fix: drop obsolete pi-mono workarounds

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

@@ -4,8 +4,6 @@ import type { SessionManager } from "@mariozechner/pi-coding-agent";
 
 import { registerUnhandledRejectionHandler } from "../../infra/unhandled-rejections.js";
 import {
-  downgradeGeminiThinkingBlocks,
-  downgradeGeminiHistory,
   isCompactionFailureError,
   isGoogleModelApi,
   sanitizeGoogleTurnOrdering,
@@ -52,42 +50,6 @@ function shouldSanitizeToolCallIds(modelApi?: string | null): boolean {
   return isGoogleModelApi(modelApi) || OPENAI_TOOL_CALL_ID_APIS.has(modelApi);
 }
 
-function filterOpenAIReasoningOnlyMessages(
-  messages: AgentMessage[],
-  modelApi?: string | null,
-): AgentMessage[] {
-  if (modelApi !== "openai-responses") return messages;
-  return messages.filter((msg) => {
-    if (!msg || typeof msg !== "object") return true;
-    if ((msg as { role?: unknown }).role !== "assistant") return true;
-    const assistant = msg as Extract<AgentMessage, { role: "assistant" }>;
-    const content = assistant.content;
-    if (!Array.isArray(content) || content.length === 0) return true;
-    let hasThinking = false;
-    let hasPairedContent = false;
-    for (const block of content) {
-      if (!block || typeof block !== "object") continue;
-      const type = (block as { type?: unknown }).type;
-      if (type === "thinking") {
-        hasThinking = true;
-        continue;
-      }
-      if (type === "toolCall" || type === "toolUse" || type === "functionCall") {
-        hasPairedContent = true;
-        break;
-      }
-      if (type === "text") {
-        const text = (block as { text?: unknown }).text;
-        if (typeof text === "string" && text.trim().length > 0) {
-          hasPairedContent = true;
-          break;
-        }
-      }
-    }
-    return !(hasThinking && !hasPairedContent);
-  });
-}
-
 function findUnsupportedSchemaKeywords(schema: unknown, path: string): string[] {
   if (!schema || typeof schema !== "object") return [];
   if (Array.isArray(schema)) {
@@ -233,7 +195,6 @@ export async function sanitizeSessionHistory(params: {
   const modelId = (params.modelId ?? "").toLowerCase();
   const isOpenRouterGemini =
     (provider === "openrouter" || provider === "opencode") && modelId.includes("gemini");
-  const isGeminiLike = isGoogleModelApi(params.modelApi) || isOpenRouterGemini;
   const sanitizedImages = await sanitizeSessionMessagesImages(params.messages, "session:history", {
     sanitizeToolCallIds: shouldSanitizeToolCallIds(params.modelApi),
     enforceToolCallLast: params.modelApi === "anthropic-messages",
@@ -242,26 +203,10 @@ export async function sanitizeSessionHistory(params: {
       ? { allowBase64Only: true, includeCamelCase: true }
       : undefined,
   });
-  // TODO REMOVE when https://github.com/badlogic/pi-mono/pull/838 is merged.
-  const openaiReasoningFiltered = filterOpenAIReasoningOnlyMessages(
-    sanitizedImages,
-    params.modelApi,
-  );
-  const repairedTools = sanitizeToolUseResultPairing(openaiReasoningFiltered);
-  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 = shouldDowngradeThinking
-    ? downgradeGeminiThinkingBlocks(repairedTools)
-    : repairedTools;
-  const shouldDowngradeHistory = shouldDowngradeThinking && !isAntigravityProvider;
-  const downgraded = shouldDowngradeHistory
-    ? downgradeGeminiHistory(downgradedThinking)
-    : downgradedThinking;
+  const repairedTools = sanitizeToolUseResultPairing(sanitizedImages);
 
   return applyGoogleTurnOrderingFix({
-    messages: downgraded,
+    messages: repairedTools,
     modelApi: params.modelApi,
     sessionManager: params.sessionManager,
     sessionId: params.sessionId,

src/agents/pi-embedded-runner/run/attempt.test.ts

@@ -36,11 +36,11 @@ describe("injectHistoryImagesIntoMessages", () => {
     const didMutate = injectHistoryImagesIntoMessages(messages, new Map([[0, [image]]]));
 
     expect(didMutate).toBe(false);
-    const content = messages[0]?.content;
-    if (!Array.isArray(content)) {
+    const first = messages[0];
+    if (!first || !Array.isArray(first.content)) {
       throw new Error("expected array content");
     }
-    expect(content).toHaveLength(2);
+    expect(first.content).toHaveLength(2);
   });
 
   it("ignores non-user messages and out-of-range indices", () => {