# Synapse API — ZKsync RPC Endpoint

> Synapse API — ZKsync RPC Endpoint 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 2026-10-18).

Proxies JSON-RPC calls to the ZKsync Era blockchain network, enabling on-chain reads and writes via standard Ethereum-compatible methods.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/zksync/rpc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-zksync-rpc-endpoint-7e4ce22e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_B8JtuJ36C_LI0UKgz7WVA

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-zksync-rpc-endpoint-7e4ce22e -d '<json body>'
```

Example prompt: Call eth_getBalance on ZKsync Era for wallet address 0xAbC...123 at the latest block and tell me how much ETH it holds.

## When to prefer this

Choose this endpoint when you need pay-per-call ZKsync Era RPC access without managing your own node or committing to a subscription plan. Ideal for agents that interact with ZKsync infrequently or want metered on-chain access billed in USDC via x402.

## Known failure modes

- Invalid RPC method name returns JSON-RPC error code -32601 (method not found)
- Malformed params array returns error code -32602 (invalid params)
- Network congestion or ZKsync node downtime returns a 503 or timeout
- Submitting an invalid or already-mined transaction returns execution revert error
- Payment failure (x402) blocks the request before it reaches the RPC layer

## 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

A standard JSON-RPC response object containing the 'result' field with on-chain data (balance, block info, tx hash, etc.) or an 'error' object with code and message if the call fails.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "method": {
   "type": "string"
  },
  "params": {
   "type": "array",
   "items": {}
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-zksync-rpc-endpoint-7e4ce22e/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)