# Synapse API — StarkNet RPC Proxy

> Synapse API — StarkNet 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 2026-10-16).

Proxies JSON-RPC method calls to the StarkNet blockchain network, enabling read and write interactions with StarkNet nodes.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/starknet/rpc?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-starknet-rpc-proxy-50f6cba8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G-eWJuHyPAZTrQIfr2Mon

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-starknet-rpc-proxy-50f6cba8 -d '<json body>'
```

Example prompt: Call the starknet_getBlockWithTxs RPC method on StarkNet with the latest block tag as the parameter and return the full block data.

## When to prefer this

Use this endpoint when you need pay-per-call access to StarkNet RPC without running your own node or managing an Infura/Alchemy subscription. Ideal for agents that make infrequent or unpredictable StarkNet queries and prefer micro-payment billing via x402 USDC rather than monthly API key plans.

## Known failure modes

- Invalid RPC method name returns JSON-RPC error with code -32601 (method not found)
- Malformed params array causes -32602 (invalid params) error
- StarkNet node unavailable or rate-limited returns 503 or timeout
- Payment failure (insufficient USDC) results in 402 response before the RPC call is made
- Requesting a non-existent block or transaction returns a StarkNet-specific error code

## 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 the standard JSON-RPC response object from the StarkNet node, including a result field containing the requested blockchain data (block info, transaction receipt, contract state, 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-starknet-rpc-proxy-50f6cba8/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)