# base-pending-block

> base-pending-block is a paid API for AI agents from x402.agentindex.world, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Fetches the current pending block on Base mainnet, including unconfirmed mempool transactions, via eth_getBlockByNumber('pending').

## Facts

- Endpoint: GET https://x402.agentindex.world/base/pending?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-pending-block-d4fbb5d1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xmeVuEEMdBeZDWWkknO0G

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-pending-block-d4fbb5d1
```

Example prompt: What transactions are currently sitting in the Base mainnet mempool — can you pull the pending block and tell me how many unconfirmed transactions there are, the current base fee per gas, and the gas limit?

## When to prefer this

Use this endpoint when you need a real-time snapshot of unconfirmed transactions on Base mainnet — ideal for mempool analysis, gas fee estimation before submitting a transaction, MEV/arbitrage scouting, or monitoring network congestion. Prefer this over confirmed-block endpoints when you specifically need pre-mining transaction data.

## Known failure modes

- Node provider unavailable or rate-limited — returns error with no block data
- Pending block temporarily empty or unavailable — may return zero transactions
- Payment not received — x402 payment required before data is returned
- Network instability causing stale or inconsistent pending block snapshot

## How this service works

The current pending Base mainnet block (mempool, not yet mined) - unconfirmed transactions via eth_getBlockByNumber('pending').

## Output

Returns a structured object representing the current pending Base mainnet block, including block number, block hash, parent hash, Unix timestamp, miner address, gas used, gas limit, base fee per gas, the count of pending transactions, and an array of all pending transaction hashes.

## 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",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "title": "PendingInput",
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "title": "BlockOutput",
     "required": [
      "number",
      "hash",
      "parent_hash",
      "timestamp",
      "miner",
      "gas_used",
      "gas_limit",
      "transaction_count",
      "transaction_hashes"
     ],
     "properties": {
      "hash": {
       "type": "string",
       "title": "Hash"
      },
      "miner": {
       "type": "string",
       "title": "Miner"
      },
      "number": {
       "type": "integer",
       "title": "Number"
      },
      "gas_used": {
       "type": "integer",
       "title": "Gas Used"
      },
      "gas_limit": {
       "type": "integer",
       "title": "Gas Limit"
      },
      "timestamp": {
       "type": "integer",
       "title": "Timestamp"
      },
      "parent_hash": {
       "type": "string",
       "title": "Parent Hash"
      },
      "base_fee_per_gas": {
       "anyOf": [
        {
         "type": "integer"
        },
        {
         "type": "null"
        }
       ],
       "title": "Base Fee Per Gas",
       "default": null
      },
      "transaction_count": {
       "type": "integer",
       "title": "Transaction Count"
      },
      "transaction_hashes": {
       "type": "array",
       "items": {
        "type": "string"
       },
       "title": "Transaction Hashes"
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-pending-block-d4fbb5d1/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.agentindex.world](https://www.zero.xyz/host/x402.agentindex.world/llms.txt)