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Jarvis Transaction Execution Preflight API
x402
Jarvis Transaction Execution Preflight API is a paid API for AI agents from jarvis-orderflow-router.yl124915300.workers.dev, paid per call via x402, $0.008/call, status unknown (last checked 2026-09-14).
Pre-flight checks a Base mainnet transaction by simulating execution readiness — verifying balances, nonce, target type, gas, and eth_call — before committing to on-chain submission.
Price / call$0.008
Success—
StatusUnknown
How this service works
One paid result for Base execution readiness: balances, nonce, target type, eth_call/gas simulation, reasons, evidence and hashes.
Output
Returns a JSON object with an 'ok' boolean, a top-level 'result' containing a 'decision' field (e.g. 'PAY' or rejection reason), plus detailed verification sub-fields: balance adequacy, current nonce, target address type (EOA vs contract), eth_call simulation output, gas estimate, human-readable failure reasons, supporting evidence, and a SHA-256 result_hash for tamper-evidence.
Example use cases
DeFi swap safety check
“Before I execute this token swap on Base, can you preflight the transaction from my wallet 0xSenderAddress to the Uniswap router 0xRouterAddress with calldata 0xSwapCalldata and value 0 wei, and tell me if it'll succeed, what gas it needs, and whether my balance covers it?”
NFT mint execution readiness
“I'm about to mint an NFT on Base mainnet — sender is 0xMyWallet, contract is 0xNFTContract, value is 5000000000000000 wei (the mint price), calldata is 0xMintCalldata — can you simulate this and confirm it won't revert before I send it?”
Smart contract deployment preflight
“Can you run an execution preflight on Base for a contract deployment — from 0xDeployerAddress to 0x0000000000000000000000000000000000000000, no value, with this bytecode as calldata 0x608060...— and tell me the decision, gas estimate, and any reasons it might fail?”
Technical details
Endpoint
POSThttps://jarvis-orderflow-router.yl124915300.workers.dev/v1/outcomes/tx-execution-preflightWhen to prefer
Choose this endpoint when you need a comprehensive, single-call preflight check for a Base mainnet transaction that combines balance verification, nonce checking, target-type detection, eth_call simulation, and gas estimation in one paid result. Prefer it over rolling your own eth_call or balance check when you want structured decision output with hashed evidence for auditability, or when operating in an x402 payment-enabled agent pipeline on Base.
Side effects
- Invalid Ethereum address format for 'to' or 'from' — returns 400 with validation error
- Unsupported chain identifier — only Base mainnet (8453) is supported
- Malformed calldata (odd-length hex, non-hex characters) — returns schema validation error
- Simulation reverts — captured in result with revert reason and evidence rather than HTTP error
- Insufficient balance detected — reflected in decision and reasons fields, not an HTTP error
- Network/RPC unavailability — returns 5xx with connectivity error
- Payment not included or failed x402 protocol — returns 402 Payment Required
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| to | string | |
| from | string | |
| chain | — | Base mainnet: base, base-mainnet, eip155:8453, or 8453 |
| value | string | Native value in wei |
| calldata | string |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"result": {
"decision": "PAY",
"verification": {
"result_hash": "sha256"
}
}
}
}Tags
x402
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