How a maximum-hop rule changes routing

A maximum-hop rule limits how many sequential token conversions a route may use. Direct-only routing is the special case that excludes intermediary tokens. Source exclusions impose another restriction by removing particular venues from the search.

Restrictions change the feasible set

Suppose a hypothetical network contains A/B, A/C and C/B markets. Direct-only search can use A/B. A two-hop search can additionally consider A-to-C-to-B. If the C/B source is excluded, the indirect alternative disappears even though A/C remains available.

Uniswap's routing configuration provides explicit hop and protocol-selection controls. These demonstrate that route restrictions are inputs to selection, not cosmetic preferences applied afterward.

What a shorter search can provide

Limiting paths can reduce search complexity and produce simpler execution plans. It can also remove an indirect path with better output. There is no general rule that the shortest route has the strongest economic result.

A source exclusion can have effects beyond its visible share in a previous quote. Removing one connecting pool can disable several multi-hop branches that depended on it. The replacement route may therefore look quite different rather than merely redistributing a small percentage.

Compare restrictions explicitly

If Service One allows three hops and Service Two allows only direct swaps, their quotes solve different problems. A comparison can still be useful, but the constraint difference should be recorded instead of attributed entirely to algorithm quality.

The same applies to allowed intermediary assets, pool versions and RFQ eligibility. Each narrows or expands the feasible set.

A missing route needs context

“No route found” under a restriction does not prove no route exists in the unrestricted market. Conversely, lifting restrictions does not guarantee usable liquidity. Connectivity and capacity remain separate conditions.

For understanding a quote, preserve the requested limits alongside the selected path. That makes later changes explainable: the market may be unchanged while the allowed search space has changed.