feat(Functions Agent): use official langchain function executor/agent for better output handling (#538)

* style(FunctionsAgent.js): remove unnecessary comments and update PREFIX variable
refactor(initializeFunctionsAgent.js): update to use initializeAgentExecutorWithOptions
deps(package.json): update langchain to v0.0.95
refactor(askGPTPlugins.js): pass endpointOption to onStart function

* fix(ChatAgent.js): handle undefined delta content in progressMessage.choices array

api/app/langchain/ChatAgent.js

@@ -546,7 +546,7 @@ Only respond with your conversational reply to the following User Message:
             return;
           }
           const token = this.isChatGptModel
-            ? progressMessage.choices[0].delta.content
+            ? progressMessage.choices?.[0]?.delta.content
             : progressMessage.choices[0].text;
           // first event's delta content is always undefined
           if (!token) {

api/app/langchain/agents/Functions/FunctionsAgent.js

@@ -7,8 +7,7 @@ const {
   SystemMessagePromptTemplate,
   HumanMessagePromptTemplate
 } = require('langchain/prompts');
-const PREFIX = `You are a helpful AI assistant. Objective: Resolve the user's query with provided functions.
+const PREFIX = `You are a helpful AI assistant.`;
-The user is demanding a function response to the query.`;
 
 function parseOutput(message) {
   if (message.additional_kwargs.function_call) {
@@ -52,9 +51,9 @@ class FunctionsAgent extends Agent {
 
     return ChatPromptTemplate.fromPromptMessages([
       SystemMessagePromptTemplate.fromTemplate(`Date: ${currentDateString}\n${prefix}`),
-      HumanMessagePromptTemplate.fromTemplate(`{chat_history}
+      new MessagesPlaceholder('chat_history'),
-Query: {input}`),
+      HumanMessagePromptTemplate.fromTemplate(`Query: {input}`),
-      new MessagesPlaceholder('agent_scratchpad')
+      new MessagesPlaceholder('agent_scratchpad'),
     ]);
   }
 

api/app/langchain/agents/Functions/initializeFunctionsAgent.js

@@ -1,32 +1,47 @@
-const FunctionsAgent = require('./FunctionsAgent');
+// const FunctionsAgent = require('./FunctionsAgent');
-const { AgentExecutor } = require('langchain/agents');
+// const { AgentExecutor, initializeAgentExecutorWithOptions } = require('langchain/agents');
+const { initializeAgentExecutorWithOptions } = require('langchain/agents');
 const { BufferMemory, ChatMessageHistory } = require('langchain/memory');
 
 const initializeFunctionsAgent = async ({
   tools,
   model,
   pastMessages,
-  currentDateString,
+  // currentDateString,
   ...rest
 }) => {
-  const agent = FunctionsAgent.fromLLMAndTools(
+  // const agent = FunctionsAgent.fromLLMAndTools(
-    model,
+  //   model,
-    tools, 
+  //   tools, 
-    {
+  //   {
-      currentDateString,
+  //     currentDateString,
-    });
+  //   });
+
 
   const memory = new BufferMemory({
     chatHistory: new ChatMessageHistory(pastMessages),
-    // returnMessages: true, // commenting this out retains memory
     memoryKey: 'chat_history',
     humanPrefix: 'User',
     aiPrefix: 'Assistant',
     inputKey: 'input',
-    outputKey: 'output'
+    outputKey: 'output',
+    returnMessages: true,
   });
 
-  return AgentExecutor.fromAgentAndTools({ agent, tools, memory, ...rest });
+  // return AgentExecutor.fromAgentAndTools({ agent, tools, memory, ...rest });
+
+  return await initializeAgentExecutorWithOptions(
+    tools,
+    model,
+    {
+      agentType: "openai-functions",
+      memory,
+      maxIterations: 4,
+      ...rest,
+    }
+  );
+
+
 };
 
 module.exports = initializeFunctionsAgent;

api/package.json

@@ -46,7 +46,7 @@
     "jsonwebtoken": "^9.0.0",
     "keyv": "^4.5.2",
     "keyv-file": "^0.2.0",
-    "langchain": "^0.0.94",
+    "langchain": "^0.0.95",
     "lodash": "^4.17.21",
     "meilisearch": "^0.33.0",
     "mongoose": "^7.1.1",

api/server/routes/ask/askGPTPlugins.js

@@ -218,6 +218,7 @@ const ask = async ({ text, endpointOption, parentMessageId = null, conversationI
       onAgentAction,
       onChainEnd,
       onStart,
+      ...endpointOption,
       onProgress: progressCallback.call(null, {
         res,
         text,

package-lock.json

@@ -63,7 +63,7 @@
         "jsonwebtoken": "^9.0.0",
         "keyv": "^4.5.2",
         "keyv-file": "^0.2.0",
-        "langchain": "^0.0.94",
+        "langchain": "^0.0.95",
         "lodash": "^4.17.21",
         "meilisearch": "^0.33.0",
         "mongoose": "^7.1.1",
@@ -130,9 +130,9 @@
       }
     },
     "api/node_modules/langchain": {
-      "version": "0.0.94",
+      "version": "0.0.95",
-      "resolved": "https://registry.npmjs.org/langchain/-/langchain-0.0.94.tgz",
+      "resolved": "https://registry.npmjs.org/langchain/-/langchain-0.0.95.tgz",
-      "integrity": "sha512-RafU2Nk005jnNgOPSi5LhXtwOhdf8nwLSWU4hRyMXwB1l3lNCwTKlYWfKwMQ9VaSEe+4fEaO8lM9yVp+y3aa9w==",
+      "integrity": "sha512-UjOr1XArTTSZB4uCayKzQs69pCahHCq/CVTc66fAymCD5uKerh8AvcemPxgRpTi8tgcdhY76j//c0e06l5aFdA==",
       "dependencies": {
         "@anthropic-ai/sdk": "^0.4.3",
         "ansi-styles": "^5.0.0",
@@ -204,6 +204,7 @@
         "replicate": "^0.9.0",
         "srt-parser-2": "^1.2.2",
         "typeorm": "^0.3.12",
+        "typesense": "^1.5.3",
         "weaviate-ts-client": "^1.0.0"
       },
       "peerDependenciesMeta": {
@@ -345,6 +346,9 @@
         "typeorm": {
           "optional": true
         },
+        "typesense": {
+          "optional": true
+        },
         "weaviate-ts-client": {
           "optional": true
         }
@@ -29549,7 +29553,7 @@
         "jsonwebtoken": "^9.0.0",
         "keyv": "^4.5.2",
         "keyv-file": "^0.2.0",
-        "langchain": "^0.0.94",
+        "langchain": "0.0.95",
         "lodash": "^4.17.21",
         "meilisearch": "^0.33.0",
         "mongoose": "^7.1.1",
@@ -29592,9 +29596,9 @@
           }
         },
         "langchain": {
-          "version": "0.0.94",
+          "version": "0.0.95",
-          "resolved": "https://registry.npmjs.org/langchain/-/langchain-0.0.94.tgz",
+          "resolved": "https://registry.npmjs.org/langchain/-/langchain-0.0.95.tgz",
-          "integrity": "sha512-RafU2Nk005jnNgOPSi5LhXtwOhdf8nwLSWU4hRyMXwB1l3lNCwTKlYWfKwMQ9VaSEe+4fEaO8lM9yVp+y3aa9w==",
+          "integrity": "sha512-UjOr1XArTTSZB4uCayKzQs69pCahHCq/CVTc66fAymCD5uKerh8AvcemPxgRpTi8tgcdhY76j//c0e06l5aFdA==",
           "requires": {
             "@anthropic-ai/sdk": "^0.4.3",
             "ansi-styles": "^5.0.0",
@@ -29644,7 +29648,7 @@
         "@radix-ui/react-icons": "^1.3.0",
         "@radix-ui/react-label": "^2.0.0",
         "@radix-ui/react-slider": "^1.1.1",
-        "@radix-ui/react-switch": "*",
+        "@radix-ui/react-switch": "^1.0.3",
         "@radix-ui/react-tabs": "^1.0.3",
         "@tailwindcss/forms": "^0.5.3",
         "@tanstack/react-query": "^4.28.0",