-  assert.equal(
-    personaSubmitBlock(submittable({ runtimeAvailable: false })),
-    "The selected runtime isn't available on this machine.",
-  );
-});
-
-test("runtime gates do not apply in edit mode", () => {
-  assert.equal(
-    personaSubmitBlock(
-      submittable({ isCreateMode: false, runtimeChosen: false }),
-    ),
-    null,
-  );
-});
-
-test("empty allowlist is reported (create and edit)", () => {
-  const reason = personaSubmitBlock(
-    submittable({ isCreateMode: false, allowlistEmpty: true }),
-  );
-  assert.match(reason, /allowed sender/);
-});
-
-test("Customize with an empty pair but satisfied global fallback points at the pair", () => {
-  const reason = personaSubmitBlock(
-    submittable({
-      aiConfigurationMode: "custom",
-      localModeSatisfied: true,
-      customAiPairSatisfied: false,
-      customProviderEmpty: true,
-      customModelEmpty: true,
-    }),
-  );
-  assert.match(reason, /Select a provider and a model/);
-  assert.match(reason, /Use AI defaults/);
-});
-
-test("Customize on Codex/Claude asks only for a model, never a provider", () => {
-  const reason = personaSubmitBlock(
-    submittable({
-      aiConfigurationMode: "custom",
-      customAiPairSatisfied: false,
-      runtimeNeedsProviderSelection: false,
-      customProviderEmpty: true,
-      customModelEmpty: true,
-    }),
-  );
-  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", () => {
-  assert.equal(
-    personaSubmitBlock(
-      submittable({
-        displayNameEmpty: true,
-        localModeSatisfied: false,
-        localModeMissingFields: ["provider", "model"],
-      }),
-    ),
-    "Enter a name for this agent.",
-  );
-});
-
-test("in-flight save/upload shows no reason (the button label communicates it)", () => {
-  assert.equal(
-    personaSubmitBlock(
-      submittable({ isPending: true, displayNameEmpty: true }),
-    ),
-    null,
-  );
-  assert.equal(
-    personaSubmitBlock(submittable({ isAvatarUploadPending: true })),
-    null,
-  );
-});
@@ -1,138 +0,0 @@
-import type { AgentAiConfigurationMode } from "./agentAiConfigurationPolicy";
-
-/**
- * Inputs for {@link personaSubmitBlock}. Every field is an OUTPUT of a gate the
- * dialog already computes for `canSubmit` — this module maps those outputs to a
- * single human-readable reason. It must not recompute policy: the derivation
- * stays a pure function of the gate results so the message can never disagree
- * with whether the button is actually disabled.
- */
-export type PersonaSubmitBlockInput = {
-  /** A save/create request is in flight (button shows "Saving..."). */
-  isPending: boolean;
-  /** The avatar upload is in flight (button shows "Uploading..."). */
-  isAvatarUploadPending: boolean;
-  /** Trimmed display name is empty. */
-  displayNameEmpty: boolean;
-  /** Create (new definition) vs edit (existing). Some gates are create-only. */
-  isCreateMode: boolean;
-  /** A runtime has been chosen (create-only gate). */
-  runtimeChosen: boolean;
-  /** The chosen runtime is available on this machine (create-only gate). */
-  runtimeAvailable: boolean;
-  /** The remote / where-to-run backend selection is incomplete (create-only). */
-  createBackendBlocked: boolean;
-  /** Respond-to allowlist mode is selected but the allowlist is empty. */
-  allowlistEmpty: boolean;
-  /** Selected AI configuration mode: inherit global defaults vs customize. */
-  aiConfigurationMode: AgentAiConfigurationMode;
-  /** `computeLocalModeGate(...).satisfied` — resolved AI config is complete. */
-  localModeSatisfied: boolean;
-  /** `computeLocalModeGate(...).missingNormalizedFields`, e.g. ["provider"]. */
-  localModeMissingFields: readonly string[];
-  /** `computeLocalModeGate(...).missingEnvKeys` — required credentials unset. */
-  localModeMissingEnvKeys: readonly string[];
-  /** `agentAiConfigurationModeSatisfied(...)` for the Customize pair. */
-  customAiPairSatisfied: boolean;
-  /** Runtime exposes a provider picker (Buzz Agent / Goose), not Codex/Claude. */
-  runtimeNeedsProviderSelection: boolean;
-  /** Customize provider field is empty. */
-  customProviderEmpty: boolean;
-  /** Customize model field is empty. */
-  customModelEmpty: boolean;
-};
-
-function joinWithAnd(parts: readonly string[]): string {
-  if (parts.length <= 1) return parts[0] ?? "";
-  if (parts.length === 2) return `${parts[0]} and ${parts[1]}`;
-  return `${parts.slice(0, -1).join(", ")}, and ${parts[parts.length - 1]}`;
-}
-
-/**
- * Describe the concrete missing pieces behind an unsatisfied AI-config gate,
- * naming the actual fix rather than a generic "configuration incomplete".
- */
-function describeMissingAiPieces(
-  fields: readonly string[],
-  envKeys: readonly string[],
-): string {
-  const parts: string[] = [];
-  if (fields.includes("provider")) parts.push("a provider");
-  if (fields.includes("model")) parts.push("a model");
-  for (const key of envKeys) parts.push(`a value for ${key}`);
-  return joinWithAnd(parts);
-}
-
-/**
- * Human-readable reason the Create/Save button is disabled, or `null` when the
- * form can be submitted. Precedence mirrors the `canSubmit` term order in
- * AgentDefinitionDialog so the surfaced reason is deterministic and always the
- * first blocking input — correcting it makes the reason advance or disappear.
- *
- * While a request or avatar upload is in flight the button communicates the
- * progress itself ("Saving..." / "Uploading..."), so no reason is returned.
- */
-export function personaSubmitBlock(
-  input: PersonaSubmitBlockInput,
-): string | null {
-  if (input.isPending || input.isAvatarUploadPending) {
-    return null;
-  }
-
-  // 1. Required definition fields.
-  if (input.displayNameEmpty) {
-    return "Enter a name for this agent.";
-  }
-
-  // 2–4. Create-only runtime / backend gates.
-  if (input.isCreateMode) {
-    if (!input.runtimeChosen) {
-      return "Choose where this agent runs.";
-    }
-    if (!input.runtimeAvailable) {
-      return "The selected runtime isn't available on this machine.";
-    }
-    if (input.createBackendBlocked) {
-      return "Finish configuring the remote backend before creating this agent.";
-    }
-  }
-
-  // 5. Access / allowlist crash-loop guard (create and edit).
-  if (input.allowlistEmpty) {
-    return "Add at least one allowed sender, or change who this agent responds to.";
-  }
-
-  // 6. Resolved AI configuration (provider/model/credentials) incomplete.
-  if (!input.localModeSatisfied) {
-    const missing = describeMissingAiPieces(
-      input.localModeMissingFields,
-      input.localModeMissingEnvKeys,
-    );
-    if (input.aiConfigurationMode === "defaults") {
-      const detail = missing ? ` — missing ${missing}` : "";
-      return `Your global AI defaults are incomplete${detail}. Set them in Settings → AI defaults, or choose Customize to configure this agent directly.`;
-    }
-    return missing
-      ? `This agent's AI configuration is missing ${missing}.`
-      : "Complete this agent's AI configuration.";
-  }
-
-  // 7. Customize pair incomplete (form provider/model empty while a global
-  // fallback keeps localMode satisfied). Provider only counts where the runtime
-  // exposes a picker — Codex/Claude drive their own provider.
-  if (!input.customAiPairSatisfied) {
-    const needProvider =
-      input.runtimeNeedsProviderSelection && input.customProviderEmpty;
-    const pieces: string[] = [];
-    if (needProvider) pieces.push("a provider");
-    if (input.customModelEmpty) pieces.push("a model");
-    const what =
-      pieces.length > 0 ? joinWithAnd(pieces) : "the AI configuration";
-    const defaultsLabel = input.runtimeNeedsProviderSelection
-      ? "Use AI defaults"
-      : "Use harness defaults";
-    return `Select ${what} for this agent, or switch to ${defaultsLabel}.`;
-  }
-
-  return null;
-}
@@ -105,26 +105,20 @@ export function useProviderApiKeyFieldState({
  envVars,
  fileSatisfiedEnvKeys,
  globalEnvVars,
-  open,
  personaSatisfied,
  provider,
  requiredEnvKeys,
-  satisfactionSettled = true,
-  setShowAdvancedFields,
 }: {
  bakedEnvKeys: readonly string[] | undefined;
  effectiveEnvVars: EnvVarsValue;
  envVars: EnvVarsValue;
  fileSatisfiedEnvKeys?: readonly string[];
  globalEnvVars: EnvVarsValue;
-  open: boolean;
  personaSatisfied?: boolean;
  provider: string;
  requiredEnvKeys: readonly string[];
-  satisfactionSettled?: boolean;
-  setShowAdvancedFields: React.Dispatch<React.SetStateAction<boolean>>;
 }): ProviderApiKeyFieldState {
-  const fieldState = React.useMemo(
+  return React.useMemo(
    () =>
      getProviderApiKeyFieldState({
        bakedEnvKeys,
@@ -147,26 +141,4 @@ export function useProviderApiKeyFieldState({
      requiredEnvKeys,
    ],
  );
-  const hasAutoOpenedAdvancedRef = React.useRef(false);
-  React.useEffect(() => {
-    if (!open) {
-      hasAutoOpenedAdvancedRef.current = false;
-      return;
-    }
-    if (
-      satisfactionSettled &&
-      fieldState.advancedRequiredEnvKeys.length > 0 &&
-      !hasAutoOpenedAdvancedRef.current
-    ) {
-      hasAutoOpenedAdvancedRef.current = true;
-      setShowAdvancedFields(true);
-    }
-  }, [
-    fieldState.advancedRequiredEnvKeys.length,
-    open,
-    satisfactionSettled,
-    setShowAdvancedFields,
-  ]);
-
-  return fieldState;
 }
@@ -21,8 +21,6 @@ export interface RequiredCredentialState {
  fileSatisfiedEnvKeys: string[];
  /** Whether any required env key is still missing (blocks Save). */
  requiredEnvKeyMissing: boolean;
-  /** True once all async satisfaction sources (baked, file config) have resolved. */
-  settled: boolean;
 }

 /**
@@ -35,7 +33,8 @@ export interface RequiredCredentialState {
 * actually be saved.
 *
 * The caller owns the visibility policy: top-level API-key fields are already
- * visible, while non-secret Advanced-only keys can open that section.
+ * visible, while non-secret keys remain available under user-controlled
+ * Advanced disclosure.
 *
 * `globalProvider` is used as the fallback when the per-agent provider is
 * empty — without it, a global-provider-only config produces no required keys
@@ -78,13 +77,12 @@ export function useRequiredCredentialState(params: {
    ? provider.trim() || globalProvider.trim()
    : "";

-  const { data: runtimeFileConfig, isLoading: fileConfigLoading } =
-    useRuntimeFileConfigQuery(prospectiveRuntimeId, { enabled: open });
+  const { data: runtimeFileConfig } = useRuntimeFileConfigQuery(
+    prospectiveRuntimeId,
+    { enabled: open },
+  );

-  const { data: bakedEnvKeys, isLoading: bakedLoading } =
-    useBakedBuildEnvKeysQuery({ enabled: open });
-
-  const settled = !fileConfigLoading && !bakedLoading;
+  const { data: bakedEnvKeys } = useBakedBuildEnvKeysQuery({ enabled: open });

  // All required keys for this runtime + provider combination.
  const allRequiredKeys = React.useMemo(
@@ -137,6 +135,5 @@ export function useRequiredCredentialState(params: {
    requiredEnvKeys,
    fileSatisfiedEnvKeys,
    requiredEnvKeyMissing,
-    settled,
  };
 }
@@ -1,6 +1,9 @@
 import * as React from "react";

-import { useAcpRuntimesQuery } from "@/features/agents/hooks";
+import {
+  useAcpRuntimesQuery,
+  useRuntimeFileConfigQuery,
+} from "@/features/agents/hooks";
 import {
  AgentConfigFields,
  EMPTY_GLOBAL_CONFIG,
@@ -138,6 +141,8 @@ function AgentDefaultsSection({
    [config.preferred_runtime, readyRuntimes],
  );
  const selectedRuntimeId = selectedRuntime?.id ?? "";
+  const { data: runtimeFileConfig } =
+    useRuntimeFileConfigQuery(selectedRuntimeId);
  const configSurfaceLoading = isLoading || runtimesQuery.isLoading;

  const configSurfaceError =
@@ -235,6 +240,7 @@ function AgentDefaultsSection({
            onCustomModelEditingChange={setIsCustomModelEditing}
            onIsCustomProviderChange={setIsCustomProvider}
            placeholderClassName="text-foreground/70"
+            runtimeFileConfig={runtimeFileConfig}
            selectClassName="h-12 rounded-2xl border-foreground/15 bg-white px-4 py-2 text-sm shadow-none hover:bg-white/95"
            disclosure="onboarding-essential"
            unstyled
@@ -49,6 +49,7 @@ import type {
 import type {
  RawAcpRuntimeCatalogEntry,
  RawInstallRuntimeResult,
+  RuntimeFileConfigSubset,
 } from "@/shared/api/tauri";
 import { normalizePubkey } from "@/shared/lib/pubkey";

@@ -355,6 +356,8 @@ type E2eConfig = {
      model: string | null;
      preferred_runtime?: string | null;
    };
+    /** File-layer config returned by runtime id. */
+    runtimeFileConfigs?: Record<string, RuntimeFileConfigSubset | null>;
    /** Baked build env returned by the display and key-name Tauri commands. */
    bakedBuildEnv?: Array<{
      key: string;
@@ -10293,9 +10296,10 @@ export function maybeInstallE2eTauriMocks() {
        return buildMockConfigSurface(configArgs.pubkey);
      }
      case "get_runtime_file_config": {
-        // No harness config file in the E2E environment — return null so
-        // dialogs fall back to normal required-field evaluation.
-        return null;
+        const runtimeId = (payload as { runtimeId?: string } | null | undefined)
+          ?.runtimeId;
+        if (!runtimeId) return null;
+        return config.mock?.runtimeFileConfigs?.[runtimeId] ?? null;
      }
      case "get_global_agent_config": {
        // Return the mutable persisted mock value, seeded from the test config.
@@ -144,7 +144,7 @@ test.describe("agent lifecycle feedback screenshots", () => {
      globalAgentConfig: {
        provider: "anthropic",
        model: "claude-opus-4-5",
-        env_vars: {},
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-test" },
      },
      globalConfigRestartedCount: 2,
    });
@@ -181,7 +181,7 @@ test.describe("agent lifecycle feedback screenshots", () => {
      globalAgentConfig: {
        provider: "anthropic",
        model: "claude-opus-4-5",
-        env_vars: {},
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-test" },
      },
    });

@@ -301,7 +301,7 @@ test.describe("agent lifecycle feedback screenshots", () => {
      globalAgentConfig: {
        provider: "anthropic",
        model: "claude-opus-4-5",
-        env_vars: {},
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-test" },
      },
      globalConfigRestartedCount: 1,
    });
@@ -329,7 +329,7 @@ test.describe("agent lifecycle feedback screenshots", () => {
      globalAgentConfig: {
        provider: "anthropic",
        model: "claude-opus-4-5",
-        env_vars: {},
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-test" },
      },
      globalConfigFailedRestartCount: 1,
    });
@@ -366,7 +366,7 @@ test.describe("agent lifecycle feedback screenshots", () => {
      globalAgentConfig: {
        provider: "anthropic",
        model: "claude-opus-4-5",
-        env_vars: {},
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-test" },
      },
      globalConfigSaveDelayMs: 2_000,
    });
@@ -174,6 +174,8 @@ test.describe("agent provider dropdown screenshots", () => {
    const dialog = page.getByTestId("persona-dialog");
    await expect(dialog).toBeVisible({ timeout: 10_000 });

+    await dialog.getByRole("tab", { name: "Customize for this agent" }).click();
+
    // Regression: the runtime trigger must not be empty — the auto-seed effect
    // must have run and selected the app default (buzz-agent in the mock catalog).
    const runtimeTrigger = dialog.locator("#persona-runtime");
@@ -182,8 +184,6 @@ test.describe("agent provider dropdown screenshots", () => {
      timeout: 8_000,
    });

-    await dialog.getByRole("tab", { name: "Customize for this agent" }).click();
-
    // Regression: the model combobox must appear (modelFieldVisible = true once
    // runtime is non-empty) and model discovery must have run, populating it.
    const modelCombobox = dialog.getByRole("combobox", { name: /model/i });
@@ -250,6 +250,6 @@ test.describe("agent provider dropdown screenshots", () => {
    await expect(
      dialog.getByRole("combobox", { name: /model/i }),
    ).toBeVisible();
-    await expect(dialog.getByText("Model changes apply only")).toBeVisible();
+    await expect(dialog.getByText("Model changes apply only")).toHaveCount(0);
  });
 });
@@ -225,7 +225,8 @@ test.describe("agent readiness gate screenshots", () => {
    });
  });

-  // Shot 05: claude runtime (CLI-login) — provider/model not required, submit enabled.
+  // Shot 05: claude runtime (CLI-login) — provider not required; an explicit
+  // model completes the custom configuration and enables submit.
  // Override the catalog to make claude fully available so it appears in the dropdown.
  test("05-create-cli-login-runtime-no-provider-required", async ({ page }) => {
    await installMockBridge(page, {
@@ -263,6 +264,7 @@ test.describe("agent readiness gate screenshots", () => {
    });

    await openCreateDialog(page);
+    await page.getByRole("tab", { name: "Customize for this agent" }).click();

    // Switch the auto-selected buzz-agent runtime to Claude Code.
    await selectDropdownOption(
@@ -271,9 +273,10 @@ test.describe("agent readiness gate screenshots", () => {
      "Claude Code",
    );

-    // Provider/model fields hidden for CLI-login runtimes.
+    // Provider stays hidden for CLI-login runtimes. Customize still requires
+    // an explicit model choice.
    await expect(page.locator("#persona-llm-provider")).not.toBeVisible();
-    // Submit enabled without provider/model.
+    await setCustomModel(page, "claude-opus-4-6");
    await expect(page.getByTestId("persona-dialog-submit")).toBeEnabled({
      timeout: 5_000,
    });
@@ -153,6 +153,64 @@ test.describe("edit agent dialog", () => {
    );
  });

+  test("keeps the custom command visible without opening Advanced", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      managedAgents: [
+        {
+          pubkey: AGENT_PUBKEY,
+          name: AGENT_NAME,
+          status: "stopped",
+          channelNames: ["agents"],
+        },
+      ],
+    });
+
+    await openEditDialog(page);
+
+    const advanced = page.getByRole("button", {
+      name: "Advanced",
+      exact: true,
+    });
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    await pickDropdownOption(page, "edit-agent-runtime", "Custom command");
+    await expect(page.locator("#edit-agent-command")).toBeVisible();
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+  });
+
+  test("marks a missing advanced credential without opening Advanced", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      managedAgents: [
+        {
+          pubkey: AGENT_PUBKEY,
+          name: AGENT_NAME,
+          status: "stopped",
+          channelNames: ["agents"],
+        },
+      ],
+    });
+
+    await openEditDialog(page);
+
+    const advanced = page.getByRole("button", {
+      name: "Advanced",
+      exact: true,
+    });
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    await pickDropdownOption(page, "edit-agent-llm-provider", "Databricks v2");
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    await expect(
+      page.getByTestId("edit-agent-advanced-required-badge"),
+    ).toHaveText("Required");
+    await expect(page.getByTestId("edit-agent-dialog-submit")).toBeDisabled();
+
+    await advanced.click();
+    await expect(page.getByLabel("Value for DATABRICKS_HOST")).toBeVisible();
+  });
+
  test("shows baked defaults in the instance editor", async ({ page }) => {
    await installMockBridge(page, {
      bakedBuildEnv: BAKED_DEFAULTS,
@@ -253,6 +253,45 @@ test.describe("global agent config screenshots", () => {
    expect(saved).toMatchObject({ preferred_runtime: "codex" });
  });

+  test("defaults honor credentials set in the harness config file", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      globalAgentConfig: {
+        preferred_runtime: "goose",
+        provider: "databricks_v2",
+        model: "goose-claude-4-6-opus",
+        env_vars: {},
+      },
+      runtimeFileConfigs: {
+        goose: {
+          provider: "databricks_v2",
+          model: "goose-claude-4-6-opus",
+          satisfiedEnvKeys: ["DATABRICKS_HOST"],
+        },
+      },
+    });
+
+    await openAiDefaultsSettings(page);
+
+    const advanced = page.getByTestId("global-agent-advanced-toggle");
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    await expect(
+      page.getByTestId("global-agent-advanced-required-badge"),
+    ).toHaveCount(0);
+
+    await page.getByTestId("global-agent-model").click();
+    await page.getByTestId("global-agent-model-option-gpt-5.5").click();
+    await expect(
+      page.getByRole("button", { name: "Save defaults" }),
+    ).toBeEnabled();
+
+    await advanced.click();
+    await expect(page.getByTestId("env-vars-file-satisfied-key")).toHaveText(
+      "DATABRICKS_HOST",
+    );
+  });
+
  test("02-create-global-provider-shows-top-level-api-key", async ({
    page,
  }) => {
@@ -267,6 +306,11 @@ test.describe("global agent config screenshots", () => {
    await openCreateDialog(page);
    await customizeAgentAi(page);

+    await expect(
+      page
+        .getByTestId("agent-custom-configuration-section")
+        .locator("#persona-runtime"),
+    ).toBeVisible();
    await expect(page.getByLabel("Anthropic API Key")).toBeVisible({
      timeout: 10_000,
    });
@@ -274,6 +318,27 @@ test.describe("global agent config screenshots", () => {
      page.getByRole("button", { name: "Advanced", exact: true }),
    ).toHaveAttribute("aria-expanded", "false");
    await expect(page.getByTestId("env-vars-required-key")).not.toBeVisible();
+
+    await waitForAnimations(page);
+    await page.getByRole("dialog").screenshot({
+      path: `${SHOTS}/02-create-custom-agent-configuration.png`,
+    });
+
+    const advanced = page.getByRole("button", {
+      name: "Advanced",
+      exact: true,
+    });
+    await selectDropdownOption(
+      page,
+      page.locator("#persona-llm-provider"),
+      "Databricks v2",
+    );
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    await expect(
+      page.getByTestId("persona-advanced-required-badge"),
+    ).toHaveText("Required");
+    await advanced.click();
+    await expect(advanced).toHaveAttribute("aria-expanded", "true");
  });

  test("03-global-env-satisfies-required-key", async ({ page }) => {
@@ -360,6 +425,11 @@ test.describe("global agent config screenshots", () => {
          value: "high",
          masked: false,
        },
+        {
+          key: "ANTHROPIC_API_KEY",
+          value: "sk-ant-baked-test",
+          masked: true,
+        },
      ],
    });

@@ -390,13 +460,99 @@ test.describe("global agent config screenshots", () => {
      timeout: 10_000,
    });

-    // The footer must explain WHY it is disabled (regression guard for the
-    // submitBlockReason wiring, not just the boolean gate): defaults mode with
-    // no resolvable provider names the missing piece and points to Settings.
-    const reason = page.getByTestId("persona-dialog-submit-reason");
-    await expect(reason).toBeVisible({ timeout: 10_000 });
-    await expect(reason).toContainText("provider");
-    await expect(reason).toContainText("Settings → AI defaults");
+    const defaults = page.getByTestId("agent-ai-defaults-notice");
+    await expect(defaults).toContainText("Global defaults not set");
+    await expect(defaults.getByText("Harness", { exact: true })).toHaveCount(0);
+    await expect(defaults.getByText("Provider", { exact: true })).toHaveCount(
+      0,
+    );
+    await expect(defaults.getByText("Model", { exact: true })).toHaveCount(0);
+
+    const setDefaults = defaults.getByRole("button", {
+      name: "Set",
+    });
+    await expect(setDefaults).toBeVisible();
+    await expect(page.getByTestId("persona-dialog-submit-reason")).toHaveCount(
+      0,
+    );
+
+    await setDefaults.click();
+    const defaultsDialog = page.getByTestId("agent-ai-defaults-dialog");
+    await expect(defaultsDialog).toBeVisible();
+    await expect(
+      defaultsDialog.getByTestId("global-agent-config-fields"),
+    ).toBeVisible();
+    await expect(defaultsDialog.getByTestId("global-agent-model")).toHaveCount(
+      0,
+    );
+
+    const harness = defaultsDialog.getByTestId("global-agent-default-harness");
+    await expect(harness).toHaveText("Buzz Agent");
+    const provider = defaultsDialog.getByTestId("global-agent-provider");
+    await expect(provider).toBeVisible();
+    await waitForAnimations(page);
+    const providerHeight = (await defaultsDialog.boundingBox())?.height ?? 0;
+
+    await provider.click();
+    await page.getByTestId("global-agent-provider-option-anthropic").click();
+    await expect(
+      defaultsDialog.getByTestId("global-agent-model"),
+    ).toBeVisible();
+    for (const field of [
+      harness,
+      provider,
+      defaultsDialog.getByTestId("global-agent-model"),
+      defaultsDialog.getByTestId("global-agent-thinking-effort-select"),
+    ]) {
+      await expect(field).toHaveClass(/h-11/);
+      await expect(field).toHaveClass(/rounded-xl/);
+      await expect(field).toHaveClass(/bg-muted\/40/);
+      await expect(field).toHaveClass(/shadow-none/);
+    }
+    await waitForAnimations(page);
+    const configuredHeight = (await defaultsDialog.boundingBox())?.height ?? 0;
+    expect(configuredHeight).toBeGreaterThan(providerHeight);
+    await expect(
+      defaultsDialog.getByTestId("global-agent-config-fields"),
+    ).not.toHaveClass(/bg-muted\/20/);
+    const harnessBox = await defaultsDialog
+      .getByTestId("global-agent-default-harness")
+      .boundingBox();
+    const providerBox = await defaultsDialog
+      .getByTestId("global-agent-provider")
+      .boundingBox();
+    expect(harnessBox?.x).toBe(providerBox?.x);
+    expect(harnessBox?.width).toBe(providerBox?.width);
+    await waitForAnimations(page);
+    await defaultsDialog.screenshot({
+      path: `${SHOTS}/04-global-defaults-dialog-flat.png`,
+    });
+    const advanced = defaultsDialog.getByTestId("global-agent-advanced-toggle");
+    await provider.click();
+    await page
+      .getByTestId("global-agent-provider-option-databricks_v2")
+      .click();
+    await expect(advanced).toHaveAttribute("aria-expanded", "false");
+    const saveDefaults = defaultsDialog.getByRole("button", {
+      name: "Save defaults",
+    });
+    await expect(
+      defaultsDialog.getByTestId("global-agent-advanced-required-badge"),
+    ).toHaveText("Required");
+    await expect(saveDefaults).toBeDisabled();
+    await advanced.click();
+    await expect(advanced).toHaveAttribute("aria-expanded", "true");
+    await defaultsDialog
+      .getByLabel("Value for DATABRICKS_HOST")
+      .fill("https://databricks.example.test");
+    await expect(saveDefaults).toBeEnabled();
+    await defaultsDialog
+      .getByRole("button", {
+        name: "Close",
+      })
+      .click();
+    await page.getByRole("button", { name: "Discard changes" }).click();
+    await expect(defaultsDialog).not.toBeVisible();

    await waitForAnimations(page);

@@ -406,6 +562,166 @@ test.describe("global agent config screenshots", () => {
    });
  });

+  test("unset defaults persist the visible Buzz Agent fallback", async ({
+    page,
+  }) => {
+    await installMockBridge(page);
+    await openCreateDialog(page);
+    await page
+      .getByTestId("agent-ai-defaults-notice")
+      .getByRole("button", { name: "Set" })
+      .click();
+
+    const defaultsDialog = page.getByTestId("agent-ai-defaults-dialog");
+    await expect(
+      defaultsDialog.getByTestId("global-agent-default-harness"),
+    ).toHaveText("Buzz Agent");
+
+    await defaultsDialog.getByTestId("global-agent-provider").click();
+    await page.getByTestId("global-agent-provider-option-anthropic").click();
+    await defaultsDialog.getByLabel("Anthropic API Key").fill("sk-ant-test");
+    await expect(
+      defaultsDialog.getByRole("button", { name: "Save defaults" }),
+    ).toBeEnabled();
+    await defaultsDialog.getByRole("button", { name: "Save defaults" }).click();
+    await expect(defaultsDialog).not.toBeVisible();
+
+    const saved = await page.evaluate(async () =>
+      (
+        window as typeof window & {
+          __BUZZ_E2E_INVOKE_MOCK_COMMAND__?: (
+            command: string,
+            payload: unknown,
+          ) => Promise<unknown>;
+        }
+      ).__BUZZ_E2E_INVOKE_MOCK_COMMAND__?.("get_global_agent_config", null),
+    );
+    expect(saved).toMatchObject({
+      preferred_runtime: "buzz-agent",
+      provider: "anthropic",
+    });
+  });
+
+  test("create defaults follow a preferred harness saved while open", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      acpRuntimesCatalog: CATALOG_WITH_CLAUDE,
+      globalAgentConfig: {
+        preferred_runtime: "buzz-agent",
+        provider: "anthropic",
+        model: "claude-opus-4-5",
+        env_vars: { ANTHROPIC_API_KEY: "sk-ant-global-value" },
+      },
+    });
+    await openCreateDialog(page);
+
+    const defaults = page.getByTestId("agent-ai-defaults-notice");
+    await expect(defaults).toContainText("Buzz Agent");
+    await defaults
+      .getByRole("button", { name: "Edit global defaults" })
+      .click();
+
+    const defaultsDialog = page.getByTestId("agent-ai-defaults-dialog");
+    const harness = defaultsDialog.getByTestId("global-agent-default-harness");
+    await harness.press("Enter");
+    await page
+      .getByTestId("global-agent-default-harness-option-claude")
+      .click();
+    await defaultsDialog.getByRole("button", { name: "Save defaults" }).click();
+    await expect(defaultsDialog).not.toBeVisible();
+
+    const harnessDefaults = page.getByTestId("agent-harness-defaults-notice");
+    await expect(harnessDefaults).toContainText("Claude Code");
+    await expect(page.getByTestId("persona-dialog-submit")).toBeEnabled();
+    await page.getByTestId("persona-dialog-submit").click();
+
+    await expect
+      .poll(() =>
+        page.evaluate(() => {
+          const log = (
+            window as Window & {
+              __BUZZ_E2E_COMMAND_LOG__?: Array<{
+                command: string;
+                payload: { input?: Record<string, unknown> };
+              }>;
+            }
+          ).__BUZZ_E2E_COMMAND_LOG__;
+          const createPayload = log?.find(
+            (entry) => entry.command === "create_persona",
+          )?.payload.input;
+          return createPayload?.runtime;
+        }),
+      )
+      .toBe("claude");
+  });
+
+  test("missing global credentials show the unset defaults notice", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      globalAgentConfig: {
+        preferred_runtime: "buzz-agent",
+        provider: "anthropic",
+        model: "claude-opus-4-5",
+        env_vars: {},
+      },
+    });
+    await openCreateDialog(page);
+
+    const defaults = page.getByTestId("agent-ai-defaults-notice");
+    await expect(defaults).toContainText("Global defaults not set");
+    await expect(defaults.getByRole("button", { name: "Set" })).toBeVisible();
+    await expect(defaults.getByText("Harness", { exact: true })).toHaveCount(0);
+    await expect(defaults.getByText("Provider", { exact: true })).toHaveCount(
+      0,
+    );
+    await expect(defaults.getByText("Model", { exact: true })).toHaveCount(0);
+    await expect(page.getByTestId("persona-dialog-submit")).toBeDisabled();
+  });
+
+  test("create exposes setup guidance when no harness is available", async ({
+    page,
+  }) => {
+    await installMockBridge(page, {
+      acpRuntimesCatalog: CATALOG_NONE_AVAILABLE,
+    });
+    await openCreateDialog(page);
+
+    const customSection = page.getByTestId(
+      "agent-custom-configuration-section",
+    );
+    const harness = customSection.locator("#persona-runtime");
+    await expect(harness).toBeVisible();
+    await expect(harness).toContainText("Choose a harness");
+
+    await selectDropdownOption(page, harness, "Buzz Agent (not installed)");
+    await expect(
+      customSection
+        .locator("p")
+        .filter({ hasText: "Buzz Agent is not installed." }),
+    ).toContainText(
+      "Buzz Agent is not installed. Visit Settings > Agents to set it up.",
+    );
+    await expect(page.getByTestId("persona-dialog-submit")).toBeDisabled();
+  });
+
+  test("create with a missing name has no footer message", async ({ page }) => {
+    await installMockBridge(page);
+
+    await page.goto("/");
+    await page.getByTestId("open-agents-view").click();
+    await page.getByTestId("new-agent-card").click();
+    await page.getByRole("menuitem", { name: "Create from scratch" }).click();
+
+    await expect(page.getByTestId("persona-dialog-submit")).toBeDisabled({
+      timeout: 10_000,
+    });
+    await expect(page.getByTestId("persona-dialog-submit-reason")).toHaveCount(
+      0,
+    );
+  });
+
  // Shot 05: Create gate ENABLED — global provider = anthropic provides a
  // default, so the empty per-agent provider is resolved → submit enabled.
  test("05-create-enabled-with-global-provider", async ({ page }) => {
@@ -419,6 +735,20 @@ test.describe("global agent config screenshots", () => {

    await openCreateDialog(page);

+    const defaultsSection = page.getByTestId(
+      "agent-defaults-configuration-section",
+    );
+    await expect(defaultsSection.locator("#persona-runtime")).toHaveCount(0);
+    await expect(
+      defaultsSection.getByTestId("agent-ai-defaults-notice"),
+    ).toBeVisible();
+    await expect(
+      defaultsSection.getByText("Harness", { exact: true }),
+    ).toBeVisible();
+    await expect(
+      defaultsSection.getByText("Buzz Agent", { exact: true }),
+    ).toBeVisible();
+
    // Global provider satisfies the provider-default rule → submit enabled.
    await expect(page.getByTestId("persona-dialog-submit")).toBeEnabled({
      timeout: 10_000,
@@ -449,12 +779,14 @@ test.describe("global agent config screenshots", () => {

    await openCreateDialog(page);

-    // Switch the auto-selected buzz-agent runtime to the CLI-login runtime.
+    // Harness selection belongs to the per-agent customization flow.
+    await customizeAgentAi(page);
    await selectDropdownOption(
      page,
      page.locator("#persona-runtime"),
      "Claude Code",
    );
+    await page.getByRole("tab", { name: "Use harness defaults" }).click();

    // Provider picker hidden — the runtime drives its own provider.
    await expect(page.locator("#persona-llm-provider")).not.toBeVisible();
@@ -636,12 +968,10 @@ test.describe("global agent config screenshots", () => {
    await expect(page.getByTestId("persona-dialog-submit")).toBeDisabled({
      timeout: 10_000,
    });
-    // … and the reason must be the Customize-pair provider gate, not the
-    // global-defaults gate (which would say "Settings → AI defaults").
-    const reason = page.getByTestId("persona-dialog-submit-reason");
-    await expect(reason).toBeVisible({ timeout: 10_000 });
-    await expect(reason).toContainText("Select a provider");
-    await expect(reason).not.toContainText("Settings → AI defaults");
+    // Disabled-state guidance belongs with the fields, not in the modal footer.
+    await expect(page.getByTestId("persona-dialog-submit-reason")).toHaveCount(
+      0,
+    );

    await waitForAnimations(page);

@@ -397,6 +397,15 @@ type MockBridgeOptions = {
    model: string | null;
    preferred_runtime?: string | null;
  };
+  /** File-layer config returned by runtime id. */
+  runtimeFileConfigs?: Record<
+    string,
+    {
+      provider: string | null;
+      model: string | null;
+      satisfiedEnvKeys: string[];
+    } | null
+  >;
  bakedBuildEnv?: Array<{
    key: string;
    masked: boolean;