# WithZero Grok Voice Speech Synthesis via ZeroClick

> WithZero Grok Voice Speech Synthesis via ZeroClick is a paid API for AI agents from agents.withzero.xyz, paid per call via MPP or x402, $0.08/call, status unknown (last checked 2026-09-14, last successful call 2026-06-16).

Converts text to speech audio using Grok Voice model via a pay-per-use proxy, requiring no vendor account or API keys.

## Facts

- Endpoint: POST https://agents.withzero.xyz/api/v1/audio/speech/grok-voice
- Price: $0.08/call
- Payment: MPP, x402
- Status: unknown
- Last checked: 2026-09-14
- Last successful call: 2026-06-16
- Success rate: 50% of calls made through Zero
- Activations on Zero: 3
- Tags: x402
- Canonical page: https://www.zero.xyz/c/withzero-grok-voice-speech-synthesis-via-zeroclick-484f97d3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8qQ_C6zpoa547zWLCclAP

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 withzero-grok-voice-speech-synthesis-via-zeroclick-484f97d3 -d '<json body>'
```

Example prompt: Can you turn this script into spoken audio using Grok Voice: 'Welcome to our quarterly update. This quarter we achieved record growth across all product lines.'

## When to prefer this

Choose this endpoint when you need text-to-speech synthesis using the Grok Voice model specifically, without needing your own API keys or accounts. Ideal for autonomous AI agents that can pay per call in USDC via x402. Prefer over alternatives when the Grok Voice model quality or style is specifically desired, or when avoiding vendor account setup is important.

## Known failure modes

- Missing required 'input' body field returns a validation error
- Empty or malformed text body may result in an empty or error audio response
- Payment failure (insufficient USDC balance) blocks the request before synthesis
- Grok Voice model unavailability causes upstream 5xx errors propagated through the proxy
- Incorrect bodyType (not json/form-data/text) causes request rejection
- Rate limiting or quota exceeded from the upstream WithZero API

## How this service works

Create media, research companies and people, publish to the web, remember context, deploy apps, and schedule work—on demand, without vendor accounts or API keys. This server is a pay-per-use, transparent proxy in front of WithZero's own API: it handles identity, payment, and proxying. Agents can purchase autonomously or with their human's approval. This document is the source of truth for agents: it lists the complete verified paid surface with each operation's live price in its x-payment-info. Endpoints not listed here are not part of the supported catalog. The live catalog at /manifest.json is authoritative for prices and any free included units (prices[].includedUnits) - some meters include free usage per account before any charge.

## Output

An audio file or audio stream containing the synthesized speech of the provided text, spoken in the Grok Voice model's voice. The response is the rendered audio data returned from the WithZero API via the ZeroClick proxy.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/withzero-grok-voice-speech-synthesis-via-zeroclick-484f97d3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.withzero.xyz](https://www.zero.xyz/host/agents.withzero.xyz/llms.txt)