# Prysm AssemblyAI Provider — Audio Transcription via x402

> Prysm AssemblyAI Provider — Audio Transcription via x402 is a paid API for AI agents from prysm-kappa.vercel.app, paid per call via x402, $0.15/call, status unknown (last checked 2026-09-13).

Transcribes audio files to text using AssemblyAI, billed per-call in USDC over the x402 protocol on Base mainnet.

## Facts

- Endpoint: POST https://prysm-kappa.vercel.app/api/v1/providers/assemblyai
- Price: $0.15/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/prysm-assemblyai-provider-audio-transcription-via-x402-cb24c526
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RpnpOCE6xP2AyPnRqBG2k

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability prysm-assemblyai-provider-audio-transcription-via-x402-cb24c526 -d '<json body>'
```

Example prompt: Can you transcribe this audio recording for me — use the AssemblyAI provider with the transcribe operation, and pass in the URL to my MP3 file at https://example.com/meeting.mp3?

## When to prefer this

Choose this endpoint when you need speech-to-text transcription powered by AssemblyAI and want to pay per-call in USDC via the x402 micropayment protocol on Base, without managing an AssemblyAI API key directly. Useful for agents operating in crypto-native payment environments.

## Known failure modes

- Invalid or inaccessible audio URL returns an error from AssemblyAI
- Unsupported audio format may cause transcription failure
- Payment failure via x402 if USDC balance is insufficient on Base mainnet
- Unknown or non-allowlisted operation string causes rejection
- Large audio files may time out or require polling for completion

## How this service works

Prysm sells paid, agent-ready provider capabilities over x402 on Base mainnet using USDC.

## Output

Returns a JSON object containing the transcription result from AssemblyAI, including the transcript text and metadata, wrapped with the provider name and operation used.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "description": "Provider-specific operation parameters.",
   "additionalProperties": true
  },
  "operation": {
   "type": "string",
   "description": "Allowlisted operation for the selected provider."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "provider": "assemblyai",
  "operation": "transcribe"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/prysm-assemblyai-provider-audio-transcription-via-x402-cb24c526/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from prysm-kappa.vercel.app](https://www.zero.xyz/host/prysm-kappa.vercel.app/llms.txt)