# Ethereum Mainnet eth_blockNumber

> Ethereum Mainnet eth_blockNumber is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-17).

Returns the latest Ethereum mainnet block number via the eth_blockNumber JSON-RPC call, requiring no input parameters.

## Facts

- Endpoint: GET https://api.arysphere.com/v1/ventures/x402_eth_reads_v1/eth_mainnet_eth_blocknumber?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-mainnet-eth-blocknumber-c4f00109
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iy-vbJ-sujhc-6b3sc_m2

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 ethereum-mainnet-eth-blocknumber-c4f00109
```

Example prompt: What is the current block number on Ethereum mainnet right now?

## When to prefer this

Use this endpoint when you need a quick, lightweight, no-parameter read of the current Ethereum mainnet chain height — particularly useful as a polling primitive for block-based monitoring, as a reference anchor for relative block queries, or to verify chain liveness. Prefer this over full block retrieval endpoints when you only need the block number and not block content.

## Known failure modes

- Network or gateway timeout resulting in no response
- Arysphere gateway unavailable returns 5xx error
- Insufficient USDC payment (x402 payment required response) if payment header is missing or malformed
- Rate limiting if too many requests are made in quick succession

## How this service works

ARYSPHERE sells AI-written verdicts on Base token contracts (a grade, a one-liner, a roast and the contract's facts) and Base/Ethereum chain reads, paid per call in USDC on Base over x402 v2. No account and no API key.

## Output

Returns a single integer representing the latest confirmed block number on the Ethereum mainnet, expressed in hexadecimal (standard eth_blockNumber RPC response format). No additional data is returned.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "hex": "0x18ff378",
  "chain": "ethereum",
  "method": "eth_blockNumber",
  "result": 26211192,
  "service": "x402_eth_reads_v1.eth_mainnet_eth_blocknumber"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-mainnet-eth-blocknumber-c4f00109/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)