# Apiosk Oracle Reading – Chainlink Aggregator on Base

> Apiosk Oracle Reading – Chainlink Aggregator on Base is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Reads the latest Chainlink price oracle round data on Base for a given pair or aggregator address and returns a signed JWS-HS256 receipt anchored to an on-chain block.

## Facts

- Endpoint: POST https://gateway.apiosk.com/attestations/oracle-reading
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/apiosk-oracle-reading-chainlink-aggregator-on-base-ae0ce83f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_v2EBD1LcUfYhBSaeR8i1k

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-oracle-reading-chainlink-aggregator-on-base-ae0ce83f -d '<json body>'
```

Example prompt: Can you get me the latest ETH/USD price from the Chainlink oracle on Base and give me a signed receipt I can verify on-chain?

## When to prefer this

Choose this endpoint when you need a cryptographically attested, on-chain verifiable price from a Chainlink oracle on Base — especially when downstream consumers need to re-verify the price independently using the included feed address and block number. Prefer over raw RPC calls when you need a signed receipt for audit trails, compliance, or agent-to-agent trust. Best for DeFi apps, collateral engines, stablecoin monitors, and any workflow requiring tamper-evident price proofs rather than a plain price lookup.

## Known failure modes

- Unknown pair name returns an error listing supported pairs (ETH/USD, BTC/USD, USDC/USD, DAI/USD, LINK/USD)
- Invalid aggregator address returns a contract call failure or revert error
- RPC connectivity issues to Base mainnet result in a timeout or upstream error
- Malformed request body missing both pair and address returns a 400 validation error
- Payment failure via x402 protocol results in HTTP 402 before data is returned

## How this service works

Call a Chainlink aggregator latestRoundData directly on Base and return the round with a signed JWS-HS256 receipt. Pass a known pair (ETH/USD, BTC/USD, USDC/USD, DAI/USD, LINK/USD) or an explicit aggregator address; the number is itself on-chain and re-checkable from the feed address + block in the envelope.

## Output

Returns the full latestRoundData struct (roundId, answer/price, startedAt, updatedAt, answeredInRound) along with a JWS-HS256 signed receipt containing the feed address and block number, enabling independent on-chain re-verification of the returned price.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/apiosk-oracle-reading-chainlink-aggregator-on-base-ae0ce83f/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)