Swaps & Routing

Networks and cross-chain swaps

The swap selector offers BNB Chain, Robinhood Chain, Base, Ethereum and Arc. Topaz routing is registered on all five networks, Relay aggregation on all five, and 0x aggregation on BNB Chain, Robinhood Chain, Base and Ethereum; available quotes depend on the pair and provider. Cross-chain swaps compare the 0x Cross-Chain service (through Topaz’s proxies) with Relay and take the better delivery. On Arc, quotes come from Topaz pools and Relay, swaps settle in USDC's six-decimal ERC-20 with no native leg, and cross-chain swaps to or from Arc go through Relay.

The app follows a cross-chain order using its stored quote ID. A successful source transaction is not a completed destination fill; monitor the order for delivery or refund status. This path is distinct from the xTOPAZ LayerZero bridge and Private Swaps.

Topaz pool discovery, liquidity and governance are live on BNB Chain, Robinhood Chain, Base, Ethereum and Arc. Quote availability still depends on the selected pair and routing service. Network availability.

The basic flow

1. Open Swap and connect your wallet. The default pair is native BNB to TOPAZ.
2. Select the input and output tokens and their networks. Review balances on the input network and keep its gas token (USDC on Arc) for gas.
3. Enter the input amount, or an output amount on routes supporting exact output.
4. Review the winning source, amount, price impact, fees, slippage and minimum received or maximum spent.
5. Review any required approval or permit, then submit and track confirmation. Cross-chain delivery is separate from the source transaction.

Topaz routing, 0x aggregation and Relay compete on every chain pair each serves. Topaz considers V2 stable/volatile, Concentrated, split and mixed routes; a winning Topaz quote executes through the Topaz Universal Router and Permit2. A winning 0x quote uses the response-scoped AllowanceHolder route. The quoter provides price information; it is not the execution contract.

Exact-input swaps

Exact input means “spend this amount.” The quote reports output and a slippage-adjusted minimum. Same-chain Topaz routing also supports exact output: “receive this amount,” bounded by a maximum input. A refreshed maximum above the amount you reviewed requires another review.

0x aggregation and cross-chain routing in this interface are exact-input paths. A route that does not support exact output must not silently change your requested trade type.

Slippage protection

Between the moment you sign and the moment your transaction is included, the price can move. Slippage tolerance is your guardrail: the swap reverts if the output drops below (1 − slippage) × quote (for exact-in) or input exceeds (1 + slippage) × quote (for exact-out).

• ✓Default 0.5% works for most stablecoin and major-pair swaps.
• ✓Set 0.1% on tight stable swaps if you want a hard cap on cost.
• ✓Long-tail tokens or shallow pools may legitimately need 1–3%. If you find yourself raising slippage above 5%, reconsider the trade — you're probably the source of most of the price impact.
• ✓Watch for transfer-fee tokens (tokens that deduct on transfer). Their minimum-out math is special; the router has fee-on-transfer-aware paths.

Price impact

Slippage tolerance is your guardrail. Price impact is the actual cost: how much your trade moves the pool's price away from the current quote. A 0.05% price-impact swap barely nudges the curve; a 5% price-impact swap leaves the pool priced 5% worse for the next trader, and you took the cost of that move.

The app shows price impact in red when it exceeds a threshold (typically 1%). If you see that warning, options are:

• ✓Break the trade into smaller chunks — but be aware each one has gas cost.
• ✓Wait for the pool to fill if you're trading against thin liquidity (or place a different order earlier in the day).
• ✓Check if a different route gives better impact — sometimes routing through a stablecoin or a different fee tier is much better than the direct pool.
• ✓For very large trades, contact the project — there may be OTC desks or aggregators specialized for size.

Routing across v2 and Slipstream

A pair can have several Topaz pools, each with its own liquidity, tick spacing or stable/volatile type. The routing service can quote split and mixed routes; the Universal Router executes a winning Topaz route. The result competes with 0x and Relay quotes, so the selected route may include other venues.

Multi-hop routes use available liquidity and supported intermediates on the selected network. Do not assume a BNB token or pool address represents the same asset or market on another chain.

MEV and front-running

BNB Chain has an active MEV (maximal extractable value) marketplace. Searchers monitor the mempool, looking for trades with high slippage tolerance they can sandwich. Topaz itself can't hide your transaction, but you can defend yourself:

• ✓Set slippage as low as the trade allows.
• ✓For large trades, use a private RPC (BloXroute, Merkle, or your wallet's MEV-protected mode if available) so the transaction reaches the block builder without hitting the public mempool.
• ✓Split a very large trade across blocks — sandwich attacks compose with single trades.
• ✓Avoid the deadline being too far in the future. Most routers default to 10–30 min; that's fine.

Fees you actually pay

A Topaz pool charges its configured swap fee on each hop. Staked liquidity's fee share flows to local voters; unstaked liquidity retains fees subject to pool rules. Other venues in a 0x or Relay route follow their own fee rules. Review the quote's complete costs rather than applying a Topaz pool fee to every routed swap.

You also pay the submitting network's native gas costs and any separately disclosed routing or cross-chain fees. Approval transactions have their own gas cost. Pool Fees.

Approvals, permits and native wrapping

Topaz swaps keep the Permit2 approval model: an unlimited ERC-20 allowance to Permit2 and a maximum router permit for its expiry window. Review this broad authorization. An insufficient nonzero allowance is reset first when required. In contrast, a 0x winner uses an exact-amount allowance to its quoted AllowanceHolder, and a Relay winner an exact-amount allowance to the router or depository its call names. Gauge stake and lock approvals are exact-amount; liquidity creation, liquidity increase and incentive deposits grant a maximum allowance on regular wallets.

BNB/WBNB and supported native/wrapped-native pairs use a one-to-one wrap or unwrap call before routing is requested. There is no swap slippage or token approval for that conversion, but gas is still required. TOPAZ-to-xTOPAZ is a vault share conversion and follows a different rate and approval flow.

The swap form offers Swap and Privacy; older /limit and /dca links open Swap. Private swaps use the Topaz Privacy service. Each has its own review and execution path.

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