feat(server): replace Pi ACP with direct SDK provider

nix/package.nix

@@ -42,7 +42,7 @@ buildNpmPackage rec {
 
   # To update: run `nix build` with lib.fakeHash, copy the `got:` hash.
   # CI auto-updates this when package-lock.json changes (see .github/workflows/).
-  npmDepsHash = "sha256-epuepM6DMEpOfzvPiS6K/qKJqGM89FqdsKHovWi2LS8=";
+  npmDepsHash = "sha256-Nk6DAnDkXd8KSCmnIDcRoM8V6rHR874PBOovuZFxbfY=";
 
   # Prevent onnxruntime-node's install script from running during automatic
   # npm rebuild (it tries to download from api.nuget.org, which fails in the sandbox).

packages/server/package.json

@@ -68,6 +68,7 @@
     "@getpaseo/relay": "0.1.48",
     "@isaacs/ttlcache": "^2.1.4",
     "@modelcontextprotocol/sdk": "^1.20.1",
+    "@mariozechner/pi-coding-agent": "^0.65.2",
     "@opencode-ai/sdk": "1.2.6",
     "@sctg/sentencepiece-js": "^1.1.0",
     "@xterm/headless": "^6.0.0",
@@ -81,7 +82,6 @@
     "node-pty": "1.2.0-beta.11",
     "onnxruntime-node": "^1.23.0",
     "openai": "^4.20.0",
-    "pi-acp": "^0.0.24",
     "pino": "^10.2.0",
     "pino-pretty": "^13.1.3",
     "qrcode": "^1.5.4",

packages/server/src/server/agent/provider-registry.ts

@@ -13,7 +13,7 @@ import { ClaudeAgentClient } from "./providers/claude-agent.js";
 import { CodexAppServerAgentClient } from "./providers/codex-app-server-agent.js";
 import { OpenCodeAgentClient, OpenCodeServerManager } from "./providers/opencode-agent.js";
 import { CopilotACPAgentClient } from "./providers/copilot-acp-agent.js";
-import { PiACPAgentClient } from "./providers/pi-acp-agent.js";
+import { PiDirectAgentClient } from "./providers/pi-direct-agent.js";
 
 import {
   AGENT_PROVIDER_DEFINITIONS,
@@ -54,7 +54,8 @@ const PROVIDER_CLIENT_FACTORIES: Record<string, ProviderClientFactory> = {
     }),
   opencode: (logger, runtimeSettings) =>
     new OpenCodeAgentClient(logger, runtimeSettings?.opencode),
-  pi: (logger, runtimeSettings) => new PiACPAgentClient({ logger, runtimeSettings: runtimeSettings?.pi }),
+  pi: (logger, runtimeSettings) =>
+    new PiDirectAgentClient({ logger, runtimeSettings: runtimeSettings?.pi }),
 };
 
 function getProviderClientFactory(provider: string): ProviderClientFactory {

packages/server/src/server/agent/providers/acp-agent.test.ts

@@ -8,7 +8,8 @@ import {
   deriveModesFromACP,
   mapACPUsage,
 } from "./acp-agent.js";
-import { transformPiModels, transformPiSessionResponse, wrapPiSession } from "./pi-acp-agent.js";
+import { transformPiSessionResponse } from "./pi-acp-agent.js";
+import { transformPiModels } from "./pi-direct-agent.js";
 import { createTestLogger } from "../../../test-utils/test-logger.js";
 
 function createSession(): ACPAgentSession {
@@ -526,84 +527,6 @@ describe("ACPAgentSession", () => {
     ]);
   });
 
-  test("Pi session wrapper hides synthetic modes and exposes them as thinking", async () => {
-    const wrapped = wrapPiSession(
-      {
-        provider: "pi",
-        id: "session-1",
-        capabilities: {
-          supportsStreaming: true,
-          supportsSessionPersistence: true,
-          supportsDynamicModes: true,
-          supportsMcpServers: false,
-          supportsReasoningStream: true,
-          supportsToolInvocations: true,
-        },
-        features: [
-          {
-            type: "select",
-            id: "thought_level",
-            label: "Thinking",
-            value: "medium",
-            options: [
-              { id: "low", label: "Low" },
-              { id: "medium", label: "Medium" },
-            ],
-          },
-        ],
-        run: vi.fn(),
-        startTurn: vi.fn(),
-        subscribe: vi.fn(() => () => {}),
-        streamHistory: async function* () {},
-        getRuntimeInfo: vi.fn(async () => ({
-          provider: "pi",
-          sessionId: "session-1",
-          model: "gpt-4.1-mini",
-          thinkingOptionId: null,
-          modeId: "xhigh",
-        })),
-        getAvailableModes: vi.fn(async () => [
-          { id: "xhigh", label: "xhigh" },
-        ]),
-        getCurrentMode: vi.fn(async () => "xhigh"),
-        setMode: vi.fn(),
-        getPendingPermissions: vi.fn(() => []),
-        respondToPermission: vi.fn(),
-        describePersistence: vi.fn(() => null),
-        interrupt: vi.fn(),
-        close: vi.fn(),
-        setThinkingOption: vi.fn(),
-      },
-      {
-        provider: "pi",
-        cwd: "/tmp/paseo-acp-test",
-        thinkingOptionId: "medium",
-      },
-    );
-
-    await expect(wrapped.getAvailableModes()).resolves.toEqual([]);
-    await expect(wrapped.getCurrentMode()).resolves.toBeNull();
-    await expect(wrapped.getRuntimeInfo()).resolves.toEqual({
-      provider: "pi",
-      sessionId: "session-1",
-      model: "gpt-4.1-mini",
-      thinkingOptionId: "xhigh",
-      modeId: null,
-    });
-    expect(wrapped.features).toEqual([
-      {
-        type: "select",
-        id: "thought_level",
-        label: "Thinking",
-        value: "xhigh",
-        options: [
-          { id: "low", label: "Low" },
-          { id: "medium", label: "Medium" },
-        ],
-      },
-    ]);
-  });
-
   test("emits assistant and reasoning chunks as deltas while user chunks stay accumulated", async () => {
     const session = createSession();
     const events: Array<{ type: string; item?: { type: string; text?: string } }> = [];

packages/server/src/server/agent/providers/claude-agent.ts

@@ -728,7 +728,7 @@ class TimelineAssembler {
     runId: string | null,
     messageIdHint: string | null,
   ): AgentTimelineItem[] {
-    const event = message.event as Record<string, unknown>;
+    const event = message.event as unknown as Record<string, unknown>;
     const eventType = readTrimmedString(event.type);
     const streamEventMessageId = this.readMessageIdFromStreamEvent(event) ?? messageIdHint;
 
@@ -2002,7 +2002,14 @@ class ClaudeAgentSession implements AgentSession {
   private toSdkUserMessage(prompt: AgentPromptInput): SDKUserMessage {
     const content: Array<
       | { type: "text"; text: string }
-      | { type: "image"; source: { type: "base64"; media_type: string; data: string } }
+      | {
+          type: "image";
+          source: {
+            type: "base64";
+            media_type: "image/jpeg" | "image/png" | "image/gif" | "image/webp";
+            data: string;
+          };
+        }
     > = [];
     if (Array.isArray(prompt)) {
       for (const chunk of prompt) {
@@ -2013,7 +2020,7 @@ class ClaudeAgentSession implements AgentSession {
             type: "image",
             source: {
               type: "base64",
-              media_type: chunk.mimeType,
+              media_type: chunk.mimeType as "image/jpeg" | "image/png" | "image/gif" | "image/webp",
               data: chunk.data,
             },
           });