# Synapse API — Base NFT Sales

> Synapse API — Base NFT Sales is a paid API for AI agents from synapse-api-brown.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-14).

Retrieves NFT sales transaction history on the Base blockchain, filtered by contract address and block range.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/base/nft/sales?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-base-nft-sales-05608eec
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QAnFKrjoFe2j0WjvDzSUy

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 synapse-api-base-nft-sales-05608eec -d '<json body>'
```

Example prompt: Pull the last 50 NFT sales for the Base contract 0xd4307e0acd12cf46fd6cf93bc264f5d5d1598792 in descending order — I want to see the most recent trades first.

## When to prefer this

Use this endpoint when you need on-chain NFT sales data specifically from the Base (Coinbase L2) blockchain, especially when you need block-level filtering or chronological ordering of sales events. Prefer this over generic NFT APIs when you need raw on-chain sales events rather than aggregated marketplace statistics.

## Known failure modes

- Invalid or non-existent contract address returns empty results or an error
- fromBlock greater than toBlock returns no results or validation error
- Limit parameter too large may cause timeout or truncated response
- Network or RPC unavailability on Base chain causes 500 error
- Missing required contractAddress field may return error or unfiltered results

## How this service works

High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.

## Output

Returns a list of NFT sale events from the Base blockchain matching the specified contract address and block range, ordered as requested, up to the specified limit. Each record typically includes sale transaction details such as block number, buyer/seller addresses, token IDs, and sale amounts.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "limit": {
   "type": "number"
  },
  "order": {
   "enum": [
    "asc",
    "desc"
   ],
   "type": "string"
  },
  "toBlock": {
   "type": "number"
  },
  "fromBlock": {
   "type": "number"
  },
  "contractAddress": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-base-nft-sales-05608eec/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synapse-api-brown.vercel.app](https://www.zero.xyz/host/synapse-api-brown.vercel.app/llms.txt)