diff --git a/.changeset/ink-dutchv3-mappings.md b/.changeset/ink-dutchv3-mappings.md
new file mode 100644
index 000000000..3dbaf96d3
--- /dev/null
+++ b/.changeset/ink-dutchv3-mappings.md
@@ -0,0 +1,14 @@
+---
+'@uniswap/uniswapx-sdk': patch
+---
+
+Add Ink (chainId 57073) DutchV3 support. The reactor and OrderQuoter are deployed and source-verified on Ink; these are the mapping entries that let the SDK resolve them.
+
+- `REACTOR_ADDRESS_MAPPING[57073][Dutch_V3]` → `0x000000007A1C8e570011EeDF86A2A35593013cBA`. This is the same address as Robinhood (4663), as chains 130/196/1868 already share `0x000000005aF6…`; `REVERSE_REACTOR_MAPPING` collapses shared addresses to one key, which is correct since both are `Dutch_V3`.
+- `UNISWAPX_ORDER_QUOTER_MAPPING[57073]` → canonical `0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58`. Required: `constructSameAddressMap` only seeds the five `NETWORKS_WITH_SAME_ADDRESS` chains, so without an explicit entry the lookup is `undefined` and `UniswapXOrderQuoter`'s constructor throws `MissingConfiguration("quoter", "57073")`.
+- `PERMIT2_MAPPING[57073]` → canonical Permit2, verified on-chain (9,152 bytes, non-zero `DOMAIN_SEPARATOR()`).
+- `EXCLUSIVE_FILLER_VALIDATION_MAPPING[57073]` → zero address, matching every other V3-only chain. Required, and the quieter of the two: without an entry the lookup is `undefined`, and `encodeExclusiveFillerData` assigns it into `ValidationInfo.additionalValidationContract` unguarded, so `undefined` propagates into order construction instead of throwing. Exclusivity itself is reactor-enforced via `ExclusivityLib`; the zero address makes the hook correctly inert.
+
+No entry is added for `Priority`, `Dutch_V2`, `Hybrid`, or the `UNISWAPX_V4_*` mappings — no such reactors are deployed on Ink, and the absence is what makes x-service's `OffChainUniswapXOrderValidator.validateReactorAddress` reject those order types for the chain.
+
+Ink needs no chain-specific order-construction handling: it is a standard OP-stack L2 with 1s blocks, a real dynamic EIP-1559 basefee, and native ETH, so `adjustmentPerGweiBaseFee` keeps its normal non-zero treatment and the native sentinel is usable. `@uniswap/sdk-core` already has full Ink coverage (`ChainId.INK`, `INK_ADDRESSES`, `WETH9[57073]`, 1s block time).
diff --git a/sdks/uniswapx-sdk/src/builder/V3DutchOrderBuilder.test.ts b/sdks/uniswapx-sdk/src/builder/V3DutchOrderBuilder.test.ts
index 2511aa390..7e162bda3 100644
--- a/sdks/uniswapx-sdk/src/builder/V3DutchOrderBuilder.test.ts
+++ b/sdks/uniswapx-sdk/src/builder/V3DutchOrderBuilder.test.ts
@@ -665,14 +665,15 @@ describe("V3DutchOrderBuilder", () => {
         );
     });
 
-    // DutchV3 rollout: Robinhood (4663) and Arc (5042). decayBlocks is the
-    // chain-realistic V3 decay window (~30s wallclock): 60 blocks at Arc's
-    // 500ms, 120 blocks at Robinhood's ~250ms under load. Confirms the reactor
-    // resolves from REACTOR_ADDRESS_MAPPING and an order decaying over that
-    // window builds.
+    // DutchV3 rollout: Robinhood (4663), Arc (5042), Ink (57073). decayBlocks is
+    // the chain-realistic V3 decay window (~30s wallclock): 60 blocks at Arc's
+    // 500ms, 120 blocks at Robinhood's ~250ms under load, 30 blocks at Ink's 1s.
+    // Confirms the reactor resolves from REACTOR_ADDRESS_MAPPING and an order
+    // decaying over that window builds.
     describe.each([
         { name: "Robinhood", chainId: 4663, reactor: "0x000000007A1C8e570011EeDF86A2A35593013cBA", decayBlocks: 120 },
         { name: "Arc", chainId: 5042, reactor: "0x0000000015134054eA82AE0bb9fda66b36402C36", decayBlocks: 60 },
+        { name: "Ink", chainId: 57073, reactor: "0x000000007A1C8e570011EeDF86A2A35593013cBA", decayBlocks: 30 },
     ])("DutchV3 rollout: $name ($chainId)", ({ chainId, reactor, decayBlocks }) => {
         it("resolves the reactor without an explicit address", () => {
             const b = new V3DutchOrderBuilder(chainId);
diff --git a/sdks/uniswapx-sdk/src/constants.test.ts b/sdks/uniswapx-sdk/src/constants.test.ts
index 7cb73c6c8..f2a3419ac 100644
--- a/sdks/uniswapx-sdk/src/constants.test.ts
+++ b/sdks/uniswapx-sdk/src/constants.test.ts
@@ -11,14 +11,17 @@ const CANONICAL_PERMIT2 = "0x000000000022D473030F116dDEE9F6B43aC78BA3";
 const CANONICAL_QUOTER = "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58";
 const ZERO = "0x0000000000000000000000000000000000000000";
 
-// DutchV3 rollout to Robinhood (4663) and Arc (5042). These guard against the
-// two ways the mappings would otherwise silently misresolve: the quoter
-// falling through to the legacy default (0x5453…) and the exclusive-filler
-// validator falling through to 0x8A66… (a contract that doesn't exist on
-// either chain).
+// DutchV3 rollout to Robinhood (4663), Arc (5042), and Ink (57073).
+// constructSameAddressMap only seeds the five NETWORKS_WITH_SAME_ADDRESS
+// chains, so a chain with no explicit entry reads back `undefined` rather than
+// a wrong-but-plausible default. These guard the two consequences: the quoter
+// lookup makes UniswapXOrderQuoter's constructor throw MissingConfiguration,
+// and the exclusive-filler lookup silently puts `undefined` into the
+// ValidationInfo that encodeExclusiveFillerData returns.
 describe.each([
   { name: "Robinhood", chainId: 4663, reactor: "0x000000007A1C8e570011EeDF86A2A35593013cBA" },
   { name: "Arc", chainId: 5042, reactor: "0x0000000015134054eA82AE0bb9fda66b36402C36" },
+  { name: "Ink", chainId: 57073, reactor: "0x000000007A1C8e570011EeDF86A2A35593013cBA" },
 ])("DutchV3 rollout: $name ($chainId)", ({ chainId, reactor }) => {
   it("getReactor resolves the deployed Dutch_V3 reactor", () => {
     expect(getReactor(chainId, OrderType.Dutch_V3).toLowerCase()).toEqual(reactor.toLowerCase());
@@ -122,6 +125,9 @@ describe("REACTOR_ADDRESS_MAPPING", () => {
         "56": {
           "Dutch_V3": "0x00000000a55e50C71b70Db3C8B58749cd1E18eB2",
         },
+        "57073": {
+          "Dutch_V3": "0x000000007A1C8e570011EeDF86A2A35593013cBA",
+        },
         "7777777": {
           "Dutch_V3": "0x000000002C9A3812e15cf233190992E9a57EDB56",
         },
diff --git a/sdks/uniswapx-sdk/src/constants.ts b/sdks/uniswapx-sdk/src/constants.ts
index 48bfb66cd..8bc10392c 100644
--- a/sdks/uniswapx-sdk/src/constants.ts
+++ b/sdks/uniswapx-sdk/src/constants.ts
@@ -45,6 +45,7 @@ export const PERMIT2_MAPPING: AddressMap = {
       42161,     // arbitrum
       42220,     // celo
       43114,     // avalanche
+      57073,     // ink
       59144,     // linea
       81457,     // blast
       84532,     // base sepolia
@@ -82,6 +83,7 @@ export const UNISWAPX_ORDER_QUOTER_MAPPING: AddressMap = {
   5042: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
   42220: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
   43114: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
+  57073: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
   81457: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
   7777777: "0x00000000a3db63Df9078cBF3dF88B4CAdD5a7F58",
 };
@@ -118,6 +120,7 @@ export const EXCLUSIVE_FILLER_VALIDATION_MAPPING: AddressMap = {
   5042: "0x0000000000000000000000000000000000000000",
   42220: "0x0000000000000000000000000000000000000000",
   43114: "0x0000000000000000000000000000000000000000",
+  57073: "0x0000000000000000000000000000000000000000",
   81457: "0x0000000000000000000000000000000000000000",
   7777777: "0x0000000000000000000000000000000000000000",
 };
@@ -236,6 +239,9 @@ export const REACTOR_ADDRESS_MAPPING: ReactorMapping = {
   43114: {
     [OrderType.Dutch_V3]: "0x00000000862cCF095823fc7576Fa6C7e6b7385ef",
   },
+  57073: {
+    [OrderType.Dutch_V3]: "0x000000007A1C8e570011EeDF86A2A35593013cBA",
+  },
   81457: {
     [OrderType.Dutch_V3]: "0x0000000086f50C5E1a2500602183D4390A7FFc98",
   },