# Base Mainnet Block Inspector

> Base Mainnet Block Inspector is a paid API for AI agents from apiacre.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Inspects a historical Base mainnet block by number or resolves a canonical tag (latest, safe, finalized), returning transaction count, gas, fee, root hashes, and head distance.

## Facts

- Endpoint: POST https://apiacre.com/v1/crypto/base-block-inspect
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-mainnet-block-inspector-19f41885
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__8Ji2Swo-PEjzqdPMyRI8

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-block-inspector-19f41885 -d '<json body>'
```

Example prompt: Can you inspect Base mainnet block number 18500000 and tell me the transaction count, gas used, total fees, and how far it is from the current chain head?

## When to prefer this

Choose this endpoint when you need detailed metadata about a specific Base mainnet block — including gas, fees, roots, and head distance — without running your own RPC node. It is ideal for agents auditing on-chain activity, verifying block finality, or monitoring chain progression on Base L2 specifically (not Ethereum mainnet or other EVM chains).

## Known failure modes

- Block number not found or not yet mined returns a 404-style error
- Invalid block tag (not latest/safe/finalized) returns a validation error
- Block number exceeds current chain head returns an out-of-range error
- Network or RPC timeout causes a 503 or timeout response
- Malformed request body returns a 400 bad request error

## How this service works

Get and inspect one historical Base mainnet block by exact number or a latest, safe, or finalized tag, returning its header timestamp, transaction count, gas use, base and blob fees, state and receipt roots, confirmations, and head-distance evidence.

## Output

Returns a structured JSON object containing block number, hash, timestamp, transaction count, gas used, gas limit, base fee per gas, state root, receipts root, transactions root, and the distance (in blocks) from the current chain head. Also indicates whether the block is canonical, safe, or finalized.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "block_tag": {
   "enum": [
    "latest",
    "safe",
    "finalized"
   ],
   "type": "string"
  },
  "block_number": {
   "anyOf": [
    {
     "type": "integer"
    },
    {
     "type": "null"
    }
   ]
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "head": {
    "latestNumber": 34600002,
    "confirmations": 3,
    "blockAtOrBeforeHead": true
   },
   "block": {
    "hash": "0x4444444444444444444444444444444444444444444444444444444444444444",
    "number": 34600000,
    "timestamp": "2026-08-11T13:00:00+00:00",
    "ageSeconds": 4,
    "parentHash": "0x3333333333333333333333333333333333333333333333333333333333333333"
   },
   "found": true,
   "source": "https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_getB...",
   "network": {
    "name": "Base Mainnet",
    "caip2": "eip155:8453",
    "chainId": 8453
   },
   "request": {
    "mode": "number",
    "blockTag": null,
    "blockNumber": 34600000,
    "rpcSelector": "0x20ff440",
    "fullTransactions": false
   },
   "readOnly": true,
   "warnings": [],
   "disclaimer": "A point-in-time RPC observation, not proof of finality beyond the requested p...",
   "observedAt": "2026-08-11T13:00:04+00:00",
   "rpcCallsMade": 3,
   "networkRequestsMade": 1,
   "transactionBroadcast": false
  },
  "meta": {
   "cached": false,
   "sources": [],
   "warnings": [],
   "duration_ms": 42,
   "next_actions": [
    {
     "path": "/v1/crypto/base-network-status",
     "title": "Base network and fee status",
     "method": "POST",
     "reason": "Compare the inspected historical or tagged block with the current Base head a...",
     "service": "crypto.base-network-status"
    }
   ]
  },
  "service": "crypto.base-block-inspect",
  "version": "1",
  "request_id": "018f1f54-7f38-7ba2-8dc3-5f90272d9f1a"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-mainnet-block-inspector-19f41885/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apiacre.com](https://www.zero.xyz/host/apiacre.com/llms.txt)