# SperaxOS Chainlink getRoundData

> SperaxOS Chainlink getRoundData is a paid API for AI agents from chat.sperax.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Fetches a specific or latest Chainlink price feed round data for a given asset pair on a supported EVM chain

## Facts

- Endpoint: POST https://chat.sperax.io/api/x402/tools/chainlink/getRoundData?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/speraxos-chainlink-getrounddata-c7ba0e75
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b1y0o_zZgPA-iTjJekJLV

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 speraxos-chainlink-getrounddata-c7ba0e75 -d '<json body>'
```

Example prompt: What's the latest Chainlink ETH/USD price on Arbitrum? Also pull round ID 18446744073709551864 so I can compare it to the current one.

## When to prefer this

Choose this endpoint when you need authoritative on-chain Chainlink price oracle data for a specific asset pair, optionally at a historical round, across major EVM chains. Prefer it over centralized exchange APIs when you need tamper-resistant, decentralized price data for DeFi logic, auditing, or smart contract verification. It is especially useful when you need historical round-level granularity rather than just the current price.

## Known failure modes

- Unsupported pair on the specified chain — Chainlink feed may not exist, returning an error or empty result
- Invalid roundId format — must be an integer string; non-numeric values will fail
- Unsupported chain name — only ethereum, arbitrum, base, bsc, polygon, optimism are valid
- Payment failure — x402 USDC payment on Base must succeed before the request is processed
- Stale or incomplete round — if a round is not yet finalized, answeredInRound may differ from roundId
- RPC/node errors — transient blockchain node issues may cause timeout or empty response

## How this service works

AI-powered DeFi intelligence APIs payable via the x402 HTTP payment protocol. No API key required — pay per request with USDC on Base. Identity-only (SIWX) endpoints are free for wallets with an agentcash identity.

## Output

Returns aggregator round data from the Chainlink price feed, including the round ID, the reported price answer (in the feed's native decimals), the timestamp when the round was started, the timestamp when the round was updated, and the round in which the answer was last computed (answeredInRound). The response reflects on-chain state at the time of the request.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "pair": {
   "type": "string",
   "description": "Pair to read, e.g. \"ETH/USD\", \"BTC-USD\", or a bare \"ETH\" (USD is assumed)."
  },
  "chain": {
   "type": "string",
   "description": "Chain to read from: ethereum, arbitrum, base, bsc, polygon or optimism. Defaults to ethereum."
  },
  "roundId": {
   "type": "string",
   "description": "Aggregator round ID to read, as an integer string. Omit for the latest round."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/speraxos-chainlink-getrounddata-c7ba0e75/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chat.sperax.io](https://www.zero.xyz/host/chat.sperax.io/llms.txt)