# Synapse API — opBNB Transaction History

> Synapse API — opBNB Transaction History 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 2026-09-15).

Retrieves paginated transaction history for addresses on the opBNB blockchain network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/opbnb/tx/history
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-opbnb-transaction-history-82df483e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lNl1gw-wToQpfCv6X9sdQ

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-opbnb-transaction-history-82df483e -d '<json body>'
```

Example prompt: Pull the last 25 opBNB transactions sent from wallet 0xABC...123, sorted newest first, and include metadata — skip any zero-value transfers.

## When to prefer this

Choose this endpoint when you need historical transaction data specifically on the opBNB (BNB Layer 2) network, with fine-grained filtering by address, block range, category, and sort order. It supports pagination for large datasets and optional metadata enrichment. Prefer this over generic blockchain explorers when programmatic, pay-per-call access is needed within an automated agent workflow.

## Known failure modes

- Invalid or malformed address returns an error or empty result
- Block range out of bounds or toBlock before fromBlock causes an error
- Unsupported category value returns a validation error
- Invalid pageKey causes pagination failure or empty response
- Payment not included or insufficient triggers a 402 Payment Required response
- Rate limiting or network congestion may cause timeouts

## 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 transaction records on the opBNB network matching the specified filters, including transaction hashes, block numbers, from/to addresses, values, and optional metadata. Supports pagination via pageKey for large result sets.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "order": {
   "enum": [
    "asc",
    "desc"
   ],
   "type": "string"
  },
  "pageKey": {
   "type": "string"
  },
  "toBlock": {
   "type": "string"
  },
  "category": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "maxCount": {
   "type": "number"
  },
  "fromBlock": {
   "type": "string"
  },
  "toAddress": {
   "type": "string"
  },
  "fromAddress": {
   "type": "string"
  },
  "withMetadata": {
   "type": "boolean"
  },
  "excludeZeroValue": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-opbnb-transaction-history-82df483e/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)