> ## Documentation Index
> Fetch the complete documentation index at: https://docs.autheo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# RPC issues

> Troubleshooting guide for JSON-RPC and REST API problems on Autheo Chain.

## Connection refused / ECONNREFUSED

**Cause**: The RPC endpoint is unreachable or the node is not running.

**Fix**:

1. Try the secondary endpoint: `https://testnet-rpc2.autheo.com`
2. Check node status: `autheod status --node <rpc-url>`
3. Verify that port 8545 (HTTP) or 8546 (WebSocket) is open in your firewall

***

## 429 Too Many Requests

**Cause**: You have exceeded the rate limit on the public RPC endpoint.

**Fix**:

* Implement exponential backoff with jitter in your application
* Reduce polling frequency (prefer event subscriptions over polling)
* Use the secondary endpoint to distribute load
* For production applications, use a [managed node provider](/validator-program/hosting-options)

***

## CORS errors in browser applications

**Cause**: Browser enforces same-origin policy; the RPC endpoint doesn't return the expected CORS headers.

**Fix**: Do not call the RPC endpoint directly from a browser. Route requests through your own backend server, which can add the appropriate CORS headers.

***

## `invalid request` (JSON-RPC error -32600)

**Cause**: The request body is malformed JSON or missing required fields.

**Fix**: Ensure the request includes `jsonrpc`, `method`, `params`, and `id` fields:

```bash theme={null}
curl -X POST https://rpc1.autheo.com \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'
```

***

## `method not found` (JSON-RPC error -32601)

**Cause**: The requested method is not supported by the node.

**Common unsupported methods**: `eth_mining`, `eth_hashrate`, `eth_submitWork`, `eth_getWork` — these are not applicable to BFT consensus chains.

**Fix**: See the [JSON-RPC methods reference](/apis/json-rpc/overview) for the list of supported methods.

***

## `execution reverted` (JSON-RPC error -32000)

**Cause**: A contract call reverted during execution.

**Fix**:

1. Simulate the call with `eth_call` first to get the revert reason
2. Check input parameters match the contract's expected types and ranges
3. Verify the caller has the required permissions

***

## WebSocket connection drops

**Cause**: WebSocket connections have a default idle timeout.

**Fix**: Implement reconnection logic with a backoff strategy:

```javascript theme={null}
function connect() {
  const ws = new ethers.WebSocketProvider("wss://rpc1.autheo.com:8546");
  
  ws.on("error", (err) => {
    console.error("WebSocket error:", err);
    setTimeout(connect, 5000); // Reconnect after 5 seconds
  });
  
  return ws;
}
```

***

## `eth_getLogs` returns empty array unexpectedly

**Cause**: The block range or filter parameters don't match any events.

**Fix**:

1. Verify the contract address is correct (checksummed EIP-55 format)
2. Check the `fromBlock` and `toBlock` values bracket the expected transaction blocks
3. Ensure the topic hash matches your event signature exactly:
   ```javascript theme={null}
   const topic = ethers.id("Transfer(address,address,uint256)");
   ```

***

## REST API 404 on block explorer endpoints

**Cause**: The requested resource doesn't exist or the URL path is incorrect.

**Fix**: Verify the endpoint against the [REST API reference](/apis/rest/overview). The base URL is:

```
https://evm-explorer.autheo.com/api/v2/
```

***

## Slow response times

**Cause**: High network load or the node is processing a large request.

**Fix**:

* Use `eth_call` instead of `eth_sendTransaction` for read-only operations
* Avoid fetching large block ranges in a single `eth_getLogs` call — paginate in chunks of 1,000–10,000 blocks
* Cache responses for data that doesn't change frequently (e.g., contract ABIs, static configuration)