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Api Endpoint

Agent Utility Suite

HVAC duct sizing calculator: any two of duct size (round or rectangular), airflow, velocity and friction rate. Round and rectangular equivalents, nearest standard sizes, friction loss per 100 ft (Darcy-Weisbach, Colebrook), velocity pressure, design checks. Equal-friction sizing, fixed-depth ducts, IP or SI. Shows every step with the numbers. $0.002 USDC per call.

Open interactive test console

Offering

Provider
x402-agent-api.onrender.com
Method
POST
Offering type
Api Endpoint
Transport type
http
Category
General Utilities
Delivery
Not provided
Pricing model
Not provided
x402 version
2

Endpoint context

URL
https://x402-agent-api.onrender.com/api/v1/hvac-duct-size
MIME type
Not provided
First seen
2026-10-16T01:50:38.788Z
Last seen
Tags
hvac, duct-sizing, engineering, mechanical-engineering, ashrae

Website

Payment pricing

x402 payment terms are the authoritative price for calling this endpoint.

Payment option 1
0.002 USDC
Atomic price: 2000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Raw x402 terms
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "payTo": "0x6847231bD28E16A0A57c59793f6B8BD8CC0043aC"
  }
]

Observed health

Status
Healthy
Latest latency
122 ms
Average latency
475 ms
HTTP status
204
Last checked
Reachability
100% over 6 checks

Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.

Input schema

{
  "additionalProperties": false,
  "properties": {
    "body": {
      "additionalProperties": false,
      "properties": {
        "airflow": {
          "description": "Airflow: CFM (IP) or L/s (SI).",
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "diameter": {
          "description": "Round duct diameter: in (IP) or mm (SI).",
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "friction_rate": {
          "description": "Friction loss: in. w.g. per 100 ft (IP, typically 0.05-0.15) or Pa/m (SI, typically 0.4-1.2). With airflow, this is equal-friction sizing.",
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "height": {
          "description": "Rectangular height: in or mm.",
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "units": {
          "default": "IP",
          "description": "\"IP\" (°F, CFM, in, BTU) or \"SI\" (°C, L/s, mm, kW). Default IP. Applies to inputs and results.",
          "enum": [
            "IP",
            "SI"
          ],
          "type": "string"
        },
        "velocity": {
          "description": "Air velocity: FPM (IP) or m/s (SI).",
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "via": {
          "description": "Optional: the tool whose next_calls suggested this call (filled in for you).",
          "maxLength": 64,
          "type": "string"
        },
        "width": {
          "description": "Rectangular width: in or mm. With height, the duct size; alone, a fixed side (e.g. a ceiling depth) the other side is solved for.",
          "exclusiveMinimum": 0,
          "type": "number"
        }
      },
      "type": "object"
    },
    "bodyType": {
      "enum": [
        "json",
        "form-data",
        "text"
      ],
      "type": "string"
    },
    "method": {
      "enum": [
        "POST"
      ],
      "type": "string"
    },
    "type": {
      "const": "http",
      "type": "string"
    }
  },
  "required": [
    "type",
    "method",
    "bodyType",
    "body"
  ],
  "type": "object"
}

Output schema

{
  "properties": {
    "example": {
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}