# Synapse API — Citrea RPC Endpoint

> Synapse API — Citrea 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 2026-10-29).

Provides JSON-RPC access to the Citrea blockchain network, enabling agents to query chain state, submit transactions, and interact with Citrea smart contracts.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/citrea/rpc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-citrea-rpc-endpoint-650484b9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xxtM4DO9h_zOtEe8mDHFJ

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-citrea-rpc-endpoint-650484b9 -d '<json body>'
```

Example prompt: Call eth_getBalance on the Citrea network for address 0xAbc123... and tell me how much cBTC is in that wallet.

## When to prefer this

Choose this endpoint when you need to interact specifically with the Citrea Bitcoin ZK-rollup network via standard JSON-RPC. It is preferable when your task requires querying Citrea chain state, submitting transactions, or calling smart contracts on Citrea, and you want pay-per-call pricing without a subscription. If you need to interact with Ethereum mainnet or other EVM chains, use a corresponding RPC endpoint for those networks instead.

## Known failure modes

- Invalid RPC method name returns JSON-RPC error -32601 (Method not found)
- Malformed params array returns JSON-RPC error -32602 (Invalid params)
- Payment failure via x402 results in 402 response before execution
- Network or node unavailability returns a 5xx or timeout error
- Unsupported Citrea-specific methods may return method not supported errors

## 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 of the requested Citrea blockchain method call, such as account balances, block information, transaction receipts, or contract return values. Errors are returned as JSON-RPC error objects with code and message fields.

## 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-citrea-rpc-endpoint-650484b9/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)