# Synapse API — Polygon RPC Endpoint

> Synapse API — Polygon 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).

Proxies JSON-RPC calls to the Polygon blockchain network, enabling agents to read chain state, submit transactions, and interact with smart contracts on Polygon.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/polygon/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-polygon-rpc-endpoint-6ae20ffe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YrUeWJ-xUSlAIw1LKnwn4

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-polygon-rpc-endpoint-6ae20ffe -d '<json body>'
```

Example prompt: Can you check the current MATIC balance for wallet address 0xAbC123... on the Polygon mainnet using an eth_getBalance RPC call?

## When to prefer this

Choose this endpoint when you need pay-per-call, no-subscription access to Polygon blockchain RPC without managing your own node or committing to a monthly RPC plan. Ideal for agents that occasionally need Polygon chain data and want to pay $0.01 USDC per call via x402 micropayments rather than provisioning an Alchemy, Infura, or QuickNode account.

## 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 upstream node unavailability causes timeout or 503
- Payment failure (insufficient USDC) results in 402 Payment Required before the call is proxied
- Calling write methods without a signed transaction will fail with execution 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 an 'id', 'jsonrpc' version field, and a 'result' field with the blockchain data (e.g. block number as hex, balance in wei, transaction receipt object, or contract call return data). On error, returns a JSON-RPC error object with code and message.

## 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-polygon-rpc-endpoint-6ae20ffe/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)