# Synapse API — Abstract Transaction History

> Synapse API — Abstract 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 2026-10-10).

Retrieves paginated transaction history for a given address or address pair across Abstract blockchain using block range and category filters.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/abstract/tx/history?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-abstract-transaction-history-2f2243a5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cR38yfSlY1Wagtv8PAOQd

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-abstract-transaction-history-2f2243a5 -d '<json body>'
```

Example prompt: Pull the last 25 transactions for wallet 0xAbc...123 on the Abstract network, ordered from newest to oldest, including token transfer metadata and excluding zero-value transfers.

## When to prefer this

Choose this endpoint when you need to query historical on-chain transaction data specifically on the Abstract blockchain network, with support for address-pair filtering, block range scoping, category filtering (ERC20, ERC721, internal, etc.), and cursor-based pagination. Prefer it over generic blockchain explorers when you need programmatic, pay-per-call access with structured JSON output suitable for agent workflows.

## Known failure modes

- Invalid address format returns a 400 error
- Unknown or unsupported category strings may return empty results or errors
- fromBlock greater than toBlock yields no results or an error
- Expired or invalid pageKey causes pagination to fail or restart
- Payment not attached results in 402 Payment Required
- Rate limiting or server errors return 500-level responses

## 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 transactions involving the specified addresses, including transfer categories, block numbers, transaction hashes, and optionally full metadata such as token name, symbol, and decimals. A pageKey is provided when more results 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-abstract-transaction-history-2f2243a5/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)