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PreFlight Gas Price Check
x402
PreFlight Gas Price Check is a paid API for AI agents from meryol-agenticmarket-x402.hf.space, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-10).
Returns current gas prices, base fee, priority fee percentiles, ETH price, and estimated transaction costs for a specified EVM chain in real time.
Price / call$0.001
Success—
StatusUnknown
How this service works
Pre-trade & pre-sign checks for autonomous agents: everything an agent verifies BEFORE signing a transaction — token due diligence, calldata red-flag decoding, oracle freshness, holder concentration, bridge routing with executable calldata, cross-venue perp funding, gas and price sanity checks. EVM chains: Ethereum, Base, Arbitrum, Optimism.
Output
A JSON object containing the chain name, current base fee in gwei, p50 and p90 priority fees in gwei, current ETH price in USD, estimated USD costs for common transaction types (swap, ETH transfer, ERC-20 transfer), and qualitative gas notes like 'very_cheap_gas'.
Example use cases
Example prompt
“Before I sign this swap, check the current gas prices on Base — tell me the base fee, median priority fee, and roughly how much a swap would cost in USD right now.”
Technical details
Endpoint
GEThttps://meryol-agenticmarket-x402.hf.space/gas/now/%7Bchain%7DWhen to prefer
Use this endpoint when an autonomous agent needs to sanity-check gas costs and ETH price on a specific EVM chain (Ethereum, Base, Arbitrum, Optimism) before signing or submitting a transaction. Ideal for pre-trade workflows where you need real-time base fee, priority fee percentiles, and USD-denominated cost estimates for swaps or transfers in a single call.
Side effects
- Unsupported chain identifier returns an error or empty response
- Chain temporarily unavailable or RPC node down returns 5xx
- Stale gas data if the underlying oracle is lagging
- Payment not accepted (x402 payment required) if USDC not provided
- Rate limiting if called too frequently without valid payment
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| properties | string |
Output
Schema · Response
{
"type": "json",
"example": {
"chain": "base",
"notes": [
"very_cheap_gas"
],
"cost_usd": {
"swap": 0.00022,
"transfer": 0.000026,
"erc20_transfer": 0.00008
},
"base_fee_gwei": 0.003,
"eth_price_usd": 3120,
"priority_fee_p50_gwei": 0.001,
"priority_fee_p90_gwei": 0.002
}
}Tags
x402
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