Errors & Troubleshooting

Standard Error Payloads and Resolution Strategies

Tower APIs return standard JSON payloads whenever a request fails or cannot be processed.

Standard Error Schema

json
{
  "success": false,
  "error": "Error message describing the failure condition",
  "status": 400
}

Common Error Codes & Troubleshooting

Error Code	HTTP Status	Root Cause	Resolution
`INVALID_API_KEY`	`401 Unauthorized`	Missing, invalid, expired, or revoked Developer API key.	Check that your key starts with `sk_live_` or `sk_test_` and is passed in `Authorization: Bearer <key>` or `x-api-key`.
`SCOPE_FORBIDDEN`	`403 Forbidden`	The API key lacks the required permission scope (e.g. `swaps`, `bridges`).	Regenerate or update your API key in the Developer Console to grant the required scope.
`INSUFFICIENT_LIQUIDITY`	`404 Not Found`	The requested trade volume exceeds total pool reserves across all Arc DEXes.	Decrease `inputAmount` or split the order into smaller increments over time.
`NO_ROUTE_FOUND`	`404 Not Found`	No liquidity pool or multi-hop path exists between the chosen token pair.	Verify that both tokens are active on Arc and have supported liquidity pools.
`SLIPPAGE_EXCEEDED`	`400 Bad Request`	Market price moved beyond configured `slippageTolerance` between quote and build steps.	Request a fresh quote or increase `slippageTolerance` (e.g. from 50 to 100 bps).
`QUOTE_EXPIRED`	`400 Bad Request`	The quote validity window elapsed before transaction broadcast.	Quotes are time-sensitive. Wrap swap executions in retry logic to fetch a fresh quote if execution takes longer than 60s.
`INVALID_TOKEN`	`400 Bad Request`	Supplied token ticker or contract address is unsupported or malformed.	Verify token contract addresses on Arc Testnet (e.g. USDC `0x3600...0000`, EURC `0x89B5...D72a`).
`UNSUPPORTED_CHAIN`	`400 Bad Request`	The supplied `chainId` is unrecognized by the RPC proxy or bridge service.	Use valid chain identifiers like `5042002` (Arc Testnet) or `84532` (Base Sepolia).
`RATE_LIMIT_EXCEEDED`	`429 Too Many Requests`	Request frequency or monthly compute unit quota exceeded.	Implement exponential backoff and adhere to the `Retry-After` header.
`WALLET_NOT_FOUND`	`400 Bad Request`	Malformed wallet address format or invalid checksum.	Verify that wallet address is a valid 42-character hexadecimal EVM address or base58 Solana address.
`UPSTREAM_ERROR`	`502 Bad Gateway`	Upstream blockchain RPC node or external price feed failed to respond.	Retry the request after a short interval; Tower's gateway automatically rotates fallback nodes.

HTTP Status Code Summary

200 OK: The request succeeded and the response contains the requested data.
400 Bad Request: Missing required parameters, invalid JSON syntax, or unsupported tokens/chains.
401 Unauthorized: Authentication failed due to a missing or invalid API key.
403 Forbidden: Valid API key provided, but lacks the necessary scope permissions.
404 Not Found: Resource, route, or liquidity pair could not be located.
429 Too Many Requests: Rate limit exceeded for your tier.
500 Internal Server Error: An unexpected server-side execution failure occurred.
502 Bad Gateway: Upstream blockchain node or indexing RPC was unreachable.