find_apisBrowse and filter every API in the catalog.
get_api_artifactsOne API's artifacts, grouped by type.
get_openapiThe primary OpenAPI for this API.
find_similar_apisAPIs that look like this one.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This API

curl "https://apis.io/api/v1/apis/gradium-s2s-api"

All apis

curl "https://apis.io/api/v1/apis?limit=25"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

openapi: 3.2.0
info:
  title: Gradium S2 S API
  description: 'This documentation covers the Gradium API.


    This API exposes our Text-To-Speech and Speech-To-Text models, which offers low-latency, high-quality & natural sounding output and best in class accuracy.


    For issues, questions, or feature requests, please contact us at support@gradium.ai'
  version: 0.1.0
servers:
- url: https://api.gradium.ai/api
  description: Gradium API
tags:
- name: S2s
paths:
  /speech/s2s:
    get:
      tags:
      - S2s
      summary: S2S WebSocket Stream
      description: 'Connect to this endpoint via WebSocket for real-time speech-to-speech: incoming audio is transcribed, optionally translated, and re-synthesized into speech.'
      parameters:
      - name: x-api-key
        in: header
        required: true
        schema:
          type: string
        description: Your Gradium API key
      responses:
        '101':
          description: WebSocket connection established
      x-codeSamples:
      - lang: cURL
        source: "wscat -c \"wss://api.gradium.ai/api/speech/s2s\" \\\n  -H \"x-api-key: your_api_key\"\n# After connection, paste:\n# {\"type\":\"setup\",\"model_name\":\"default\",\"input_format\":\"pcm\",\"output_format\":\"pcm\",\"voice_id\":\"YTpq7expH9539ERJ\",\"json_config\":{\"target_language\":\"en\"}}\n"
      - lang: Python
        source: "import asyncio\nimport base64\nimport json\n\nimport websockets\n\nIN_CHUNK_BYTES = 1920 * 2  # 80 ms at 24 kHz, 16-bit mono.\n\n\nasync def speech_to_speech(api_key: str, pcm_audio: bytes, voice_id: str) -> bytes:\n    setup = {\n        \"type\": \"setup\",\n        \"model_name\": \"default\",\n        \"input_format\": \"pcm\",\n        \"output_format\": \"pcm\",\n        \"voice_id\": voice_id,\n        \"json_config\": {\"target_language\": \"en\"},\n    }\n    out_audio = []\n\n    async with websockets.connect(\n        \"wss://api.gradium.ai/api/speech/s2s\",\n        additional_headers={\"x-api-key\": api_key},\n    ) as ws:\n        await ws.send(json.dumps(setup))\n        ready = json.loads(await ws.recv())\n        assert ready[\"type\"] == \"ready\"\n\n        async def producer():\n            for off in range(0, len(pcm_audio), IN_CHUNK_BYTES):\n                chunk = pcm_audio[off : off + IN_CHUNK_BYTES]\n                await ws.send(json.dumps({\n                    \"type\": \"audio\",\n                    \"audio\": base64.b64encode(chunk).decode(),\n                }))\n            await ws.send(json.dumps({\"type\": \"end_of_stream\"}))\n\n        async def consumer():\n            while True:\n                msg = json.loads(await ws.recv())\n                if msg[\"type\"] == \"text\":\n                    print(msg[\"text\"])\n                elif msg[\"type\"] == \"audio\":\n                    out_audio.append(base64.b64decode(msg[\"audio\"]))\n                elif msg[\"type\"] == \"end_of_stream\":\n                    return\n                elif msg[\"type\"] == \"error\":\n                    raise RuntimeError(msg[\"message\"])\n\n        await asyncio.gather(producer(), consumer())\n\n    return b\"\".join(out_audio)\n\n\nasyncio.run(speech_to_speech(\"your_api_key\", open(\"input.pcm\", \"rb\").read(), \"YTpq7expH9539ERJ\"))\n"
      operationId: getSpeechS2s
      x-operation-id-source: derived
x-tagGroups:
- name: Documentation
  tags:
  - Documentation
  - FAQ
  - Release notes
- name: API Reference
  tags:
  - TTS
  - STT
  - Voices
  - Pronunciations
  - Credits