TenderLens：結合 WhatsApp 與 Gemma，為承包商打造自主投標助理

This article is submitted for the **Hacktoberfest Open-Source AI Challenge: Week 2 (Side Hustle).

Target Categories: **Overall Winner, **Best Use of Render, **Best Use of Gemma, **Best Use of Temporal.

1. The Real-World Side Hustle Problem

In Trinidad & Tobago (and throughout the Commonwealth Caribbean), billions of dollars in state contracts are awarded annually under public procurement laws. Small and medium contractors—plumbers, HVAC technicians, electrical contractors, janitorial services—desperately want these jobs.

Yet, over 60% of bids from small contractors get disqualified before technical evaluation begins.

Why? Not because their prices or craft are inadequate, but because of administrative bureaucracy and silent lead-time traps:

1. The Starting Point is Paper, Not Portals: Contractors don't browse clean procurement APIs. They spot a tender notice printed in the Sunday Guardian, Express, or Newsday newspaper, or see a screenshot forwarded in an industry WhatsApp group.
2. The 10-Day Statutory Bottleneck: In Trinidad & Tobago, obtaining a Board of Inland Revenue (BIR) Tax Clearance Certificate or VAT Clearance takes 5 to 10 business days. A National Insurance Board (NIS) compliance certificate takes 3 to 5 business days. If a contractor starts gathering documents in the final week before closing, they have already lost.
3. The Hidden Logistics Clauses: State agencies (like WASA or UDeCOTT) routinely require bidders to attend a mandatory site visit—but require registering representative names and ID numbers at least two (2) business days in advance. Miss that registration cut-off, and you are disqualified on the spot.

Contractors are busy on job sites. They don't need another generic PDF summarizer that tells them what they already know. They need proactive follow-through.

2. What I Built: TenderLens

TenderLens is an open-source AI tender readiness and follow-through assistant that lives right in the contractor's WhatsApp.

Instead of waiting for the contractor to remember deadlines, TenderLens actively drives the bid process from the first Sunday morning newspaper clipping through to final bid package assembly.

journey
    title The Contractor Journey with TenderLens
    section 1. Notice Discovery
      Spot tender in Sunday newspaper: 5: Contractor
      Snap photo to WhatsApp: 5: Contractor
      Extract dates, ref & package instructions: 5: TenderLens (Gemma 2)
      Auto-draft package request email to agency: 5: TenderLens
    section 2. Site Visit & Early Milestones
      Alert 2 days before Site Visit registration: 5: TenderLens (Temporal)
      Contractor confirms site visit registered: 4: Contractor
    section 3. Full Bid Intake
      Forward downloaded RFP PDF / upload bundle: 5: Contractor
      Extract BIR/NIS/VAT & Bid Bond checklists: 5: TenderLens
    section 4. Proactive Follow-Through
      Scheduled check-ins on outstanding statutory docs: 5: TenderLens (Temporal)
      Escalate approaching submission deadline: 5: TenderLens
      Bid successfully submitted on time: 5: Contractor

3. How It Works (The 4-Stage Workflow)

Stage 1: The True Entry Point — The Newspaper Ad

A contractor snaps a photo of a newspaper notice (like the authentic WASA tender notice below) and forwards it to TenderLens on WhatsApp.

TenderLens extracts:

• Procuring Entity: Water and Sewerage Authority (WASA)
• Ref No: W.T.C. - 40/2026
• Line of Business: 72102100 - Pest Control
• Crucial Deadlines: ITT publication, Mandatory Pre-Bid Site Visit (August 4 @ 10:00 AM), 2-day advance attendee registration notice, queries deadline, and closing deadline (August 26 @ 2:00 PM).
• Immediate Action: Automatically drafts a formal document request email addressed to purchasingandstores@wasa.gov.tt for Oracle ERP issuance.

Stage 2: Full RFP Compliance Matrix

Once the contractor receives access to the 50–100 page RFP package, they forward the document or drop it onto the TenderLens secure upload portal.

TenderLens scans the document and isolates every mandatory clause with exact page citations:

• Valid BIR Tax Clearance (Page 3 — ⚠️ 5-10 day lead-time warning)
• Valid NIS Compliance Certificate (Page 3 — ⚠️ 3-5 day lead-time)
• VAT Clearance Certificate (Page 3)
• Bid Security / Tender Bond of TT$50,000 (Page 4)
• Mandatory Site Visit Certificate (Page 2)

Stage 3: Proactive Follow-Through (The Differentiator)

Deterministic code, not LLM memory, controls follow-through. Using Temporal durable workflows, TenderLens maintains a multi-week timer loop.

If the contractor hasn't confirmed their BIR certificate with 10 days to go, TenderLens initiates a proactive WhatsApp check-in:

"TenderLens Check-in for W.T.C. - 40/2026: Your BIR Tax Clearance Certificate is still marked as outstanding. IRD typically requires 5–10 business days for processing. Have you submitted your application? Reply: Done, Waiting on IRD, or Need help."

When the contractor replies "Waiting on IRD", the Temporal workflow updates state and reschedules the next check-in.

4. Architecture: Why Open Innovation Matters

Tender preparation requires commercial confidentiality. Contractors are handling sensitive pricing, tax clearance documents, banking credentials, and proprietary methodology. Uploading these indiscriminately to closed, multi-tenant proprietary chatbots raises serious privacy and data ownership concerns.

By building on open-source AI and open-weight models, TenderLens keeps costs predictable and guarantees data sovereignty.

graph TD
    User([Contractor on WhatsApp]) <-->|Images, PDFs, Messages| Bridge[WhatsApp Cloud API Gateway]
    Bridge <--> Agent[TenderLens Agent Core]

    subgraph Core Engine [Render Hosted Services]
        Agent <--> Tools[TenderLens Procurement Tools]
        Tools --> AdParser[Tender Notice Image Parser]
        Tools --> EmailDrafter[Procurement Request Email Drafter]
        Tools --> PDFParser[Full RFP Compliance Parser]
        Tools --> TemporalClient[Temporal Workflow Client]

        TemporalClient <--> TemporalWorker[Temporal Worker & Workflows]
        TemporalWorker --> DB[(Managed PostgreSQL)]
    end

    subgraph AI Inference Layer
        Agent <--> Gemma[Google Gemma 2 Open-Weight LLM]
    end

    TemporalWorker -->|Scheduled Proactive Check-ins & Alerts| Bridge

The Stack Breakdown:

• LLM Engine: Gemma by Google — open-weight inference handling dense procurement clauses, date reasoning, and multilingual local nuance.
• Agent Harness: TenderLens Agent function-calling patterns with 6 registered procurement tools.
• Orchestration: Temporal Durable Workflows (TenderFollowThroughWorkflow) managing multi-week timers, signals, and queries that survive server restarts.
• Hosting & Database: Render Blueprint (render.yaml) automating deployment of the FastAPI Web Gateway, Temporal Worker, and Managed PostgreSQL database.
• Security: HMAC-SHA256 Signed Magic Upload Tokens with short TTL for secure drag-and-drop uploads of packages >100 MB.

5. The Commercial Side Hustle Hypothesis

In conversations with local contractors in Trinidad, missing a single TT$250,000 maintenance contract because an administrative certificate expired costs thousands of times more than a TT$350 readiness check.

6. Live Interactive Demo (Test It Yourself!)

To make testing instant for hackathon judges and readers without needing a WhatsApp developer sandbox, I built an Interactive Web WhatsApp Simulator:

Try clicking the 1-tap quick action buttons in the demo:

1. 📷 1. Send WASA Ad: Ingests the authentic Trinidad newspaper ad and extracts critical dates.
2. ✉️ 2. Request ERP Email: Generates the official package request email.
3. 📄 3. Send Full RFP: Parses 10 compliance items with exact page citations.
4. ⏰ 4. Trigger Check-in: Fires a simulated Temporal proactive follow-up notification.
5. 📊 5. Check Status: Displays live bid readiness score.

7. Submission Checklist & Category Qualifications

• [x] Theme: Side Hustle: Commercial B2B service for local contractors solving a quantifiable revenue problem.
• [x] Best Use of Render: Complete multi-service blueprint in render.yaml deploying FastAPI, Temporal background worker, and PostgreSQL.
• [x] Best Use of Gemma: Powered by Google's open-weight Gemma model for procurement reasoning.
• [x] Best Use of Temporal: Multi-week durable workflows managing timers, signals, and proactive check-in activities.