Payments · x402 · early usage

Measured USDC transfer costs on Base, Polygon, Arbitrum, Ethereum and XDC: simulated ga…

Measured USDC transfer costs on Base, Polygon, Arbitrum, Ethereum and XDC: simulated gas, current token prices, fresh chain heads and applicable rollup L1 fees. Inputs and block references accompany each figure. Cheapest first; unmeasurable chains are exclude…

by api.402rates.com · discovered, not yet claimed by its owner · updated 2026-10-09

30d calls3

30d payers3

MethodGET

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Tags: settlement · gas-costs · usdc · cross-chain · transfer-cost · bazaar

Call contract

Method: GET
Input: query parameters
Output: json
Last paid call: 2026-10-09

Input example from Bazaar metadata

{
  "chains": "base,polygon,arbitrum,ethereum,xdc"
}

Output example

{
  "cheapest": {
    "caveats": [],
    "chain": "xdc",
    "compared_chains": [
      "xdc"
    ],
    "est_cost_usd": 0.0000188,
    "excluded_chains": [],
    "runner_up": null,
    "scope": "transaction_fee_total",
    "stability": {
      "historical_claim": false,
      "level": "unknown"
    }
  },
  "data": [
    {
      "chain": "xdc",
      "cost_basis": "complete",
      "cost_bps": [
        {
          "fee_bps": 0.00188,
          "notional_usd": 100
        },
        {
          "fee_bps": 0.000188,
          "notional_usd": 1000
        },
        {
          "fee_bps": 0.0000188,
          "notional_usd": 10000
        }
      ],
      "est_cost_usd": 0.0000188,
      "fee_components": {
        "execution_usd": 0.0000188,
        "l1_data_usd": null,
        "total_usd": 0.0000188
      },
      "fee_model": "single_layer",
      "gas_price_wei": "250000000",
      "gas_units": 46680,
      "gas_units_assumed": null,
      "gas_units_method": "eth_estimateGas",
      "gas_units_scenario": "transfer to an address with an existing USDC balance",
      "head_age_s": 3,
      "l1_data_fee_included": null,
      "transfer_amount_atomic": 1000000,
      "tx_type": "usdc_transfer"
    }
  ],
  "meta": {
    "attributions": [
      {
        "fallback_used": false,
        "fetched_at": "2026-08-30T22:14:03.011Z",
        "message": "Data provided by CoinGecko",
        "quote_asset": "usd",
        "source_id": "coingecko.simple.licensed.xdc",
        "url": "https://www.coingecko.com/en/api"
      }
    ],
    "capability": "compass.settlement.costs",
    "chains_requested": [
      "xdc"
    ],
    "chains_unavailable": [],
    "fee_completeness": "complete",
    "freshness": {
      "all_sources_within_policy": true,
      "cache_ttl_s": 119,
      "oldest_source_age_s": 1,
      "policy_max_age_s": 120,
      "valid_until": "2026-08-30T22:16:02.904Z"
    },
    "generated_at": "2026-08-30T22:14:03.117Z",
    "limitations": "a simulated transfer to an address that already holds the token; a first transfer to a fresh address costs more, and no bridge, mint or subscription cost is included",
    "request_id": "req_example1",
    "schema_version": "0.5.0",
    "sources": [
      {
        "block": 85797652,
        "fetched_at": "2026-08-30T22:14:02.904Z",
        "id": "xdc.rpc.gas_price",
        "kind": "onchain_read",
        "max_age_s": 120
      },
      {
        "fetched_at": "2026-08-30T22:14:02.904Z",
        "id": "xdc.rpc.gas_units",
        "kind": "onchain_simulation",
        "max_age_s": 120,
        "method": "eth_estimateGas"
      },
      {
        "attribution": "Data provided by CoinGecko",
        "fallback_used": false,
        "fetched_at": "2026-08-30T22:14:03.011Z",
        "id": "coingecko.simple.licensed.xdc",
        "kind": "public_api",
        "license_basis": "operator_attestation",
        "licensed": true,
        "max_age_s": 120,
        "quote_asset": "usd",
        "url": "https://www.coingecko.com/en/api"
      }
    ],
    "units": {
      "est_cost_usd": "usd",
      "fee_bps": "basis_points",
      "gas_price_wei": "wei",
      "transfer_amount_atomic": "usdc_atomic"
    },
    "version": "0.1.0"
  },
  "related": [
    "compass.rwa.yields",
    "compass.ping"
  ]
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/25911.json for the price and payment options.
Pay. Call GET https://api.402rates.com/v1/settlement/costs. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, Polygon, Arbitrum One, eip155:50, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.01 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base, Polygon, Arbitrum One, eip155:50
Demand: 3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.01	0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98	300s
exact	Polygon eip155:137	USDC	$0.01	0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98	300s
exact	Arbitrum One eip155:42161	USDC	$0.01	0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98	300s
exact	eip155:50 eip155:50	0xfA2958CB79b0491CC627c1557F441eF849Ca8eb1	10000	0xedb1a894761F0a142d80D09F82Ff7CF99158Bb19	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:137",
    "payTo": "0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98",
    "asset": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:42161",
    "payTo": "0xf567Cfe0FDb87A1D6Ca330e3f30f0D3DA0F7cb98",
    "asset": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:50",
    "payTo": "0xedb1a894761F0a142d80D09F82Ff7CF99158Bb19",
    "asset": "0xfA2958CB79b0491CC627c1557F441eF849Ca8eb1",
    "amount": "10000",
    "maxTimeoutSeconds": 120
  }
]

Schemas

Output schema (JSON Schema)

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

Example shape — generated from the schema, not a captured live response

{
  "example": {},
  "type": "string"
}

Examples

curl

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

JavaScript

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

Python

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

Details

Provider: api.402rates.com
Endpoint: https://api.402rates.com/v1/settlement/costs
Machine-readable: /resources/25911.json