feat(AI Agent Tool Node): Add Agent Tool (#17108)

packages/@n8n/nodes-langchain/nodes/agents/Agent/V2/utils.ts

@@ -0,0 +1,95 @@
+// Function used in the inputs expression to figure out which inputs to
+
+import {
+	type INodeInputConfiguration,
+	type INodeInputFilter,
+	type NodeConnectionType,
+} from 'n8n-workflow';
+
+// display based on the agent type
+export function getInputs(
+	hasMainInput?: boolean,
+	hasOutputParser?: boolean,
+	needsFallback?: boolean,
+): Array<NodeConnectionType | INodeInputConfiguration> {
+	interface SpecialInput {
+		type: NodeConnectionType;
+		filter?: INodeInputFilter;
+		displayName: string;
+		required?: boolean;
+	}
+
+	const getInputData = (
+		inputs: SpecialInput[],
+	): Array<NodeConnectionType | INodeInputConfiguration> => {
+		return inputs.map(({ type, filter, displayName, required }) => {
+			const input: INodeInputConfiguration = {
+				type,
+				displayName,
+				required,
+				maxConnections: ['ai_languageModel', 'ai_memory', 'ai_outputParser'].includes(type)
+					? 1
+					: undefined,
+			};
+
+			if (filter) {
+				input.filter = filter;
+			}
+
+			return input;
+		});
+	};
+
+	let specialInputs: SpecialInput[] = [
+		{
+			type: 'ai_languageModel',
+			displayName: 'Chat Model',
+			required: true,
+			filter: {
+				excludedNodes: [
+					'@n8n/n8n-nodes-langchain.lmCohere',
+					'@n8n/n8n-nodes-langchain.lmOllama',
+					'n8n/n8n-nodes-langchain.lmOpenAi',
+					'@n8n/n8n-nodes-langchain.lmOpenHuggingFaceInference',
+				],
+			},
+		},
+		{
+			type: 'ai_languageModel',
+			displayName: 'Fallback Model',
+			required: true,
+			filter: {
+				excludedNodes: [
+					'@n8n/n8n-nodes-langchain.lmCohere',
+					'@n8n/n8n-nodes-langchain.lmOllama',
+					'n8n/n8n-nodes-langchain.lmOpenAi',
+					'@n8n/n8n-nodes-langchain.lmOpenHuggingFaceInference',
+				],
+			},
+		},
+		{
+			displayName: 'Memory',
+			type: 'ai_memory',
+		},
+		{
+			displayName: 'Tool',
+			type: 'ai_tool',
+		},
+		{
+			displayName: 'Output Parser',
+			type: 'ai_outputParser',
+		},
+	];
+
+	if (hasOutputParser === false) {
+		specialInputs = specialInputs.filter((input) => input.type !== 'ai_outputParser');
+	}
+	if (needsFallback === false) {
+		specialInputs = specialInputs.filter((input) => input.displayName !== 'Fallback Model');
+	}
+
+	// Note cannot use NodeConnectionType.Main
+	// otherwise expression won't evaluate correctly on the FE
+	const mainInputs = hasMainInput ? ['main' as NodeConnectionType] : [];
+	return [...mainInputs, ...getInputData(specialInputs)];
+}