Implemented LangChain and Gemini AI to generate AI enhanced Cv

netlify/functions/enhanceWithAi.mts

@@ -1,6 +1,9 @@
-import { GoogleGenerativeAI } from '@google/generative-ai';
+import { ChatPromptTemplate } from '@langchain/core/prompts';
+import getLLMWrapper from '../utils/getLLMWrapper.js';
+
 const enhanceWithAi = async ({
   apiKey,
+  provider,
   professionalSummary,
   education,
   experience,
@@ -12,10 +15,20 @@ const enhanceWithAi = async ({
     if (!apiKey) {
       throw new Error('API key is required');
     }
-    const genAI = new GoogleGenerativeAI(apiKey);
-    const model = genAI.getGenerativeModel({ model: 'gemini-1.5-flash' });
 
-    const systemPrompt = `You are an expert AI resume writer specializing in creating ATS-optimized, recruiter-friendly CVs for tech professionals with career transitions and non-traditional backgrounds.
+    const inputValues = {
+      professionalSummary,
+      education,
+      experience,
+      projects,
+      skills: skills.join(', '),
+      profileVsJobCriteria,
+    };
+
+    const promptTemplate = ChatPromptTemplate.fromMessages([
+      [
+        'system',
+        `You are an expert AI resume writer specializing in creating ATS-optimized, recruiter-friendly CVs for tech professionals with career transitions and non-traditional backgrounds.
 
 **Your Task:** Enhance the provided CV data by optimizing it for:
 - ATS (Applicant Tracking System) compatibility
@@ -24,14 +37,6 @@ const enhanceWithAi = async ({
 - Professional narrative coherence
 - Keyword optimization for the specified skills
 
-**Input Data:**
-- Professional Summary: ${professionalSummary}
-- Education: ${JSON.stringify(education)}
-- Experience: ${experience}
-- Projects: ${JSON.stringify(projects)}
-- Skills: ${skills.join(', ')}
-- Job Criteria: ${profileVsJobCriteria}
-
 **Enhancement Guidelines:**
 1. **Professional Summary**: Craft a compelling, recruiter-hooking 3-4 sentence summary that bridges past experience with tech aspirations, aligning with job criteria.
 2. **Skills**: Extract and return the 4-5 most relevant technical skills and 3-5 key soft skills by analyzing both the ProfileVsJobCriteria field and the transferable experience. Present each skill as a bullet point.
@@ -50,9 +55,9 @@ const enhanceWithAi = async ({
 - Present both technical and soft skills as bullet points.
 
 **Required Output Format (JSON only):**
-{
+{{ 
   "professionalSummary": "Enhanced 3-4 sentence professional summary connecting background to tech career goals and job requirements",
-  "skills": {
+  "skills": {{ 
     "technical": [
       "tech skill1",
       "tech skill2"
@@ -61,9 +66,9 @@ const enhanceWithAi = async ({
       "soft skill1",
       "soft skill2"
     ]
-  },
+      }},
 "transferableExperience": [
-  {
+  {{
     "company": "Company Name",
     "position": "Job Title/Role", 
     "startDate": "Month Year",
@@ -72,19 +77,19 @@ const enhanceWithAi = async ({
       "Bullet point 1 highlighting transferable skills and relevant achievements",
       "Bullet point 2 with quantified results where possible"
     ]
-  }
+      }}
 ],
   "education": [
-    {
+    {{
       "institution": "Name of school/bootcamp",
       "program": "Degree/certificate name",
       "startDate": "Month Year",
       "endDate": "Month Year",
       "highlights": "Key projects or relevant coursework"
-    }
+      }}
   ],
   "projects": [
-   {
+   {{
       "name": "Project name",
       "description": "Brief explanation of project and economic, social impact and problems solved",
        "technologiesUsed": [
@@ -93,27 +98,36 @@ const enhanceWithAi = async ({
       ],
       "deployedLink": "URL if deployed",
       "githubLink": "Repository URL"
-    }
+      }}
   ]
-}
+      }}
+Only return valid JSON without any additional formatting or commentary.`,
+      ],
+      [
+        'user',
+        `Professional Summary: {professionalSummary}, Education: {education}, Experience: {experience}, Projects: {projects}, Skills: {skills}, Job Criteria: {profileVsJobCriteria}`,
+      ],
+    ]);
 
-Only return valid JSON without any additional formatting or commentary.`;
+    const model = getLLMWrapper({ provider, apiKey, temperature: 0.3 });
+    const promptValue = await promptTemplate.invoke(inputValues);
+    const response = await model.invoke(promptValue);
 
-    const result = await model.generateContent({
-      contents: [{ role: 'user', parts: [{ text: systemPrompt }] }],
-    });
+    if (!response.content) {
+      throw new Error('No response content from model');
+    }
 
-    const responseText = result.response.text();
-    const cleanedResponse = responseText
+    console.log(response.content);
+    const cleanedResponse = response.content
       .replace(/```json\n?/g, '')
       .replace(/```\n?/g, '')
       .trim();
 
     try {
       return JSON.parse(cleanedResponse);
     } catch (parseError) {
-      console.error('Invalid JSON response from Gemini:', cleanedResponse);
-      throw new Error('AI returned invalid JSON format');
+      console.error(`Invalid JSON response from ${provider}:`, cleanedResponse);
+      throw new Error(`${provider} returned invalid JSON format`);
     }
   } catch (error) {
     console.error('CV Enhancement Error:', error);

netlify/functions/generateCv.mts

@@ -7,10 +7,15 @@ const cvSchema = yup.object().shape({
   apiKey: yup
     .string()
     .required('API key is required')
-    .test('is-valid-api-key', 'Invalid API key format', (value) => {
-      if (!value) return false;
-      return validateApiKey(value);
+    .test('is-valid-api-key', 'Invalid API key format', function (value) {
+      const provider = this?.parent?.provider;
+      if (!value || !provider) return false;
+      return validateApiKey(value, provider);
     }),
+  provider: yup
+    .string()
+    .oneOf(['Gemini', 'OpenAI', 'Claude', 'TogetherAI'], 'Invalid provider')
+    .required('Provider is required'),
   personalInfo: yup.object().shape({
     fullName: yup.string().required('Full name is required'),
     email: yup.string().email().required('Email is required'),
@@ -108,6 +113,7 @@ const generateCv = async (event) => {
 
     const {
       apiKey,
+      provider,
       personalInfo,
       professionalSummary,
       transferableExperience,
@@ -133,6 +139,7 @@ const generateCv = async (event) => {
         .filter(Boolean),
       profileVsJobCriteria: jobcriteria,
       apiKey,
+      provider,
     };
 
     const enhancedCV = await enhanceWithAi(aiInput);

netlify/utils/getLLMWrapper.js

@@ -0,0 +1,46 @@
+import { ChatOpenAI } from '@langchain/openai';
+import { ChatAnthropic } from '@langchain/anthropic';
+import { ChatGoogleGenerativeAI } from '@langchain/google-genai';
+import { ChatTogetherAI } from '@langchain/community/chat_models/togetherai';
+
+export default function getLLMWrapper({ provider, apiKey, temperature = 0.3 }) {
+  switch (provider) {
+    case 'OpenAI': {
+      const model = 'gpt-4';
+      return new ChatOpenAI({
+        openAIApiKey: apiKey,
+        modelName: model,
+        temperature,
+      });
+    }
+
+    case 'Claude': {
+      const model = 'claude-3-sonnet-20240229';
+      return new ChatAnthropic({
+        anthropicApiKey: apiKey,
+        modelName: model,
+        temperature,
+      });
+    }
+
+    case 'Gemini': {
+      const model = 'gemini-1.5-flash';
+      return new ChatGoogleGenerativeAI({
+        apiKey,
+        model,
+        temperature: 0,
+      });
+    }
+    case 'TogetherAI': {
+      const model = 'mistralai/Mixtral-8x7B-Instruct-v0.1';
+      return new ChatTogetherAI({
+        togetherAIApiKey: apiKey,
+        modelName: model,
+        temperature,
+      });
+    }
+
+    default:
+      throw new Error(`Unsupported provider: ${provider}`);
+  }
+}

netlify/utils/validations.js

@@ -1,5 +1,21 @@
-const validateApiKey = (key) => {
+const validateApiKey = (key, provider) => {
   const trimmedKey = key.trim();
-  return /^AIza[0-9A-Za-z-_]{35}$/.test(trimmedKey);
+  if (!trimmedKey || !provider) return false;
+  switch (provider) {
+    case 'Gemini':
+      return /^AIza[0-9A-Za-z-_]{35}$/.test(trimmedKey);
+
+    case 'OpenAI':
+      return /^sk-([a-zA-Z0-9-_]){20,}$/.test(trimmedKey);
+
+    case 'Claude':
+      return /^sk-ant-[a-zA-Z0-9]{40,}$/.test(trimmedKey);
+
+    case 'TogetherAI':
+      return /^[a-zA-Z0-9]{64,}$/.test(trimmedKey);
+
+    default:
+      return false;
+  }
 };
 export default validateApiKey;