Ethereum

Ethereum

FAQ

Authentication & Access

• How do I get an API key? Sign up at TheRPC.io, open the Dashboard, go to API Keys, and generate one. It authenticates against the Ethereum endpoint right away.
• Can I have more than one key? Yes, and it is worth it. A key per app and per environment means you can revoke a leaked staging key without disrupting production chain 1 traffic, and the Dashboard shows CU usage broken out per key so you can see which workload is spending.
• What if a key leaks? Revoke it from the Dashboard immediately — a revoked key stops authenticating on the spot — then generate a replacement and swap it into your environment. A leaked key on a public repo can be drained of CUs within minutes, so do not wait.

API Usage

• HTTP or WebSocket? Use the HTTP endpoint for one-off reads and broadcasts — eth_getBalance, eth_call, eth_sendRawTransaction. Use the WebSocket endpoint when you need the node to push data to you: new blocks each 12-second slot, live logs, or pending transactions via eth_subscribe, which only works over WebSocket.
• How do I handle rate limits? Back off exponentially when you see the rate-limit error code and retry, rather than hammering the endpoint. If you hit limits steadily rather than in bursts, that is a signal to upgrade your plan.
• What timeouts should I set? Around 30 seconds for HTTP requests, a 60-second WebSocket ping/pong interval to keep the connection alive, and roughly 30 seconds for subscription setup operations.

Error Handling

The Ethereum endpoint returns the standard JSON-RPC error codes, summarized in the table below: -32700 for unparseable JSON, -32600 for a malformed request object, -32601 for an unknown method name, which is usually a misspelling or a namespace your tier has not unlocked, -32602 for bad params like a malformed address or block tag, -32603 for an internal node error, and the -32000 to -32099 range for server-side conditions. Four habits keep error handling sane: always check whether the error field is present before reading result; retry transient failures and rate limits with exponential backoff rather than tight loops; log the code and message so you can tell a bad address from a node hiccup; and set request timeouts so a slow call fails cleanly instead of hanging.

Common Error Response

1{
2  "jsonrpc": "2.0",
3  "error": {
4    "code": -32601,
5    "message": "Method not found"
6  },
7  "id": 1
8}

Standard JSON-RPC Error Codes

Technical Questions

• How do I track a pending transaction? Poll eth_getTransactionReceipt by hash — a null result means it is still pending, a receipt means it landed. For a push-based approach, subscribe to newHeads over WebSocket and check for your hash as each block arrives.
• How do I keep my own transactions in order? Sequence them by nonce. Fetch the current nonce with eth_getTransactionCount, then assign each outgoing transaction the next integer and submit them through an application-level queue so a gap never leaves later ones stuck in the queued pool.
• How do I deal with reorgs? At the chain head, short single-block reorgs are possible before a block is justified, so do not treat a fresh latest block as settled. For anything involving money, read at the finalized tag via eth_getBlockByNumber — once Casper FFG finalizes a checkpoint (about 12.8 minutes, two epochs), it cannot be reverted without a third of all staked ETH being slashed. Wait for confirmations by watching eth_blockNumber climb, or use safe when you want a softer guarantee than finalized but firmer than latest.

Transaction Tracking Example

1// Example of transaction tracking
2const receipt = await web3.eth.getTransactionReceipt(txHash);
3if (receipt) {
4  console.log(`Transaction confirmed in block ${receipt.blockNumber}`);
5}

Performance

• How do I cut down on calls? Batch independent reads into a single JSON-RPC array so several balances or block lookups go over one HTTP round trip. Switch to WebSocket subscriptions for anything real-time so you stop polling. Cache values that change slowly — chain ID, contract bytecode, old finalized blocks — and tune polling intervals to the 12-second slot rather than spinning faster than blocks are produced.
• What about high throughput? Pool and reuse connections instead of opening one per request, queue outgoing requests so you stay under your rate limit, watch the rate-limit response headers to see headroom in real time, and move heavy or latency-sensitive workloads onto a higher plan with dedicated capacity.

Network Specific

• How do I switch networks? Change the endpoint URL and nothing else. The same API key authenticates everywhere, and the JSON-RPC request format is identical, so moving from Ethereum mainnet to Sepolia or back is a one-line swap. Confirm where you landed by calling net_version, which returns 1 for mainnet.
• How do I verify I'm on Ethereum mainnet? Call eth_chainId; it returns 0x1, the hex for chain ID 1. Because the code is portable across networks, this check is the cheapest guard against accidentally sending a real transaction against a testnet or vice versa.

Development & Integration

• Which library should I use? In JavaScript or TypeScript, ethers.js or web3.js. In Python, web3.py. In Java or Kotlin, web3j. Each speaks plain JSON-RPC under the hood, so they all point at the Ethereum endpoint the same way — see Tools & SDKs for the full list including Go, Rust, PHP, and more.
• How do I test an integration before going live? Start against a testnet like Sepolia with a separate test key, wire up error handling for the JSON-RPC codes early, and sanity-check connectivity with a cheap eth_blockNumber call before anything heavier. Watch latency and CU usage in the Dashboard as you ramp up, then point the same code at chain 1 by swapping the endpoint.