# Apiosk Gateway – USDC/EURe Spot Rate (Uniswap v3 Polygon)

> Apiosk Gateway – USDC/EURe Spot Rate (Uniswap v3 Polygon) is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-15).

Returns a cryptographically signed mid-price spot rate for USDC/EURe derived directly from the EURe/USDC 0.30% Uniswap v3 pool on Polygon via slot0() sqrtPriceX96.

## Facts

- Endpoint: POST https://gateway.apiosk.com/attestations/usdc-eure
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apiosk-gateway-usdc-eure-spot-rate-uniswap-v3-polygon-5901993a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FnClVjBKBcagPerQuot_X

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 apiosk-gateway-usdc-eure-spot-rate-uniswap-v3-polygon-5901993a -d '<json body>'
```

Example prompt: What's the current on-chain USDC to EURe mid-price right now? I need a signed, independently verifiable rate pulled straight from the Uniswap v3 EURe/USDC pool on Polygon.

## When to prefer this

Choose this endpoint when you need a cryptographically signed, independently verifiable USDC/EURe mid-price sourced directly from on-chain Uniswap v3 slot0() data on Polygon — particularly for euro off-ramp pricing, DeFi arbitrage, or compliance audit trails where a trusted off-chain API quote is insufficient. Prefer over generic forex APIs when on-chain provenance and re-checkability matter.

## Known failure modes

- Polygon RPC unavailable – eth_call to slot0() fails, endpoint returns an error
- Pool liquidity too low to produce a reliable mid-price
- Payment not settled via x402 – returns HTTP 402
- Stale block data if node is behind – rate may lag by a block
- Invalid or missing payment header – request rejected

## How this service works

Signed USDC/EURe spot rate read directly from the EURe/USDC 0.30% Uniswap v3 pool on Polygon (mid-price from sqrtPriceX96). The on-chain rate behind the euro off-ramp; the envelope carries the exact eth_call slot0() so the number is independently re-checkable. Excludes the pool fee and slippage.

## Output

A signed attestation envelope containing the mid-price spot rate for USDC/EURe computed from sqrtPriceX96 returned by slot0() on the EURe/USDC 0.30% Uniswap v3 pool on Polygon. Includes the raw eth_call data so the price is independently re-checkable on-chain. Does not include pool fee or slippage.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apiosk-gateway-usdc-eure-spot-rate-uniswap-v3-polygon-5901993a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gateway.apiosk.com](https://www.zero.xyz/host/gateway.apiosk.com/llms.txt)