Roundhouse AI

onchain-gas

EVM gas oracle for any major chain - Ethereum, Base, Arbitrum, Optimism, Polygon, BNB, Avalanche: next-block baseFee plus slow, med and fast priority-fee tiers (maxFeePerGas and maxPriorityFeePerGas), read live from chain state in one call. Choose network (default Ethereum). EIP-1559 and legacy handled.

TradingLiveeip155:8453Exactvia cdp
https://api.agentstools.dev/gas
CryptoGasGas-oracleOnchainEvm
Calls · 30d
11↓ 9.3%
This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far.
$42.97
Verified settled volume
3,793 settlements proven x402 by their on-chain EIP-3009 marker.
$0.0050
Listed price
As published in the catalog. Always read the live 402 before paying.
11
Calls · 30d
Upstream's own call count for this endpoint, not ours.
3
Unique payers · 30d
Last called 2026-09-08 08:42Z
—
Upstream on-chain volume
Reported by the source catalog.
Paid to
0xF22e558a00D91Ee12A1F50C52186FecB8dDFf493

The wallet the 402 directs payment to. Its whole payment record — every payer, every chain — is on the merchant page.

Asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Provider

The payTo wallet does not resolve to a registered ERC-8004 agent. That is not a verdict on the service — most of the catalog is unregistered.

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "error": "Payment required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0xF22e558a00D91Ee12A1F50C52186FecB8dDFf493",
      "amount": "5000",
      "scheme": "exact",
      "network": "eip155:8453",
      "maxTimeoutSeconds": 300
    }
  ],
  "resource": {
    "url": "https://api.agentstools.dev/gas",
    "tags": [
      "crypto",
      "gas",
      "gas-oracle",
      "onchain",
      "evm",
      "ethereum",
      "base",
      "arbitrum",
      "optimism",
      "polygon",
      "bnb",
      "avalanche",
      "eip1559",
      "basefee",
      "priority-fee",
      "market-data"
    ],
    "mimeType": "application/json",
    "description": "EVM gas oracle for any major chain - Ethereum, Base, Arbitrum, Optimism, Polygon, BNB, Avalanche: next-block baseFee plus slow, med and fast priority-fee tiers (maxFeePerGas and maxPriorityFeePerGas), read live from chain state in one call. Choose network (default Ethereum). EIP-1559 and legacy handled.",
    "serviceName": "onchain-gas"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "network": "ethereum"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "ts": 1756700000,
            "type": "eip1559",
            "block": 25881728,
            "chain": "eip155:1",
            "tiers": {
              "med": {
                "max_fee_gwei": 0.1892,
                "priority_gwei": 0.084
              },
              "fast": {
                "max_fee_gwei": 1.8051,
                "priority_gwei": 1.7
              },
              "slow": {
                "max_fee_gwei": 0.108,
                "priority_gwei": 0.0029
              }
            },
            "network": "ethereum",
            "base_fee_wei": 105129473,
            "base_fee_gwei": 0.1051,
            "gas_price_wei": 189159879,
            "gas_price_gwei": 0.1892
          }
        }
      },
      "schema": {
        "type": "object",
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "required": [
          "input"
        ],
        "properties": {
          "input": {
            "type": "object",
            "required": [
              "type",
              "method"
            ],
            "properties": {
              "type": {
                "type": "string",
                "const": "http"
              },
              "method": {
                "enum": [
                  "GET",
                  "HEAD",
                  "DELETE"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "required": [],
                "properties": {
                  "network": {
                    "enum": [
                      "ethereum",
                      "base",
                      "arbitrum",
                      "optimism",
                      "polygon",
                      "bnb",
                      "avalanche"
                    ],
                    "type": "string",
                    "description": "EVM network (default ethereum)."
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 2
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

0.005USDC≈ $0.005 USD
on Base · exact scheme

Pay 0.005 USDC on Base to 0xF22e…Ff493. The signed payment is good for 5 minutes.

Paid to
0xF22e…Ff493
USD Coin contract
0x8335…02913
Payment window
5 minutes
As published
5000 smallest units
The catalog’s raw entry
[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0xF22e558a00D91Ee12A1F50C52186FecB8dDFf493",
    "amount": "5000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 300
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "network": "ethereum"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "ts": 1756700000,
          "type": "eip1559",
          "block": 25881728,
          "chain": "eip155:1",
          "tiers": {
            "med": {
              "max_fee_gwei": 0.1892,
              "priority_gwei": 0.084
            },
            "fast": {
              "max_fee_gwei": 1.8051,
              "priority_gwei": 1.7
            },
            "slow": {
              "max_fee_gwei": 0.108,
              "priority_gwei": 0.0029
            }
          },
          "network": "ethereum",
          "base_fee_wei": 105129473,
          "base_fee_gwei": 0.1051,
          "gas_price_wei": 189159879,
          "gas_price_gwei": 0.1892
        }
      }
    },
    "schema": {
      "type": "object",
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "required": [
        "input"
      ],
      "properties": {
        "input": {
          "type": "object",
          "required": [
            "type",
            "method"
          ],
          "properties": {
            "type": {
              "type": "string",
              "const": "http"
            },
            "method": {
              "enum": [
                "GET",
                "HEAD",
                "DELETE"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "required": [],
              "properties": {
                "network": {
                  "enum": [
                    "ethereum",
                    "base",
                    "arbitrum",
                    "optimism",
                    "polygon",
                    "bnb",
                    "avalanche"
                  ],
                  "type": "string",
                  "description": "EVM network (default ethereum)."
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog
2026-09-08 08:42Z
Last indexed by Roundhouse
2026-09-24 13:30Z
Last enriched (probe, favicon, geo)
2026-09-13 05:15Z
x402 version
2
Max timeout
300s
Liveness probe
HTTP 402
Report

Hand this page to an agent

Copy the prompt and paste it into Claude, an MCP client or your own agent — it will vet this service and call it over the free read API. No key, no account.

GET api.roundhouseai.io/v0/endpoints

This endpoint's own trailing-30-day call count, as published by the upstream catalog and snapshotted daily. 30 snapshots so far. Verified volume counts only settlements with an on-chain EIP-3009 marker.

Open skill.md
Show the prompt
Using Roundhouse, look up the x402 service onchain-gas and tell me whether it is
worth paying: what a call costs, whether the endpoint answered when last probed, and what
its payment record actually shows.

curl -s 'https://api.roundhouseai.io/v0/endpoints?q=onchain-gas'
curl -s 'https://api.roundhouseai.io/v0/merchants/<the payTo wallet returned above>'

Then call it: read the price from the live 402 at https://api.agentstools.dev/gas, never from
a cached figure, and pay with an x402 client.

The /v0 API needs an API key (`authorization: Bearer rh_live_…`) on everything except
/v0/unified* and /v0/endpoints. Mint a personal key for $0.01 at GET https://api.roundhouseai.io/v0/test/x402,
or use an organization key from https://roundhouseai.io/dashboard/team.

If you do not have Roundhouse tools or skills installed, read
https://roundhouseai.io/skill.md first — it is the whole procedure.