# Base Mainnet Current Block Number

> Base Mainnet Current Block Number is a paid API for AI agents from x402-data-api.sigrunner.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-16).

Returns the current block number on the Base mainnet blockchain.

## Facts

- Endpoint: GET https://x402-data-api.sigrunner.workers.dev/chain/block-number
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-mainnet-current-block-number-27d6408e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jExOP4eKhsQ1XMMfnTlNf

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 base-mainnet-current-block-number-27d6408e
```

Example prompt: What's the current block number on Base mainnet right now?

## When to prefer this

Use this endpoint when you need the current Base mainnet block number for timing, confirmation depth checks, or synchronizing on-chain events. Prefer this over general Ethereum block number APIs when working specifically on the Base L2 network.

## Known failure modes

- RPC node unavailable — returns 5xx error
- Rate limit exceeded — returns 429 with retry-after header
- Payment not provided or invalid — returns 402 requiring x402 payment
- Network timeout if Base node is syncing

## How this service works

Current Base mainnet block number.

## Output

Returns the current block number (chain height) of the Base mainnet as an integer, reflecting the latest confirmed block at time of request.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "block_number": 27738421
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-mainnet-current-block-number-27d6408e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-data-api.sigrunner.workers.dev](https://www.zero.xyz/host/x402-data-api.sigrunner.workers.dev/llms.txt)