From 19cd24c07aa1ee547fb71cd9a70d331ef0bbae65 Mon Sep 17 00:00:00 2001
From: Leivur Djurhuus <leivur7@msn.com>
Date: Thu, 12 Mar 2026 15:29:20 -0500
Subject: [PATCH] fix: Send plain text history to prevent orphaned tool_use
 block errors
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Claude's API requires every tool_use block to be followed by a matching
tool_result. Since tool interactions are fully resolved server-side within
a single request, the client should only send plain text in conversation
history — never structured content blocks that contain tool_use references.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 src/hooks/use-chat.ts | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/hooks/use-chat.ts b/src/hooks/use-chat.ts
index d92fce9..876c434 100644
--- a/src/hooks/use-chat.ts
+++ b/src/hooks/use-chat.ts
@@ -26,8 +26,6 @@ export interface ChatMessage {
   isLoading?: boolean;
   /** Tool calls in progress or completed during this assistant turn */
   toolCalls?: ToolStatus[];
-  /** Structured content blocks for multi-turn context (sent to API) */
-  contentBlocks?: any[];
   /** Clickable entity suggestions for disambiguation */
   suggestions?: EntitySuggestion[];
 }
@@ -115,10 +113,12 @@ export function useChat(context?: ChatContext) {
       setIsLoading(true);
 
       try {
-        // Build message history for the API, preserving structured content blocks
+        // Build message history for the API — send plain text only.
+        // Tool interactions are resolved server-side within a single request,
+        // so we never send tool_use/tool_result blocks back in history.
         const apiMessages = [...messages, userMsg].map((m) => ({
           role: m.role,
-          content: m.contentBlocks || m.content,
+          content: m.content,
         }));
 
         abortRef.current = new AbortController();
@@ -194,10 +194,6 @@ export function useChat(context?: ChatContext) {
                         provider: data.provider,
                         isLoading: false,
                         suggestions: data.suggestions,
-                        // Store structured blocks for multi-turn context
-                        contentBlocks: data.content
-                          ? [{ type: "text", text: data.content }]
-                          : undefined,
                       }
                     : m
                 )