Tender Eligibility Analyzer API

A Node.js backend API that automates tender eligibility analysis using Google Gemini 2.5 Flash AI. The system processes multiple tender PDFs, analyzes company eligibility, performs SKU matching, calculates pricing, and sends automated email notifications with detailed reports.

Features

📄 Extract text from PDF and DOCX documents
🤖 AI-powered summarization using Google Gemini 2.5 Flash
📊 Comprehensive eligibility analysis and table generation
🔄 Advanced 9-step workflow for Tender 2 processing
🎯 SKU matching with intelligent scoring algorithm
💰 Automated pricing calculations with real value extraction
✉️ Automated email notifications with DOCX/CSV reports
🚀 RESTful API with 6 main endpoints
🔑 Multi-key API rotation (supports up to 4 Gemini API keys)
📦 Postman collection for easy testing

Prerequisites

Node.js (v14 or higher)
npm or yarn
Google Gemini API keys (1-4 keys recommended for better rate limit handling)
SendGrid account with API key (free tier: 100 emails/day)

Installation

Clone or download this project
Install dependencies
```
npm install
```
Set up environment variables

Create a .env file in the root directory (or copy from .env.example):
```
PORT=3000
GEMINI_API_KEY_1=your_first_gemini_api_key
GEMINI_API_KEY_2=your_second_gemini_api_key
GEMINI_API_KEY_3=your_third_gemini_api_key
GEMINI_API_KEY_4=your_fourth_gemini_api_key
SENDGRID_API_KEY=your_sendgrid_api_key
SENDGRID_FROM_EMAIL=your_verified_sender@example.com
EMAIL_TO=recipient@example.com
```
API Key Rotation (Aggressive Strategy):
- The system supports up to 4 Gemini API keys for optimal performance
- Aggressive rotation: Switches to next key on EVERY error (not just rate limits)
- Maximum retries: 3x the number of configured keys
- Automatic exponential backoff with jitter for single-key setups
- You can use 1-4 keys; more keys = better reliability and throughput
Important:
- Get your Gemini API keys from Google AI Studio
- Configure 2-4 API keys for optimal performance and rate limit handling
- For SendGrid:
  - Sign up at SendGrid (free tier: 100 emails/day)
  - Create an API key from Settings → API Keys
  - Verify a sender email address from Settings → Sender Authentication
  - Use the API key for SENDGRID_API_KEY and verified email for SENDGRID_FROM_EMAIL
Start the server
```
npm start
```
Or for development with auto-reload:
```
npm run dev
```

The server will start on http://localhost:3000

API Endpoints

1. Upload Tender PDFs

POST /api/upload-tender/:tenderId

Upload up to 5 tender PDFs. The system will:

Extract text from each PDF
Generate detailed summaries using AI
Save summaries in summaries/tenderId/

Example:

curl -X POST http://localhost:3000/api/upload-tender/tender1 \
  -F "pdfs=@document1.pdf" \
  -F "pdfs=@document2.pdf"

Parameters:

tenderId: tender1 or tender2
pdfs: Array of PDF files (multipart/form-data)

2. Upload Company Information

POST /api/upload-company

Upload company information document (PDF or DOCX).

Example:

curl -X POST http://localhost:3000/api/upload-company \
  -F "document=@company_info.docx"

Parameters:

document: PDF or DOCX file (multipart/form-data)

3. Analyze Tender Eligibility

POST /api/analyze-tender/:tenderId

Analyzes tender eligibility by:

Concatenating all 5 PDF summaries
Cross-referencing with company info
Generating eligibility analysis table

Example:

curl -X POST http://localhost:3000/api/analyze-tender/tender1

Response:

{
  "success": true,
  "message": "Eligibility analysis completed for tender1",
  "tenderId": "tender1",
  "tablePath": "analysis/tender1/table.txt",
  "summary": {
    "totalSummaries": 5,
    "comprehensiveSummaryLength": 15234,
    "companyInfoLength": 8921,
    "eligibilityTableLength": 3456
  }
}

4. Check Eligibility

POST /api/check-eligibility/:tenderId

Checks final eligibility (YES/NO) and:

If NO: Generates DOCX report and sends email
If YES: Returns eligibility status

Example:

curl -X POST http://localhost:3000/api/check-eligibility/tender1

Response:

{
  "success": true,
  "message": "Company is NOT eligible for tender1",
  "tenderId": "tender1",
  "eligible": false,
  "decision": "NO",
  "emailSent": true,
  "docxPath": "analysis/tender1/eligibility_report.docx"
}

5. Process All Tenders

POST /api/process-all

Automates the entire workflow for both tenders sequentially.

Example:

curl -X POST http://localhost:3000/api/process-all

Response:

{
  "success": true,
  "message": "All tenders processed",
  "summary": {
    "eligible": 0,
    "notEligible": 2,
    "total": 2
  },
  "results": {
    "tender1": {
      "success": true,
      "eligible": false,
      "decision": "NO",
      "emailSent": true
    },
    "tender2": {
      "success": true,
      "eligible": false,
      "decision": "NO",
      "emailSent": true
    }
  }
}

6. Process Tender 2 Workflow (Advanced 9-Step Pipeline)

POST /api/process-tender2-workflow

Complete automated workflow for Tender 2 with advanced features:

Process 5 PDFs → Generate individual summaries
Concatenate summaries → Combine all summaries
Generate comprehensive summary → Create unified analysis
Eligibility check → YES/NO decision
Build Table B1 → Matching operations table (if eligible)
Match SKUs → Intelligent SKU matching with scoring
Calculate pricing → Real value extraction and pricing
Generate holistic table → Combined summary table
Email result → Send appropriate report

Example:

curl -X POST http://localhost:3000/api/process-tender2-workflow

Response (Eligible):

{
  "success": true,
  "message": "Tender 2 workflow completed successfully",
  "eligibility": "YES",
  "emailSent": true,
  "workflowDir": "workflows/tender2",
  "outputs": {
    "summary1": "workflows/tender2/summary_1.txt",
    "comprehensiveSummary": "workflows/tender2/comprehensive_summary.txt",
    "eligibilityResult": "workflows/tender2/eligibility_result.txt",
    "tableB1": "workflows/tender2/table_b1.csv",
    "matchedSKUs": "workflows/tender2/matched_skus.txt",
    "pricingTable": "workflows/tender2/pricing_table.csv",
    "holisticTable": "workflows/tender2/holistic_summary_table.csv"
  }
}

Response (Not Eligible):

{
  "success": true,
  "message": "Tender 2 workflow completed - Company NOT eligible",
  "eligibility": "NO",
  "emailSent": true,
  "docxPath": "analysis/tender2/eligibility_report.docx",
  "workflowDir": "workflows/tender2"
}

Required Input Files:

5 PDFs in Tendor-2/ directory
Tender_SKU_Matching_Descriptions.txt (SKU master file)
company_profile.json (company information)

Key Features:

Conditional execution: Steps 5-9 only run if eligible
Real value extraction from documents (no placeholders)
CSV table outputs for structured data
Intelligent SKU matching with weighted scoring
Automated pricing calculations

Testing with Postman

Import postman_collection.json into Postman
Configure environment variables if needed
Start testing the endpoints

Project Structure

project-root/
├── src/
│   ├── controllers/
│   │   ├── tenderController.js              # Tender PDF upload handling
│   │   ├── companyController.js             # Company info upload handling
│   │   ├── analysisController.js            # Eligibility analysis logic
│   │   ├── eligibilityController.js         # Final eligibility check & email
│   │   └── tender2WorkflowController.js     # 9-step Tender 2 workflow
│   ├── services/
│   │   ├── pdfService.js                    # PDF text extraction
│   │   ├── docxService.js                   # DOCX text extraction
│   │   ├── groqService.js                   # Gemini AI integration (all prompts)
│   │   ├── emailService.js                  # Email sending with attachments
│   │   └── docService.js                    # DOCX report generation
│   ├── utils/
│   │   ├── csvUtils.js                      # CSV conversion utilities
│   │   ├── distanceUtils.js                 # Distance calculation utilities
│   │   └── docxTableUtils.js                # DOCX table formatting
│   ├── routes/
│   │   └── apiRoutes.js                     # API endpoint definitions
│   └── config/
│       └── groqClient.js                    # Gemini client with key rotation
├── uploads/                                  # Uploaded files (auto-generated)
│   ├── tender1/
│   ├── tender2/
│   └── company/
├── summaries/                                # Generated summaries (auto-generated)
│   ├── tender1/
│   └── tender2/
├── analysis/                                 # Analysis results (auto-generated)
│   ├── tender1/
│   └── tender2/
├── workflows/                                # Tender 2 workflow outputs (auto-generated)
│   └── tender2/
├── Tendor-1/                                 # Tender 1 input PDFs
├── Tendor-2/                                 # Tender 2 input PDFs
├── server.js                                 # Express server entry point
├── package.json                              # Dependencies and scripts
├── .env                                      # Environment variables (create from template)
├── env.template                              # Environment variables template
├── .gitignore                                # Git ignore rules
├── README.md                                 # Main documentation (this file)
├── TENDER2_WORKFLOW_README.md                # Detailed Tender 2 workflow docs
├── QUICK_START.md                            # Quick start guide
├── INSTALL.md                                # Installation guide
├── POSTMAN_SETUP_GUIDE.md                    # Postman testing guide
├── postman_collection.json                   # Postman API collection
└── Tender_SKU_Matching_Descriptions.txt      # SKU master file for matching

Workflows

Standard Workflow (Tender 1 & 2)

Upload Tender PDFs → System extracts text and generates summaries
Upload Company Info → System extracts and saves text
Analyze Tender → System creates eligibility analysis table
Check Eligibility → System decides YES/NO and emails if NO
Process All → Automated workflow for both tenders

Advanced Tender 2 Workflow (9-Step Pipeline)

Process 5 PDFs → Individual summaries generated
Concatenate Summaries → Combined into single document
Comprehensive Summary → Unified analysis created
Eligibility Check → YES/NO decision made
Build Table B1 → Matching operations table (if YES)
Match SKUs → Intelligent matching with scoring (if YES)
Calculate Pricing → Real value extraction and pricing (if YES)
Generate Holistic Table → Combined summary table (if YES)
Email Result → Appropriate report sent based on eligibility

AI Model

The system uses Google's Gemini 2.5 Flash model with:

Ultra-large context window (2M tokens support)
Fast and efficient inference
Cost-effective for large documents
Excellent for summarization, analysis, and complex reasoning tasks
Enhanced capabilities over previous versions

Current Model: gemini-2.5-flash (configured in src/config/groqClient.js)

Model Configuration:

Default max output tokens: 65,536
Adaptive timeout: 7 minutes for all requests
Temperature: 0.3-0.7 (depending on task)
Safety settings: Configured to BLOCK_NONE for all categories

Note: You can change the model in src/config/groqClient.js line 140.

Email Configuration

Not Eligible (Standard Workflow)

Subject: "Tender Eligibility Analysis Result - NOT ELIGIBLE - {TENDER_ID}"
Body: "Please find attached the detailed eligibility analysis report."
Attachment: DOCX file with eligibility table

Eligible (Tender 2 Workflow)

Subject: "Tender 2 - Holistic Summary Table - ELIGIBLE"
Body: "Company is eligible for Tender 2. Please find attached the holistic summary table."
Attachment: CSV file with holistic summary table

Not Eligible (Tender 2 Workflow)

Subject: "Tender 2 Eligibility Analysis Result - NOT ELIGIBLE"
Body: "Please find attached the detailed eligibility analysis report."
Attachment: DOCX file with eligibility analysis

API Key Rotation System

The system implements an aggressive rotation strategy for optimal reliability:

Key Features

Multi-key support: Configure 1-4 Gemini API keys
Aggressive rotation: Switches to next key on EVERY error (not just rate limits)
Smart retry logic: Maximum retries = 3x number of configured keys
Exponential backoff: For single-key setups with jitter
Automatic recovery: Seamlessly handles quota exhaustion and rate limits

How It Works

System starts with API key #1
On any error (rate limit, quota, timeout, etc.), immediately rotates to next key
Tracks which keys have been attempted to avoid infinite loops
After trying all keys, throws error with detailed message
Short delay (1 second) after rotation to avoid cascading rate limits

Configuration

GEMINI_API_KEY_1=your_first_key    # Required
GEMINI_API_KEY_2=your_second_key   # Optional
GEMINI_API_KEY_3=your_third_key    # Optional
GEMINI_API_KEY_4=your_fourth_key   # Optional

Recommendation: Use all 4 keys for maximum reliability and throughput.

Error Handling

All endpoints include comprehensive error handling and logging:

console.log for successful operations
console.error for errors with detailed stack traces
Structured JSON error responses
Automatic API key rotation on failures
Graceful degradation with fallback mechanisms

Dependencies

express: Web framework
multer: File upload handling
@google/generative-ai: Google Gemini AI API integration
nodemailer: Email functionality with attachment support
pdf-parse: PDF text extraction
mammoth: DOCX text extraction
docx: Generate DOCX reports with tables
fs-extra: Enhanced file system operations
dotenv: Environment variables management

Dev Dependencies

nodemon: Auto-reload during development

Additional Documentation

For more detailed information, refer to these guides:

TENDER2_WORKFLOW_README.md - Detailed Tender 2 workflow documentation
QUICK_START.md - Quick start guide
INSTALL.md - Detailed installation instructions
POSTMAN_SETUP_GUIDE.md - Postman testing guide

Key Features Summary

🔄 Advanced Workflows

Standard workflow: Upload → Analyze → Check → Email
Tender 2 workflow: 9-step pipeline with SKU matching and pricing

🤖 AI-Powered Analysis

Comprehensive tender summarization
Eligibility criteria extraction and matching
Intelligent SKU matching with weighted scoring
Real value extraction from documents

🔑 Robust API Key Management

Support for up to 4 Gemini API keys
Aggressive rotation on every error
Automatic retry with exponential backoff
Maximum reliability and throughput

📊 Data Processing

PDF and DOCX text extraction
CSV table generation
DOCX report creation with formatted tables
Real-time distance and pricing calculations

✉️ Automated Notifications

Email reports for eligible and non-eligible cases
DOCX and CSV attachments
Customizable email templates

Troubleshooting

Common Issues

API Key Errors:

Ensure all API keys are valid and active
Check quota limits on Google AI Studio
Verify .env file is properly configured

File Upload Issues:

Check file size limits (default: no limit set)
Ensure directories have write permissions
Verify file formats (PDF, DOCX supported)

Email Not Sending:

Verify SendGrid API key is correct and active
Check sender email is verified in SendGrid dashboard
Ensure SENDGRID_API_KEY and SENDGRID_FROM_EMAIL are set correctly
Check SendGrid dashboard for delivery logs and errors

Workflow Failures:

Check all required input files exist
Review console logs for detailed error messages
Verify API keys have sufficient quota

Performance Optimization

With 4 API Keys

Throughput: ~4x higher than single key
Reliability: Automatic failover on errors
Rate Limits: Distributed across multiple keys
Recommended for: Production environments

With 1 API Key

Throughput: Standard rate limits apply
Reliability: Exponential backoff on errors
Rate Limits: Single key quota
Recommended for: Development/testing

Support

For issues or questions:

Check console logs for detailed error messages
Review output files in respective directories
Verify API response messages
Check the additional documentation files

Quick Reference

Environment Variables (4 API Keys)

PORT=3000
GEMINI_API_KEY_1=your_first_gemini_api_key
GEMINI_API_KEY_2=your_second_gemini_api_key
GEMINI_API_KEY_3=your_third_gemini_api_key
GEMINI_API_KEY_4=your_fourth_gemini_api_key
SENDGRID_API_KEY=your_sendgrid_api_key
SENDGRID_FROM_EMAIL=your_verified_sender@example.com
EMAIL_TO=recipient@example.com

Quick Start Commands

# Install dependencies
npm install

# Start server
npm start

# Development mode (auto-reload)
npm run dev

# Test Gemini API
curl http://localhost:3000/api/test-gemini

# Health check
curl http://localhost:3000/health

API Endpoints Summary

Endpoint	Method	Description
`/api/upload-tender/:tenderId`	POST	Upload tender PDFs
`/api/upload-company`	POST	Upload company info
`/api/analyze-tender/:tenderId`	POST	Analyze eligibility
`/api/check-eligibility/:tenderId`	POST	Check & email result
`/api/process-all`	POST	Process all tenders
`/api/process-tender2-workflow`	POST	Run Tender 2 pipeline
`/api/test-gemini`	GET	Test Gemini API
`/health`	GET	Health check

Directory Structure Quick Reference

uploads/        → Uploaded PDFs and documents
summaries/      → AI-generated summaries
analysis/       → Eligibility analysis results
workflows/      → Tender 2 workflow outputs
Tendor-1/       → Tender 1 input PDFs
Tendor-2/       → Tender 2 input PDFs

License

ISC

Name		Name	Last commit message	Last commit date
Latest commit History 15 Commits
Tendor-1		Tendor-1
Tendor-2		Tendor-2
public		public
src		src
summaries		summaries
workflows/tender1		workflows/tender1
.env.example		.env.example
.env.local		.env.local
.gitignore		.gitignore
INSTALL.md		INSTALL.md
POSTMAN_SETUP_GUIDE.md		POSTMAN_SETUP_GUIDE.md
README.md		README.md
Tender_SKU_Matching_Descriptions.txt		Tender_SKU_Matching_Descriptions.txt
Untitled document (3).docx		Untitled document (3).docx
env.template		env.template
package-lock.json		package-lock.json
package.json		package.json
postman_collection.json		postman_collection.json
server.js		server.js
test-sku-upload.js		test-sku-upload.js
testEmail.js		testEmail.js

Folders and files

Latest commit

History

Repository files navigation

Tender Eligibility Analyzer API

Features

Prerequisites

Installation

API Endpoints

1. Upload Tender PDFs

2. Upload Company Information

3. Analyze Tender Eligibility

4. Check Eligibility

5. Process All Tenders

6. Process Tender 2 Workflow (Advanced 9-Step Pipeline)

Testing with Postman

Project Structure

Workflows

Standard Workflow (Tender 1 & 2)

Advanced Tender 2 Workflow (9-Step Pipeline)

AI Model

Email Configuration

Not Eligible (Standard Workflow)

Eligible (Tender 2 Workflow)

Not Eligible (Tender 2 Workflow)

API Key Rotation System

Key Features

How It Works

Configuration

Error Handling

Dependencies

Dev Dependencies

Additional Documentation

Key Features Summary

🔄 Advanced Workflows

🤖 AI-Powered Analysis

🔑 Robust API Key Management

📊 Data Processing

✉️ Automated Notifications

Troubleshooting

Common Issues

Performance Optimization

With 4 API Keys

With 1 API Key

Support

Quick Reference

Environment Variables (4 API Keys)

Quick Start Commands

API Endpoints Summary

Directory Structure Quick Reference

License

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