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BaseBrief x402 – Base Chain Token State Lookup
x402
BaseBrief x402 – Base Chain Token State Lookup 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 gas prices, token balances, token metadata, and allowances for a given Base mainnet address, charged at $0.004 per call via x402.
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 containing point-in-time on-chain evidence for the queried Base mainnet address, including: current gas price, native and ERC-20 token balances, token metadata (symbol, decimals, name), allowances for specified spenders, the current block number, chain ID (8453), and a limitations array noting the data is a point-in-time snapshot from Base JSON-RPC.
Example use cases
DeFi bot pre-trade state check
“Before executing this swap, check the token balance and current allowance for address 0xAbCd1234...5678 on Base mainnet so I know if I have enough funds and approval set.”
Portfolio dashboard data refresh
“Fetch the latest token balances and metadata for wallet 0xDeAd0000...BeeF on Base mainnet — I want to update my portfolio tracker with the current on-chain state.”
Gas cost estimation for a dApp
“What's the current gas price on Base right now for address 0x1111...2222? I need to estimate transaction fees before sending a batch of transfers.”
Technical details
Endpoint
GEThttps://basebrief-x402.savannah-5966.chatgpt.site/api/v1/base/tokenWhen to prefer
Choose this endpoint when you need real-time, point-in-time on-chain state for a Base mainnet address — specifically gas prices, token balances, ERC-20 metadata, or allowances — in a single cheap paid call ($0.004). Prefer it over general Ethereum RPC endpoints when you specifically need Base L2 data and want a structured, agent-friendly JSON response without managing your own RPC infrastructure. It is especially suitable for AI agents that need to check wallet state before executing DeFi operations or building portfolio dashboards.
Side effects
- Invalid address format (not matching ^0x[0-9a-fA-F]{40}$) returns a validation error
- Missing required `address` query parameter returns a 400 bad request
- Payment not provided or insufficient USDC causes x402 payment-required response
- Base JSON-RPC node unavailability may cause timeouts or 5xx errors
- Querying a non-existent or zero-balance address returns valid empty/zero data rather than an error
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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