# EVM Pending Block Status

> EVM Pending Block Status is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns the pending block details for an EVM chain, including queued transaction count, base fee, and gas usage, giving a real-time view of mempool congestion without an indexer.

## Facts

- Endpoint: GET https://agent402.tools/api/chain/pending
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-pending-block-status-d6cca166
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_w05WMZElR1FOVECgoHnaM

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-pending-block-status-d6cca166
```

Example prompt: What does the current pending block look like on Ethereum — how many transactions are queued, what's the base fee in gwei, and how close are we to the gas limit?

## When to prefer this

Use this endpoint when you need a real-time, lightweight snapshot of EVM chain congestion — specifically pending transaction queue depth, base fee, and gas utilization — without spinning up your own node or relying on a third-party indexer. Ideal for agents that need to decide whether to submit a transaction now or wait, or to compare gas conditions across supported EVM chains.

## Known failure modes

- Unsupported network name returns an error — only ethereum, base, polygon, arbitrum, optimism are valid
- Node-level variance: pending block contents differ between nodes so results may not match other sources
- No indexer backing means very recent transactions may not appear
- Missing or malformed query parameters may result in default values being applied silently
- Payment failure (402) if USDC balance is insufficient

## How this service works

The chain's pending block: how many transactions are queued for the next block, the base fee they will pay, and the gas already used against the limit. This is the node's own view of what is about to be mined, so it answers "is the chain congested right now" without an indexer. Transaction hashes are included when the node returns them. EVM chains: ethereum, base, polygon, arbitrum, optimism.

## Output

Returns a JSON object with the network name, pending block number, number of queued transactions, base fee in wei and gwei, gas used, gas limit, and block timestamp. Optionally includes an array of pending transaction hashes. Includes a note that the pending block is the node's own view and not a consensus value.

## 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",
     "required": [],
     "properties": {
      "hashes": {
       "type": "boolean",
       "description": "Include the pending transaction hashes (default false, counts only)"
      },
      "network": {
       "type": "string",
       "description": "ethereum | base | polygon | arbitrum | optimism (default base)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "network",
      "number",
      "transactionCount",
      "baseFeePerGas",
      "baseFeePerGasGwei",
      "gasUsed",
      "gasLimit",
      "timestamp",
      "note"
     ],
     "properties": {
      "note": {
       "type": "string"
      },
      "number": {
       "type": "string"
      },
      "gasUsed": {
       "type": "string"
      },
      "network": {
       "type": "string"
      },
      "gasLimit": {
       "type": "string"
      },
      "timestamp": {
       "type": "string"
      },
      "baseFeePerGas": {
       "type": "string"
      },
      "transactionCount": {
       "type": "integer"
      },
      "baseFeePerGasGwei": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "A pending block is the node's own view and differs between nodes; it is not a consensus value.",
  "number": "34881204",
  "gasUsed": "12904331",
  "network": "base",
  "gasLimit": "150000000",
  "timestamp": "2026-09-12T21:30:11.000Z",
  "baseFeePerGas": "4218231",
  "transactionCount": 61,
  "baseFeePerGasGwei": "0.004218"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-pending-block-status-d6cca166/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)