ElevenLabs

Lightweight, dependency-free, in-memory ElevenLabs API fake for testing code that uses the real elevenlabs SDK (and the language-agnostic REST API). Text-to-speech returns deterministic audio/mpeg bytes derived from a hash of the text + voice id, so tests are repeatable.

Default port: 4753

Quick start

import { ElevenlabsServer } from "./services/elevenlabs/src/server.js";

const server = new ElevenlabsServer(4753);
await server.start();
// ... run your app/tests ...
await server.stop();

Point the real elevenlabs client at it via baseUrl:

import { ElevenLabsClient } from "elevenlabs";

const client = new ElevenLabsClient({
  apiKey: "parlel",
  baseUrl: "http://127.0.0.1:4753",
});

const audio = await client.textToSpeech.convert("21m00Tcm4TlvDq8ikWAM", {
  text: "Hello world",
  model_id: "eleven_multilingual_v2",
});
// audio => a deterministic audio/mpeg byte stream

Implemented operations

All /v1/* routes require an xi-api-key header (any non-empty key is accepted). State is in-memory and ephemeral.

POST /v1/text-to-speech/{voice_id} — synthesize speech, returns audio/mpeg bytes (deterministic). The optional /stream suffix is also accepted.
GET /v1/voices — list available voices.
GET /v1/voices/{voice_id} — retrieve one voice.
GET /v1/models — list TTS models.
GET /v1/user — user info including subscription.
GET /v1/user/subscription — subscription details.

Service & inspection operations (parlel extensions)

GET / — service metadata.
GET /health — health check ({ status: "ok" }).
POST /__parlel/reset — reset all in-memory state.
GET /__parlel/requests — list captured TTS requests (text + voice).
DELETE /__parlel/requests — clear the captured request log.

SDK usage example

from elevenlabs.client import ElevenLabs

client = ElevenLabs(api_key="parlel", base_url="http://127.0.0.1:4753")
audio = client.text_to_speech.convert(
    voice_id="21m00Tcm4TlvDq8ikWAM",
    text="Hello world",
    model_id="eleven_multilingual_v2",
)
with open("out.mp3", "wb") as f:
    for chunk in audio:
        f.write(chunk)

Access via MCP / preview URL

HTTP services are auto-exposed at the Daytona preview URL. Send requests to the preview URL with the x-daytona-preview-token header. Set ELEVENLABS_BASE_URL to the preview URL.

Surface coverage

This emulator faithfully replicates the API surface most application code and agents exercise. Anything below the supported lines is either an intentional design choice for a fast, zero-cost local emulator (✓ By design) or a candidate for a future release (⟳ Roadmap) — never a silent inaccuracy.

Legend: ✅ fully supported · ◐ accepted (stored, not strictly enforced) · ✓ by design · ⟳ on the roadmap.

Feature	Status
`text_to_speech` (deterministic audio/mpeg)	✅ Supported
`voices` list/retrieve	✅ Supported
`models` list	✅ Supported
`user` / `user.subscription`	✅ Supported
`/stream` suffix	✅ Supported (same bytes)
Request inspection	✅ Supported (parlel extension)
Real speech synthesis / playable audio	✓ By design — Intentional for a local, zero-cost test emulator
Speech-to-text / voice cloning / dubbing	⟳ Roadmap
Voice settings application	◐ Accepted, not applied
`xi-api-key` validity / quota	✓ By design — Never throttles — local tests run at full speed, zero cost

Manifest

See services/elevenlabs/manifest.json:

name: elevenlabs, image: parlel/elevenlabs:1
port: 4753, protocol: http, healthcheck: /health, startup ≈ 100ms
env: ELEVENLABS_API_KEY, ELEVENLABS_BASE_URL

Configuration — `test.env`

Copy these into your test.env (used by the bridge sidecar flow). Tokens are Parlel's seeded test credentials — any non-empty value is accepted by the emulator, so you rarely need to change them. Swap in real credentials only when pointing at the live service in prod.env.

ELEVENLABS_API_KEY=parlel
ELEVENLABS_BASE_URL=http://parlel-bridge:4753