ThinnestAI vs Vapi
Vapi is the default dev voice-AI platform most Indian builders evaluate first. Here's the honest head-to-head on pricing, phone ops, and Indian-language support.
- ThinnestAI is roughly 65% cheaper at the platform layer alone (₹1.5/min vs Vapi's $0.05/min platform fee ≈ ₹4.2/min), before the BYOK provider stack.
- ThinnestAI bills in INR with GST-compliant invoices. Vapi is USD-only Stripe billing — painful for Indian ITC claims.
- ThinnestAI handles Indian phone numbers natively (DLT-compliant via Vobiz and Twilio BYOK). With Vapi, DLT/TRAI compliance is your problem.
Real pricing math, three volume tiers
Vapi's all-in cost is publicly reported at $0.25–$0.33/min once a typical provider stack is layered in. We use a mid-point ≈ $0.25/min (₹21). ThinnestAI uses ₹1.5/min platform fee plus the ThinnestAI Stack (curated LLMs for intelligence and low latency + Sarvam v2 TTS and STT) landing at ₹3–4/min all-in. Converted at ₹83/$.
Pricing sourced from public rate cards as of April 2026. Your actual costs depend on prompt length, output tokens, provider choice, and BYOK status. Verify current rates on each vendor's pricing page before committing.
Feature-by-feature comparison
| Feature | ThinnestAI | Vapi |
|---|---|---|
| Platform fee | ₹1.5/min | $0.05/min (~₹4.2/min) |
| Billing currency | INR with GST invoices | USD only (Stripe) |
| Indian phone number procurement | Native — Twilio + Vobiz BYOK, DLT-compliant | DIY via Twilio/Telnyx |
| BYOK providers (LLM/STT/TTS) | Full BYOK | Full BYOK |
| No-code flow editor | Yes — drag-and-drop flow editor | Yes — Vapi Workflows |
| Indian language routing | Opinionated Indic routing (Sarvam, Deepgram Nova, ElevenLabs Multilingual) | Pass-through, no opinion |
| Developer community size | Growing, India-focused | Massive global community, many templates |
| Docs & SDKs | REST, Python, JS | REST, Node, Python, Web, huge examples repo |
You are building an English-first global product
- Your users are primarily English-speaking (US, UK, EU, ANZ).
- You want access to the largest template / community library in the voice AI space.
- USD Stripe billing is not a concern for your entity.
- You are happy to wire up DLT / TRAI compliance yourself via Twilio.
You are building for Bharat
- You serve Hindi, Marathi, Tamil, Telugu or any Indian-language audience.
- You need INR billing and GST-compliant tax invoices, not USD Stripe charges.
- You want native Indian phone number procurement (DLT-compliant via Vobiz / Twilio BYOK).
- You want to bring your own LLM / STT / TTS and mix providers per agent.
- A flat ₹1.5/min platform fee beats per-provider stacking for cost predictability.
Frequently asked questions
How does ThinnestAI compare to Vapi on price?
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Vapi charges $0.05/min as a flat platform fee, plus pass-through for whichever providers you pick. Real-world all-in is $0.25–$0.33/min per Bessemer's own portfolio commentary. ThinnestAI is ₹1.5/min platform fee plus the ThinnestAI Stack (curated LLMs for intelligence and low latency + Sarvam v2 TTS and STT) landing at ₹3–4/min all-in — roughly 80% cheaper at the same volume.
Can ThinnestAI do everything Vapi can?
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For Indian-market use cases, yes — same BYOK provider flexibility, same native phone/SIP integration, same no-code flow editor, plus INR billing and DLT-compliant phone number procurement that Vapi does not offer. For global English-first products Vapi has a larger template library and more community examples.
Why does INR billing matter?
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Indian businesses claiming Input Tax Credit (ITC) need GST-compliant tax invoices in INR from the vendor. USD Stripe charges from Vapi do not qualify. ThinnestAI issues GST invoices, which means roughly 18% of your spend comes back as ITC for GST-registered businesses.
Is ThinnestAI as developer-friendly as Vapi?
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ThinnestAI offers REST APIs, Python and JS SDKs, webhooks, and a no-code flow editor. Vapi has a larger community and more templates, but the core dev experience (start an agent, swap providers, deploy) is comparable.
Can I migrate from Vapi to ThinnestAI?
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Yes. Since both are BYOK, you can reuse the same provider accounts (OpenAI, Deepgram, ElevenLabs) and just point them at ThinnestAI. Flow logic needs to be rebuilt in the ThinnestAI editor, but prompts and provider config carry over.
Try ThinnestAI free
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