Add Pi as a curated agent harness provider

src/features/chat/ui/AgentModelPicker.tsx

@@ -80,6 +80,13 @@ type PopoverContentAlign = NonNullable<
 >;
 const REASONING_EFFORT_COLUMN_TRANSITION_MS = 240;
 const PICKER_WIDTH_COMPACT_PX = 420;
+// Harness agents (pi-acp, codex-acp, etc.) can report long ACP model names
+// (e.g. provider/id names), so they get wider pickers than Goose, whose
+// curated model names are short. With a reasoning-effort column present,
+// the agent (11.75rem) + reasoning (11rem) columns alone consume ~23rem,
+// so the picker needs extra width for the model column to breathe.
+const PICKER_WIDTH_HARNESS_PX = 560;
+const PICKER_WIDTH_HARNESS_EXPANDED_PX = 736;
 const PICKER_WIDTH_EXPANDED_PX = 596;
 
 function toSentenceCaseLabel(value: string | undefined): string {
@@ -395,10 +402,19 @@ export function AgentModelPicker({
     !modelBrowsing &&
     (agents.length > 1 || hasAgentNeedingSetup);
   const showReasoningEffortColumn = showReasoningEffort;
+  // Harness agents get wider pickers (and flexible model columns) whenever
+  // their agent column is visible, with or without a reasoning-effort
+  // column, so long ACP model names are not truncated. Goose is excluded
+  // because its curated model names are short.
+  const widenForHarnessAgent = showAgentColumn && selectedAgentId !== "goose";
   const isWidePicker = showReasoningEffortColumn && showAgentColumn;
   const pickerWidth = isWidePicker
-    ? PICKER_WIDTH_EXPANDED_PX
-    : PICKER_WIDTH_COMPACT_PX;
+    ? widenForHarnessAgent
+      ? PICKER_WIDTH_HARNESS_EXPANDED_PX
+      : PICKER_WIDTH_EXPANDED_PX
+    : widenForHarnessAgent
+      ? PICKER_WIDTH_HARNESS_PX
+      : PICKER_WIDTH_COMPACT_PX;
 
   // Land keyboard focus in the revealed column, since the reveal button that
   // held focus unmounts with it.
@@ -500,7 +516,13 @@ export function AgentModelPicker({
           // gated single-column layout has no dead vertical space below the
           // model list.
           "flex max-h-[min(24rem,50vh)] flex-col overflow-hidden p-1 transition-[width] duration-[240ms] ease-[cubic-bezier(0.2,0,0,1)]",
-          isWidePicker ? "w-[37.25rem]" : "w-[26.25rem]",
+          isWidePicker
+            ? widenForHarnessAgent
+              ? "w-[46rem]"
+              : "w-[37.25rem]"
+            : widenForHarnessAgent
+              ? "w-[35rem]"
+              : "w-[26.25rem]",
         )}
         onInteractOutside={(event) => {
           classifyOutsideInteraction(event.target);
@@ -672,7 +694,11 @@ export function AgentModelPicker({
               data-col="model"
               className={cn(
                 "flex min-h-0 min-w-0 overflow-hidden p-1",
-                showAgentColumn ? "ml-1 w-56 shrink-0" : "flex-1",
+                showAgentColumn
+                  ? widenForHarnessAgent
+                    ? "ml-1 flex-1"
+                    : "ml-1 w-56 shrink-0"
+                  : "flex-1",
               )}
             >
               {modelsLoading ? (

src/features/chat/ui/AgentModelPickerLists.tsx

@@ -399,7 +399,10 @@ export const RecommendedModelList = forwardRef<
                         {providerIcon}
                       </span>
                     ) : null}
-                    <div className="min-w-0 flex-1 truncate">
+                    <div
+                      className="min-w-0 flex-1 truncate"
+                      title={getModelDisplayName(model)}
+                    >
                       {getModelDisplayName(model)}
                     </div>
                   </div>

src/features/chat/ui/__tests__/AgentModelPicker.test.tsx

@@ -52,6 +52,67 @@ describe("AgentModelPicker", () => {
     ).toHaveTextContent("GPT-4o");
   });
 
+  // Harness agents (pi-acp, codex-acp, etc.) get a wider picker in the
+  // new-chat composer because their ACP model names can be long; Goose keeps
+  // the compact layout.
+  it("widens the new-chat picker for a harness agent without reasoning effort", async () => {
+    const user = userEvent.setup();
+    render(
+      <AgentModelPicker
+        agents={AGENTS}
+        selectedAgentId="claude-acp"
+        onAgentChange={vi.fn()}
+        currentModelId="claude-sonnet-4"
+        currentModelName="Claude Sonnet 4"
+        availableModels={[{ id: "claude-sonnet-4", name: "Claude Sonnet 4" }]}
+        onModelChange={vi.fn()}
+      />,
+    );
+
+    await user.click(
+      screen.getByRole("button", { name: /choose agent and model/i }),
+    );
+
+    expect(screen.getByRole("dialog")).toHaveClass("w-[35rem]");
+  });
+
+  // With a reasoning-effort column present the harness picker grows further,
+  // because the agent (11.75rem) and reasoning (11rem) columns alone consume
+  // most of the Goose expanded width and the model column needs room for
+  // long ACP names (e.g. "databricks / databricks-glm-5-3").
+  it("widens the expanded picker for a harness agent with reasoning effort", async () => {
+    const user = userEvent.setup();
+    render(
+      <AgentModelPicker
+        agents={AGENTS}
+        selectedAgentId="claude-acp"
+        onAgentChange={vi.fn()}
+        currentModelId="claude-sonnet-4"
+        currentModelName="Claude Sonnet 4"
+        availableModels={[{ id: "claude-sonnet-4", name: "Claude Sonnet 4" }]}
+        onModelChange={vi.fn()}
+        reasoningEffort={{
+          config: {
+            configId: "thinking_effort",
+            currentValue: "medium",
+            options: [
+              { id: "low", name: "low" },
+              { id: "medium", name: "medium" },
+              { id: "high", name: "high" },
+            ],
+          },
+          onChange: vi.fn(),
+        }}
+      />,
+    );
+
+    await user.click(
+      screen.getByRole("button", { name: /choose agent and model/i }),
+    );
+
+    expect(screen.getByRole("dialog")).toHaveClass("w-[46rem]");
+  });
+
   it("routes not-ready Goose to Providers settings with a connect action", async () => {
     const user = userEvent.setup();
     const onAgentChange = vi.fn();
@@ -1418,6 +1479,35 @@ describe("AgentModelPicker", () => {
       expect(content).toHaveClass("w-[37.25rem]");
     });
 
+    // Without a reasoning-effort column the gated reveal widens to the
+    // harness width so long model names (e.g. pi-acp provider/id names) are
+    // not truncated. Goose is excluded, so use a harness agent here.
+    it("widens to the harness width when no reasoning-effort column is present", async () => {
+      const user = userEvent.setup();
+
+      render(
+        <AgentModelPicker
+          agents={AGENTS}
+          selectedAgentId="claude-acp"
+          onAgentChange={vi.fn()}
+          currentModelId="claude-sonnet-4"
+          currentModelName="Claude Sonnet 4"
+          availableModels={[{ id: "claude-sonnet-4", name: "Claude Sonnet 4" }]}
+          onModelChange={vi.fn()}
+          providerColumnMode="gated"
+        />,
+      );
+
+      await openPicker(user);
+
+      const content = document.querySelector('[data-slot="popover-content"]');
+      expect(content).toHaveClass("w-[26.25rem]");
+
+      await user.click(screen.getByRole("button", { name: /switch agent/i }));
+
+      expect(content).toHaveClass("w-[35rem]");
+    });
+
     it("hides the switch-agent button when the only agent is ready", async () => {
       const user = userEvent.setup();
       renderGated({ agents: [{ id: "goose", label: "Goose" }] });

src/features/providers/curatedProviders.ts

@@ -80,22 +80,19 @@ export const CURATED_PROVIDER_CATALOG: ProviderCatalogEntry[] = [
     supportsAuth: true,
     supportsAuthStatus: true,
   },
-  // full pi support in a future update
-  // {
-  //   id: "pi-acp",
-  //   displayName: "Pi",
-  //   category: "agent",
-  //   description: "Pi ACP agent",
-  //   setupMethod: "cli_auth",
-  //   binaryName: "pi-acp",
-  //   group: "default",
-  //   aliases: ["pi-acp", "pi"],
-  //   supportsInstall: false,
-  //   supportsAuth: false,
-  //   supportsAuthStatus: false,
-  //   supportsModelList: false,
-  //   modelSelectionHint: "Use the Pi CLI to configure the model.",
-  // },
+  {
+    id: "pi-acp",
+    displayName: "Pi",
+    category: "agent",
+    description: "Pi coding agent",
+    setupMethod: "cli_auth",
+    binaryName: "pi-acp",
+    group: "default",
+    aliases: ["pi-acp", "pi"],
+    supportsInstall: false,
+    supportsAuth: false,
+    supportsAuthStatus: false,
+  },
   {
     id: "databricks_v2",
     displayName: "Databricks AI Gateway",

src/features/providers/hooks/useProviderModels.test.tsx

@@ -127,6 +127,7 @@ describe("useProviderModels", () => {
       "codex-acp",
       "copilot-acp",
       "cursor-agent",
+      "pi-acp",
     ]);
 
     act(() => {
@@ -151,6 +152,7 @@ describe("useProviderModels", () => {
       "codex-acp",
       "copilot-acp",
       "cursor-agent",
+      "pi-acp",
     ]);
 
     act(() => {

src/features/providers/providerCatalog.test.ts

@@ -78,6 +78,7 @@ describe("provider catalog selectors", () => {
       "copilot-acp",
       "amp-acp",
       "cursor-agent",
+      "pi-acp",
     ]);
     expect(getModelProviders().map((provider) => provider.id)).toEqual([
       "databricks_v2",

src/shared/api/__tests__/acp.test.ts

@@ -1094,6 +1094,7 @@ describe("acpCreateSession", () => {
     "copilot-acp",
     "amp-acp",
     "cursor-agent",
+    "pi-acp",
   ])("keeps the %s harness outside Goose provider policy", async (harnessId) => {
     await setRuntimeConfig(managedRuntimeConfig);
     mockNewSession.mockResolvedValue({ sessionId: `session-${harnessId}` });

src/shared/ui/icons/ProviderIcons.tsx

@@ -420,6 +420,27 @@ export function CopilotIcon({ className = "" }: { className?: string }) {
   );
 }
 
+export function PiIcon({ className = "" }: { className?: string }) {
+  return (
+    <svg
+      width="24"
+      height="24"
+      viewBox="0 0 800 800"
+      xmlns="http://www.w3.org/2000/svg"
+      className={className}
+      aria-hidden="true"
+    >
+      <title>Pi</title>
+      <path
+        fill="currentColor"
+        fillRule="evenodd"
+        d="M165.29 165.29H517.36V400H400V517.36H282.65V634.72H165.29ZM282.65 282.65V400H400V282.65Z"
+      />
+      <path fill="currentColor" d="M517.36 400H634.72V634.72H517.36Z" />
+    </svg>
+  );
+}
+
 const PROVIDER_ICON_MAP: Record<string, (className: string) => ReactNode> = {
   goose: (className) => (
     <GooseIcon className={`${className} text-foreground`} />
@@ -451,6 +472,8 @@ const PROVIDER_ICON_MAP: Record<string, (className: string) => ReactNode> = {
   snowflake: (className) => <SnowflakeIcon className={className} />,
   xai: (className) => <XAIIcon className={className} />,
   lmstudio: (className) => <OllamaIcon className={className} />,
+  "pi-acp": (className) => <PiIcon className={className} />,
+  pi: (className) => <PiIcon className={className} />,
 };
 
 function normalizeProviderId(providerId: string) {