BASE USDC · BEFORE SIGNING · X402 V2

Check the payment intent before the wallet signs it.

Name: Base USDC Payment Intent Preflight API
Price: 0.001 USD
Availability: InStock

Submit the proposed payer, recipient, amount, chain and token. BountyWorth applies your recipient and spend policy, then reads live Base balances, account type and gas conditions without signing or broadcasting anything.

Free live sample0.001 USDC / callNo signing or custody

Open the free live sample

01 · BIND

Describe the proposal

Provide sender, recipient, six-decimal USDC amount, chain id and token contract. Optionally bind an independently trusted recipient and maximum spend.

02 · MATCH

Reject shape errors

Fail closed when the chain is not Base, the token is not official Base USDC, the recipient mismatches policy, or the amount exceeds the ceiling.

03 · READ

Check live capacity

Read the payer's official USDC, native ETH, nonce, bytecode, current Base gas price and latest block in one bounded public-chain snapshot.

04 · DECIDE

Return an explicit verdict

Receive ready_for_estimate, a precise policy block, a balance/gas failure, or contract_wallet_review with machine-readable checks and caveats.

POLICY + LIVE CHAIN STATE

More than an amount-string comparison.

The response combines deterministic transaction-shape checks with the actual payer's point-in-time Base balances and gas conditions.

{
  "checks": {
    "correctBaseNetwork": true,
    "officialBaseUsdc": true,
    "recipientMatchesExpected": true,
    "withinMaximum": true,
    "enoughUsdc": true,
    "enoughNativeGasForEstimate": true
  },
  "verdict": "ready_for_estimate",
  "ready": true
}

INTEGRATION

HTTP or remote MCP

GET /api/base-usdc-payment-intent?sample=1Free

A fixed public Base example proves the RPC and policy path without a wallet.

GET /api/base-usdc-payment-intent0.001 USDC

Call with valid query input to receive exact x402 terms, then retry the identical request with PAYMENT-SIGNATURE.

POST /mcp0.001 USDC

Call check_base_usdc_payment_intent through stateless Streamable HTTP.

GET /openapi.jsonFree

Read the complete required-query contract, output schema and executable example.

SAFETY CONTRACT

Observation and policy checks, never authorization.

No private key, seed phrase, wallet connection, signature, allowance, API key or login is requested.
No transaction is simulated, signed, submitted, replaced or accepted on the caller's behalf.
The caller owns the trusted recipient, maximum-spend policy and final authorization decision.
Contract wallets can require a bundler, paymaster or account-specific policy that public balances cannot prove.

Inspect the unpaid 402 contract →