# Autumn Eight Text-to-Speech (TTS) Endpoint

> Autumn Eight Text-to-Speech (TTS) Endpoint is a paid API for AI agents from x402.autumn8.net, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Converts text input into spoken audio output, payable per-call via x402 micropayment protocol

## Facts

- Endpoint: POST https://x402.autumn8.net/v1/audio/speech?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/autumn-eight-text-to-speech-tts-endpoint-2780b310
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uManzQuyr1K6QltBS2HlY

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 autumn-eight-text-to-speech-tts-endpoint-2780b310 -d '<json body>'
```

Example prompt: Read out the following script in a natural voice and give me the audio file: 'Welcome to our platform. We're glad you're here. Let's get started.'

## When to prefer this

Choose this endpoint when you need pay-per-call text-to-speech with no subscription commitment, especially in autonomous agent pipelines that use x402 micropayments (USDC). It is well-suited for workflows where spending is metered per inference call rather than billed monthly. Prefer it over subscription TTS APIs when operating agentic systems that need programmatic, per-request payment authorization without human-in-the-loop billing setup.

## Known failure modes

- Payment not provided or insufficient USDC balance via x402 — returns 402 Payment Required
- Text input too long for a single call — may return a 400 or truncation error
- Unsupported voice or format parameter — returns 400 Bad Request
- Service unavailability or inference backend error — returns 500 or 503
- Malformed request body — returns 400 with validation details

## How this service works

Agent-payable inference. Chat, embeddings, rerank, transcription and speech.

## Output

Returns a synthesized audio file (e.g. MP3 or WAV) containing the spoken version of the input text, produced by an AI voice model and delivered as binary audio content

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/autumn-eight-text-to-speech-tts-endpoint-2780b310/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.autumn8.net](https://www.zero.xyz/host/x402.autumn8.net/llms.txt)