Index onlineMerchant portal
Api Endpoint

HALOWERK kettenwerk

Reads the fee history of the last 20 blocks on Ethereum, Base, Arbitrum, Optimism, Polygon or BNB Smart Chain and returns what a transaction costs right now. Priority fees come from the 10th, 50th and 90th percentile of the tips actually paid in those blocks — the percentile used is named, not hidden. On rollups the L1 data fee is quoted separately from the L2 execution fee, because it is often the larger part and an estimate that merges them is simply wrong; the L1 part is computed from the cha

Open interactive test console

Offering

Provider
kette.halowerk.com
Method
POST
Offering type
Api Endpoint
Transport type
http
Category
Security
Delivery
Not provided
Pricing model
Not provided
x402 version
2

Endpoint context

URL
https://kette.halowerk.com/gas
MIME type
Not provided
First seen
2026-10-16T03:02:07.735Z
Last seen
Tags
None supplied

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": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E"
  }
]

Observed health

Status
Healthy
Latest latency
316 ms
Average latency
654 ms
HTTP status
204
Last checked
Reachability
100% over 10 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": {
        "chain": {
          "description": "Chain to read fees from.",
          "enum": [
            "ethereum",
            "base",
            "arbitrum",
            "optimism",
            "polygon",
            "bsc"
          ],
          "type": "string"
        },
        "speed": {
          "default": "alle",
          "description": "Which speed level to highlight. All three are always returned.",
          "enum": [
            "langsam",
            "normal",
            "schnell",
            "alle"
          ],
          "type": "string"
        },
        "tx_type": {
          "default": "erc20_transfer",
          "description": "Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer.",
          "enum": [
            "native_transfer",
            "erc20_transfer",
            "erc20_approve",
            "swap",
            "nft_mint",
            "contract_deploy"
          ],
          "type": "string"
        }
      },
      "required": [
        "chain"
      ],
      "type": "object"
    },
    "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 schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "additionalProperties": false,
          "properties": {
            "chain": {
              "description": "Chain to read fees from.",
              "enum": [
                "ethereum",
                "base",
                "arbitrum",
                "optimism",
                "polygon",
                "bsc"
              ],
              "type": "string"
            },
            "speed": {
              "default": "alle",
              "description": "Which speed level to highlight. All three are always returned.",
              "enum": [
                "langsam",
                "normal",
                "schnell",
                "alle"
              ],
              "type": "string"
            },
            "tx_type": {
              "default": "erc20_transfer",
              "description": "Transaction profile used for the total cost estimate. Its assumed gas limit and byte size are stated in the answer.",
              "enum": [
                "native_transfer",
                "erc20_transfer",
                "erc20_approve",
                "swap",
                "nft_mint",
                "contract_deploy"
              ],
              "type": "string"
            }
          },
          "required": [
            "chain"
          ],
          "type": "object"
        },
        "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"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}