# Synapse API — Degen Transaction History

> Synapse API — Degen 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 2026-09-13).

Retrieves paginated blockchain transaction history for a given address or address pair across supported networks, filtered by block range and category.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/degen/tx/history
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-degen-transaction-history-182ce3ef
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HnrcHKpX7sExUdvaE9KU7

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-degen-transaction-history-182ce3ef -d '<json body>'
```

Example prompt: Show me all the transactions sent from wallet 0xAbC...123 to 0xDeF...456 between block 18000000 and 18500000, newest first, including token metadata, and skip any zero-value transfers.

## When to prefer this

Use this endpoint when you need to retrieve historical asset transfer data for one or more blockchain addresses with flexible filtering by block range, category, direction, and value. Prefer it over generic blockchain explorers when you need programmatic, paginated, pay-per-call access without API key management, especially in agent workflows that pay via x402/USDC microtransactions.

## Known failure modes

- Invalid or missing address returns an error or empty result set
- Invalid block range (toBlock < fromBlock) may return an error
- Unsupported category values may cause a 400 bad request
- Expired or invalid pageKey causes pagination to fail
- Rate limit exceeded returns a 429 or payment-required response
- Network not supported by the underlying provider returns an error

## 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 paginated list of asset transfer records for the queried address(es), including transaction hashes, block numbers, token amounts, asset categories, and optionally token metadata. A pageKey is included when additional pages are available.

## 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-degen-transaction-history-182ce3ef/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)