# Ethereum Mainnet Latest Block Number

> Ethereum Mainnet Latest Block Number is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-29).

Returns the current latest block number on Ethereum mainnet (eip155:1) via a read-only eth_blockNumber call

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/eth-block-number?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-mainnet-latest-block-number-c9c5ea42
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UvDUTrcy4E7YK4UBSXA5E

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-latest-block-number-c9c5ea42 -d '<json body>'
```

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

## When to prefer this

Use this endpoint when an agent needs a quick, cheap, read-only lookup of the current Ethereum mainnet block number without running a full node or maintaining an RPC connection. Ideal for lightweight agents that need periodic chain height checks, synchronization verification, or timestamping on-chain events by block number. At $0.001 USDC per call it is cost-effective for frequent polling. Try the free sandbox endpoint first for testing.

## Known failure modes

- Network or RPC node unavailability returns a 5xx error
- Invalid or non-'latest' tag value returns a 4xx validation error
- Payment failure or insufficient USDC balance returns a 402 Payment Required
- Rate limiting may return a 429 Too Many Requests error

## How this service works

Call when an agent needs the latest Ethereum mainnet block number. Send tag latest, or an empty object. Read-only eth_blockNumber on eip155:1. No spend. Send JSON {"tag":"latest"}. Exact $0.001 USDC on Base. Try unpaid POST /v1/sandbox/eth-block-number first.

## Output

Returns the current latest block number on Ethereum mainnet as a numeric value, representing the chain height at the time of the request.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tag": {
   "type": "string",
   "const": "latest",
   "examples": [
    "latest"
   ],
   "description": "Block tag. Only latest is accepted. Example: latest. Omit it for the same current Ethereum mainnet block number. No address."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-mainnet-latest-block-number-c9c5ea42/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)