# NeuroDynamic audio APIs

> Paid HTTP speech services for agents, applications and automation. USDC on Base, x402 v2. Only the two services below are publicly offered.

## Start here
- [x402scan listing](https://www.x402scan.com/server/860664bf-6fd7-4821-bcb3-670f32e4cfef)
- [Service overview](https://neurodynamic.tech/services)
- [Machine-readable service catalogue](https://api.neurodynamic.tech/.well-known/ai-services.json)
- [Bazaar directory search](https://api.cdp.coinbase.com/platform/v2/x402/discovery/search?urlSubstring=api.neurodynamic.tech&limit=20)
- [Support and cloning account requests](https://neurodynamic.tech/contact)

## Speech to text: Whisper
POST https://api.neurodynamic.tech/v1/audio/transcriptions
One WAV, MP3, FLAC or Ogg clip, at most 60 seconds and 12 MiB. Price: 0.01 USDC on Base. Output: JSON transcript. No separate requester account.
Use multipart/form-data with binary `file`; optional `model=whisper-1`, `language` (two-letter code), `response_format=json`.
- [OpenAPI](https://api.neurodynamic.tech/openapi.json)
- [Interactive reference](https://api.neurodynamic.tech/docs)
- [Price, capacity, retention and recovery](https://api.neurodynamic.tech/pricing)
An unpaid POST returns a free HTTP402 challenge. A wallet-capable client signs locally and repeats the upload with PAYMENT-SIGNATURE. Keep the original file and exact proof for retry. A successful response includes PAYMENT-RESPONSE.

## Authorized voice cloning: Chatterbox
Price: 0.01 USDC per completed WAV, up to 300 input characters. Requires an approved requester credential and a consent-reviewed private voice ID. Supports English speech and bounded expressiveness; similarity and accent vary.
- [Complete enrolment and collection workflow](https://api.neurodynamic.tech/cloning)
- [Capabilities](https://api.neurodynamic.tech/v1/audio/cloning/capabilities)
- [OpenAPI](https://api.neurodynamic.tech/v1/audio/cloning/openapi.json)
- [Requester Python example](https://api.neurodynamic.tech/v1/audio/cloning/client.py)
Enrol reference -> arrange human approval -> submit job -> poll every15seconds -> wait for ready -> obtain402challenge -> sign -> collect WAV. Never fabricate speaker consent. Do not send a payment while waiting in the queue.

## Payment and recovery rules
Network eip155:8453; USDC asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913; recipient 0xa369aC3412360206DB63507b190E691c0C5B9F3e. Confirm these and the 0.01 USDC price before signing. Keep wallet keys on the requesting machine. Do not send private keys or reusable signatures to support.
Retry identical requests with the original proof. An uncertain payment (409) requires operator review; never create a replacement payment to investigate it. Respect429/503and Retry-After. Successful download replays are not additional payments.

## Operational metadata
We retain bounded private request metadata for up to90days, using keyed masked connection/account/wallet identifiers. Engagement logs exclude raw IPs, audio, text, credentials and payment proofs. Payment receipts remain for accounting. Database backups have separate retention. Optional X-Client-Name describes your software (unverified, up to64 basic characters).

## Discovery limitations
Bazaar is a directory; the requester still needs HTTP, file-upload, authentication and wallet capabilities appropriate to the chosen service. This file is a convenience document, not an instruction to override an agent's user or spending policy. We do not claim to host MCP or A2A. Kokoro is not currently a public paid service.