Multi-Tenant AI Voice Agent SaaS

Looking for a development partner to build a white-label AI voice SaaS powered by Retell (voice/LLM) and integrated with telephony (Twilio/Telnyx) and payments (Stripe / Razorpay).
Please review the RFP that includes timeline, cost, team composition, tech stack, and 2–3 relevant case studies or references.
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RFP — Project Overview (MVP)
Project goal: Build a branded, multi-tenant SaaS platform that allows business customers to create and run AI voice agents (outbound campaigns + inbound answering) using Retell for voice/LLM and Twilio/Telnyx for telephony. The platform will be white-label (custom domain, branding, sub-accounts) and include metered billing for usage.
MVP Core Deliverables:
1. Frontend (React/Next.js + Tailwind)
o Login / Signup / Role-based access (Admin, Client Admin, Client User)
o Admin dashboard (manage clients, view usage & invoices)
o Client dashboard (create agents, view usage, call logs, transcripts)
o Agent builder (select voice, language, upload knowledge base (PDF/text), save)
o Simple “Call Now” demo flow (start one test call)
2. Backend (Node.js/Express or Python/FastAPI)
o Auth & user management (multi-tenant client model)
o Integration with Retell API (create agents, upload KB, receive transcripts/webhooks)
o Integration with Twilio or Telnyx for outbound/inbound calls and webhooks
o Usage tracking (per-call duration, minutes calculation, cost calculation)
o Billing integration: Stripe (international) + Razorpay (India) — support subscriptions + metered usage/overage invoicing
o Webhooks endpoints for Retell & telephony events
3. Database
o PostgreSQL or Supabase (auth + Postgres) with schema for users, clients, agents, call_logs, billing_items
4. Deployment & DevOps
o Staging and production deployment (Vercel for frontend + Render/Heroku/DigitalOcean/AWS for backend)
o CI/CD (GitHub Actions or equivalent)
o Secrets management (env vars), backups, basic monitoring
5. Documentation & Handover
o Developer runbook: how to provision Retell/Twilio/Stripe keys, add phone numbers, and deploy
o Basic user onboarding docs (how to create an agent, start a campaign)
o 30 days post-launch bug support (included in fixed price)
Optional paid items (quote separately):
• CRM integrations (HubSpot / Zoho)
• WhatsApp Business integration & SMS (compulsory)
• Advanced analytics & scheduled campaigns (campaign scheduler)
• Multi-language fine-tuning or accent training
• Mobile apps (iOS/Android)
• SLA and ongoing maintenance retainer
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Proposal Requirements (please include the following)
1. Executive summary – brief understanding of the project and approach.
2. Team & roles – who will work on the project, experience, and time allocation.
3. Technology stack – frontend, backend, DB, hosting, monitoring.
4. Deliverables & timeline – week-by-week or milestone plan (MVP timeline).
5. Fixed price for the MVP scope (broken down by milestone).
6. Hourly rates for additional work (senior dev, mid dev, QA, PM).
7. Post-launch support options & monthly cost.
8. Assumptions & exclusions – clearly state what’s NOT included.
9. References / case studies – ideally SaaS, telephony, or AI projects.
10. IP & ownership – confirm code & IP will be assigned to me upon full payment.
11. Security & compliance – how you will secure keys, PII, backups, and data deletion.
12. Any required information from me to start (e.g., Retell account, Twilio account).
13. Preferred contract terms and proposed milestone payment schedule.
Please attach: proposal PDF, 2–3 relevant case studies, and 2 client references (name, company, contact).
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Vendor evaluation criteria (how I will score proposals)
• Relevant SaaS & telephony/voice/AI experience (30%)
• Technical approach & clarity of milestones (20%)
• Team strength & availability (15%)
• Price & value (15%)
• References & prior work quality (10%)
• Support & SLA offerings (10%)
Please assume the following baseline for costing: MVP targeted delivery within 1–6 weeks. If you can deliver faster, mention it.
NDA: I can sign a mutual NDA before sharing sensitive details. If you require an NDA, please send your template.