# Pending Transactions & Tips (EVM Gas Pricer)

> Pending Transactions & Tips (EVM Gas Pricer) is a paid API for AI agents from bess-x402.onrender.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-29).

Returns pending block statistics for EVM chains including transaction count, priority-fee and gas-price percentiles, most-called contracts, and largest native transfers to help price gas.

## Facts

- Endpoint: GET https://bess-x402.onrender.com/v1/evm/pending?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pending-transactions-tips-evm-gas-pricer-2f86ccbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QsnIRxSfq6_jOJRpvoUU5

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 pending-transactions-tips-evm-gas-pricer-2f86ccbc
```

Example prompt: What's the current gas situation on Base — give me the priority fee percentiles and the top 10 largest native transfers in the pending block so I can figure out what tip to set.

## When to prefer this

Choose this endpoint when you need real-time mempool data — gas price percentiles, priority fees, and pending transaction volume — for Ethereum or major EVM L2s (Base, Arbitrum, Optimism, Polygon). It is ideal for gas estimation before submitting transactions, detecting network congestion, or identifying large on-chain transfers in flight. Prefer it over static gas price feeds when you need percentile-based fee recommendations or want to see which contracts are hot in the current block.

## Known failure modes

- Unsupported chain value returns an error — only ethereum, base, arbitrum, optimism, and polygon are valid
- Limit out of range (must be 1–50) returns a validation error
- Network timeout or RPC node unavailability may cause delayed or failed responses
- Payment failure via x402 protocol results in 402 response before data is returned
- Stale or empty pending block if the chosen chain has very low activity

## How this service works

An EVM chain's pending block (Ethereum, Base, Arbitrum, Optimism, Polygon): transaction count, priority-fee and gas-price percentiles, most-called contracts and largest native transfers. Use to price gas.

## Output

Returns a JSON object with the pending block's transaction count, gas price and priority fee percentiles (e.g. p10, p25, p50, p75, p90), a list of the most frequently called smart contracts, and the largest native-asset transfers up to the requested limit — all scoped to the chosen EVM chain's current mempool.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "chain": {
       "type": "string",
       "description": "ethereum, base, arbitrum, optimism or polygon"
      },
      "limit": {
       "type": "integer",
       "description": "Largest transfers to list (1-50)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pending-transactions-tips-evm-gas-pricer-2f86ccbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bess-x402.onrender.com](https://www.zero.xyz/host/bess-x402.onrender.com/llms.txt)