API · x402

Transaction explainer / decoder: plain-English swaps, transfers, approvals (flags unlim…

by UnlockBot Onchain Intel (x402) · verified provider · updated 2026-10-14

30d calls—

30d payers—

MethodHTTP

Outputjson

What it does

Transaction explainer / decoder: plain-English swaps, transfers, approvals (flags unlimited approvals). Decodes an Ethereum, Base or Arbitrum transaction: a one-line plain-English summary, type (swap, transfer, approval, deployment), decoded method name, token transfers with symbols and amounts, approvals (flags UNLIMITED), event names, fee and status, plus risk notes. Good for agents that verify their own transactions or explain wallet activity to users. Keywords: decode transaction, explain transaction, tx decoder, swap, approval, unlimited approval, calldata, event logs, receipt.

Tags: crypto · defi · onchain · x402 · base · Wallets · Utility · Security

Call contract

Method: HTTP
Input: HTTP request
Output: json

No input exampleProvider did not publish one in Bazaar metadata.

No output exampleProvider did not publish one in Bazaar metadata.

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/59824.json for the price and payment options.
Pay. Call GET https://fimp2cx2ybjb.hostc.app/tx-explain. 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, 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

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.01	0x21e4F3c6EcDb0F0CADC59511BF675B9BcBbeD304	120s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x21e4F3c6EcDb0F0CADC59511BF675B9BcBbeD304",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "amountUsd": 0.01,
    "maxTimeoutSeconds": 120
  }
]

Examples

curl

curl "https://fimp2cx2ybjb.hostc.app/tx-explain"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

JavaScript

const res = await fetch("https://fimp2cx2ybjb.hostc.app/tx-explain");
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://fimp2cx2ybjb.hostc.app/tx-explain")
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: UnlockBot Onchain Intel (x402)
Endpoint: https://fimp2cx2ybjb.hostc.app/tx-explain
Machine-readable: /resources/59824.json