[codyborn]

What

Removes .max(20) from slippageTolerance in the quote schema.

Companion PR in the backend monorepo (uniroute carries the same bound): https://github.com/Uniswap/backend/pull/12251

Why

This bound arrived in bc187beb (2021-06-29, "New responses") as one line in a bulk pass that converted the quote schema to typed Joi and put defensive limits on every field at once — tokenIn/Out .max(40), amount .max(20), deadline .max(600), a recipient regex. The deadline line right below it still carries // 180 mins, same as interface max, which is the tell: these mirrored the interface's caps, and the interface bounded slippage at 20% then.

The interface has since moved to a 100% max with a warning at 20%, and the Trading API's copy of the bound was removed in January 2025 with product sign-off (CX-877) — but only in that one layer, leaving routing as the only place still enforcing it.

Effect today: slippage above 20% returns no quote and the app shows a generic "no quotes available" with no explanation. FOT and thin-liquidity tokens routinely need more headroom. Reported four separate times since 2021, and generating routing alert noise since Feb 2025.

No execution-safety argument supports the specific value. minimumAmountOut is amountOut / (1 + slippage), which asymptotes toward zero without reaching it — 100% slippage still floors the trade at half the quote. The ceiling belongs to the client, which already has one and already warns.

Why min(0) stays

The SDK asserts slippage >= 0 in minimumAmountOut, so a negative value would throw downstream rather than degrade. Joi.number() already rejects NaN and Infinity by default — verified:

20 accept · 21 accept · 50 accept · 1000 accept
-1 REJECT "must be greater than or equal to 0"
NaN REJECT "must be a number"
±Infinity REJECT "cannot be infinity"

So dropping .max(20) alone is sufficient here. (The uniroute validator needed an explicit finite/non-negative check instead, since it hand-rolls validation on a proto double rather than going through Joi.)

Rollout note

uniroute and routing-api both serve and both carry this bound. Requests over 20% keep failing on whichever path lands second.

🤖 Generated with Claude Code

[codyborn]

Closing — routing-api is no longer in the serving path, so this bound is dead code and does not need changing.

The live fix is https://github.com/Uniswap/backend/pull/12251, which removes the same 20% cap from uniroute's quote validator.

Leaving the historical note here for anyone who greps this line later: .max(20) originated in bc187be (2021-06-29) as one line in a bulk pass that put defensive limits on every field of the then-new v1 quote schema, mirroring the interface's cap at the time. It was never a deliberate execution-safety decision.

[graphite-app]

Graphite Automations

"Request reviewers once CI passes on routing-api repo" took an action on this PR • (08/18/26)

3 reviewers were added and 1 assignee was added to this PR based on Siyu Jiang (See-You John)'s automation.