diff --git a/.changeset/hungry-monkeys-wonder.md b/.changeset/hungry-monkeys-wonder.md
new file mode 100644
index 000000000..dbf6aa213
--- /dev/null
+++ b/.changeset/hungry-monkeys-wonder.md
@@ -0,0 +1,7 @@
+---
+'@siafoundation/walletd-js': minor
+'@siafoundation/walletd-react': minor
+'@siafoundation/walletd-types': minor
+---
+
+Added construct APIs for both v1 and v2 transactions.
diff --git a/.changeset/perfect-turtles-kiss.md b/.changeset/perfect-turtles-kiss.md
new file mode 100644
index 000000000..75a64a9a0
--- /dev/null
+++ b/.changeset/perfect-turtles-kiss.md
@@ -0,0 +1,7 @@
+---
+'@siafoundation/walletd-js': minor
+'@siafoundation/walletd-react': minor
+'@siafoundation/walletd-types': minor
+---
+
+Added the basis ChainIndex parameter to txpool broadcast API.
diff --git a/.changeset/tricky-carrots-deny.md b/.changeset/tricky-carrots-deny.md
new file mode 100644
index 000000000..6fba0fa3f
--- /dev/null
+++ b/.changeset/tricky-carrots-deny.md
@@ -0,0 +1,7 @@
+---
+'@siafoundation/walletd-js': minor
+'@siafoundation/walletd-react': minor
+'@siafoundation/walletd-types': minor
+---
+
+Added the basis ChainIndex value to txpool transactions response.
diff --git a/libs/types/src/v2.ts b/libs/types/src/v2.ts
index 3d613a5a2..0b5c17d9a 100644
--- a/libs/types/src/v2.ts
+++ b/libs/types/src/v2.ts
@@ -11,9 +11,13 @@ import {
   SiafundOutput,
   Signature,
   StateElement,
+  UnlockConditions,
 } from './core'
 
-export type SpendPolicy = string
+export type SpendPolicy = {
+  type: 'uc'
+  policy: UnlockConditions
+}
 
 export type V2SiacoinInput = {
   parent: SiacoinElement
diff --git a/libs/walletd-js/src/index.ts b/libs/walletd-js/src/index.ts
index 87cb5dd73..dee23fc93 100644
--- a/libs/walletd-js/src/index.ts
+++ b/libs/walletd-js/src/index.ts
@@ -47,6 +47,12 @@ import {
   WalletBalanceParams,
   WalletBalancePayload,
   WalletBalanceResponse,
+  WalletConstructV1TransactionParams,
+  WalletConstructV1TransactionPayload,
+  WalletConstructV1TransactionResponse,
+  WalletConstructV2TransactionParams,
+  WalletConstructV2TransactionPayload,
+  WalletConstructV2TransactionResponse,
   WalletDeleteParams,
   WalletDeletePayload,
   WalletDeleteResponse,
@@ -93,6 +99,8 @@ import {
   walletsIdAddressesAddrRoute,
   walletsIdAddressesRoute,
   walletsIdBalanceRoute,
+  walletsIdConstructTransactionRoute,
+  walletsIdConstructV2TransactionRoute,
   walletsIdEventsRoute,
   walletsIdEventsUnconfirmedRoute,
   walletsIdFundRoute,
@@ -245,5 +253,15 @@ export function Walletd({ api, password }: { api: string; password?: string }) {
       WalletReleasePayload,
       WalletReleaseResponse
     >(axios, 'post', walletsIdReleaseRoute),
+    walletConstructV1Transaction: buildRequestHandler<
+      WalletConstructV1TransactionParams,
+      WalletConstructV1TransactionPayload,
+      WalletConstructV1TransactionResponse
+    >(axios, 'post', walletsIdConstructTransactionRoute),
+    walletConstructV2Transaction: buildRequestHandler<
+      WalletConstructV2TransactionParams,
+      WalletConstructV2TransactionPayload,
+      WalletConstructV2TransactionResponse
+    >(axios, 'post', walletsIdConstructV2TransactionRoute),
   }
 }
diff --git a/libs/walletd-react/src/api.ts b/libs/walletd-react/src/api.ts
index e81660ce4..8a43cad0a 100644
--- a/libs/walletd-react/src/api.ts
+++ b/libs/walletd-react/src/api.ts
@@ -51,6 +51,12 @@ import {
   WalletAddressesResponse,
   WalletBalanceParams,
   WalletBalanceResponse,
+  WalletConstructV1TransactionParams,
+  WalletConstructV1TransactionPayload,
+  WalletConstructV1TransactionResponse,
+  WalletConstructV2TransactionParams,
+  WalletConstructV2TransactionPayload,
+  WalletConstructV2TransactionResponse,
   WalletDeleteParams,
   WalletDeletePayload,
   WalletDeleteResponse,
@@ -92,6 +98,8 @@ import {
   walletsIdAddressesAddrRoute,
   walletsIdAddressesRoute,
   walletsIdBalanceRoute,
+  walletsIdConstructTransactionRoute,
+  walletsIdConstructV2TransactionRoute,
   walletsIdEventsRoute,
   walletsIdEventsUnconfirmedRoute,
   walletsIdFundRoute,
@@ -460,3 +468,23 @@ export function useWalletRelease(
 ) {
   return usePostFunc({ ...args, route: walletsIdReleaseRoute })
 }
+
+export function useWalletConstructV1Transaction(
+  args?: HookArgsCallback<
+    WalletConstructV1TransactionParams,
+    WalletConstructV1TransactionPayload,
+    WalletConstructV1TransactionResponse
+  >
+) {
+  return usePostFunc({ ...args, route: walletsIdConstructTransactionRoute })
+}
+
+export function useWalletConstructV2Transaction(
+  args?: HookArgsCallback<
+    WalletConstructV2TransactionParams,
+    WalletConstructV2TransactionPayload,
+    WalletConstructV2TransactionResponse
+  >
+) {
+  return usePostFunc({ ...args, route: walletsIdConstructV2TransactionRoute })
+}
diff --git a/libs/walletd-types/src/api.ts b/libs/walletd-types/src/api.ts
index 6dc9eaac0..58b11d139 100644
--- a/libs/walletd-types/src/api.ts
+++ b/libs/walletd-types/src/api.ts
@@ -11,6 +11,10 @@ import {
   Transaction,
   V2Transaction,
   WalletEvent,
+  SiacoinOutput,
+  Address,
+  SiafundOutput,
+  TransactionID,
 } from '@siafoundation/types'
 import { GatewayPeer, Wallet, WalletAddress, WalletMetadata } from './types'
 
@@ -37,6 +41,10 @@ export const walletsIdFundRoute = '/wallets/:id/fund'
 export const walletsIdFundSfRoute = '/wallets/:id/fundsf'
 export const walletsIdReserveRoute = '/wallets/:id/reserve'
 export const walletsIdReleaseRoute = '/wallets/:id/release'
+export const walletsIdConstructTransactionRoute =
+  '/wallets/:id/construct/transaction'
+export const walletsIdConstructV2TransactionRoute =
+  '/wallets/:id/construct/v2/transaction'
 
 // state
 
@@ -79,6 +87,7 @@ export type SyncerConnectResponse = never
 export type TxPoolTransactionsParams = void
 export type TxPoolTransactionsPayload = void
 export type TxPoolTransactionsResponse = {
+  basis: ChainIndex
   transactions: Transaction[]
   v2transactions: V2Transaction[]
 }
@@ -89,6 +98,7 @@ export type TxPoolFeeResponse = Currency
 
 export type TxPoolBroadcastParams = void
 export type TxPoolBroadcastPayload = {
+  basis: ChainIndex
   transactions: Transaction[]
   v2transactions: V2Transaction[]
 }
@@ -226,3 +236,34 @@ export type WalletReleasePayload = {
   siafundOutputs?: SiafundOutputID[]
 }
 export type WalletReleaseResponse = void
+
+export type WalletConstructV1TransactionParams = {
+  id: string
+}
+export type WalletConstructV1TransactionPayload = {
+  siacoins?: SiacoinOutput[]
+  siafunds?: SiafundOutput[]
+  changeAddress: Address
+}
+
+export type WalletConstructV1TransactionResponse = {
+  basis: ChainIndex
+  id: TransactionID
+  transaction: Transaction
+  estimatedFee: Currency
+}
+
+export type WalletConstructV2TransactionParams = {
+  id: string
+}
+export type WalletConstructV2TransactionPayload = {
+  siacoins?: SiacoinOutput[]
+  siafunds?: SiafundOutput[]
+  changeAddress: Address
+}
+export type WalletConstructV2TransactionResponse = {
+  basis: ChainIndex
+  id: TransactionID
+  transaction: V2Transaction
+  estimatedFee: Currency
+}