# Basebuilder2 Trading - Mempool Pending Transactions

> Basebuilder2 Trading - Mempool Pending Transactions is a paid API for AI agents from bbx-trading.vercel.app, paid per call via x402, $0.188704/call, status unknown (last checked 2026-10-20).

Retrieves pending (unconfirmed) transactions from the blockchain mempool

## Facts

- Endpoint: POST https://bbx-trading.vercel.app/api/mempool/pending?utm_source=zero.xyz
- Price: $0.188704/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/basebuilder2-trading-mempool-pending-transactions-66e06f38
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jxbDeRseRVnJB5-OWXKK_

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 basebuilder2-trading-mempool-pending-transactions-66e06f38 -d '<json body>'
```

Example prompt: Pull the current list of pending transactions sitting in the mempool from BBX Trading so I can see what's waiting to be confirmed on-chain right now.

## When to prefer this

Choose this endpoint when you need real-time visibility into unconfirmed blockchain transactions for trading strategy, congestion monitoring, or pre-confirmation analysis. It is part of a paid x402-gated trading API hub, so prefer it when you need programmatic mempool access integrated into an automated trading or monitoring workflow.

## Known failure modes

- Mempool data may be stale or incomplete if the underlying node is not fully synced
- Empty result set if mempool is clear or filters are too restrictive
- HTTP 402 Payment Required if x402 payment header is missing or insufficient
- Service unavailability due to Vercel cold starts or backend node downtime
- Rate limiting or quota exhaustion after excessive calls
- Malformed POST body may result in 400 Bad Request

## How this service works

BaseBuilder Trading API hub - 20 paid endpoints

## Output

Returns a list of pending (unconfirmed) transactions currently sitting in the blockchain mempool, likely including transaction hashes, sender/receiver addresses, value amounts, gas prices, and timestamps or nonce data depending on the underlying chain queried.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/basebuilder2-trading-mempool-pending-transactions-66e06f38/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bbx-trading.vercel.app](https://www.zero.xyz/host/bbx-trading.vercel.app/llms.txt)