diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..f48c6f1
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,50 @@
+---
+name: CI
+
+on:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [lts/-2, lts/-1]
+
+    name: Node.js ${{ matrix.node-version }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Configure Node.js
+        uses: actions/setup-node@v3
+        with:
+          cache: npm
+          node-version: ${{ matrix.node-version }}
+
+      # Install npm greater-than-or-equal-to 7 for consistent dependency resolution.
+      # We can remove this when Node.js 16 is the oldest LTS (2023-04-30).
+      - name: Update npm
+        run: npm install --global 'npm@>7'
+
+      - name: Cache node_modules
+        uses: actions/cache@v3
+        id: cache-node-modules
+        with:
+          path: node_modules
+          key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }}
+
+      - name: Install dependencies
+        if: steps.cache-node-modules.outputs.cache-hit != 'true'
+        run: npm ci
+
+      - name: Compile TypeScript
+        run: npm run build
+
+      - name: Test
+        run: npm test
diff --git a/package-lock.json b/package-lock.json
index 0f635e2..5780392 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -45,7 +45,7 @@
     },
     "@babel/runtime": {
       "version": "7.17.9",
-      "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/@babel/runtime/-/runtime-7.17.9.tgz",
+      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.17.9.tgz",
       "integrity": "sha512-lSiBBvodq29uShpWGNbgFdKYNiFDo5/HIYsaCEY9ff4sb10x9jizo2+pRrSyF4jKZCXqgzuqBOQKbUm90gQwJg==",
       "requires": {
         "regenerator-runtime": "^0.13.4"
@@ -78,7 +78,7 @@
       "dependencies": {
         "axios": {
           "version": "0.19.2",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/axios/-/axios-0.19.2.tgz",
+          "resolved": "https://registry.npmjs.org/axios/-/axios-0.19.2.tgz",
           "integrity": "sha512-fjgm5MvRHLhx+osE2xoekY70AhARk3a6hkN+3Io1jc00jtquGvxYlKlsFUhmUET0V5te6CcZI7lcv2Ym61mjHA==",
           "dev": true,
           "requires": {
@@ -175,7 +175,7 @@
         },
         "ethers": {
           "version": "4.0.49",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/ethers/-/ethers-4.0.49.tgz",
+          "resolved": "https://registry.npmjs.org/ethers/-/ethers-4.0.49.tgz",
           "integrity": "sha512-kPltTvWiyu+OktYy1IStSO16i2e7cS9D9OxZ81q2UUaiNPVrm/RTcbxamCXF9VUSKzJIdJV68EAIhTEVBalRWg==",
           "dev": true,
           "requires": {
@@ -192,7 +192,7 @@
         },
         "hash.js": {
           "version": "1.1.3",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/hash.js/-/hash.js-1.1.3.tgz",
+          "resolved": "https://registry.npmjs.org/hash.js/-/hash.js-1.1.3.tgz",
           "integrity": "sha512-/UETyP0W22QILqS+6HowevwhEFJ3MBJnwTf75Qob9Wz9t0DPuisL8kW8YZMK62dHAKE1c1p+gY1TtOLY+USEHA==",
           "dev": true,
           "requires": {
@@ -214,19 +214,19 @@
         },
         "scrypt-js": {
           "version": "2.0.4",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/scrypt-js/-/scrypt-js-2.0.4.tgz",
+          "resolved": "https://registry.npmjs.org/scrypt-js/-/scrypt-js-2.0.4.tgz",
           "integrity": "sha512-4KsaGcPnuhtCZQCxFxN3GVYIhKFPTdLd8PLC552XwbMndtD0cjRFAhDuuydXQ0h08ZfPgzqe6EKHozpuH74iDw==",
           "dev": true
         },
         "semver": {
           "version": "5.7.1",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/semver/-/semver-5.7.1.tgz",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
           "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
           "dev": true
         },
         "tronweb": {
           "version": "2.10.2",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/tronweb/-/tronweb-2.10.2.tgz",
+          "resolved": "https://registry.npmjs.org/tronweb/-/tronweb-2.10.2.tgz",
           "integrity": "sha512-k3DT5W5GVX/9lSLp7yE8vlyz8AfZLHbDBRif1qEZ5RJLTFlddb0ERnc9OqKzDO/kL2dBjB8kCV/7nW2RXaps8A==",
           "dev": true,
           "requires": {
@@ -245,7 +245,7 @@
           "dependencies": {
             "bignumber.js": {
               "version": "7.2.1",
-              "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/bignumber.js/-/bignumber.js-7.2.1.tgz",
+              "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-7.2.1.tgz",
               "integrity": "sha512-S4XzBk5sMB+Rcb/LNcpzXr57VRTxgAvaAEDAl1AwRx27j00hT84O6OkteE7u8UB3NuaaygCRrEpqox4uDOrbdQ==",
               "dev": true
             }
@@ -259,7 +259,7 @@
         },
         "validator": {
           "version": "10.11.0",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/validator/-/validator-10.11.0.tgz",
+          "resolved": "https://registry.npmjs.org/validator/-/validator-10.11.0.tgz",
           "integrity": "sha512-X/p3UZerAIsbBfN/IwahhYaBbY68EN/UQBWHtsbXGT5bfrH/p4NQzUCG1kF/rtKaNpnJ7jAu6NGTdSNtyNIXMw==",
           "dev": true
         }
@@ -333,7 +333,7 @@
       "integrity": "sha512-Zgr/N7wHTdMsc+C519JkZCqe6rfrNW8LSnscTISi5NfMTPbvDs/TvWrcuKi36JLVU5SYAPx55JGrSVOhQ1mmeg==",
       "dev": true,
       "requires": {
-        "@umpirsky/country-list": "git://github.com/umpirsky/country-list.git#05fda51",
+        "@umpirsky/country-list": "git+https://github.com/umpirsky/country-list.git#05fda51",
         "bigi": "^1.1.0",
         "bignumber.js": "^7.2.0",
         "bls12377js": "git+https://github.com/celo-org/bls12377js.git#400bcaeec9e7620b040bfad833268f5289699cac",
@@ -1529,8 +1529,8 @@
       }
     },
     "@umpirsky/country-list": {
-      "version": "git://github.com/umpirsky/country-list.git#05fda51cd97b3294e8175ffed06104c44b3c71d7",
-      "from": "git://github.com/umpirsky/country-list.git#05fda51",
+      "version": "git+https://github.com/umpirsky/country-list.git#05fda51cd97b3294e8175ffed06104c44b3c71d7",
+      "from": "git+https://github.com/umpirsky/country-list.git#05fda51",
       "dev": true
     },
     "@web3-js/scrypt-shim": {
@@ -2062,7 +2062,7 @@
     },
     "axios": {
       "version": "0.24.0",
-      "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/axios/-/axios-0.24.0.tgz",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-0.24.0.tgz",
       "integrity": "sha512-Q6cWsys88HoPgAaFAVUb0WpPk0O8iTeisR9IMqy9G8AbO4NlpVknrnQS03zzF9PGAWgO3cgletO3VjV/P7VztA==",
       "requires": {
         "follow-redirects": "^1.14.4"
@@ -2070,7 +2070,7 @@
       "dependencies": {
         "follow-redirects": {
           "version": "1.14.9",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/follow-redirects/-/follow-redirects-1.14.9.tgz",
+          "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.14.9.tgz",
           "integrity": "sha512-MQDfihBQYMcyy5dhRDJUHcw7lb2Pv/TuE6xP1vyraLukNDHKbDxDNaOE3NbCAdKQApno+GPRyo1YAp89yCjK4w=="
         }
       }
@@ -5902,7 +5902,7 @@
     },
     "injectpromise": {
       "version": "1.0.0",
-      "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/injectpromise/-/injectpromise-1.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/injectpromise/-/injectpromise-1.0.0.tgz",
       "integrity": "sha512-qNq5wy4qX4uWHcVFOEU+RqZkoVG65FhvGkyDWbuBxILMjK6A1LFf5A1mgXZkD4nRx5FCorD81X/XvPKp/zVfPA=="
     },
     "int64-buffer": {
@@ -9705,7 +9705,7 @@
     },
     "tronweb": {
       "version": "4.1.0",
-      "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/tronweb/-/tronweb-4.1.0.tgz",
+      "resolved": "https://registry.npmjs.org/tronweb/-/tronweb-4.1.0.tgz",
       "integrity": "sha512-aCBLnww8db5UQaewZFs4XJcgLhXuQG6Qxnbuhnw1LlFMBGWr7kX3OMK+Ld3weGHvZfoxgH6q5+LMhp/xewHrIg==",
       "requires": {
         "@babel/runtime": "^7.0.0",
@@ -9759,12 +9759,12 @@
         },
         "lodash": {
           "version": "4.17.21",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/lodash/-/lodash-4.17.21.tgz",
+          "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
           "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
         },
         "semver": {
           "version": "5.7.1",
-          "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/semver/-/semver-5.7.1.tgz",
+          "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
           "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
         }
       }
@@ -10084,7 +10084,7 @@
     },
     "validator": {
       "version": "13.7.0",
-      "resolved": "https://artifactory.bitgo-ci.com/artifactory/api/npm/npm/validator/-/validator-13.7.0.tgz",
+      "resolved": "https://registry.npmjs.org/validator/-/validator-13.7.0.tgz",
       "integrity": "sha512-nYXQLCBkpJ8X6ltALua9dRrZDHVYxjJ1wgskNt1lH9fzGjs3tgojGSCBjmEPwkWS1y29+DrizMTW19Pr9uB2nw=="
     },
     "varuint-bitcoin": {