Contract event logs

Fetch contract event logs (eth_getLogs) on Ethereum, Base, Polygon, Arbitrum, or Optimism - bounded so it always answers: block range capped at 2000 blocks (default: the last 100, auto-narrowed for busy contracts), at most 200 logs returned (truncated flag set if more matched). Send POST /api/event-logs with the required field address and pay $0.003 per call over x402 or MPP (there is no free tier). It returns a JSON object with network, address, fromBlock, toBlock, count and 2 more.

Filter by contract address and optional topic0 (event signature hash). Keyless multi-endpoint failover.

Category: Crypto & onchain data · Tags: crypto event events logs getlogs transfer topic rpc · Also found as: events logs eth_getlogs

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Parameters

Example request

curl -i -X POST https://agent402.tools/api/event-logs \
  -H "Content-Type: application/json" \
  -d '{"address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","topic0":"0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef","network":"base"}'

Without payment this returns HTTP 402 Payment Required with the exact price for event-logs; any x402 v2 or MPP client pays it and retries.

Example response

{
  "network": "base",
  "address": "0x8335…",
  "fromBlock": 26999500,
  "toBlock": 27000000,
  "count": 87,
  "truncated": false,
  "logs": [
    {
      "blockNumber": 26999512,
      "txHash": "0x…",
      "topics": [
        "0xddf2…"
      ],
      "data": "0x…"
    }
  ]
}

From an MCP client

catalog.call {
  "slug": "event-logs",
  "params": {
    "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "topic0": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
    "network": "base"
  }
}

The hosted connector at https://agent402.tools/mcp needs a payment for event-logs; the stdio package pays it from a wallet or from AGENT402_CREDITS_KEY. Local install: npx -y agent402-mcp.

Errors and behavior

• address is required. An input the tool rejects returns an HTTP 4xx whose body carries error, tool, expected, required and example, so the caller can correct it.
• A paid call that ends in any status of 400 or above is not charged over x402, MPP or a prepaid credits key: settlement is cancelled when the tool fails. The exception is a Tempo push credential, a transfer the buyer sent before the call: it settles before the tool runs, so if the tool then fails the payment is recorded as a refund owed to the paying wallet.
• Wallet-only: this tool reaches the network or stored state, so it has no proof-of-work tier. A prepaid card-credits key issued earlier (Authorization: Bearer a402_...) also pays it.
• A GET or HEAD to /api/event-logs returns the same 402 quote, so the price can be read without a body.
• An Idempotency-Key header makes a retried paid call replay the first 200 instead of charging again (an answer larger than 1 MB is not replayed).

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
client.setSpendControls?.(false); // keep your own spending ceiling in code
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/event-logs", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "topic0": "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
    "network": "base"
  }),
});

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