# x402.donnyautomation.com – Best Execution Router (OP Mainnet)

> x402.donnyautomation.com – Best Execution Router (OP Mainnet) is a paid API for AI agents from x402.donnyautomation.com, paid per call via x402, $0.01/call, status down (last checked 2026-10-21).

Returns the best DEX buy and sell venues, cross-exchange spread in bps, fee-adjusted arbitrage spread, and optimal trade size for a token pair on Optimism (OP Mainnet) across SushiSwap and Uniswap v3 fee tiers.

## Facts

- Endpoint: POST https://x402.donnyautomation.com/optimism/route?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: down
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-donnyautomation-com-best-execution-router-op-mainnet-18b3acb6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8aabdPPq9gyMOPgGpfO8h

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 x402-donnyautomation-com-best-execution-router-op-mainnet-18b3acb6 -d '<json body>'
```

Example prompt: What's the best DEX to buy WETH/USDC on Optimism right now — compare SushiSwap and Uniswap v3 and tell me the arbitrage spread and optimal trade size.

## When to prefer this

Choose this endpoint when you need real-time smart order routing or cross-DEX arbitrage intelligence specifically on Optimism (OP Mainnet), comparing SushiSwap and Uniswap v3 fee tiers. Prefer it over generic price feeds when you need a venue recommendation (buy here, sell there) plus a fee-adjusted spread and optimal sizing in a single call. Use sibling endpoints for Arbitrum One, BSC, Polygon, or Avalanche.

## Known failure modes

- Unsupported token pair returns an error or empty result
- Token symbol not found on OP Mainnet causes lookup failure
- Low liquidity on one or both venues may result in unreliable spread estimates
- Rate limiting or payment failure returns a 402 response requiring USDC micropayment
- Network congestion on Optimism may cause stale or delayed price data

## How this service works

Pay-per-call (x402/USDC on Base) market-data, geocoding, randomness and hook-risk endpoints. Free demo route included.

## Output

Returns the cheapest venue to buy on and the highest-paying venue to sell into for the requested token pair on OP Mainnet, along with the raw cross-exchange spread in basis points, the fee-adjusted gross arbitrage spread, and a recommended optimal trade size for capturing that spread.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ts": "2026-07-31T00:00:00.000Z",
  "chainId": 10,
  "network": "optimism"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-donnyautomation-com-best-execution-router-op-mainnet-18b3acb6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.donnyautomation.com](https://www.zero.xyz/host/x402.donnyautomation.com/llms.txt)