Integrate OpenAI inside ToolChain conditional

The OpenAI conditionality was moved inside the ToolChain declaration to streamline and simplify the code. This simple restructuring ensures that the OpenAI API key and instance of OpenAI are only created if there are tool messages present.

Author: nyvyn

src/agents/GraphRunner.ts

@@ -62,28 +62,28 @@ export class GraphRunner extends RunnableChain<GraphRunnerInput, GraphRunnerOutp
         // Signals calling a new agent,
         logger(`Calling agent: ${node.name}`);
 
-        const converted: ChatCompletionMessageParam[] = state.messages.map((message) => {
-            const content = typeof message.content === "string" ? message.content : JSON.stringify(message.content);
-            if (message instanceof AIMessage) {
-                return {content, role: "assistant"};
-            } else if (message instanceof HumanMessage) {
-                return {content, role: "user"};
-            } else if (message instanceof SystemMessage) {
-                return {content, role: "system"};
-            } else if (message instanceof ToolMessage) {
-                return {content, role: "tool", tool_call_id: message.tool_call_id};
-            } else {
-                throw new Error("Unknown message type.");
-            }
-        });
-
-        if (node.instructions) converted.push({content: node.instructions, role: "user"});
-
         let message: BaseMessage;
         if (tools.length > 0) {
             const openAiApiKey = process.env.OPENAI_API_KEY;
             const openai = new OpenAI({apiKey: openAiApiKey});
 
+            const converted: ChatCompletionMessageParam[] = state.messages.map((message) => {
+                const content = typeof message.content === "string" ? message.content : JSON.stringify(message.content);
+                if (message instanceof AIMessage) {
+                    return {content, role: "assistant"};
+                } else if (message instanceof HumanMessage) {
+                    return {content, role: "user"};
+                } else if (message instanceof SystemMessage) {
+                    return {content, role: "system"};
+                } else if (message instanceof ToolMessage) {
+                    return {content, role: "tool", tool_call_id: message.tool_call_id};
+                } else {
+                    throw new Error("Unknown message type.");
+                }
+            });
+
+            if (node.instructions) converted.push({content: node.instructions, role: "user"});
+
             const runner = new ToolChain({
                 openai: openai,
                 model: GPT4_TEXT,