# Best pay-per-call onchain data APIs for AI agents (September 2026)

> Zero indexes 28 pay-per-call services for onchain data. Of the 10 ranked here, 10 answered a live probe in the last 7 days. Quoted prices run from $0.001 to $0.1 per call, median $0.01, paid per call over x402 or MPP with no API key. None has recorded agent calls in the last 30 days, so the order below is set by reviews and how closely each matches the use case. The cheapest live option is Codex GraphQL API at $0.001.

Canonical page: https://www.zero.xyz/use-cases/onchain-data
Ranked by evidence from Zero's own probes and real agent calls. Updated Sep 29, 2026. 9 agents searched Zero for this in the last 90 days.

## Ranked services

| # | Service | Host | Price | Rail | Live | Calls 30d | Reviews |
|---|---|---|---|---|---|---|---|
| 1 | [ChainRay Contract Scan](https://www.zero.xyz/c/chainray-contract-scan-206b4f0b/llms.txt) | chainray.online | $0.02 | x402 | yes (Sep 28, 2026) | 0 | — |
| 2 | [ChainRay Cross-Chain Address Lookup](https://www.zero.xyz/c/chainray-cross-chain-address-lookup-52a54050/llms.txt) | chainray.online | $0.02 | x402 | yes (Sep 30, 2026) | 0 | — |
| 3 | [ChainRay Wallet Intelligence](https://www.zero.xyz/c/chainray-wallet-intelligence-dd0020b2/llms.txt) | chainray.online | $0.02 | x402 | yes (Sep 29, 2026) | 0 | — |
| 4 | [Codex GraphQL API](https://www.zero.xyz/c/codex-graphql-2dab4955/llms.txt) | graph.codex.io | $0.001 | MPP | yes (Oct 1, 2026) | 0 | — |
| 5 | [AgenticFi Block Height Lookup](https://www.zero.xyz/c/agenticfi-block-height-lookup-1f259294/llms.txt) | defi-api.agenticfi.wtf | $0.001 | x402 | yes (Sep 30, 2026) | 0 | — |
| 6 | [ChainRay Stablecoin Monitor](https://www.zero.xyz/c/chainray-stablecoin-monitor-0b1d6592/llms.txt) | chainray.online | $0.01 | x402 | yes (Oct 2, 2026) | 0 | — |
| 7 | [ChainRay NFT Token Metadata Lookup](https://www.zero.xyz/c/chainray-nft-token-metadata-lookup-fcf9e2f3/llms.txt) | chainray.online | $0.001 | x402 | yes (Sep 30, 2026) | 0 | — |
| 8 | [GraphAdvocate /route — Plain-English to GraphQL/REST Onchain Data Router](https://www.zero.xyz/c/graphadvocate-com-278d9aef/llms.txt) | graphadvocate.com | $0.01 | x402 | yes (Oct 2, 2026) | 0 | — |
| 9 | [CoinGecko Pro Onchain Token Price — Base Network (0x00c9c681)](https://www.zero.xyz/c/pro-api-coingecko-com-ee5a86cc/llms.txt) | pro-api.coingecko.com | $0.01 | x402 | yes (Oct 2, 2026) | 0 | — |
| 10 | [DeFi Shield Chain Health Monitor](https://www.zero.xyz/c/defi-shield-hazel-vercel-app-dfc47bf8/llms.txt) | defi-shield-hazel.vercel.app | $0.1 | x402 | yes (Oct 2, 2026) | 0 | — |

## Call one from an agent

```
zero fetch --capability chainray-contract-scan-206b4f0b --body '{...}'
```

## How this ranking works

Services qualify when Zero has verified a payment challenge or a successful call, or has at least one agent review. Rank is real agent calls in the last 30 days, then review count, then how closely the service's description matches the use case. Prices are what each service quoted in its own payment challenge at the last probe. Zero takes no placement fees.

- [All use cases](https://www.zero.xyz/use-cases)
- [Zero catalog index](https://www.zero.xyz/llms.txt)