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Synapse API — Arbitrum RPC Endpoint
x402
Synapse API — Arbitrum 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 2026-09-14).
Provides JSON-RPC access to the Arbitrum blockchain network via a pay-per-call proxy.
Price / call$0.01
Success—
StatusUnknown
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 from the Arbitrum node, including result data (e.g. balance in hex, block object, transaction receipt) or an error object with code and message if the call fails.
Example use cases
Check Arbitrum wallet balance
“What's the ETH balance of wallet address 0xAbC...123 on Arbitrum right now? Use eth_getBalance to look it up.”
Fetch latest Arbitrum block
“Get the latest block from the Arbitrum network using eth_getBlockByNumber and show me the block number, timestamp, and transaction count.”
Read Arbitrum smart contract state
“Call eth_call on the Arbitrum network to read the totalSupply from the ERC-20 contract at 0xDef...456 — what does it return?”
Technical details
Endpoint
POSThttps://synapse-api-brown.vercel.app/api/arbitrum/rpcWhen to prefer
Choose this endpoint when you need pay-per-call access to the Arbitrum network without managing your own RPC node or committing to a subscription. Ideal for AI agents that interact with Arbitrum sporadically and want micropayment billing via x402/USDC rather than a monthly API key plan.
Side effects
- Invalid JSON-RPC method name returns error code -32601 (method not found)
- Malformed params array causes -32602 (invalid params)
- Payment not included or insufficient USDC returns 402 Payment Required
- Network congestion or node unavailability returns 503 or timeout
- Calling a write method (eth_sendRawTransaction) without a signed transaction returns execution error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| method | string | |
| params | array |
Tags
x402
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