AssemblyAI API
assemblyai.com
Provides REST and WebSocket APIs for speech-to-text transcription, audio understanding, voice agents, and applying LLMs to audio data.
The AssemblyAI API API uses api key authentication; has usage based pricing; offers a free tier (Try the API for free; start free, pay-as-you-go after that with no commitments); rate limits: LLM Gateway limited to a number of requests per 60-second window (per model); 429 on exceed; check X-RateLimit headers; contact to increase. Verified 2026-07-13 with per-field source links.
Free tier
Try the API for free; start free, pay-as-you-go after that with no commitments
assemblyai.com ↗Pricing
Pay-as-you-go: Universal-3.5 Pro $0.21/hr, Universal-2 $0.15/hr, Realtime from $0.15/hr, Voice Agent $4.50/hr; Speech Understanding and Guardrails add-ons per hour; LLM Gateway priced per 1M tokens; custom enterprise rates via contact sales
assemblyai.com ↗Rate limits
LLM Gateway limited to a number of requests per 60-second window (per model); 429 on exceed; check X-RateLimit headers; contact to increase
assemblyai.com ↗OpenAPI spec
not documented null
no sourceMCP server
not documented null
no source