The whole stack runs on day one
Vapi gives you an API to glue voice agents together at $0.05 a minute for hosting plus whatever your model provider charges on top, with $10 per phone line per month. The Build plan ships without SSO, RBAC, SOC 2 reports, or an SLA, and compliance is sold separately at $2,000 a month for HIPAA and $1,000 a month for zero data retention. SpeechifyAI rolls all of that into a single per-minute rate from $0.07 on Pro that covers the LLM, the speech stack, the workflow runtime, tool calling, webhooks, and SOC 2 Type II compliance without the per-feature procurement add-ons.