# EVM Block Height

> EVM Block Height is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Returns the latest block number, timestamp, and staleness (age in seconds) for any supported EVM chain, useful for checking node sync status.

## Facts

- Endpoint: POST https://flat-rate-llm.kikoribera03.workers.dev/v1/evm/block
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-block-height-bbfd8eb6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Wx1qTBtrNFHRCtRoldqnJ

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 evm-block-height-bbfd8eb6 -d '<json body>'
```

Example prompt: What's the current block height on Ethereum right now, and how stale is the chain head — is the node in sync?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.001) single-chain block height and freshness check — ideal before submitting transactions, monitoring node health, or confirming a chain is live. Prefer the sibling 'Chain health check' endpoint if you need to check multiple chains at once. This endpoint is purpose-built for sync status checks via eth_getBlockByNumber and returns a minimal, clean payload.

## Known failure modes

- Unsupported chain returns an error or empty response
- Network timeout if the upstream RPC node is unresponsive
- Payment failure (402) if USDC balance is insufficient
- Stale data if upstream node itself is out of sync — ageSeconds will be large but call still succeeds

## How this service works

60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.

## Output

A JSON object containing the latest block number (blockNumber), the Unix timestamp of that block (timestamp), and how many seconds ago that block was produced (ageSeconds), allowing an agent to determine whether the chain is actively producing blocks and the node is in sync.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "type": "string",
   "description": "base | ethereum | polygon | arbitrum | optimism."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "timestamp": {
   "type": "number"
  },
  "ageSeconds": {
   "type": "number"
  },
  "blockNumber": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-block-height-bbfd8eb6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from flat-rate-llm.kikoribera03.workers.dev](https://www.zero.xyz/host/flat-rate-llm.kikoribera03.workers.dev/llms.txt)