AI text-to-speech (ElevenLabs) — pay per call with USDC on Base

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xe9030014F5DAe217d0A152f02A043567b16c1aBf",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "53501",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "bodyFields": {
          "input": {
            "description": "Text to synthesize into speech",
            "type": "string"
          },
          "model": {
            "description": "Speech model ID (e.g., elevenlabs/flash-v2.5)",
            "type": "string"
          },
          "response_format": {
            "description": "Audio format: mp3 (default), opus, pcm, wav",
            "type": "string"
          },
          "speed": {
            "description": "Playback speed 0.7-1.2 (optional)",
            "type": "number"
          },
          "voice": {
            "description": "Voice alias or raw ElevenLabs voice_id",
            "type": "string"
          }
        },
        "discoverable": true,
        "method": "POST",
        "type": "http"
      },
      "output": null
    },
    "schema": {
      "properties": {
        "input": {
          "properties": {
            "body": {
              "properties": {
                "input": {
                  "description": "Text to synthesize into speech",
                  "type": "string"
                },
                "model": {
                  "description": "Speech model ID (e.g., elevenlabs/flash-v2.5)",
                  "type": "string"
                },
                "response_format": {
                  "description": "Audio format: mp3 (default), opus, pcm, wav",
                  "type": "string"
                },
                "speed": {
                  "description": "Playback speed 0.7-1.2 (optional)",
                  "type": "number"
                },
                "voice": {
                  "description": "Voice alias (e.g., sarah, george) or raw ElevenLabs voice_id",
                  "type": "string"
                }
              },
              "required": [
                "input"
              ],
              "type": "object"
            }
          },
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "properties": {
                "characters": {
                  "type": "number"
                },
                "format": {
                  "type": "string"
                },
                "url": {
                  "type": "string"
                }
              },
              "type": "object"
            }
          },
          "type": "object"
        }
      },
      "type": "object"
    }
  }
}

curl "https://blockrun.ai/api/v1/audio/speech"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://blockrun.ai/api/v1/audio/speech");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://blockrun.ai/api/v1/audio/speech")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header