When evaluating voice AI platforms, the advertised per-minute rate is almost never the actual cost. Understanding what's included — and what's stacked on top — is the only way to make an accurate comparison.
The Four Cost Components of Voice AI
Every voice AI call has four cost layers:
- STT (Speech-to-Text): Transcribing what the caller says. Typically $0.006–0.024/min on global providers.
- LLM (Language Model): Understanding and generating responses. Typically $0.002–0.04/min depending on model.
- TTS (Text-to-Speech): Generating the AI's voice response. Typically $0.015–0.03/min.
- Telephony: The phone call itself. In India, ₹0.50–1.50/min on most cloud telephony platforms.
Stacked individually at mid-market rates, these four components total ₹8–20 per minute before any platform margin.
What "Bundled" Actually Means
Platforms that advertise bundled all-in pricing have negotiated bulk rates across these providers and absorbed them into a single line. This is generally better value — but verify what's actually included.
Questions to ask any vendor:
- Is telephony (the phone call) included in your per-minute rate?
- Is the LLM included, or do I need my own OpenAI/Anthropic key?
- Is Indian language STT included, or just English?
- Are there any per-call setup fees?
Agni pricing: ₹8–₹9.5/min is all-in. Voice (STT + TTS), LLM inference, emotion engine, and telephony are all included. No separate API keys required. No stacking.
The Hidden Cost: Latency-Related Failure
A call that takes 800ms to respond doesn't just feel bad — it has measurably lower completion rates. In India, where customers are often on variable mobile connections, high latency correlates directly with call abandonment. A cheaper platform that has worse latency may actually cost more in terms of outcome-per-rupee-spent.
Platform Fee vs Usage Fee
Most voice AI platforms have two cost components: a monthly platform fee and a usage fee. The platform fee is the cost of access; the usage fee is the cost of calls made.
At low volumes, the platform fee dominates the economics. At high volumes, the usage fee dominates. Calculate your break-even point before committing to any plan.
Example: At 2,000 calls/month, ₹2/min platform overhead from a ₹2,000 platform fee matters. At 20,000 calls/month, it's ₹0.20/min — noise.
The True Cost Comparison
| Platform | Advertised | All-in estimate |
|---|---|---|
| Agni | ₹8–₹9.5/min | ₹8–₹9.5/min (bundled) |
| Bolna | Variable | ₹7–12/min (estimated) |
| Retell (US-based) | $0.08/min | ₹18–30/min (+ telephony + LLM) |
| Vapi (US-based) | $0.05/min | ₹15–28/min (stacked) |
| Human agent (India) | ₹25K/mo salary | ₹18–24/min (fully loaded) |
At 10,000 calls per month at 3 minutes average duration, the difference between ₹6/min (Agni) and ₹25/min (US platform + stacking) is ₹5.7 lakh per month — ₹68 lakh per year.
