# UOS Genesis Transaction Preflight Check

> UOS Genesis Transaction Preflight Check is a paid API for AI agents from genesis.palsus2023.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-12).

Validates a machine transaction before execution by checking amount, authority, counterparty, spend limit, network, token, policy, and risk.

## Facts

- Endpoint: POST https://genesis.palsus2023.workers.dev/v1/transaction_preflight?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/uos-genesis-transaction-preflight-check-93218d8e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NtqXwrZo6vEFPUUSlUyUm

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 uos-genesis-transaction-preflight-check-93218d8e -d '<json body>'
```

Example prompt: Before I send this USDC payment on Base, run a preflight check on the transaction to verify the amount, counterparty, spend limits, token, network, and risk policy are all clear.

## When to prefer this

Use this endpoint when an autonomous agent or machine needs to validate a Base USDC transaction before executing it — especially when spend limits, counterparty risk, token/network correctness, or policy compliance must be confirmed before committing funds. Prefer this over post-hoc checks or skipping validation entirely when operating in autonomous payment workflows where irreversible transactions could violate limits or policies.

## Known failure modes

- Missing required 'input' field returns validation error
- Invalid body type or method enum causes schema rejection
- Transaction fails policy check — success returns false with reason in result
- Network or token mismatch detected — preflight fails
- Spend limit exceeded — validation returns failure
- x402 payment not included or insufficient USDC causes 402 Payment Required
- Cloudflare Worker timeout or upstream unavailability causes 5xx error

## How this service works

Autonomous paid machine utilities using x402 and Base USDC.

## Output

A JSON object containing a machine-readable result string (prefixed 'GENESIS*'), the service name ('transaction_preflight'), and a success boolean indicating whether the transaction passed all preflight checks including amount, authority, counterparty, spend limit, network, token, policy, and risk validation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "input": {
       "type": "string",
       "description": "Checks amount, authority, counterparty, spend limit, network, token, policy and risk before a machine transaction."
      }
     },
     "additionalProperties": true
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object"
  }
 },
 "additionalProperties": true
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": "GENESIS* machine-readable service result",
  "service": "transaction_preflight",
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/uos-genesis-transaction-preflight-check-93218d8e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from genesis.palsus2023.workers.dev](https://www.zero.xyz/host/genesis.palsus2023.workers.dev/llms.txt)