Tag-per-Track: Agentic-First Musical Audio Analysis API

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xD33906178569f35EFF2E1665A14b06b455fF531F",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "maxTimeoutSeconds": 600
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "fileUrl": "https://example.com/audio.mp3"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "example": {
          "data": {
            "bpm": 120,
            "genres": [
              {
                "confidence": 0.95,
                "label": "electronic"
              }
            ],
            "instruments": [
              {
                "confidence": 0.99,
                "label": "synthesizer"
              }
            ],
            "key": "C",
            "moods": [
              {
                "confidence": 0.8,
                "label": "happy"
              }
            ],
            "scale": "major"
          },
          "message": "Analysis successful. Payment confirmed on-chain.",
          "success": true
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "properties": {
                "fileUrl": {
                  "description": "URL of the audio file to analyze (mp3, wav, etc.)",
                  "type": "string"
                }
              },
              "required": [
                "fileUrl"
              ]
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST",
                "PUT",
                "PATCH"
              ],
              "type": "string"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://api.tag-per-track.cloud/api/analyze"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://api.tag-per-track.cloud/api/analyze");
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://api.tag-per-track.cloud/api/analyze")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header