diff --git a/src/LLMOrbiter.js b/src/LLMOrbiter.js
index b293d8f..30610b9 100644
--- a/src/LLMOrbiter.js
+++ b/src/LLMOrbiter.js
@@ -221,12 +221,11 @@ class LLMOrbiter {
                 break;
             }
 
-            // Execute each tool call locally
+                  const pendingAppendedMessages = [];
             for (let callIdx = 0; callIdx < toolCalls.length; callIdx++) {
                 const callItem = toolCalls[callIdx];
-                const fnName = callItem.function?.name;
+                const fnName = callItem.function.name;
                 const invokeFn = toolMap.get(fnName);
-
                 let result;
                 let isError = false;
                 let errorMsg = null;
@@ -251,7 +250,11 @@ class LLMOrbiter {
                         call(onToolCall, { name: fnName, args });
 
                         try {
-                            result = await invokeFn(args, { signal: runSignal });
+                            result = await invokeFn(args, {
+                                signal: runSignal,
+                                messages,
+                                appendMessage: (msg) => pendingAppendedMessages.push(msg),
+                            });
                         } catch (err) {
                             // An abort must propagate, not be recorded as a tool error.
                             if (runSignal.aborted) throw ensureAbortError(runSignal.reason);
@@ -291,6 +294,12 @@ class LLMOrbiter {
                             errorMsg = typeof result.error === 'string' ? result.error : JSON.stringify(result.error);
                             call(onToolError, { name: fnName, error: errorMsg, args });
                         }
+
+                        if (result && typeof result === 'object' && Array.isArray(result.appendMessages)) {
+                            for (const msg of result.appendMessages) {
+                                pendingAppendedMessages.push(msg);
+                            }
+                        }
                     }
                 }
 
@@ -309,6 +318,12 @@ class LLMOrbiter {
             }
 
             if (hasDirectReturn) break;
+
+            if (pendingAppendedMessages.length > 0) {
+                for (const msg of pendingAppendedMessages) {
+                    messages.push(msg);
+                }
+            }
         }