# Synapse API — Katana RPC Endpoint

> Synapse API — Katana 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 2026-09-13).

Exposes a JSON-RPC interface for the Katana blockchain node, enabling interaction with Katana-compatible chain methods via pay-per-call x402 payments

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/katana/rpc
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-katana-rpc-endpoint-7f76aa5a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CgKhrp8MksYJ14kGQKmHh

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-katana-rpc-endpoint-7f76aa5a -d '<json body>'
```

Example prompt: Send a JSON-RPC call to the Katana network using method 'eth_blockNumber' with an empty params array and return me the current block number.

## When to prefer this

Choose this endpoint when you need pay-per-call, no-subscription access to a Katana-compatible blockchain node via standard JSON-RPC, particularly when you want to avoid running your own node or committing to a monthly RPC plan. Best for low-frequency or one-off on-chain queries and transaction submissions on the Katana network.

## Known failure modes

- Invalid RPC method name returns a JSON-RPC error with code -32601
- Malformed params array causes -32602 invalid params error
- Payment not provided or insufficient USDC results in HTTP 402 Payment Required
- Network congestion or node unavailability causes timeout or -32603 internal error
- Submitting an already-mined or invalid transaction returns execution reverted 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

A JSON-RPC response object containing the result field with the on-chain data, transaction hash, block details, or error object depending on the method called.

## 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-katana-rpc-endpoint-7f76aa5a/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)