# YieldSignal USDC Base Yield

> YieldSignal USDC Base Yield is a paid API for AI agents from yieldsignal.vercel.app, paid per call via x402, $0.1/call, status unknown (last checked 2026-10-27).

Returns real-time risk-weighted USDC lending APYs across major Base DeFi protocols (Aave, Compound, Morpho, Moonwell, Euler, Fluid), with source-tagged readings and EIP-712 signed responses.

## Facts

- Endpoint: GET https://yieldsignal.vercel.app/signal/usdc-base-yield?utm_source=zero.xyz
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/yieldsignal-usdc-base-yield-d1443962
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zg07_flTjBiSzmBMk1jzQ

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 yieldsignal-usdc-base-yield-d1443962
```

Example prompt: What's the best risk-weighted APY I can get for lending USDC right now across all the major Base DeFi protocols — show me which protocol leads and where the data is sourced from?

## When to prefer this

Use this endpoint when you need current, source-verified, risk-weighted USDC lending yield data specifically on the Base network across multiple protocols in a single call. Prefer this over scraping individual protocol dashboards or DefiLlama directly when you want cryptographically signed data with source provenance. Especially useful for yield optimization agents, portfolio rebalancers, or any system that needs tamper-evident DeFi APY data.

## Known failure modes

- Onchain RPC errors may prevent Aave/Compound/Morpho reads
- DefiLlama API downtime may affect Moonwell/Euler/Fluid data
- Payment not received — 402 returned if x402 USDC payment not completed
- Stale or unavailable data for one or more protocols returned with partial results
- EIP-712 signature verification fails if headers are malformed or signer rotated

## How this service works

Real-time risk-weighted USDC lending APY on Base: Aave/Compound/Morpho read onchain, Moonwell/Euler/Fluid via DefiLlama, source tagged per reading (never estimated). EIP-712 signed by the payment-receiving address (see X-Signal-* headers), which also holds an ERC-8004 identity and attests readings on-chain via EAS. Verified per-asset accuracy is free at /accuracy.json; raw on-chain attestations at /track-record.

## Output

A signed JSON response listing current USDC lending APYs for each protocol on Base (Aave, Compound, Morpho, Moonwell, Euler, Fluid), tagged by data source (onchain vs DefiLlama), risk-weighted rankings, and EIP-712 cryptographic signature headers (X-Signal-Signature, X-Signal-Signer, X-Signal-Eip712-Payload) for authenticity verification.

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/yieldsignal-usdc-base-yield-d1443962/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from yieldsignal.vercel.app](https://www.zero.xyz/host/yieldsignal.vercel.app/llms.txt)