# CryptoShark Block Number Lookup

> CryptoShark Block Number Lookup is a paid API for AI agents from cryptoshark.duckdns.org, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-19).

Returns the current block number for Base, Ethereum, or Ethereum Classic blockchain networks using redundant public RPC workers

## Facts

- Endpoint: GET https://cryptoshark.duckdns.org/chain/block-number
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cryptoshark-block-number-lookup-5f542c6d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mLV7VIrEId2hpwclRLf6W

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 cryptoshark-block-number-lookup-5f542c6d
```

Example prompt: What is the current block number on the Base network right now?

## When to prefer this

Choose this endpoint when you need a lightweight, low-cost way to fetch the current block number for Base, Ethereum, or Ethereum Classic without setting up your own RPC infrastructure. It is ideal for monitoring chain progress, gating time-sensitive operations, or confirming chain state in agent workflows. Prefer it over full node queries or heavier blockchain APIs when block height is the only data needed.

## Known failure modes

- Unsupported network value returns an error (only 'base', 'ethereum', 'etc' are valid)
- RPC node temporarily unavailable causing timeout or stale data
- Network congestion on the underlying RPC provider causing delayed response
- Missing or malformed query parameters result in a 400-level error

## How this service works

Block number for Base, Ethereum, or Ethereum Classic using redundant public RPC workers

## Output

Returns the current block number (block height) as an integer for the requested blockchain network (Base, Ethereum, or Ethereum Classic), reflecting the latest confirmed block on-chain via redundant public RPC nodes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "hash": {
       "type": "string",
       "description": "Required by transaction and receipt routes"
      },
      "address": {
       "type": "string",
       "description": "Required by balance and code routes"
      },
      "network": {
       "enum": [
        "base",
        "ethereum",
        "etc"
       ],
       "type": "string",
       "default": "base"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cryptoshark-block-number-lookup-5f542c6d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from cryptoshark.duckdns.org](https://www.zero.xyz/host/cryptoshark.duckdns.org/llms.txt)