fix: exclude google-antigravity from history downgrade hack (#894)

* Agent: exclude google-antigravity from history downgrade hack

* Lint: fix formatting in test

* Lint: formatting and unused vars in test

* fix: preserve google-antigravity tool calls (#894) (thanks @mukhtharcm)

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Docs: clarify multi-gateway rescue bot guidance. (#969) — thanks @bjesuiter.
 - Agents: add Current Date & Time system prompt section with configurable time format (auto/12/24).
 - Agents: avoid false positives when logging unsupported Google tool schema keywords.
+- Agents: skip Gemini history downgrades for google-antigravity to preserve tool calls. (#894) — thanks @mukhtharcm.
 - Status: restore usage summary line for current provider when no OAuth profiles exist.
 - Tools: normalize Slack/Discord message timestamps with `timestampMs`/`timestampUtc` while keeping raw provider fields.
 - macOS: add `system.which` for prompt-free remote skill discovery (with gateway fallback to `system.run`).

src/agents/pi-embedded-runner.sanitize-session-history.test.ts

@@ -0,0 +1,109 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { SessionManager } from "@mariozechner/pi-coding-agent";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import * as helpers from "./pi-embedded-helpers.js";
+import { sanitizeSessionHistory } from "./pi-embedded-runner/google.js";
+
+// Mock dependencies
+vi.mock("./pi-embedded-helpers.js", async () => {
+  const actual = await vi.importActual("./pi-embedded-helpers.js");
+  return {
+    ...actual,
+    isGoogleModelApi: vi.fn(),
+    downgradeGeminiHistory: vi.fn(),
+    sanitizeSessionMessagesImages: vi
+      .fn()
+      .mockImplementation(async (msgs) => msgs),
+  };
+});
+
+// We don't mock session-transcript-repair.js as it is a pure function and complicates mocking.
+// We rely on the real implementation which should pass through our simple messages.
+
+describe("sanitizeSessionHistory", () => {
+  const mockSessionManager = {
+    getEntries: vi.fn().mockReturnValue([]),
+    appendCustomEntry: vi.fn(),
+  } as unknown as SessionManager;
+
+  const mockMessages: AgentMessage[] = [{ role: "user", content: "hello" }];
+
+  beforeEach(() => {
+    vi.resetAllMocks();
+    vi.mocked(helpers.sanitizeSessionMessagesImages).mockImplementation(
+      async (msgs) => msgs,
+    );
+    // Default mock implementation
+    vi.mocked(helpers.downgradeGeminiHistory).mockImplementation((msgs) => {
+      if (!msgs) return [];
+      return [...msgs, { role: "system", content: "downgraded" }];
+    });
+  });
+
+  it("should downgrade history for Google models if provider is not google-antigravity", async () => {
+    vi.mocked(helpers.isGoogleModelApi).mockReturnValue(true);
+
+    const result = await sanitizeSessionHistory({
+      messages: mockMessages,
+      modelApi: "google-gemini",
+      provider: "google-vertex",
+      sessionManager: mockSessionManager,
+      sessionId: "test-session",
+    });
+
+    expect(helpers.isGoogleModelApi).toHaveBeenCalledWith("google-gemini");
+    expect(helpers.downgradeGeminiHistory).toHaveBeenCalled();
+    // Check if the result contains the downgraded message
+    expect(result).toContainEqual({ role: "system", content: "downgraded" });
+  });
+
+  it("should NOT downgrade history for google-antigravity provider", async () => {
+    vi.mocked(helpers.isGoogleModelApi).mockReturnValue(true);
+
+    const result = await sanitizeSessionHistory({
+      messages: mockMessages,
+      modelApi: "google-gemini",
+      provider: "google-antigravity",
+      sessionManager: mockSessionManager,
+      sessionId: "test-session",
+    });
+
+    expect(helpers.isGoogleModelApi).toHaveBeenCalledWith("google-gemini");
+    expect(helpers.downgradeGeminiHistory).not.toHaveBeenCalled();
+    // Result should not contain the downgraded message
+    expect(result).not.toContainEqual({
+      role: "system",
+      content: "downgraded",
+    });
+  });
+
+  it("should NOT downgrade history for non-Google models", async () => {
+    vi.mocked(helpers.isGoogleModelApi).mockReturnValue(false);
+
+    const _result = await sanitizeSessionHistory({
+      messages: mockMessages,
+      modelApi: "anthropic-messages",
+      provider: "anthropic",
+      sessionManager: mockSessionManager,
+      sessionId: "test-session",
+    });
+
+    expect(helpers.isGoogleModelApi).toHaveBeenCalledWith("anthropic-messages");
+    expect(helpers.downgradeGeminiHistory).not.toHaveBeenCalled();
+  });
+
+  it("should downgrade history if provider is undefined but model is Google", async () => {
+    vi.mocked(helpers.isGoogleModelApi).mockReturnValue(true);
+
+    const _result = await sanitizeSessionHistory({
+      messages: mockMessages,
+      modelApi: "google-gemini",
+      provider: undefined,
+      sessionManager: mockSessionManager,
+      sessionId: "test-session",
+    });
+
+    expect(helpers.isGoogleModelApi).toHaveBeenCalledWith("google-gemini");
+    expect(helpers.downgradeGeminiHistory).toHaveBeenCalled();
+  });
+});

src/agents/pi-embedded-runner/google.ts

@@ -204,12 +204,15 @@ export async function sanitizeSessionHistory(params: {
       : undefined,
   });
   const repairedTools = sanitizeToolUseResultPairing(sanitizedImages);
-  const shouldDowngradeGemini = isGeminiLike && !isAntigravityClaudeModel;
+  const isAntigravityProvider =
+    provider === "google-antigravity" || params.modelApi === "google-antigravity";
+  const shouldDowngradeThinking = isGeminiLike && !isAntigravityClaudeModel;
   // Gemini rejects unsigned thinking blocks; downgrade them before send to avoid INVALID_ARGUMENT.
-  const downgradedThinking = shouldDowngradeGemini
+  const downgradedThinking = shouldDowngradeThinking
     ? downgradeGeminiThinkingBlocks(repairedTools)
     : repairedTools;
-  const downgraded = shouldDowngradeGemini
+  const shouldDowngradeHistory = shouldDowngradeThinking && !isAntigravityProvider;
+  const downgraded = shouldDowngradeHistory
     ? downgradeGeminiHistory(downgradedThinking)
     : downgradedThinking;