fix: sanitize tool-call inputs to prevent LiteLLM invalid dict error (#2890)

src/__tests__/ai_messages_utils.test.ts

@@ -267,6 +267,93 @@ describe("parseAiMessagesJson", () => {
       expect(part.providerOptions).toBeUndefined();
     });
 
+    it("should sanitize tool-call with empty string input to empty object", () => {
+      const msg: DbMessageForParsing = {
+        id: 30,
+        role: "assistant",
+        content: "fallback",
+        aiMessagesJson: {
+          sdkVersion: AI_MESSAGES_SDK_VERSION,
+          messages: [
+            {
+              role: "assistant",
+              content: [
+                {
+                  type: "tool-call",
+                  toolCallId: "call-456",
+                  toolName: "execute_sql",
+                  input: "",
+                },
+              ],
+            },
+          ] as ModelMessage[],
+        },
+      };
+
+      const result = parseAiMessagesJson(msg);
+      const part = (result[0].content as any[])[0];
+      expect(part.toolCallId).toBe("call-456");
+      expect(part.input).toEqual({});
+    });
+
+    it("should sanitize tool-call with null input to empty object", () => {
+      const msg: DbMessageForParsing = {
+        id: 31,
+        role: "assistant",
+        content: "fallback",
+        aiMessagesJson: {
+          sdkVersion: AI_MESSAGES_SDK_VERSION,
+          messages: [
+            {
+              role: "assistant",
+              content: [
+                {
+                  type: "tool-call",
+                  toolCallId: "call-789",
+                  toolName: "read_file",
+                  input: null,
+                },
+              ],
+            },
+          ] as ModelMessage[],
+        },
+      };
+
+      const result = parseAiMessagesJson(msg);
+      const part = (result[0].content as any[])[0];
+      expect(part.toolCallId).toBe("call-789");
+      expect(part.input).toEqual({});
+    });
+
+    it("should preserve valid tool-call input objects", () => {
+      const msg: DbMessageForParsing = {
+        id: 32,
+        role: "assistant",
+        content: "fallback",
+        aiMessagesJson: {
+          sdkVersion: AI_MESSAGES_SDK_VERSION,
+          messages: [
+            {
+              role: "assistant",
+              content: [
+                {
+                  type: "tool-call",
+                  toolCallId: "call-valid",
+                  toolName: "read_file",
+                  input: { path: "/test" },
+                },
+              ],
+            },
+          ] as ModelMessage[],
+        },
+      };
+
+      const result = parseAiMessagesJson(msg);
+      const part = (result[0].content as any[])[0];
+      expect(part.toolCallId).toBe("call-valid");
+      expect(part.input).toEqual({ path: "/test" });
+    });
+
     it("should strip itemId from reasoning parts but preserve reasoningEncryptedContent when followed by output", () => {
       const msg: DbMessageForParsing = {
         id: 22,

src/ipc/utils/ai_messages_utils.ts

@@ -51,6 +51,7 @@ function stripItemIdFromPart(part: Record<string, unknown>): boolean {
  * Clean up a message's content parts for OpenAI compatibility:
  * 1. Strip itemId from provider metadata (prevents "Item with id not found" errors)
  * 2. Filter orphaned reasoning parts (prevents "reasoning without following item" errors)
+ * 3. Ensure tool-call input is always a valid object (prevents LiteLLM sending empty string as input when converting OpenAI→Anthropic format)
  *
  * When messages contain `providerMetadata.openai.itemId` values, the AI SDK converts
  * these to `item_reference` payloads. If OpenAI has expired those items, this causes
@@ -63,7 +64,7 @@ function stripItemIdFromPart(part: Record<string, unknown>): boolean {
  *
  * Returns the original message if no changes were needed, or a new message with cleaned content.
  */
-export function cleanMessageForOpenAI<T extends ModelMessage>(message: T): T {
+export function cleanMessage<T extends ModelMessage>(message: T): T {
   if (typeof message.content === "string" || !Array.isArray(message.content)) {
     return message;
   }
@@ -94,6 +95,16 @@ export function cleanMessageForOpenAI<T extends ModelMessage>(message: T): T {
       didModify = true;
     }
 
+    // Ensure tool-call input is always a valid object (prevents LiteLLM
+    // sending empty string as input when converting OpenAI→Anthropic format)
+    if (
+      part.type === "tool-call" &&
+      (!part.input || typeof part.input !== "object")
+    ) {
+      part.input = {};
+      didModify = true;
+    }
+
     cleanedContent.push(part);
   }
 
@@ -104,11 +115,8 @@ export function cleanMessageForOpenAI<T extends ModelMessage>(message: T): T {
   return { ...message, content: cleanedContent } as T;
 }
 
-/**
- * Clean all messages in an array for OpenAI compatibility.
- */
-function cleanMessagesForOpenAI(messages: ModelMessage[]): ModelMessage[] {
-  return messages.map(cleanMessageForOpenAI);
+function cleanMessages(messages: ModelMessage[]): ModelMessage[] {
+  return messages.map(cleanMessage);
 }
 
 /** Maximum size in bytes for ai_messages_json (10MB) */
@@ -163,7 +171,7 @@ export function parseAiMessagesJson(msg: DbMessageForParsing): ModelMessage[] {
       Array.isArray(parsed) &&
       parsed.every((m) => m && typeof m.role === "string")
     ) {
-      return cleanMessagesForOpenAI(parsed);
+      return cleanMessages(parsed);
     }
 
     if (
@@ -177,7 +185,7 @@ export function parseAiMessagesJson(msg: DbMessageForParsing): ModelMessage[] {
         (m: ModelMessage) => m && typeof m.role === "string",
       )
     ) {
-      return cleanMessagesForOpenAI((parsed as AiMessagesJsonV6).messages);
+      return cleanMessages((parsed as AiMessagesJsonV6).messages);
     }
   }
 

src/pro/main/ipc/handlers/local_agent/local_agent_handler.ts

@@ -1358,7 +1358,8 @@ function maybeCaptureRetryReplayEvent(
       type: "tool-call",
       toolCallId: part.toolCallId,
       toolName: part.toolName,
-      input: part.input,
+      input:
+        typeof part.input === "object" && part.input !== null ? part.input : {},
     });
     return;
   }

src/pro/main/ipc/handlers/local_agent/prepare_step_utils.ts

@@ -7,7 +7,7 @@
 
 import { ImagePart, ModelMessage, TextPart, UserModelMessage } from "ai";
 import type { UserMessageContentPart, Todo } from "./tools/types";
-import { cleanMessageForOpenAI } from "@/ipc/utils/ai_messages_utils";
+import { cleanMessage } from "@/ipc/utils/ai_messages_utils";
 
 /**
  * Check if a single todo is incomplete (pending or in_progress).
@@ -158,7 +158,7 @@ export function prepareStepMessages<
   // Clean messages for OpenAI compatibility during multi-step agent flows:
   // 1. Strip itemId to prevent "Item with id not found" errors
   // 2. Filter orphaned reasoning to prevent "reasoning without following item" errors
-  const filteredMessages = messages.map(cleanMessageForOpenAI);
+  const filteredMessages = messages.map(cleanMessage);
 
   // Check if we need to return modified options
   const hasInjections = allInjectedMessages.length > 0;