# Jarvis Transaction Execution Preflight API

> 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.

## Facts

- Endpoint: POST https://jarvis-orderflow-router.yl124915300.workers.dev/v1/outcomes/tx-execution-preflight
- Price: $0.008/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/jarvis-transaction-execution-preflight-api-9061e88b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_d_DOdynjkcL6AS5t0cMtb

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability jarvis-transaction-execution-preflight-api-9061e88b -d '<json body>'
```

Example prompt: Before I submit this transaction on Base mainnet, can you run a preflight check — from 0xAbC123...sender to 0xDeF456...contract, value 0 wei, calldata 0xa9059cbb...— and tell me if my balance and nonce are good, whether it'll revert, and what gas it needs?

## When to prefer this

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.

## Known failure modes

- 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

## 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.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$"
  },
  "from": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$"
  },
  "chain": {
   "type": [
    "string",
    "integer"
   ],
   "description": "Base mainnet: base, base-mainnet, eip155:8453, or 8453"
  },
  "value": {
   "type": "string",
   "default": "0",
   "pattern": "^(0|[1-9][0-9]*|0x[0-9a-fA-F]+)$",
   "description": "Native value in wei"
  },
  "calldata": {
   "type": "string",
   "default": "0x",
   "pattern": "^0x(?:[0-9a-fA-F]{2})*$"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "result": {
   "decision": "PAY",
   "verification": {
    "result_hash": "sha256"
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/jarvis-transaction-execution-preflight-api-9061e88b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from jarvis-orderflow-router.yl124915300.workers.dev](https://www.zero.xyz/host/jarvis-orderflow-router.yl124915300.workers.dev/llms.txt)