REST API errors

HTTP status codes

Code	Meaning	Common cause
`200 OK`	Success	Request completed successfully
`400 Bad Request`	Invalid parameters	Malformed address, invalid block number, or missing required parameter
`404 Not Found`	Resource not found	Address has no data, block doesn’t exist, or transaction hash not found
`422 Unprocessable Entity`	Validation error	Parameter value is out of range or wrong type
`429 Too Many Requests`	Rate limited	Too many requests in a short period
`500 Internal Server Error`	Server error	Retry with backoff

Error response format

All error responses return a JSON body with a message field:

{
  "message": "Not found"
}

Common errors

400 — Invalid address format

{"message": "Invalid address hash"}

Fix: Ensure the address is a valid EIP-55 checksummed hex address (0x..., 40 hex characters). Use ethers.getAddress(address) to checksum an address.

404 — Address or transaction not found

{"message": "Not found"}

Fix: The address may have no on-chain activity, or the transaction hash may be incorrect. Verify on the block explorer.

429 — Rate limited

Fix: Reduce request frequency and implement exponential backoff. See JSON-RPC rate limits for backoff strategies — the same approach applies to REST requests.

Example error handling in JavaScript

async function apiRequest(path) {
  const response = await fetch(`https://evm-explorer.autheo.com/api/v2${path}`);

  if (!response.ok) {
    const error = await response.json().catch(() => ({ message: "Unknown error" }));
    throw new Error(`API error ${response.status}: ${error.message}`);
  }

  return response.json();
}

try {
  const data = await apiRequest("/addresses/0x<address>");
  console.log(data);
} catch (err) {
  console.error(err.message);
}

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HTTP status codes

Error response format

Common errors

400 — Invalid address format

404 — Address or transaction not found

429 — Rate limited

Example error handling in JavaScript

​HTTP status codes

​Error response format

​Common errors

​400 — Invalid address format

​404 — Address or transaction not found

​429 — Rate limited

​Example error handling in JavaScript

HTTP status codes

Error response format

Common errors

400 — Invalid address format

404 — Address or transaction not found

429 — Rate limited

Example error handling in JavaScript