Merge pull request #503 from FlowiseAI/bugfix/ChainToolWithLLMChain

Bugfix/ChainTool with LLMChain

packages/components/nodes/tools/ChainTool/ChainTool.ts

@@ -1,7 +1,7 @@
 import { INode, INodeData, INodeParams } from '../../../src/Interface'
 import { getBaseClasses } from '../../../src/utils'
-import { ChainTool } from 'langchain/tools'
 import { BaseChain } from 'langchain/chains'
+import { ChainTool } from './core'
 
 class ChainTool_Tools implements INode {
     label: string

packages/components/nodes/tools/ChainTool/core.ts

@@ -0,0 +1,25 @@
+import { DynamicTool, DynamicToolInput } from 'langchain/tools'
+import { BaseChain } from 'langchain/chains'
+
+export interface ChainToolInput extends Omit<DynamicToolInput, 'func'> {
+    chain: BaseChain
+}
+
+export class ChainTool extends DynamicTool {
+    chain: BaseChain
+
+    constructor({ chain, ...rest }: ChainToolInput) {
+        super({
+            ...rest,
+            func: async (input, runManager) => {
+                // To enable LLM Chain which has promptValues
+                if ((chain as any).prompt && (chain as any).prompt.promptValues) {
+                    const values = await chain.call((chain as any).prompt.promptValues, runManager?.getChild())
+                    return values?.text
+                }
+                return chain.run(input, runManager?.getChild())
+            }
+        })
+        this.chain = chain
+    }
+}