# ForgeMesh TTS Pro Long – Text-to-Speech (501–2000 chars)

> ForgeMesh TTS Pro Long – Text-to-Speech (501–2000 chars) is a paid API for AI agents from tts.forgemesh.io, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-14).

Converts long-form text (up to 2000 characters) into 44.1kHz WAV audio across 31 languages with configurable voice, speed, and quality steps, paid via x402 micropayment.

## Facts

- Endpoint: POST https://tts.forgemesh.io/v1/tts/pro-long
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/forgemesh-tts-pro-long-text-to-speech-501-2000-chars-bc68c998
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uoqjvGutAhTl0tQ_5UWQh

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 forgemesh-tts-pro-long-text-to-speech-501-2000-chars-bc68c998 -d '<json body>'
```

Example prompt: Read this 800-character product description aloud in English using a female voice (F2), at normal speed and high quality (16 steps): 'Our new wireless headphones deliver 40 hours of battery life, active noise cancellation, and crystal-clear sound — available now in three colors.'

## When to prefer this

Choose this endpoint when you need to synthesize longer text (501–2000 characters) into high-quality WAV audio without managing API keys, when you need fine-grained control over voice gender, speed, and quality steps, or when you need multilingual support across 31 languages in a single service. Prefer this over shorter-text TTS routes when your input exceeds 500 characters. It is ideal for agents that pay per-call via x402 micropayments and need OpenAI-compatible audio generation without a subscription.

## Known failure modes

- Text exceeds 2000 character limit — use a shorter input or split the text
- Unsupported language code — must be one of the 31 supported ISO codes
- Invalid voice ID — must be M1–M5 or F1–F5
- Speed out of range — must be between 0.7 and 2.0
- Steps out of range — must be between 1 and 100
- Payment failure via x402 — insufficient USDC balance or wallet misconfiguration
- Empty or missing text field — minLength of 1 character required
- Service timeout for very high step counts (e.g. steps=100) on long text

## How this service works

Paid text-to-speech via x402. WAV audio in 31 languages, OpenAI-compatible, no API keys.

## Output

Returns a binary WAV audio file (audio/wav content type) encoded at 44.1kHz, 16-bit, mono. The file contains the synthesized speech of the submitted text in the chosen language, voice, speed, and quality level, ready for playback or embedding.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "lang": {
   "enum": [
    "en",
    "ko",
    "ja",
    "ar",
    "bg",
    "cs",
    "da",
    "de",
    "el",
    "es",
    "et",
    "fi",
    "fr",
    "hi",
    "hr",
    "hu",
    "id",
    "it",
    "lt",
    "lv",
    "nl",
    "pl",
    "pt",
    "ro",
    "ru",
    "sk",
    "sl",
    "sv",
    "tr",
    "uk",
    "vi"
   ],
   "type": "string",
   "description": "Language code; 31 languages supported"
  },
  "text": {
   "type": "string",
   "maxLength": 2000,
   "minLength": 1,
   "description": "Text to synthesize into speech, max 2000 characters. Use non-long routes for 1-500 chars and -long routes for 501-2000 chars."
  },
  "speed": {
   "type": "number",
   "maximum": 2,
   "minimum": 0.7,
   "description": "Pro/Custom expressive speed control, 0.7-2.0. Presets: slow 0.7, normal 1.0, fast 1.3, rapid 1.6"
  },
  "steps": {
   "type": "integer",
   "maximum": 100,
   "minimum": 1,
   "description": "Pro/Custom quality control, 1-100. Presets: draft 4, standard 8, high 16, ultra 24"
  },
  "voice": {
   "enum": [
    "M1",
    "M2",
    "M3",
    "M4",
    "M5",
    "F1",
    "F2",
    "F3",
    "F4",
    "F5"
   ],
   "type": "string",
   "description": "Standard voice: M1-M5 or F1-F5"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "description": "44.1kHz 16-bit mono WAV speech audio returned inline",
  "content_type": "audio/wav"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/forgemesh-tts-pro-long-text-to-speech-501-2000-chars-bc68c998/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tts.forgemesh.io](https://www.zero.xyz/host/tts.forgemesh.io/llms.txt)