# Synapse API — NFT Sales by Contract

> Synapse API — NFT Sales by Contract 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 2026-10-20).

Retrieves historical NFT sales events for a given contract address, optionally filtered by block range and result count.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/bob/nft/sales?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/synapse-api-nft-sales-by-contract-9e103d14
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bAT04TjagUzVrp2mvUHvZ

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-nft-sales-by-contract-9e103d14 -d '<json body>'
```

Example prompt: Pull the last 50 NFT sales for contract 0xBC4CA0EdA7647A8aB7C2061c2E118A18a936f13d in descending order — I want to see the most recent sales first.

## When to prefer this

Use this endpoint when you need paginated, block-range-filtered historical NFT sales data for a specific contract on supported blockchain networks. Prefer this over generic blockchain explorers when you need programmatic access with pay-per-call pricing and structured JSON output for agent workflows.

## Known failure modes

- Invalid or missing contract address returns an error or empty result
- fromBlock greater than toBlock causes empty result set or validation error
- Limit value too large may cause timeout or truncated response
- Contract address with no recorded sales returns an empty array
- Network or payment failure results in 402 or 5xx response

## 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 for the specified contract address, including transaction details such as block numbers, sale prices, buyer/seller addresses, and token IDs, filtered by the provided block range and limited to the requested count.

## 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-nft-sales-by-contract-9e103d14/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)