# The prompt

From the Lero API docs: https://lero.studio/docs/en/ai#prompt. Everything in one file: https://lero.studio/docs/en/llms-full.txt.

Want Lero in your product's code? Paste this prompt into your coding agent (Claude Code, Codex, Cursor or another one that reads the web). It reads the docs and writes the integration. The same text is in [prompt.md](https://lero.studio/docs/en/prompt.md).

```markdown
# Integrate the Lero API

You will integrate the Lero voice API into my project. Follow these instructions.

## What Lero is

Lero turns text into speech in Brazilian Portuguese, with a regional accent. You send the text and the voice and get back an MP3. Voices: `rio` (Rio de Janeiro), `sp` (São Paulo), `niteroi` (Niterói). Model: `Lero v1`.

Lero also transcribes Brazilian Portuguese audio (Speech-to-Text): you send the file or a link and get back the text, the sentences with their timestamps, or ready subtitles (SRT or VTT).

## Read before writing code

1. https://lero.studio/docs/en/llms-full.txt: the complete reference in Markdown.
2. https://lero.studio/docs/en/openapi.json: the OpenAPI 3.1 contract of the routes.

Follow the contract. Do not invent routes, fields or error codes.

## Connection

- Base URL: https://app.lero.studio/api/v1
- Every request carries the header `Authorization: Bearer <key>`.
- Read the key from the `LERO_API_KEY` environment variable. Never write the key in the code.
- Call the API only from the server. Never from the browser or a mobile app: whoever has the key spends the credits.

## Routes

1. `POST /v1/tts` with `{"texto": "...", "voz": "rio"}`: returns the MP3 (`audio/mpeg`). With `Accept: application/json` (without `*/*`), returns JSON with the audio as base64 in the `audio` field.
2. `POST /v1/stt` with the file in the `audio` field as `multipart/form-data` (up to 4 MB), or JSON with `url` (public https link, up to 500 MB): returns JSON with `texto` and `segmentos` (the sentences with `inicio` and `fim` in seconds). With `formato` `texto`, `srt` or `vtt`, returns the file itself. Optional: `timestamps` (`palavra`), `palavras_chave`, `formatar`. Only if the request involves transcription, dictation or subtitles.
3. `GET /v1/voices`: the list of voices. Free.
4. `GET /v1/balance`: the account credits and the plan. Free.
5. Conversational Agent (live voice over WebRTC): `GET /v1/agents` and `POST /v1/agents/conversation`. Only if the request is a live voice agent; follow the "Conversational Agent: step by step" section of llms-full.txt.

## Rules

- Speech: 1 credit per character of the text, charged before generating and refunded if generation fails.
- Speech: up to 500 characters per request. For longer text, split it into sentences (never mid-word) and join the MP3s in order.
- Transcription: 150 credits per minute of audio, charged only on success. Up to 2 h per request. Files over 4 MB go by `url`.
- Up to 60 requests per minute per account. On `429` or `503`, wait the seconds in the `Retry-After` header and try again.
- Speech takes a few seconds and transcription a few minutes (1 h of audio in about 2 min): use a 300 s timeout.
- Handle errors by the `erro` field (stable code), never by the `mensagem` text.
- Keep the MP3 and the transcript if you will use them again: each request spends credits, and Lero does not keep the audio or the text.
- Log the `X-Pedido-Id`, for support.

## Deliverables

- An API client with a timeout, waits on `Retry-After` and error handling by `erro`.
- Tests with mocked responses built from the `openapi.json` examples.
- A short summary of what was done and how to run it.
```