Error codes

Contract error codes returned by the Aquarius AMM router and pools, and how to handle them.

When a contract call fails, the simulation (or transaction) reports a numeric error code, for example, Error(Contract, #2006). The codes below cover the errors an integrator is most likely to encounter.

Swap & liquidity guards

The errors you should expect and handle in normal operation:

Code	Name	When it happens	How to handle
2006	OutMinNotSatisfied	Exact-input swap: output fell below your out_min. Also raised on deposits (min_shares) and withdrawals (min_amounts)	Re-quote and retry; consider a wider slippage tolerance
2020	InMaxNotSatisfied	Exact-output swap: required input exceeds your max_in	Re-quote and retry
2005	InMinNotSatisfied	Exact-output swap at pool level: output below minimum	Re-quote and retry
2018	ZeroAmount	Zero passed as a swap/deposit amount	Validate input before calling
2019	InsufficientBalance	Account balance can't cover the transfer	Check balances before submitting

For multi-hop swaps (swap_chained), the slippage guard is enforced end-to-end — intermediate hops are unconstrained; only the final output is checked against out_min.

Routing & setup errors

Usually indicate a bug in the integration rather than market conditions:

Code	Name	When it happens	How to handle
301	PoolNotFound	No pool exists for the given tokens + pool hash	Re-discover pools via get_pools(tokens)
302	BadFee	Fee tier not in the allowed set for the pool type	Use 10 / 30 / 100 bps (volatile & concentrated)
307	PathIsEmpty	swap_chained called with an empty swaps chain	Always pass the XDR from the Find Path API
2002	TokensNotSorted	Token vector not sorted by contract address	Sort with the order_token_ids helper

Pause states

Aquarius contracts have independent kill switches for emergency response. If operations are paused you'll see: 205 PoolDepositKilled, 206 PoolSwapKilled, 207 PoolClaimKilled (standard pools), or 2139 GaugesClaimKilled (concentrated pool incentives). These are not integration bugs — check Discord for status.

Concentrated-pool specific

Code	Name	When it happens
2121	InsufficientLiquidity	The swap exhausted all liquidity in the pool

API-level failures

The backend API signals differently — see Backend API: no route is HTTP 200 + success: false; invalid input is HTTP 400.

Parsing results: since Stellar protocol 23, transaction metadata uses version 4 (TransactionMetaV4). Code that reads meta.v3.soroban_meta directly will find None — use the version-aware pattern shown in the code examples, or meta.value().sorobanMeta() in JavaScript.