Transcribe audio

AssemblyAI

Speech-to-text API that transcribes recorded and live audio into text with word timestamps, speaker labels and analysis options.

MCP server

Official MCP server: Yes, remote6
Address or package: https://mcp.assemblyai.com/mcp (Streamable HTTP, transcribes and analyzes audio); https://www.assemblyai.com/docs/mcp (docs search only)6
Docs MCP server purpose: Searches and reads the docs; does not transcribe6
Account MCP server without credentials: HTTP 401 invalid_token to initialize and tools/list; tool list could not be read18
Docs MCP server tools/list: 3 tools, no credentials needed18

MCP tools

Account server at https://mcp.assemblyai.com/mcp, from the docs page. The server needs sign-in, so annotations could not be read.

Tool	What it does	Read-only
`submit_transcript`	Starts a transcription of a public audio or video URL and returns a `transcript_id`	Not stated
`get_transcript`	Returns the status of a transcript, and the full results when completed	Not stated
`summarize_transcript`	Summarizes a completed transcript with LLM Gateway	Not stated
`understand_transcript`	Runs Speech Understanding on a completed transcript	Not stated
`delete_transcript`	Permanently deletes a transcript and its data	Not stated

Source6MCP server

MCP tools (docs server)

https://www.assemblyai.com/docs/mcp, from tools/list sent without credentials. These tools search documentation; none transcribes audio.

Tool	What it does	Read-only
`search_assembly_ai`	Searches the AssemblyAI knowledge base for docs, examples and API references	Yes
`query_docs_filesystem_assembly_ai`	Runs read-only shell-like queries (`rg`, `cat`, `head`) over the docs and OpenAPI specs	Yes
`submit_feedback`	Reports a problem with the documentation site	No

Source18Checked by supermarket.dev

API

Endpoint	What it does
`POST /v2/upload`	Uploads a local file as raw binary and returns an `upload_url`
`POST /v2/transcript`	Submits a transcription job from an audio URL
`GET /v2/transcript/{id}`	Returns job status and the transcript
`DELETE /v2/transcript/{id}`	Deletes a transcript
`GET /v2/transcript/{id}/{subtitle_format}`	Exports subtitles
`GET /v2/transcript/{id}/sentences` and `/paragraphs`	Returns the transcript split into sentences or paragraphs
`wss://streaming.assemblyai.com/v3/ws`	Real-time streaming transcription over WebSocket
`POST https://token.assemblyai.com/v1/token`	Mints a temporary token for browser or mobile streaming

Source12Build with AI coding agents

Features

Default model: universal-3-5-pro, with automatic fallback to universal-2 for other languages9
Default model, free vs paid accounts: Can differ between free and paid accounts; set speech_models explicitly1
Languages: Pre-recorded: 99 (Universal-2), 18 (Universal-3.5 Pro); streaming: 32 (Universal-3.6 Pro Realtime)8
Languages, Universal-3.5 Pro: 188
Languages, Universal-3.6 Pro Realtime: 32, with code switching8
Speaker labels: Yes, pre-recorded and streaming; streaming add-on is $0.12 per hour1
Speaker labels, pre-recorded: Yes; $0.02 per hour standard, $0.065 per hour experimental1
Word timestamps: Yes, included by default12
Live streaming: Yes, over WebSocket2
Max file size: 5 GB per request and 10 hours; 2.2 GB for local upload13
Audio input: Public URL or uploaded file; most common audio and video formats, no transcoding needed10
Audio input, streaming: PCM16 little-endian, mono, 16 kHz binary frames12

Read from AssemblyAI’s own pages on 2026-11-04. Every number links to the page a value came from. For agents, the same facts as markdown: /tools/transcribe-audio/assemblyai.md