diff --git a/.changeset/tricky-bees-sneeze.md b/.changeset/tricky-bees-sneeze.md
new file mode 100644
index 0000000000000..3d4f236162e61
--- /dev/null
+++ b/.changeset/tricky-bees-sneeze.md
@@ -0,0 +1,5 @@
+---
+'@eth-optimism/integration-tests': patch
+---
+
+Updates integration tests to start using SDK
diff --git a/integration-tests/package.json b/integration-tests/package.json
index b38ed522d33bb..61feb8cc0d394 100644
--- a/integration-tests/package.json
+++ b/integration-tests/package.json
@@ -31,6 +31,7 @@
     "@eth-optimism/contracts": "0.5.11",
     "@eth-optimism/core-utils": "0.7.5",
     "@eth-optimism/message-relayer": "0.2.15",
+    "@eth-optimism/sdk": "0.0.7",
     "@ethersproject/abstract-provider": "^5.5.1",
     "@ethersproject/providers": "^5.4.5",
     "@ethersproject/transactions": "^5.4.0",
diff --git a/integration-tests/test/basic-l1-l2-communication.spec.ts b/integration-tests/test/basic-l1-l2-communication.spec.ts
index d7324d018a2a7..6a95735fbbb43 100644
--- a/integration-tests/test/basic-l1-l2-communication.spec.ts
+++ b/integration-tests/test/basic-l1-l2-communication.spec.ts
@@ -1,17 +1,20 @@
 /* Imports: External */
 import { Contract, ContractFactory } from 'ethers'
 import { ethers } from 'hardhat'
-import { applyL1ToL2Alias, awaitCondition } from '@eth-optimism/core-utils'
+import { MessageDirection, MessageStatus } from '@eth-optimism/sdk'
+import {
+  applyL1ToL2Alias,
+  awaitCondition,
+  sleep,
+} from '@eth-optimism/core-utils'
 
 /* Imports: Internal */
 import { expect } from './shared/setup'
-import { Direction } from './shared/watcher-utils'
 import { OptimismEnv } from './shared/env'
 import {
   DEFAULT_TEST_GAS_L1,
   DEFAULT_TEST_GAS_L2,
   envConfig,
-  sleep,
   withdrawalTest,
 } from './shared/utils'
 
@@ -56,23 +59,35 @@ describe('Basic L1<>L2 Communication', async () => {
         const value = `0x${'77'.repeat(32)}`
 
         // Send L2 -> L1 message.
-        const transaction = await env.l2Messenger.sendMessage(
-          L1SimpleStorage.address,
-          L1SimpleStorage.interface.encodeFunctionData('setValue', [value]),
-          5000000,
+        const transaction = await env.messenger.sendMessage(
+          {
+            direction: MessageDirection.L2_TO_L1,
+            target: L1SimpleStorage.address,
+            message: L1SimpleStorage.interface.encodeFunctionData('setValue', [
+              value,
+            ]),
+          },
           {
-            gasLimit: DEFAULT_TEST_GAS_L2,
+            overrides: {
+              gasLimit: DEFAULT_TEST_GAS_L2,
+            },
           }
         )
-        await transaction.wait()
-        await env.relayXDomainMessages(transaction)
-        await env.waitForXDomainTransaction(transaction, Direction.L2ToL1)
+
+        let status: MessageStatus
+        while (status !== MessageStatus.READY_FOR_RELAY) {
+          status = await env.messenger.getMessageStatus(transaction)
+          await sleep(1000)
+        }
+
+        await env.messenger.finalizeMessage(transaction)
+        await env.messenger.waitForMessageReceipt(transaction)
 
         expect(await L1SimpleStorage.msgSender()).to.equal(
-          env.l1Messenger.address
+          env.messenger.contracts.l1.L1CrossDomainMessenger.address
         )
         expect(await L1SimpleStorage.xDomainSender()).to.equal(
-          env.l2Wallet.address
+          await env.messenger.l2Signer.getAddress()
         )
         expect(await L1SimpleStorage.value()).to.equal(value)
         expect((await L1SimpleStorage.totalCount()).toNumber()).to.equal(1)
@@ -85,25 +100,36 @@ describe('Basic L1<>L2 Communication', async () => {
       const value = `0x${'42'.repeat(32)}`
 
       // Send L1 -> L2 message.
-      const transaction = await env.l1Messenger.sendMessage(
-        L2SimpleStorage.address,
-        L2SimpleStorage.interface.encodeFunctionData('setValue', [value]),
-        5000000,
+      const transaction = await env.messenger.sendMessage(
+        {
+          direction: MessageDirection.L1_TO_L2,
+          target: L2SimpleStorage.address,
+          message: L2SimpleStorage.interface.encodeFunctionData('setValue', [
+            value,
+          ]),
+        },
         {
-          gasLimit: DEFAULT_TEST_GAS_L1,
+          l2GasLimit: 5000000,
+          overrides: {
+            gasLimit: DEFAULT_TEST_GAS_L1,
+          },
         }
       )
 
-      await env.waitForXDomainTransaction(transaction, Direction.L1ToL2)
+      const receipt = await env.messenger.waitForMessageReceipt(transaction)
 
+      console.log(await env.messenger.l2Signer.getAddress())
+      expect(receipt.transactionReceipt.status).to.equal(1)
       expect(await L2SimpleStorage.msgSender()).to.equal(
-        env.l2Messenger.address
+        env.messenger.contracts.l2.L2CrossDomainMessenger.address
       )
       expect(await L2SimpleStorage.txOrigin()).to.equal(
-        applyL1ToL2Alias(env.l1Messenger.address)
+        applyL1ToL2Alias(
+          env.messenger.contracts.l1.L1CrossDomainMessenger.address
+        )
       )
       expect(await L2SimpleStorage.xDomainSender()).to.equal(
-        env.l1Wallet.address
+        await env.messenger.l1Signer.getAddress()
       )
       expect(await L2SimpleStorage.value()).to.equal(value)
       expect((await L2SimpleStorage.totalCount()).toNumber()).to.equal(1)
@@ -117,9 +143,10 @@ describe('Basic L1<>L2 Communication', async () => {
       const value = `0x${'42'.repeat(32)}`
 
       // Send L1 -> L2 message.
-      const tx = await env.ctc
-        .connect(env.l1Wallet)
-        .enqueue(
+      const tx =
+        await env.messenger.contracts.l1.CanonicalTransactionChain.connect(
+          env.messenger.l1Signer
+        ).enqueue(
           L2SimpleStorage.address,
           5000000,
           L2SimpleStorage.interface.encodeFunctionData('setValueNotXDomain', [
@@ -129,11 +156,12 @@ describe('Basic L1<>L2 Communication', async () => {
             gasLimit: DEFAULT_TEST_GAS_L1,
           }
         )
+
       const receipt = await tx.wait()
 
       const waitUntilBlock =
         receipt.blockNumber + envConfig.DTL_ENQUEUE_CONFIRMATIONS
-      let currBlock = await env.l1Provider.getBlockNumber()
+      let currBlock = await env.messenger.l1Provider.getBlockNumber()
       while (currBlock <= waitUntilBlock) {
         const progress =
           envConfig.DTL_ENQUEUE_CONFIRMATIONS - (waitUntilBlock - currBlock)
@@ -141,66 +169,28 @@ describe('Basic L1<>L2 Communication', async () => {
           `Waiting for ${progress}/${envConfig.DTL_ENQUEUE_CONFIRMATIONS} confirmations.`
         )
         await sleep(5000)
-        currBlock = await env.l1Provider.getBlockNumber()
+        currBlock = await env.messenger.l1Provider.getBlockNumber()
       }
       console.log('Enqueue should be confirmed.')
 
       await awaitCondition(
         async () => {
           const sender = await L2SimpleStorage.msgSender()
-          return sender === env.l1Wallet.address
+          return sender === (await env.messenger.l1Signer.getAddress())
         },
         2000,
         60
       )
 
       // No aliasing when an EOA goes directly to L2.
-      expect(await L2SimpleStorage.msgSender()).to.equal(env.l1Wallet.address)
-      expect(await L2SimpleStorage.txOrigin()).to.equal(env.l1Wallet.address)
-      expect(await L2SimpleStorage.value()).to.equal(value)
-      expect((await L2SimpleStorage.totalCount()).toNumber()).to.equal(1)
-    })
-
-    it('should have a receipt with a status of 1 for a successful message', async () => {
-      const value = `0x${'42'.repeat(32)}`
-
-      // Send L1 -> L2 message.
-      const transaction = await env.l1Messenger.sendMessage(
-        L2SimpleStorage.address,
-        L2SimpleStorage.interface.encodeFunctionData('setValue', [value]),
-        5000000,
-        {
-          gasLimit: DEFAULT_TEST_GAS_L1,
-        }
-      )
-      await transaction.wait()
-
-      const { remoteReceipt } = await env.waitForXDomainTransaction(
-        transaction,
-        Direction.L1ToL2
-      )
-
-      expect(remoteReceipt.status).to.equal(1)
-    })
-
-    // SKIP: until we decide what should be done in this case
-    it.skip('should have a receipt with a status of 0 for a failed message', async () => {
-      // Send L1 -> L2 message.
-      const transaction = await env.l1Messenger.sendMessage(
-        L2Reverter.address,
-        L2Reverter.interface.encodeFunctionData('doRevert', []),
-        5000000,
-        {
-          gasLimit: DEFAULT_TEST_GAS_L1,
-        }
+      expect(await L2SimpleStorage.msgSender()).to.equal(
+        await env.messenger.l1Signer.getAddress()
       )
-
-      const { remoteReceipt } = await env.waitForXDomainTransaction(
-        transaction,
-        Direction.L1ToL2
+      expect(await L2SimpleStorage.txOrigin()).to.equal(
+        await env.messenger.l1Signer.getAddress()
       )
-
-      expect(remoteReceipt.status).to.equal(0)
+      expect(await L2SimpleStorage.value()).to.equal(value)
+      expect((await L2SimpleStorage.totalCount()).toNumber()).to.equal(1)
     })
   })
 })
diff --git a/integration-tests/test/shared/env.ts b/integration-tests/test/shared/env.ts
index 9821787fd2589..d41b7d19f0153 100644
--- a/integration-tests/test/shared/env.ts
+++ b/integration-tests/test/shared/env.ts
@@ -4,6 +4,7 @@ import { TransactionResponse } from '@ethersproject/providers'
 import { getContractFactory, predeploys } from '@eth-optimism/contracts'
 import { Watcher } from '@eth-optimism/core-utils'
 import { getMessagesAndProofsForL2Transaction } from '@eth-optimism/message-relayer'
+import { CrossChainMessenger } from '@eth-optimism/sdk'
 
 /* Imports: Internal */
 import {
@@ -55,6 +56,7 @@ export class OptimismEnv {
   l2Wallet: Wallet
 
   // The providers
+  messenger: CrossChainMessenger
   l1Provider: providers.JsonRpcProvider
   l2Provider: providers.JsonRpcProvider
   replicaProvider: providers.JsonRpcProvider
@@ -73,6 +75,7 @@ export class OptimismEnv {
     this.watcher = args.watcher
     this.l1Wallet = args.l1Wallet
     this.l2Wallet = args.l2Wallet
+    this.messenger = args.messenger
     this.l1Provider = args.l1Provider
     this.l2Provider = args.l2Provider
     this.replicaProvider = args.replicaProvider
@@ -126,6 +129,13 @@ export class OptimismEnv {
       .connect(l2Wallet)
       .attach(predeploys.OVM_L1BlockNumber)
 
+    const network = await l1Provider.getNetwork()
+    const messenger = new CrossChainMessenger({
+      l1SignerOrProvider: l1Wallet,
+      l2SignerOrProvider: l2Wallet,
+      l1ChainId: network.chainId,
+    })
+
     return new OptimismEnv({
       addressManager,
       l1Bridge,
@@ -141,6 +151,7 @@ export class OptimismEnv {
       watcher,
       l1Wallet,
       l2Wallet,
+      messenger,
       l1Provider,
       l2Provider,
       verifierProvider,
diff --git a/ops/docker/Dockerfile.integration-tests b/ops/docker/Dockerfile.integration-tests
index d90824da6b7f8..cf98d55d2df6f 100644
--- a/ops/docker/Dockerfile.integration-tests
+++ b/ops/docker/Dockerfile.integration-tests
@@ -12,6 +12,9 @@ COPY --from=builder /optimism/*.json /optimism/yarn.lock ./
 COPY --from=builder /optimism/node_modules ./node_modules
 
 # copy deps (would have been nice if docker followed the symlinks required)
+COPY --from=builder /optimism/packages/sdk/package.json ./packages/sdk/package.json
+COPY --from=builder /optimism/packages/sdk/dist ./packages/sdk/dist
+
 COPY --from=builder /optimism/packages/core-utils/package.json ./packages/core-utils/package.json
 COPY --from=builder /optimism/packages/core-utils/dist ./packages/core-utils/dist
 
diff --git a/ops/docker/Dockerfile.packages b/ops/docker/Dockerfile.packages
index d0339511c5e4f..915b1e5fc3a54 100644
--- a/ops/docker/Dockerfile.packages
+++ b/ops/docker/Dockerfile.packages
@@ -13,6 +13,7 @@ RUN apt-get update -y && apt-get install -y git curl jq python3
 # us to cache the installation steps
 WORKDIR /opt/optimism
 COPY *.json yarn.lock ./
+COPY packages/sdk/package.json ./packages/sdk/package.json
 COPY packages/core-utils/package.json ./packages/core-utils/package.json
 COPY packages/common-ts/package.json ./packages/common-ts/package.json
 COPY packages/contracts/package.json ./packages/contracts/package.json
diff --git a/packages/sdk/src/utils/contracts.ts b/packages/sdk/src/utils/contracts.ts
index 80d1ea6d22393..50c80314d5ec7 100644
--- a/packages/sdk/src/utils/contracts.ts
+++ b/packages/sdk/src/utils/contracts.ts
@@ -90,16 +90,14 @@ export const CONTRACT_ADDRESSES: {
     l2: DEFAULT_L2_CONTRACT_ADDRESSES,
   },
   // Hardhat local
-  // TODO: Get the actual addresses for this, temporary addresses here are fine for now until we
-  // start using this package in the integration tests.
   31337: {
     l1: {
-      AddressManager: '0x2F7E3cAC91b5148d336BbffB224B4dC79F09f01D',
-      L1CrossDomainMessenger: '0xEcC89b9EDD804850C4F343A278Be902be11AaF42',
-      L1StandardBridge: '0x73298186A143a54c20ae98EEE5a025bD5979De02',
-      StateCommitmentChain: '0x1afcA918eff169eE20fF8AB6Be75f3E872eE1C1A',
-      CanonicalTransactionChain: '0x2ebA8c4EfDB39A8Cd8f9eD65c50ec079f7CEBD81',
-      BondManager: '0xE5AE60bD6F8DEe4D0c2BC9268e23B92F1cacC58F',
+      AddressManager: '0x5FbDB2315678afecb367f032d93F642f64180aa3',
+      L1CrossDomainMessenger: '0x8A791620dd6260079BF849Dc5567aDC3F2FdC318',
+      L1StandardBridge: '0x610178dA211FEF7D417bC0e6FeD39F05609AD788',
+      StateCommitmentChain: '0xDc64a140Aa3E981100a9becA4E685f962f0cF6C9',
+      CanonicalTransactionChain: '0xCf7Ed3AccA5a467e9e704C703E8D87F634fB0Fc9',
+      BondManager: '0x5FC8d32690cc91D4c39d9d3abcBD16989F875707',
     },
     l2: DEFAULT_L2_CONTRACT_ADDRESSES,
   },
diff --git a/packages/sdk/src/utils/merkle-utils.ts b/packages/sdk/src/utils/merkle-utils.ts
index 0bde061a6ebfc..5e47edfcdc0b0 100644
--- a/packages/sdk/src/utils/merkle-utils.ts
+++ b/packages/sdk/src/utils/merkle-utils.ts
@@ -6,7 +6,7 @@ import {
   toRpcHexString,
 } from '@eth-optimism/core-utils'
 import { MerkleTree } from 'merkletreejs'
-import rlp from 'rlp'
+import * as rlp from 'rlp'
 
 /**
  * Generates a Merkle proof (using the particular scheme we use within Lib_MerkleTree).