# Synapse API — Sei Network RPC Proxy

> Synapse API — Sei Network RPC Proxy 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 2026-09-14).

Proxies JSON-RPC method calls to the Sei blockchain network, enabling reads and writes against Sei chain state via a pay-per-call model.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/sei/rpc
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-sei-network-rpc-proxy-fcd68af9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_veTpeIgqGA29iPm6v0CUo

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-sei-network-rpc-proxy-fcd68af9 -d '<json body>'
```

Example prompt: Call the Sei blockchain RPC with the method eth_getBalance and pass the wallet address 0xAbC123... as the parameter — I need to see the current SEI balance on-chain.

## When to prefer this

Use this endpoint when you need direct, pay-per-call access to the Sei blockchain RPC without managing your own node or committing to a subscription. Ideal for agents that need occasional or low-volume Sei chain queries, or for applications that want to avoid node infrastructure overhead while supporting Sei specifically.

## Known failure modes

- Invalid JSON-RPC method name returns error code -32601 Method not found
- Malformed params array causes parse error -32700
- Network congestion or Sei node unavailability returns 503 or timeout
- Payment failure (x402) if USDC balance is insufficient
- Invalid transaction data in eth_sendRawTransaction returns revert or invalid input 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 standard JSON-RPC response object containing the result field with the on-chain data (e.g. balance, block, receipt, or contract return value), 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-sei-network-rpc-proxy-fcd68af9/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)