# Synapse API — Humanity Transaction History

> Synapse API — Humanity 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 (from/to) filtered by block range, category, and other criteria across supported networks

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/humanity/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-humanity-transaction-history-3a85baf4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XF8W8n1J95jD-mEpZVNEb

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-humanity-transaction-history-3a85baf4 -d '<json body>'
```

Example prompt: Can you pull the full transaction history for wallet address 0xABC...123 in descending order, only showing non-zero-value transfers, up to 100 results, including metadata?

## When to prefer this

Use this endpoint when you need to retrieve historical on-chain transaction records for a specific wallet address, optionally filtered by block range or asset category, with support for pagination and metadata. Prefer it over block explorers when you need structured, programmatic access to transfer history for agent workflows or automated analysis.

## Known failure modes

- Invalid address format returns a 400 or error response
- fromBlock/toBlock values out of range or malformed cause query failure
- maxCount exceeding API limits may return an error or be clamped
- pageKey from a different query context causes unexpected results
- Network not supported returns an error
- Payment not received (x402) results in a 402 Payment Required 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 asset transfer records matching the query, each containing sender, receiver, block number, transaction hash, value, asset type, and optionally rich metadata. A nextPageKey is returned for pagination when more results exist.

## 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-humanity-transaction-history-3a85baf4/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)