# Synapse API — SEI NFT Sales

> Synapse API — SEI 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 2026-10-29).

Retrieves NFT sales events on the SEI blockchain, filterable by contract address and block range

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/sei/nft/sales?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-sei-nft-sales-47b87fb1
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yvdnNnNht51DKLSCikuGq

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-sei-nft-sales-47b87fb1 -d '<json body>'
```

Example prompt: Pull the last 50 NFT sales for contract 0xABC123 on SEI, from block 1000000 to 1100000, ordered by most recent first.

## When to prefer this

Use this endpoint when you specifically need NFT sales data from the SEI blockchain and want block-level filtering granularity. It is ideal for agents tracking NFT market activity, auditing collection sales history, or building analytics dashboards scoped to SEI. Prefer this over generic blockchain explorers when you need structured, paginated sales data without parsing raw logs.

## Known failure modes

- Invalid contract address format returns validation error
- Block range too large may result in timeout or truncated results
- fromBlock greater than toBlock returns empty or error response
- Network unavailability on SEI indexer returns 503 or empty payload
- Invalid order enum value returns 400 bad request
- Payment not included or insufficient USDC results in 402 payment required

## 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 on the SEI blockchain, each likely including transaction hash, contract address, token ID, sale price, buyer/seller addresses, and the block number in which the sale occurred, filtered and ordered according to the request parameters.

## 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-sei-nft-sales-47b87fb1/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)