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AssemblyAI

$50 in free credits, no card; speech-to-text plus LeMUR LLM audio intelligence

AssemblyAI is a speech-to-text API with batch and streaming transcription plus audio intelligence add-ons: speaker diarization, entity/topic detection, summarization and the LeMUR framework for running LLM prompts over transcripts. You submit audio by URL or upload, poll the transcript id, then read the result.

Free tier

$50 one-time free credit, no card (~333 hours on Universal-2 at $0.15/hr); then pay-as-you-go

Rate limits

~5 concurrent transcriptions on free/PAYG; extra files queue rather than run in parallel

Auth

API key

Base URL

https://api.assemblyai.com

What you'd build with it

  • Transcribe and summarize call recordings in an automation
  • Run LeMUR LLM prompts ('what were the action items?') over a transcript
  • Auto-detect speakers and topics for a meeting-notes Skill

Key endpoints

  • POST/v2/transcriptSubmit audio (by URL) for transcription, returns a transcript id
  • GET/v2/transcript/{id}Poll a transcript by id for status and final text
  • POST/v2/uploadUpload a local audio file before transcribing
Members

Members get the runnable recipe

Sign in free to copy the example request, see a sample response, and read the gotchas.

Tags

speech-to-textaudiotranscriptionllmvoice