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BaseBrief x402 — Base Address State (Gas, Balances, Tokens, Allowances)
x402
BaseBrief x402 — Base Address State (Gas, Balances, Tokens, Allowances) is a paid API for AI agents from basebrief-x402.savannah-5966.chatgpt.site, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-15).
Returns point-in-time on-chain state for a Base mainnet address: ETH/token balances, gas data, token metadata, and ERC-20 allowances.
Price / call$0.004
Success—
StatusUnknown
How this service works
Gas, balances, token metadata and allowances for $0.004 per result.
Output
A JSON object with point-in-time on-chain evidence: chain name, chain ID (8453), current block number, ETH balance, ERC-20 token balances with metadata (symbol, decimals, name), and spender allowances for the queried address. Also includes a limitations array noting the point-in-time nature of the data.
Example use cases
Pre-transaction wallet validation
“Before I send that USDC transfer on Base, check the current balance and USDC allowance for my wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 — I want to make sure I have enough and the allowance is set correctly.”
DeFi portfolio snapshot on Base
“Give me a full snapshot of what tokens and ETH are held by 0xAbCd1234abcd1234abcd1234abcd1234abcd1234 on Base mainnet, including any token metadata like decimals and symbols.”
Gas budget check before agent transaction
“What are the current gas prices on Base, and does wallet 0x1111222233334444555566667777888899990000 have enough ETH to cover a typical transaction right now?”
Technical details
Endpoint
GEThttps://basebrief-x402.savannah-5966.chatgpt.site/api/v1/base/addressWhen to prefer
Choose this endpoint when you need live, point-in-time on-chain state for a specific Base mainnet address — especially gas prices, token balances, ERC-20 allowances, and token metadata — without running your own Base RPC node. Ideal for AI agents that need to verify wallet state before executing transactions or reporting portfolio data on Base (chain ID 8453). Prefer this over generic Ethereum endpoints when the target chain is specifically Base mainnet.
Side effects
- Invalid or malformed address (not matching ^0x[0-9a-fA-F]{40}$) returns a validation error
- Address not found or zero-balance address may return empty token/balance arrays
- Payment not included or insufficient (x402 payment required) returns 402 Payment Required
- Base RPC node temporarily unavailable may cause timeout or 503
- Rate limiting if too many requests in a short window
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"evidence": {
"chain": "Base mainnet",
"chainId": 8453,
"blockNumber": "35123456",
"pointInTime": true
},
"limitations": [
"Point-in-time direct Base JSON-RPC evidence."
]
}
}Tags
x402
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