Block402 Build with Block402

Agent-native. x402-only.

Block402

Blockchain intelligence
for AI agents.

Ethereum and Bitcoin mainnet data, ready for your agent. Read balances, blocks, transactions and more through one pay-per-request API.

Make your first request Explore pricing

No subscription. No credit card. Only x402.

Ethereum and Bitcoin. One API.

Available now / more networks coming
  • ETHEthereumAvailable
  • BBaseComing soon
  • SOLSolanaComing soon
  • BTCBitcoinAvailable
  • BNBBNB ChainComing soon

Ethereum: 37 read-only RPC methods and simulations. Bitcoin: seven read-only methods. Mainnet blockchain data; payments use USDC on Base mainnet.

01 / Native to the agent economy

HTTP does the handshake.
USDC does the rest.

Read balances. Inspect transactions. Query contracts. Pay for the data you request, not another monthly plan.

  1. 01

    Request the data

    Send a bounded JSON-RPC request to a chain endpoint.

    POST /rpc/ethereum
  2. 02

    Authorize the quote

    The 402 response specifies the exact amount. Your agent signs a USDC authorization.

    402 PAYMENT-REQUIRED
  3. 03

    Get data and a receipt

    Data is delivered after recorded settlement. Recover a paid result with the same private request key.

    200 PAYMENT-RESPONSE

02 / Launch rate card

Small requests.
Straightforward prices.

Pay as you go. Settle in USDC on Base, whichever chain you query.

01

Lightweight

The state of the network.

0.0025USDC

per request

  • Block height and slot
  • Network identity
  • Latest block hash
eth_blockNumber
02

Standard

The context your agent needs.

0.005USDC

per request

  • Wallet balances
  • Transaction receipts
  • Bounded account reads
eth_getBalance
03

Compute

More work. More detail.

0.01USDC

per request

  • Bounded contract calls
  • Logs and block receipts
  • Account and storage proofs
eth_call

Current prices in USDC on Base mainnet. The endpoint's 402 quote is authoritative. Request and response limits apply; no unbounded scans, traces, or unsupported history. Cache hits have the same price.

Estimate your usage

Estimated total5.00 USDC

Free health checks. Unbilled pre-settlement errors. No extra fee to recover a retained paid result.

On the roadmap Batch settlement for lower-cost, high-volume workloads. Not available yet.

03 / From request to result

A wallet.
A request. You're in.

Start with an unpaid quote. Our agent client handles the x402 handshake, a private request key, a spending budget and recovery.

Example request

Endpoint path/rpc/ethereum

These examples target our production API. Start with an unpaid quote; no wallet connection or payment happens on this page.

Install the agent client Wallet examples API documentation Agent guide (llms.txt) Official x402 documentation 
# Retain this private key for retries of this request.
export BLOCK402_RECOVERY_KEY=$(openssl rand -hex 32)

curl --include https://api.block402.xyz/rpc/ethereum \
  -H 'Content-Type: application/json' \
  -H "Idempotency-Key: $BLOCK402_RECOVERY_KEY" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'
Expected without payment: 402 + PAYMENT-REQUIREDx402 v2

One logical request, one private recovery key. Persist the key before sending. Reuse it on retries. A 202 payment_pending response means wait and reconcile, not authorize a new payment.

Agent setup

44 tools.
A budget you control.

Use the local MCP bridge with a dedicated buyer wallet, or connect an x402-capable client to the remote server. Listing tools is free; a plain MCP connection does not supply payment handling.

Set up your agent Try balance, receipt and simulation demos

Read-only blockchain operations. Prices: 0.0025, 0.005 and 0.01 USDC on Base mainnet. No subscription or API key. Archive state is not guaranteed.

Remote MCP ยท Streamable HTTP
{
  "mcpServers": {
    "block402": {
      "url": "https://api.block402.xyz/mcp"
    }
  }
}
For clients with built-in x402 payment support.

04 / Good to know

Built for agents.
No fine-print surprises.

Which currency and network do I pay with?

Payments use USDC on Base mainnet (chain ID 8453), whether you query Ethereum or Bitcoin mainnet data. The 402 response identifies the exact token, network, recipient, and amount.

Can I use a credit card or Stripe?

No. All Block402 customer payments use x402. There are no card payments, Stripe checkout, or recurring card subscriptions.

Am I charged if a request fails?

Invalid requests and upstream errors before settlement are not charged. A timeout during settlement may still mean a payment succeeded. Keep the original request key and recover the receipt instead of paying again. Results are retained for seven days by default.

Are all five chains available now?

Ethereum and Bitcoin mainnet RPC are available now. Base, Solana and BNB Chain are coming later. Ethereum includes 37 methods for balances, blocks, transactions, receipts, logs, proofs and simulations. Payments use USDC on Base mainnet.

Do you offer archive RPC or unlimited queries?

Historical blocks and transactions are supported. Ethereum historical state and proofs depend on data retained by our node; archive state is not guaranteed. Batch RPC, transaction submission, debug, trace, and unbounded scans are not enabled.

Intelligence without the billing friction.

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