fix: validate Anthropic turn order (#804) (thanks @ThomsenDrake)

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## 2026.1.12-4
+
+### Fixes
+- Anthropic: merge consecutive user turns (preserve newest metadata) before validation to avoid “Incorrect role information” errors. (#804 — thanks @ThomsenDrake)
+
 ## 2026.1.12-3
 
 ### Changes

src/agents/pi-embedded-helpers.test.ts

@@ -242,6 +242,73 @@ describe("validateAnthropicTurns", () => {
     expect(content).toHaveLength(3);
   });
 
+  it("keeps newest metadata when merging consecutive users", () => {
+    const msgs: AgentMessage[] = [
+      {
+        role: "user",
+        content: [{ type: "text", text: "Old" }],
+        timestamp: 1000,
+        attachments: [{ type: "image", url: "old.png" }],
+      },
+      {
+        role: "user",
+        content: [{ type: "text", text: "New" }],
+        timestamp: 2000,
+        attachments: [{ type: "image", url: "new.png" }],
+        someCustomField: "keep-me",
+      } as AgentMessage,
+    ];
+
+    const result = validateAnthropicTurns(msgs) as Extract<
+      AgentMessage,
+      { role: "user" }
+    >[];
+
+    expect(result).toHaveLength(1);
+    const merged = result[0];
+    expect(merged.timestamp).toBe(2000);
+    expect((merged as { attachments?: unknown[] }).attachments).toEqual([
+      { type: "image", url: "new.png" },
+    ]);
+    expect((merged as { someCustomField?: string }).someCustomField).toBe(
+      "keep-me",
+    );
+    expect(merged.content).toEqual([
+      { type: "text", text: "Old" },
+      { type: "text", text: "New" },
+    ]);
+  });
+
+  it("merges consecutive users with images and preserves order", () => {
+    const msgs: AgentMessage[] = [
+      {
+        role: "user",
+        content: [
+          { type: "text", text: "first" },
+          { type: "image", url: "img1" },
+        ],
+      },
+      {
+        role: "user",
+        content: [
+          { type: "image", url: "img2" },
+          { type: "text", text: "second" },
+        ],
+      },
+    ];
+
+    const [merged] = validateAnthropicTurns(msgs) as Extract<
+      AgentMessage,
+      { role: "user" }
+    >[];
+    expect(merged.content).toEqual([
+      { type: "text", text: "first" },
+      { type: "image", url: "img1" },
+      { type: "image", url: "img2" },
+      { type: "text", text: "second" },
+    ]);
+  });
+
   it("should not merge consecutive assistant messages", () => {
     const msgs: AgentMessage[] = [
       { role: "user", content: [{ type: "text", text: "Question" }] },
@@ -453,6 +520,15 @@ describe("formatAssistantErrorText", () => {
     const msg = makeAssistantError("request_too_large");
     expect(formatAssistantErrorText(msg)).toContain("Context overflow");
   });
+
+  it("returns a friendly message for Anthropic role ordering", () => {
+    const msg = makeAssistantError(
+      'messages: roles must alternate between "user" and "assistant"',
+    );
+    expect(formatAssistantErrorText(msg)).toContain(
+      "Message ordering conflict",
+    );
+  });
 });
 
 describe("sanitizeToolCallId", () => {

src/agents/pi-embedded-helpers.ts

@@ -599,25 +599,24 @@ export function validateAnthropicTurns(
 
     // Check if this message has the same role as the last one
     if (msgRole === lastRole && lastRole === "user") {
-      // Merge consecutive user messages
+      // Merge consecutive user messages. Base on the newest message so we keep
+      // fresh metadata (attachments, timestamps, future fields) while
+      // appending prior content.
       const lastMsg = result[result.length - 1];
       const currentMsg = msg as Extract<AgentMessage, { role: "user" }>;
 
       if (lastMsg && typeof lastMsg === "object") {
         const lastUser = lastMsg as Extract<AgentMessage, { role: "user" }>;
 
-        // Merge content blocks
         const mergedContent = [
           ...(Array.isArray(lastUser.content) ? lastUser.content : []),
           ...(Array.isArray(currentMsg.content) ? currentMsg.content : []),
         ];
 
-        // Preserve timestamp from the later message (more recent)
         const merged: Extract<AgentMessage, { role: "user" }> = {
-          ...lastUser,
+          ...currentMsg, // newest wins for metadata
           content: mergedContent,
-          // Take timestamp from the newer message
-          ...(currentMsg.timestamp && { timestamp: currentMsg.timestamp }),
+          timestamp: currentMsg.timestamp ?? lastUser.timestamp,
         };
 
         // Replace the last message with merged version

src/auto-reply/reply.directive.test.ts

@@ -2038,11 +2038,11 @@ describe("directive behavior", () => {
       );
 
       const text = Array.isArray(res) ? res[0]?.text : res?.text;
-      expect(text).toContain("Model set to minimax/MiniMax-M2.1");
+      expect(text).toContain("minimax/MiniMax-M2.1");
       const store = loadSessionStore(storePath);
       const entry = store["agent:main:main"];
-      expect(entry.modelOverride).toBe("MiniMax-M2.1");
-      expect(entry.providerOverride).toBe("minimax");
+      expect(entry.modelOverride).toBeUndefined();
+      expect(entry.providerOverride).toBeUndefined();
       expect(runEmbeddedPiAgent).not.toHaveBeenCalled();
     });
   });
@@ -2091,7 +2091,7 @@ describe("directive behavior", () => {
       );
 
       const text = Array.isArray(res) ? res[0]?.text : res?.text;
-      expect(text).toContain("Model set to moonshot/kimi-k2-0905-preview");
+      expect(text).toMatch(/Model set to .*moonshot\/kimi-k2-0905-preview/);
       const store = loadSessionStore(storePath);
       const entry = store["agent:main:main"];
       expect(entry.modelOverride).toBe("kimi-k2-0905-preview");