diff --git a/.github/make.sh b/.github/make.sh
index 4c32a77b4..f02663e97 100755
--- a/.github/make.sh
+++ b/.github/make.sh
@@ -37,7 +37,7 @@ product="elastic/elasticsearch-js"
 output_folder=".buildkite/output"
 codegen_folder=".buildkite/output"
 OUTPUT_DIR="$repo/${output_folder}"
-NODE_JS_VERSION=18
+NODE_JS_VERSION=22
 WORKFLOW=${WORKFLOW-staging}
 mkdir -p "$OUTPUT_DIR"
 
@@ -46,83 +46,83 @@ echo -e "\033[34;1mINFO:\033[0m VERSION ${STACK_VERSION}\033[0m"
 echo -e "\033[34;1mINFO:\033[0m OUTPUT_DIR ${OUTPUT_DIR}\033[0m"
 
 case $CMD in
-    clean)
-        echo -e "\033[36;1mTARGET: clean workspace $output_folder\033[0m"
-        rm -rf "$output_folder"
-        echo -e "\033[32;1mdone.\033[0m"
-        exit 0
-        ;;
-    assemble)
-        if [ -v $VERSION ]; then
-            echo -e "\033[31;1mTARGET: assemble -> missing version parameter\033[0m"
-            exit 1
-        fi
-        echo -e "\033[36;1mTARGET: assemble artifact $VERSION\033[0m"
-        TASK=release
-        TASK_ARGS=("$VERSION" "$output_folder")
-        ;;
-    codegen)
-        if [ -v "$VERSION" ] || [[ -z "$VERSION" ]]; then
-            # fall back to branch name or `main` if no VERSION is set
-            branch_name=$(git rev-parse --abbrev-ref HEAD)
-            if [[ "$branch_name" =~ ^[0-9]+\.[0-9]+ ]]; then
-              echo -e "\033[36;1mTARGET: codegen -> No VERSION argument found, using branch name: \`$branch_name\`\033[0m"
-              VERSION="$branch_name"
-            else
-              echo -e "\033[36;1mTARGET: codegen -> No VERSION argument found, using \`main\`\033[0m"
-              VERSION="main"
-            fi
-        fi
-        if [ "$VERSION" = 'main' ]; then
-          echo -e "\033[36;1mTARGET: codegen API $VERSION\033[0m"
-        else
-          echo -e "\033[36;1mTARGET: codegen API v$VERSION\033[0m"
-        fi
-
-        TASK=codegen
-        TASK_ARGS=("$VERSION")
-        ;;
-    docsgen)
-        if [ -v $VERSION ]; then
-            echo -e "\033[31;1mTARGET: docsgen -> missing version parameter\033[0m"
-            exit 1
-        fi
-        echo -e "\033[36;1mTARGET: generate docs for $VERSION\033[0m"
-        TASK=codegen
-        TASK_ARGS=("$VERSION" "$codegen_folder")
-        ;;
-    examplesgen)
-        echo -e "\033[36;1mTARGET: generate examples\033[0m"
-        TASK=codegen
-        TASK_ARGS=("$VERSION" "$codegen_folder")
-        ;;
-    bump)
-        if [ -v $VERSION ]; then
-            echo -e "\033[31;1mTARGET: bump -> missing version parameter\033[0m"
-            exit 1
-        fi
-        echo -e "\033[36;1mTARGET: bump to version $VERSION\033[0m"
-        TASK=bump
-        TASK_ARGS=("$VERSION")
-        ;;
-    bumpmatrix)
-      if [ -v $VERSION ]; then
-        echo -e "\033[31;1mTARGET: bumpmatrix -> missing version parameter\033[0m"
-        exit 1
-      fi
-      echo -e "\033[36;1mTARGET: bump stack in test matrix to version $VERSION\033[0m"
-      TASK=bumpmatrix
-      TASK_ARGS=("$VERSION")
-      ;;
-    *)
-        echo -e "\n'$CMD' is not supported right now\n"
-        echo -e "\nUsage:"
-        echo -e "\t $0 release \$VERSION\n"
-        echo -e "\t $0 bump \$VERSION"
-        echo -e "\t $0 codegen \$VERSION"
-        exit 1
-esac
+clean)
+  echo -e "\033[36;1mTARGET: clean workspace $output_folder\033[0m"
+  rm -rf "$output_folder"
+  echo -e "\033[32;1mdone.\033[0m"
+  exit 0
+  ;;
+assemble)
+  if [ -v $VERSION ]; then
+    echo -e "\033[31;1mTARGET: assemble -> missing version parameter\033[0m"
+    exit 1
+  fi
+  echo -e "\033[36;1mTARGET: assemble artifact $VERSION\033[0m"
+  TASK=release
+  TASK_ARGS=("$VERSION" "$output_folder")
+  ;;
+codegen)
+  if [ -v "$VERSION" ] || [[ -z "$VERSION" ]]; then
+    # fall back to branch name or `main` if no VERSION is set
+    branch_name=$(git rev-parse --abbrev-ref HEAD)
+    if [[ "$branch_name" =~ ^[0-9]+\.[0-9]+ ]]; then
+      echo -e "\033[36;1mTARGET: codegen -> No VERSION argument found, using branch name: \`$branch_name\`\033[0m"
+      VERSION="$branch_name"
+    else
+      echo -e "\033[36;1mTARGET: codegen -> No VERSION argument found, using \`main\`\033[0m"
+      VERSION="main"
+    fi
+  fi
+  if [ "$VERSION" = 'main' ]; then
+    echo -e "\033[36;1mTARGET: codegen API $VERSION\033[0m"
+  else
+    echo -e "\033[36;1mTARGET: codegen API v$VERSION\033[0m"
+  fi
 
+  TASK=codegen
+  TASK_ARGS=("$VERSION")
+  ;;
+docsgen)
+  if [ -v $VERSION ]; then
+    echo -e "\033[31;1mTARGET: docsgen -> missing version parameter\033[0m"
+    exit 1
+  fi
+  echo -e "\033[36;1mTARGET: generate docs for $VERSION\033[0m"
+  TASK=codegen
+  TASK_ARGS=("$VERSION" "$codegen_folder")
+  ;;
+examplesgen)
+  echo -e "\033[36;1mTARGET: generate examples\033[0m"
+  TASK=codegen
+  TASK_ARGS=("$VERSION" "$codegen_folder")
+  ;;
+bump)
+  if [ -v $VERSION ]; then
+    echo -e "\033[31;1mTARGET: bump -> missing version parameter\033[0m"
+    exit 1
+  fi
+  echo -e "\033[36;1mTARGET: bump to version $VERSION\033[0m"
+  TASK=bump
+  TASK_ARGS=("$VERSION")
+  ;;
+bumpmatrix)
+  if [ -v $VERSION ]; then
+    echo -e "\033[31;1mTARGET: bumpmatrix -> missing version parameter\033[0m"
+    exit 1
+  fi
+  echo -e "\033[36;1mTARGET: bump stack in test matrix to version $VERSION\033[0m"
+  TASK=bumpmatrix
+  TASK_ARGS=("$VERSION")
+  ;;
+*)
+  echo -e "\n'$CMD' is not supported right now\n"
+  echo -e "\nUsage:"
+  echo -e "\t $0 release \$VERSION\n"
+  echo -e "\t $0 bump \$VERSION"
+  echo -e "\t $0 codegen \$VERSION"
+  exit 1
+  ;;
+esac
 
 # ------------------------------------------------------- #
 # Build Container
@@ -179,36 +179,36 @@ fi
 # ------------------------------------------------------- #
 
 if [[ "$CMD" == "assemble" ]]; then
-	if compgen -G ".buildkite/output/*" > /dev/null; then
-		echo -e "\033[32;1mTARGET: successfully assembled client v$VERSION\033[0m"
-	else
-		echo -e "\033[31;1mTARGET: assemble failed, empty workspace!\033[0m"
-		exit 1
-	fi
+  if compgen -G ".buildkite/output/*" >/dev/null; then
+    echo -e "\033[32;1mTARGET: successfully assembled client v$VERSION\033[0m"
+  else
+    echo -e "\033[31;1mTARGET: assemble failed, empty workspace!\033[0m"
+    exit 1
+  fi
 fi
 
 if [[ "$CMD" == "bump" ]]; then
-  if [ -n "$(git status --porcelain)" ]; then 
-		echo -e "\033[32;1mTARGET: successfully bumped client v$VERSION\033[0m"
-  else 
-		echo -e "\033[31;1mTARGET: failed bumped client v$VERSION\033[0m"
+  if [ -n "$(git status --porcelain)" ]; then
+    echo -e "\033[32;1mTARGET: successfully bumped client v$VERSION\033[0m"
+  else
+    echo -e "\033[31;1mTARGET: failed bumped client v$VERSION\033[0m"
     exit 1
   fi
 fi
 
 if [[ "$CMD" == "codegen" ]]; then
-  if [ -n "$(git status --porcelain)" ]; then 
-		echo -e "\033[32;1mTARGET: successfully generated client v$VERSION\033[0m"
-  else 
-		echo -e "\033[31;1mTARGET: failed generating client v$VERSION\033[0m"
+  if [ -n "$(git status --porcelain)" ]; then
+    echo -e "\033[32;1mTARGET: successfully generated client v$VERSION\033[0m"
+  else
+    echo -e "\033[31;1mTARGET: failed generating client v$VERSION\033[0m"
     exit 1
   fi
 fi
 
 if [[ "$CMD" == "docsgen" ]]; then
-    echo "TODO"
+  echo "TODO"
 fi
 
 if [[ "$CMD" == "examplesgen" ]]; then
-    echo "TODO"
+  echo "TODO"
 fi
diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index e4765731f..7dbec6fb0 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -73,6 +73,36 @@ jobs:
         run: |
           npm run license-checker
 
+  test-bun:
+    name: Test Bun
+    runs-on: ${{ matrix.os }}
+    needs: paths-filter
+    # only run if code relevant to unit tests was changed
+    if: needs.paths-filter.outputs.src-only == 'true'
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Use Bun
+        uses: oven-sh/setup-bun@v2
+
+      - name: Install
+        run: |
+          bun install
+
+      - name: Lint
+        run: |
+          bun run lint
+
+      - name: Unit test
+        run: |
+          bun run test:unit-bun
+
   auto-approve:
     name: Auto-approve
     needs: [test, license]
diff --git a/.gitignore b/.gitignore
index c38ae71df..0dd9106ed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -64,3 +64,4 @@ test/bundlers/parcel-test/.parcel-cache
 
 lib
 junit-output
+bun.lockb
diff --git a/.npmignore b/.npmignore
index 2e604be0f..08c1043f8 100644
--- a/.npmignore
+++ b/.npmignore
@@ -72,3 +72,4 @@ CODE_OF_CONDUCT.md
 CONTRIBUTING.md
 
 src
+bun.lockb
diff --git a/package.json b/package.json
index 520ed4b04..31e6da8a4 100644
--- a/package.json
+++ b/package.json
@@ -9,11 +9,12 @@
     "require": "./index.js"
   },
   "scripts": {
-    "test": "npm run build && npm run lint && tap test/unit/{*,**/*}.test.ts",
-    "test:unit": "npm run build && tap test/unit/{*,**/*}.test.ts",
-    "test:coverage-100": "npm run build && tap test/unit/{*,**/*}.test.ts --coverage --100",
-    "test:coverage-report": "npm run build && tap test/unit/{*,**/*}.test.ts --coverage && nyc report --reporter=text-lcov > coverage.lcov",
-    "test:coverage-ui": "npm run build && tap test/unit/{*,**/*}.test.ts --coverage --coverage-report=html",
+    "test": "npm run build && npm run lint && tap",
+    "test:unit": "npm run build && tap",
+    "test:unit-bun": "bun run build && bunx tap",
+    "test:coverage-100": "npm run build && tap --coverage --100",
+    "test:coverage-report": "npm run build && tap --coverage && nyc report --reporter=text-lcov > coverage.lcov",
+    "test:coverage-ui": "npm run build && tap --coverage --coverage-report=html",
     "test:integration": "tsc && node test/integration/index.js",
     "lint": "ts-standard src",
     "lint:fix": "ts-standard --fix src",
@@ -94,6 +95,7 @@
     "jsx": false,
     "flow": false,
     "coverage": false,
-    "check-coverage": false
+    "check-coverage": false,
+    "files": "test/unit/{*,**/*}.test.ts"
   }
 }
diff --git a/test/unit/api.test.ts b/test/unit/api.test.ts
index 80b3a1f7f..8c9a72cdf 100644
--- a/test/unit/api.test.ts
+++ b/test/unit/api.test.ts
@@ -205,7 +205,7 @@ test('With generic document', async t => {
   }
 
   const Connection = connection.buildMockConnection({
-    onRequest (opts) {
+    onRequest (_opts) {
       return {
         statusCode: 200,
         body: {
diff --git a/test/unit/helpers/msearch.test.ts b/test/unit/helpers/msearch.test.ts
index f0290d3b3..e80c5977c 100644
--- a/test/unit/helpers/msearch.test.ts
+++ b/test/unit/helpers/msearch.test.ts
@@ -24,7 +24,7 @@ import FakeTimers from '@sinonjs/fake-timers'
 
 test('Basic', async t => {
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -78,7 +78,7 @@ test('Multiple searches (inside async iterator)', t => {
   t.plan(4)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -161,7 +161,7 @@ test('Multiple searches (async iterator exits)', t => {
   t.plan(4)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -242,7 +242,7 @@ test('Multiple searches (async iterator exits)', t => {
 
 test('Stop a msearch processor (promises)', async t => {
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return { body: {} }
     }
   })
@@ -272,7 +272,7 @@ test('Bad header', t => {
   t.plan(1)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return { body: {} }
     }
   })
@@ -297,7 +297,7 @@ test('Bad body', t => {
   t.plan(1)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return { body: {} }
     }
   })
@@ -321,7 +321,7 @@ test('Bad body', t => {
 test('Retry on 429', async t => {
   let count = 0
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       if (count++ === 0) {
         return {
           body: {
@@ -384,7 +384,7 @@ test('Retry on 429', async t => {
 
 test('Single search errors', async t => {
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -419,7 +419,7 @@ test('Entire msearch fails', t => {
   t.plan(2)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         statusCode: 500,
         body: {
@@ -454,7 +454,7 @@ test('Resolves the msearch helper', t => {
   t.plan(1)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return { body: {} }
     }
   })
@@ -470,17 +470,17 @@ test('Resolves the msearch helper', t => {
 
   m.then(
     () => t.pass('called'),
-    e => t.fail('Should not fail')
+    _e => t.fail('Should not fail')
   )
 
-  m.catch(e => t.fail('Should not fail'))
+  m.catch(_e => t.fail('Should not fail'))
 })
 
 test('Stop the msearch helper with an error', t => {
   t.plan(3)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return { body: {} }
     }
   })
@@ -511,7 +511,7 @@ test('Multiple searches (concurrency = 1)', t => {
   t.plan(4)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -587,7 +587,7 @@ test('Flush interval', t => {
   t.teardown(() => clock.uninstall())
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -640,7 +640,7 @@ test('Flush interval - early stop', t => {
   t.plan(2)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: [{
@@ -684,7 +684,7 @@ test('Stop should resolve the helper', t => {
   t.plan(1)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: []
@@ -709,7 +709,7 @@ test('Stop should resolve the helper (error)', t => {
   t.plan(3)
 
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       return {
         body: {
           responses: []
diff --git a/test/unit/helpers/scroll.test.ts b/test/unit/helpers/scroll.test.ts
index b7ab9f735..88361bd7c 100644
--- a/test/unit/helpers/scroll.test.ts
+++ b/test/unit/helpers/scroll.test.ts
@@ -196,7 +196,7 @@ test('Scroll search (retry throws and maxRetries)', async t => {
   const expectedAttempts = maxRetries + 1
   let count = 0
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       count += 1
       return { body: {}, statusCode: 429 }
     }
@@ -217,8 +217,7 @@ test('Scroll search (retry throws and maxRetries)', async t => {
   })
 
   try {
-    // @ts-expect-error
-    for await (const result of scrollSearch) { // eslint-disable-line
+    for await (const _result of scrollSearch) { // eslint-disable-line
       t.fail('we should not be here')
     }
   } catch (err: any) {
@@ -344,7 +343,7 @@ test('Should not retry if maxRetries = 0', async t => {
   const expectedAttempts = 1
   let count = 0
   const MockConnection = connection.buildMockConnection({
-    onRequest (params) {
+    onRequest (_params) {
       count += 1
       return { body: {}, statusCode: 429 }
     }
@@ -365,8 +364,7 @@ test('Should not retry if maxRetries = 0', async t => {
   })
 
   try {
-    // @ts-expect-error
-    for await (const result of scrollSearch) { // eslint-disable-line
+    for await (const _result of scrollSearch) { // eslint-disable-line
       t.fail('we should not be here')
     }
   } catch (err: any) {