diff --git a/.github/workflows/bench-skill-rowbinary.yml b/.github/workflows/bench-skill-rowbinary.yml
new file mode 100644
index 000000000..16b312939
--- /dev/null
+++ b/.github/workflows/bench-skill-rowbinary.yml
@@ -0,0 +1,101 @@
+name: "skill: rowbinary benchmarks"
+
+# Runs the RowBinary skill's benchmark suite (npm run bench) against a live
+# ClickHouse server so the numbers cited externally (e.g. the @clickhouse/rowbinary
+# blog post: RowBinary vs JSON, monomorphized vs API-combinator readers) have a
+# timestamped, third-party-reproducible CI log + a machine-readable JSON artifact
+# behind them — not just a maintainer's laptop.
+#
+# Decoupled from the correctness suite (tests-skill-rowbinary.yml): benchmarks are
+# slower and their throughput numbers are noisy, so they shouldn't gate every PR.
+# This runs on demand (workflow_dispatch) and on PRs that touch the skill or this
+# workflow.
+
+permissions: {}
+on:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - .github/workflows/bench-skill-rowbinary.yml
+      - skills/clickhouse-js-node-rowbinary/**
+      - packages/datatype-parser/**
+
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+
+env:
+  # Network resilience: npm's default of 2 fetch retries is not enough for
+  # the transient registry errors (ECONNRESET) we regularly hit in CI.
+  NPM_CONFIG_FETCH_RETRIES: "5"
+  NPM_CONFIG_FETCH_RETRY_MINTIMEOUT: "10000"
+  NPM_CONFIG_FETCH_RETRY_MAXTIMEOUT: "60000"
+  NPM_CONFIG_FETCH_TIMEOUT: "600000"
+
+jobs:
+  benchmarks:
+    timeout-minutes: 20
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: skills/clickhouse-js-node-rowbinary
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+
+      - name: Start ClickHouse (latest) in Docker
+        uses: hoverkraft-tech/compose-action@11beaa1c2dae4e8ed7b1665aa074723b6cecb0e4 # v3.0.0
+        env:
+          CLICKHOUSE_VERSION: latest
+        with:
+          # The benchmarks only need the single-node HTTP server on :8123.
+          compose-file: "docker-compose.yml"
+          services: "clickhouse"
+          down-flags: "--volumes"
+
+      - name: Setup NodeJS
+        uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
+        with:
+          node-version: 24
+
+      - name: Record environment (CPU, Node, ClickHouse version)
+        run: |
+          echo "Node:       $(node -v)"
+          echo "CPU cores:  $(nproc)"
+          grep -m1 'model name' /proc/cpuinfo || true
+          # The server may still be starting; poll briefly so the version is captured.
+          for _ in $(seq 1 30); do
+            chv=$(curl -s 'http://localhost:8123/?query=SELECT%20version()')
+            [ -n "$chv" ] && break
+            sleep 1
+          done
+          echo "ClickHouse: ${chv:-<unavailable>}"
+
+      # Build + pack the in-repo @clickhouse/datatype-parser so the skill is
+      # benchmarked against THIS checkout, not the version published to npm. The
+      # committed package.json keeps a published range for end users; we only
+      # override node_modules below (`npm install <tarball> --no-save`).
+      - name: Pack local @clickhouse/datatype-parser
+        working-directory: ${{ github.workspace }}
+        run: |
+          npm ci
+          npm pack --workspace @clickhouse/datatype-parser --pack-destination "${{ runner.temp }}"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Use the local datatype-parser build
+        run: npm install "${{ runner.temp }}"/clickhouse-datatype-parser-*.tgz --no-save
+
+      # Prints the human-readable tinybench summary (per-bench hz + "Nx faster"
+      # lines, incl. the ledger RowBinary-vs-JSON comparison) to the job log, and
+      # writes the same numbers as JSON for the uploaded artifact.
+      - name: Run benchmarks
+        run: npm run bench -- --outputJson "${{ runner.temp }}/rowbinary-bench-results.json"
+
+      - name: Upload benchmark results (JSON)
+        if: ${{ always() }}
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
+        with:
+          name: rowbinary-bench-results
+          path: ${{ runner.temp }}/rowbinary-bench-results.json
+          if-no-files-found: error
diff --git a/.github/workflows/examples.yml b/.github/workflows/examples.yml
index 22757f7b1..996ae342d 100644
--- a/.github/workflows/examples.yml
+++ b/.github/workflows/examples.yml
@@ -17,10 +17,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/examples.yml"
   pull_request:
     paths:
@@ -33,10 +33,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/examples.yml"
 
 concurrency:
diff --git a/.github/workflows/tests-bun.yml b/.github/workflows/tests-bun.yml
index 897bdffbf..6ab380e8d 100644
--- a/.github/workflows/tests-bun.yml
+++ b/.github/workflows/tests-bun.yml
@@ -16,10 +16,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-bun.yml"
   pull_request:
     paths:
@@ -31,10 +31,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-bun.yml"
 
 concurrency:
@@ -42,23 +42,6 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  common-unit-tests:
-    timeout-minutes: 5
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
-
-      - name: Setup Bun
-        uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2.2.0
-
-      - name: Install dependencies
-        run: |
-          bun install
-
-      - name: Run common unit tests
-        run: |
-          npm run test:common:unit:bun
-
   node-unit-tests:
     timeout-minutes: 5
     runs-on: ubuntu-latest
diff --git a/.github/workflows/tests-dist.yml b/.github/workflows/tests-dist.yml
index 49279e0cd..70f5ba967 100644
--- a/.github/workflows/tests-dist.yml
+++ b/.github/workflows/tests-dist.yml
@@ -16,10 +16,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-dist.yml"
   pull_request:
     paths:
@@ -31,10 +31,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-dist.yml"
 
   schedule:
diff --git a/.github/workflows/tests-node.yml b/.github/workflows/tests-node.yml
index b509b334f..a06a8f976 100644
--- a/.github/workflows/tests-node.yml
+++ b/.github/workflows/tests-node.yml
@@ -16,10 +16,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-node.yml"
   pull_request:
     paths:
@@ -31,10 +31,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-node.yml"
 
   schedule:
@@ -100,48 +100,6 @@ jobs:
           fi
           cat prettier-output.txt
 
-  common-unit-tests:
-    timeout-minutes: 5
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        node: [20, 22, 24, 26]
-    steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
-
-      - name: Setup NodeJS ${{ matrix.node }}
-        uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
-        with:
-          node-version: ${{ matrix.node }}
-
-      - name: Install dependencies
-        run: |
-          npm install
-
-      - name: Run unit tests
-        run: |
-          npm run test:common:unit:node
-
-      - name: Export coverage metrics
-        env:
-          COVERAGE_REPORT_NAME: ${{ github.job }} (${{ matrix.node }})
-        run: |
-          node .scripts/export-coverage-metrics.mjs
-
-      - name: Upload coverage to Codecov
-        # Codecov token is not available for Dependabot PRs or PRs from forks; skip the upload in those cases.
-        # Upload coverage from a single canonical combination (Node 24) so Codecov
-        # receives exactly one upload per flag (see codecov.yml).
-        if: ${{ github.triggering_actor != 'dependabot[bot]' && (github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository) && matrix.node == 24 }}
-        uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v6.0.2
-        with:
-          name: node-common-unit
-          flags: node-common-unit
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: ./coverage/lcov.info
-          fail_ci_if_error: true
-
   unit-tests:
     timeout-minutes: 5
     runs-on: ubuntu-latest
diff --git a/.github/workflows/tests-oss-dependents.yml b/.github/workflows/tests-oss-dependents.yml
index c48d22987..cf7edd61b 100644
--- a/.github/workflows/tests-oss-dependents.yml
+++ b/.github/workflows/tests-oss-dependents.yml
@@ -16,10 +16,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-oss-dependents.yml"
   pull_request:
     paths:
@@ -31,10 +31,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-oss-dependents.yml"
 
   schedule:
diff --git a/.github/workflows/tests-web.yml b/.github/workflows/tests-web.yml
index 4fb2bae42..a3424a48e 100644
--- a/.github/workflows/tests-web.yml
+++ b/.github/workflows/tests-web.yml
@@ -16,10 +16,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-web.yml"
   pull_request:
     paths:
@@ -31,10 +31,10 @@ on:
       - "tsconfig.dev.json"
       - "eslint.config.base.mjs"
       - "docker-compose.yml"
-      - "vitest.node.config.ts"
-      - "vitest.node.setup.ts"
-      - "vitest.web.config.ts"
-      - "vitest.web.setup.ts"
+      - "packages/client-node/vitest.config.ts"
+      - "packages/client-node/vitest.setup.ts"
+      - "packages/client-web/vitest.config.ts"
+      - "packages/client-web/vitest.setup.ts"
       - ".github/workflows/tests-web.yml"
 
   schedule:
@@ -59,51 +59,6 @@ env:
   NPM_CONFIG_FETCH_TIMEOUT: "600000"
 
 jobs:
-  common-unit-tests:
-    timeout-minutes: 5
-    runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        browser: [chromium, firefox] # We're not testing in WebKit atm
-    steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
-
-      - name: Setup NodeJS
-        uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
-        with:
-          node-version: 24
-
-      - name: Install dependencies
-        run: |
-          npm install
-          npx playwright install ${{ matrix.browser }}
-
-      - name: Run unit tests (${{ matrix.browser }})
-        env:
-          BROWSER: ${{ matrix.browser }}
-        run: |
-          npm run test:common:unit:web
-
-      - name: Export coverage metrics
-        env:
-          COVERAGE_REPORT_NAME: ${{ github.job }} (${{ matrix.browser }})
-        run: |
-          node .scripts/export-coverage-metrics.mjs
-
-      - name: Upload coverage to Codecov
-        # Codecov token is not available for Dependabot PRs or PRs from forks; skip the upload in those cases.
-        # Upload coverage from a single canonical combination (Chromium) so Codecov
-        # receives exactly one upload per flag (see codecov.yml).
-        if: ${{ github.triggering_actor != 'dependabot[bot]' && (github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository) && matrix.browser == 'chromium' }}
-        uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v6.0.2
-        with:
-          name: web-common-unit
-          flags: web-common-unit
-          token: ${{ secrets.CODECOV_TOKEN }}
-          files: ./coverage/lcov.info
-          fail_ci_if_error: true
-
   all-tests-local-single-node:
     timeout-minutes: 5
     runs-on: ubuntu-latest
diff --git a/.gitignore b/.gitignore
index aed1a6009..4af759539 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,5 @@ out
 coverage
 coverage-web
 .nyc_output
-packages/*/README.md
 packages/*/LICENSE
 packages/*/skills/
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 2c3ef219b..4df45ab5a 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -53,13 +53,12 @@ everyone in the community can safely benefit from your contribution.
 
 We use [Vitest](https://vitest.dev/) as the test runner and the testing framework. It covers a variety of testing needs, including unit and integration tests, and supports both Node.js, Web environments and edge runtimes.
 
-The repository uses three consolidated Vitest configuration files:
+The repository keeps two Vitest configuration files, embedded in the client packages:
 
-- `vitest.client-common.config.ts` - Tests for the common client package
-- `vitest.node.config.ts` - Tests for the Node.js client package
-- `vitest.web.config.ts` - Tests for the Web client package
+- `packages/client-node/vitest.config.ts` - Tests for the Node.js client package
+- `packages/client-web/vitest.config.ts` - Tests for the Web client package
 
-Each config supports multiple test modes controlled by the `TEST_MODE` environment variable, allowing different test scenarios (unit, integration, TLS, etc.) to be run with a single configuration file.
+The shared (common) sources live in `packages/client-common` and are bundled into both clients; the common specs are run as part of the Node.js and Web test suites, so the common code is covered without a separate config. Each config supports multiple test modes controlled by the `TEST_MODE` environment variable, allowing different test scenarios (unit, integration, TLS, etc.) to be run with a single configuration file.
 
 ### Type checking and linting
 
@@ -89,11 +88,11 @@ treat all warnings as errors that must be fixed before merging.
 Does not require a running ClickHouse server.
 
 ```bash
-# Run common unit tests
-npm run test:common:unit
-
-# Run Node.js unit tests
+# Run Node.js unit tests (also runs the common unit tests)
 npm run test:node:unit
+
+# Run Web unit tests (also runs the common unit tests)
+npm run test:web:unit
 ```
 
 ### Running integration tests
diff --git a/codecov.yml b/codecov.yml
index f5fbfcea2..88e312ce9 100644
--- a/codecov.yml
+++ b/codecov.yml
@@ -16,18 +16,16 @@ coverage:
 #     ClickHouse `latest`).
 #
 #   flag                       workflow / job
-#   node-common-unit           node / common-unit-tests
 #   node-unit                  node / unit-tests
 #   node-integration-single    node / integration-tests-local-single-node
 #   node-integration-cluster   node / integration-tests-local-cluster
 #   node-integration-cloud     node / integration-tests-cloud
-#   web-common-unit            web  / common-unit-tests
 #   web-all-single             web  / all-tests-local-single-node
 #   web-integration-cluster    web  / integration-tests-local-cluster
 #   web-integration-cloud      web  / integration-tests-cloud
-#                              => 9 uploads total (one per flag)
+#                              => 7 uploads total (one per flag)
 #
-# `after_n_builds` therefore equals the number of flags (9). When a flag is
+# `after_n_builds` therefore equals the number of flags (7). When a flag is
 # added or removed, update this value and the `individual_flags` list to match.
 codecov:
   # Wait for the other CI checks to finish before notifying, in addition to the
@@ -36,11 +34,11 @@ codecov:
     wait_for_ci: true
     # Total number of expected uploads before Codecov posts the final commit
     # status/notification: one upload per flag (see the table above).
-    after_n_builds: 9
+    after_n_builds: 7
 
 comment:
   # Wait for all uploads before posting/updating the PR comment.
-  after_n_builds: 9
+  after_n_builds: 7
 
 flag_management:
   default_rules:
@@ -49,12 +47,10 @@ flag_management:
     # flag uploads exactly once, so per-flag statuses post after a single build.
     carryforward: true
   individual_flags:
-    - name: node-common-unit
     - name: node-unit
     - name: node-integration-single
     - name: node-integration-cluster
     - name: node-integration-cloud
-    - name: web-common-unit
     - name: web-all-single
     - name: web-integration-cluster
     - name: web-integration-cloud
diff --git a/package.json b/package.json
index 764d19367..8a465a4b2 100644
--- a/package.json
+++ b/package.json
@@ -24,29 +24,24 @@
     "prettify": "prettier --write .",
     "prettier:check": "prettier --check .",
     "test": "echo -e \"Please specify a test script to run. See \\033[1mnpm run\\033[0m for reference.\" && exit 1",
-    "test:common:unit:node": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=common vitest -c vitest.node.config.ts",
-    "test:common:unit:bun": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=common bun --bun vitest -c vitest.node.config.ts",
-    "test:common:unit:web": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=common vitest -c vitest.web.config.ts",
-    "test:common:integration:node": "TEST_MODE=common-integration vitest -c vitest.node.config.ts",
-    "test:common:integration:web": "TEST_MODE=common-integration vitest -c vitest.web.config.ts",
-    "test:node:unit": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit vitest -c vitest.node.config.ts",
-    "test:node:unit:bun": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit bun --bun vitest -c vitest.node.config.ts",
-    "test:node:integration:tls": "TEST_MODE=tls vitest -c vitest.node.config.ts",
-    "test:node:integration": "TEST_MODE=integration vitest -c vitest.node.config.ts",
-    "test:node:integration:dist": "npm run build && TEST_TARGET=dist TEST_MODE=integration vitest -c vitest.node.config.ts",
-    "test:node:oss-dependents": "TEST_MODE=oss-dependents vitest -c vitest.node.config.ts",
-    "test:node:integration:local_cluster": "CLICKHOUSE_TEST_ENVIRONMENT=local_cluster TEST_MODE=integration vitest -c vitest.node.config.ts",
-    "test:node:integration:cloud": "CLICKHOUSE_TEST_ENVIRONMENT=cloud TEST_MODE=integration vitest -c vitest.node.config.ts",
-    "test:node:all": "TEST_MODE=all vitest -c vitest.node.config.ts",
-    "test:node:coverage": "VITEST_COVERAGE=true TEST_MODE=all vitest -c vitest.node.config.ts",
-    "test:web:unit": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit vitest -c vitest.web.config.ts",
-    "test:web:integration": "TEST_MODE=integration vitest -c vitest.web.config.ts",
-    "test:web:integration:dist": "npm run build && TEST_TARGET=dist TEST_MODE=integration vitest -c vitest.web.config.ts",
-    "test:web:integration:local_cluster": "TEST_MODE=integration CLICKHOUSE_TEST_ENVIRONMENT=local_cluster vitest -c vitest.web.config.ts",
-    "test:web:integration:cloud": "TEST_MODE=integration CLICKHOUSE_TEST_ENVIRONMENT=cloud vitest -c vitest.web.config.ts",
-    "test:web:integration:cloud:jwt": "TEST_MODE=jwt CLICKHOUSE_TEST_ENVIRONMENT=cloud vitest -c vitest.web.config.ts",
-    "test:web:all": "TEST_MODE=all vitest -c vitest.web.config.ts",
-    "test:web:coverage": "VITEST_COVERAGE=true TEST_MODE=all vitest -c vitest.web.config.ts",
+    "test:node:unit": "npm --prefix packages/client-node run test:unit",
+    "test:node:unit:bun": "npm --prefix packages/client-node run test:unit:bun",
+    "test:node:integration:tls": "npm --prefix packages/client-node run test:integration:tls",
+    "test:node:integration": "npm --prefix packages/client-node run test:integration",
+    "test:node:integration:dist": "npm --prefix packages/client-node run test:integration:dist",
+    "test:node:oss-dependents": "npm --prefix packages/client-node run test:oss-dependents",
+    "test:node:integration:local_cluster": "npm --prefix packages/client-node run test:integration:local_cluster",
+    "test:node:integration:cloud": "npm --prefix packages/client-node run test:integration:cloud",
+    "test:node:all": "npm --prefix packages/client-node run test:all",
+    "test:node:coverage": "npm --prefix packages/client-node run test:coverage",
+    "test:web:unit": "npm --prefix packages/client-web run test:unit",
+    "test:web:integration": "npm --prefix packages/client-web run test:integration",
+    "test:web:integration:dist": "npm --prefix packages/client-web run test:integration:dist",
+    "test:web:integration:local_cluster": "npm --prefix packages/client-web run test:integration:local_cluster",
+    "test:web:integration:cloud": "npm --prefix packages/client-web run test:integration:cloud",
+    "test:web:integration:cloud:jwt": "npm --prefix packages/client-web run test:integration:cloud:jwt",
+    "test:web:all": "npm --prefix packages/client-web run test:all",
+    "test:web:coverage": "npm --prefix packages/client-web run test:coverage",
     "//": "See https://github.com/kylebarron/parquet-wasm/issues/798",
     "postinstall": "cd node_modules/parquet-wasm && npm pkg delete type",
     "prepare": "husky"
diff --git a/packages/client-common/README.md b/packages/client-common/README.md
new file mode 100644
index 000000000..b7cb27636
--- /dev/null
+++ b/packages/client-common/README.md
@@ -0,0 +1,55 @@
+# @clickhouse/client-common
+
+> [!WARNING]
+> **This package is deprecated and is no longer maintained as a dependency.**
+> It is no longer used by [`@clickhouse/client`](https://www.npmjs.com/package/@clickhouse/client)
+> (Node.js) or [`@clickhouse/client-web`](https://www.npmjs.com/package/@clickhouse/client-web)
+> (Web), and there is **no replacement package** to depend on. Do not add this
+> package to new projects.
+>
+> - Building a ClickHouse app on **Node.js**? Install
+>   [`@clickhouse/client`](https://www.npmjs.com/package/@clickhouse/client).
+> - Building for the **browser / edge runtimes**? Install
+>   [`@clickhouse/client-web`](https://www.npmjs.com/package/@clickhouse/client-web).
+
+## What this package was for
+
+Historically, the shared code between `@clickhouse/client` (Node.js) and
+`@clickhouse/client-web` lived in this third published package,
+`@clickhouse/client-common`, which both of them depended on. It exposed the
+shared types and the base framework that were also intended to be the foundation
+for building **custom client implementations** for alternative runtimes (such as
+Bun or Cloudflare Workers) or alternative protocols (such as the native
+ClickHouse protocol or gRPC over a proxy).
+
+## Why it is deprecated
+
+The shared-package approach is being retired to simplify versioning across the
+packages and to avoid the bundling/duplication issues that several downstream
+users have hit.
+
+What this means in practice:
+
+- The shared code is **not** being moved into a new shared package; there is no
+  replacement to depend on.
+- Instead, the shared code is now inlined / co-located inside each runtime
+  package (`@clickhouse/client`, `@clickhouse/client-web`, …). Going forward,
+  each runtime package is **self-contained** and published independently.
+
+## Building a client for an alternative runtime or protocol
+
+The new, recommended approach is to **fork an existing in-tree client package and
+iterate on it** — copy the pieces you need into your own package the same way
+`client-node` and `client-web` do, rather than depending on a shared package.
+
+See
+[Building specialized clients for alternative runtimes and protocols](https://github.com/ClickHouse/clickhouse-js/blob/main/ALTERNATIVE_CLIENTS.md)
+for the full guide.
+
+## Changelog
+
+See [`CHANGELOG.md`](https://github.com/ClickHouse/clickhouse-js/blob/main/packages/client-common/CHANGELOG.md).
+
+## License
+
+[Apache 2.0](https://github.com/ClickHouse/clickhouse-js/blob/main/LICENSE)
diff --git a/packages/client-common/package.json b/packages/client-common/package.json
index e5893e09a..cd04443af 100644
--- a/packages/client-common/package.json
+++ b/packages/client-common/package.json
@@ -22,7 +22,7 @@
   ],
   "scripts": {
     "pack": "npm pack",
-    "prepack": "cp ../../README.md ../../LICENSE .",
+    "prepack": "cp ../../LICENSE .",
     "typecheck": "tsc --noEmit",
     "lint": "eslint --max-warnings=0 .",
     "lint:fix": "eslint . --fix",
diff --git a/packages/client-node/CHANGELOG.md b/packages/client-node/CHANGELOG.md
index 7ae3e0373..faa822daa 100644
--- a/packages/client-node/CHANGELOG.md
+++ b/packages/client-node/CHANGELOG.md
@@ -1,3 +1,11 @@
+# 1.23.1
+
+## Bug Fixes
+
+- Re-export `EXCEPTION_TAG_HEADER_NAME` and `extractErrorAtTheEndOfChunk` from `@clickhouse/client`. Both are part of the (now deprecated) `@clickhouse/client-common` public API but were missed when its surface was bundled into and re-exported from the client packages in 1.23.0 ([#845]). Reported downstream by Langfuse. ([#935])
+
+[#935]: https://github.com/ClickHouse/clickhouse-js/pull/935
+
 # 1.23.0
 
 ## Migration Notes
diff --git a/packages/client-node/README.md b/packages/client-node/README.md
new file mode 100644
index 000000000..1b2bb94cd
--- /dev/null
+++ b/packages/client-node/README.md
@@ -0,0 +1,89 @@
+# @clickhouse/client
+
+Official Node.js client for [ClickHouse](https://clickhouse.com/), written
+purely in TypeScript and thoroughly tested against actual ClickHouse versions.
+
+It is built on top of the Node.js [HTTP](https://nodejs.org/api/http.html) and
+[Stream](https://nodejs.org/api/stream.html) APIs and supports streaming for
+both selects and inserts. The client has zero external dependencies and is
+optimized for maximum performance.
+
+> Looking for a browser / edge runtime (Cloudflare Workers, etc.) instead? Use
+> [`@clickhouse/client-web`](https://www.npmjs.com/package/@clickhouse/client-web).
+
+## Installation
+
+```sh
+npm i @clickhouse/client
+```
+
+## Environment requirements
+
+Node.js must be available in the environment to run the client. The client is
+compatible with all the [maintained](https://github.com/nodejs/release#readme)
+Node.js releases.
+
+| Node.js version | Supported? |
+| --------------- | ---------- |
+| 26.x            | ✔          |
+| 24.x            | ✔          |
+| 22.x            | ✔          |
+| 20.x            | ✔          |
+
+If using TypeScript, version
+[4.5](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html)
+or above is required to enable
+[inline import and export syntax](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html#type-modifiers-on-import-names).
+
+## Compatibility with ClickHouse
+
+| Client version | ClickHouse |
+| -------------- | ---------- |
+| 1.12.0+        | 24.8+      |
+
+The client may work with older versions too; however, this is best-effort
+support and is not guaranteed.
+
+## Quick start
+
+```ts
+import { createClient } from "@clickhouse/client";
+
+const client = createClient({
+  url: process.env.CLICKHOUSE_URL ?? "http://localhost:8123",
+  username: process.env.CLICKHOUSE_USER ?? "default",
+  password: process.env.CLICKHOUSE_PASSWORD ?? "",
+});
+
+const resultSet = await client.query({
+  query: "SELECT * FROM system.tables",
+  format: "JSONEachRow",
+});
+
+const tables = await resultSet.json();
+console.log(tables);
+
+await client.close();
+```
+
+See more examples in the
+[examples directory](https://github.com/ClickHouse/clickhouse-js/tree/main/examples).
+
+## Documentation
+
+See the [ClickHouse website](https://clickhouse.com/docs/integrations/javascript)
+for the full documentation.
+
+## Changelog
+
+See [`CHANGELOG.md`](https://github.com/ClickHouse/clickhouse-js/blob/main/packages/client-node/CHANGELOG.md).
+
+## Contact us
+
+If you have any questions or need help, feel free to reach out to us in the
+[Community Slack](https://clickhouse.com/slack) (`#clickhouse-js` channel) or
+via [GitHub issues](https://github.com/ClickHouse/clickhouse-js/issues).
+
+## License
+
+[Apache 2.0](https://github.com/ClickHouse/clickhouse-js/blob/main/LICENSE)
diff --git a/packages/client-node/eslint.config.mjs b/packages/client-node/eslint.config.mjs
index d142e6c9f..cc8c651d5 100644
--- a/packages/client-node/eslint.config.mjs
+++ b/packages/client-node/eslint.config.mjs
@@ -19,8 +19,9 @@ export default defineConfig(
     ignores: [
       "./__tests__/**/*.ts",
       "eslint.config.mjs",
-      "vitest.*.config.ts",
-      "vitest.*.setup.ts",
+      "vitest.config.ts",
+      "vitest.setup.ts",
+      "vitest.otel.js",
       "coverage",
       "out",
       "dist",
diff --git a/packages/client-node/package.json b/packages/client-node/package.json
index d8e0941e9..21495a03a 100644
--- a/packages/client-node/package.json
+++ b/packages/client-node/package.json
@@ -42,11 +42,21 @@
   },
   "scripts": {
     "pack": "npm pack",
-    "prepack": "rm -rf skills && cp ../../README.md ../../LICENSE . && cp -r ../../skills . && RBP=skills/clickhouse-js-node-rowbinary && rm -rf $RBP/tests $RBP/node_modules $RBP/dist $RBP/package.json $RBP/package-lock.json $RBP/tsconfig.json $RBP/tsconfig.build.json $RBP/vitest.config.ts $RBP/.gitignore $RBP/LICENSE $RBP/eval_result*.md",
+    "prepack": "rm -rf skills && cp ../../LICENSE . && cp -r ../../skills . && RBP=skills/clickhouse-js-node-rowbinary && rm -rf $RBP/tests $RBP/node_modules $RBP/dist $RBP/package.json $RBP/package-lock.json $RBP/tsconfig.json $RBP/tsconfig.build.json $RBP/vitest.config.ts $RBP/.gitignore $RBP/LICENSE $RBP/eval_result*.md",
     "typecheck": "tsc --noEmit",
     "lint": "eslint --max-warnings=0 .",
     "lint:fix": "eslint . --fix",
-    "build": "rm -rf dist; tsc"
+    "build": "rm -rf dist; tsc",
+    "test:unit": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit vitest",
+    "test:unit:bun": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit bun --bun vitest",
+    "test:integration": "TEST_MODE=integration vitest",
+    "test:integration:tls": "TEST_MODE=tls vitest",
+    "test:integration:dist": "npm --prefix ../.. run build && TEST_TARGET=dist TEST_MODE=integration vitest",
+    "test:integration:local_cluster": "CLICKHOUSE_TEST_ENVIRONMENT=local_cluster TEST_MODE=integration vitest",
+    "test:integration:cloud": "CLICKHOUSE_TEST_ENVIRONMENT=cloud TEST_MODE=integration vitest",
+    "test:oss-dependents": "TEST_MODE=oss-dependents vitest",
+    "test:all": "TEST_MODE=all vitest",
+    "test:coverage": "VITEST_COVERAGE=true TEST_MODE=all vitest"
   },
   "dependencies": {},
   "devDependencies": {
diff --git a/packages/client-node/src/index.ts b/packages/client-node/src/index.ts
index 638f85035..9d3938272 100644
--- a/packages/client-node/src/index.ts
+++ b/packages/client-node/src/index.ts
@@ -93,6 +93,8 @@ import {
   ClickHouseSpanStatusCode as ClickHouseSpanStatusCode_,
   ClickHouseSpanKind as ClickHouseSpanKind_,
   defaultJSONHandling as defaultJSONHandling_,
+  EXCEPTION_TAG_HEADER_NAME as EXCEPTION_TAG_HEADER_NAME_,
+  extractErrorAtTheEndOfChunk as extractErrorAtTheEndOfChunk_,
 } from "./common/index";
 
 export const ClickHouseError = ClickHouseError_;
@@ -121,3 +123,5 @@ export const ClickHouseSpanNames = ClickHouseSpanNames_;
 export const ClickHouseSpanStatusCode = ClickHouseSpanStatusCode_;
 export const ClickHouseSpanKind = ClickHouseSpanKind_;
 export const defaultJSONHandling = defaultJSONHandling_;
+export const EXCEPTION_TAG_HEADER_NAME = EXCEPTION_TAG_HEADER_NAME_;
+export const extractErrorAtTheEndOfChunk = extractErrorAtTheEndOfChunk_;
diff --git a/vitest.node.config.ts b/packages/client-node/vitest.config.ts
similarity index 89%
rename from vitest.node.config.ts
rename to packages/client-node/vitest.config.ts
index 88268c89e..f29503b36 100644
--- a/vitest.node.config.ts
+++ b/packages/client-node/vitest.config.ts
@@ -1,17 +1,27 @@
 import { defineConfig } from "vitest/config";
+import { fileURLToPath } from "node:url";
+
+// Embedded in the node client package, but rooted at the repo so the shared
+// (common) sources and specs are reachable. The node and web packages run the
+// common tests so the common code is exercised and shows up in coverage.
+const root = fileURLToPath(new URL("../..", import.meta.url));
+
+// The package scripts run vitest via `npm --prefix packages/client-node`, which
+// sets the process cwd to the package dir. Some specs read fixtures/certs via
+// repo-root-relative paths (e.g. node_streaming_e2e, tls), so pin the cwd to the
+// repo root to match `root` above. Workers inherit this cwd when they spawn.
+process.chdir(root);
 
 const testMode = process.env.TEST_MODE;
 if (
   testMode !== "unit" &&
   testMode !== "integration" &&
   testMode !== "tls" &&
-  testMode !== "common" &&
-  testMode !== "common-integration" &&
   testMode !== "oss-dependents" &&
   testMode !== "all"
 ) {
   throw new Error(
-    `Unsupported TEST_MODE: [${testMode}]. Supported modes are: unit, integration, tls, common, common-integration, oss-dependents, all.`,
+    `Unsupported TEST_MODE: [${testMode}]. Supported modes are: unit, integration, tls, oss-dependents, all.`,
   );
 }
 
@@ -37,27 +47,22 @@ if (testTarget !== "src" && testTarget !== "dist") {
 
 const collections = {
   unit: [
+    "packages/client-common/__tests__/unit/*.test.ts",
+    "packages/client-common/__tests__/utils/*.test.ts",
     "packages/client-node/__tests__/unit/*.test.ts",
     "packages/client-node/__tests__/utils/*.test.ts",
   ],
   integration: [
-    "packages/client-node/__tests__/integration/*.test.ts",
     "packages/client-common/__tests__/integration/*.test.ts",
+    "packages/client-node/__tests__/integration/*.test.ts",
   ],
   // TLS tests require a specific environment setup
   // This list is integration + TLS tests
   tls: [
-    "packages/client-node/__tests__/integration/*.test.ts",
     "packages/client-common/__tests__/integration/*.test.ts",
+    "packages/client-node/__tests__/integration/*.test.ts",
     "packages/client-node/__tests__/tls/*.test.ts",
   ],
-  common: [
-    "packages/client-common/__tests__/unit/*.test.ts",
-    "packages/client-common/__tests__/utils/*.test.ts",
-  ],
-  "common-integration": [
-    "packages/client-common/__tests__/integration/*.test.ts",
-  ],
   // Runnable reproductions of how the top OSS dependents use the client.
   // These specs import only the public package names, so they default to
   // TEST_TARGET=dist (see above) and resolve to the BUILT workspace packages:
@@ -78,6 +83,7 @@ const collections = {
 };
 
 export default defineConfig({
+  root,
   test: {
     // Increase maxWorkers to speed up integration tests
     // as we're not bound by the CPU here.
@@ -86,7 +92,7 @@ export default defineConfig({
     hookTimeout: 300_000,
     testTimeout: 300_000,
     slowTestThreshold: testMode === "unit" ? 10_000 : undefined,
-    setupFiles: ["vitest.node.setup.ts"],
+    setupFiles: ["packages/client-node/vitest.setup.ts"],
     include: collections[testMode],
     coverage: {
       enabled: process.env.VITEST_COVERAGE === "true",
@@ -118,7 +124,7 @@ export default defineConfig({
           process.env.VITEST_OTEL_ENABLED === "true" &&
           // not set in dependabot PRs
           !!process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
-        sdkPath: "./vitest.node.otel.js",
+        sdkPath: "./packages/client-node/vitest.otel.js",
       },
     },
     retry: process.env.CI ? 2 : 0,
diff --git a/vitest.node.otel.js b/packages/client-node/vitest.otel.js
similarity index 100%
rename from vitest.node.otel.js
rename to packages/client-node/vitest.otel.js
diff --git a/vitest.node.setup.ts b/packages/client-node/vitest.setup.ts
similarity index 100%
rename from vitest.node.setup.ts
rename to packages/client-node/vitest.setup.ts
diff --git a/packages/client-web/CHANGELOG.md b/packages/client-web/CHANGELOG.md
index 7ae3e0373..1883e1f6d 100644
--- a/packages/client-web/CHANGELOG.md
+++ b/packages/client-web/CHANGELOG.md
@@ -1,3 +1,11 @@
+# 1.23.1
+
+## Bug Fixes
+
+- Re-export `EXCEPTION_TAG_HEADER_NAME` and `extractErrorAtTheEndOfChunk` from `@clickhouse/client-web`. Both are part of the (now deprecated) `@clickhouse/client-common` public API but were missed when its surface was bundled into and re-exported from the client packages in 1.23.0 ([#845]). Reported downstream by Langfuse. ([#935])
+
+[#935]: https://github.com/ClickHouse/clickhouse-js/pull/935
+
 # 1.23.0
 
 ## Migration Notes
diff --git a/packages/client-web/README.md b/packages/client-web/README.md
new file mode 100644
index 000000000..14b13f535
--- /dev/null
+++ b/packages/client-web/README.md
@@ -0,0 +1,86 @@
+# @clickhouse/client-web
+
+Official Web client for [ClickHouse](https://clickhouse.com/), written purely in
+TypeScript and thoroughly tested against actual ClickHouse versions.
+
+It is built on top of the
+[Fetch](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) and
+[Web Streams](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) APIs
+and supports streaming for selects. It is compatible with Chrome/Firefox
+browsers and Cloudflare Workers. The client has zero external dependencies and is
+optimized for maximum performance.
+
+> Running on Node.js? Use
+> [`@clickhouse/client`](https://www.npmjs.com/package/@clickhouse/client)
+> instead, which additionally supports streaming for inserts.
+
+## Installation
+
+```sh
+npm i @clickhouse/client-web
+```
+
+## Environment requirements
+
+The client targets runtimes that provide the standard
+[Fetch](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) and
+[Web Streams](https://developer.mozilla.org/en-US/docs/Web/API/Streams_API) APIs,
+such as modern Chrome/Firefox browsers and Cloudflare Workers.
+
+If using TypeScript, version
+[4.5](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html)
+or above is required to enable
+[inline import and export syntax](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-5.html#type-modifiers-on-import-names).
+
+## Compatibility with ClickHouse
+
+| Client version | ClickHouse |
+| -------------- | ---------- |
+| 1.12.0+        | 24.8+      |
+
+The client may work with older versions too; however, this is best-effort
+support and is not guaranteed.
+
+## Quick start
+
+```ts
+import { createClient } from "@clickhouse/client-web";
+
+const client = createClient({
+  url: "http://localhost:8123",
+  username: "default",
+  password: "",
+});
+
+const resultSet = await client.query({
+  query: "SELECT * FROM system.tables",
+  format: "JSONEachRow",
+});
+
+const tables = await resultSet.json();
+console.log(tables);
+
+await client.close();
+```
+
+See more examples in the
+[examples directory](https://github.com/ClickHouse/clickhouse-js/tree/main/examples).
+
+## Documentation
+
+See the [ClickHouse website](https://clickhouse.com/docs/integrations/javascript)
+for the full documentation.
+
+## Changelog
+
+See [`CHANGELOG.md`](https://github.com/ClickHouse/clickhouse-js/blob/main/packages/client-web/CHANGELOG.md).
+
+## Contact us
+
+If you have any questions or need help, feel free to reach out to us in the
+[Community Slack](https://clickhouse.com/slack) (`#clickhouse-js` channel) or
+via [GitHub issues](https://github.com/ClickHouse/clickhouse-js/issues).
+
+## License
+
+[Apache 2.0](https://github.com/ClickHouse/clickhouse-js/blob/main/LICENSE)
diff --git a/packages/client-web/eslint.config.mjs b/packages/client-web/eslint.config.mjs
index 0a540ee80..7217144d0 100644
--- a/packages/client-web/eslint.config.mjs
+++ b/packages/client-web/eslint.config.mjs
@@ -13,8 +13,9 @@ export default defineConfig(
     ignores: [
       "./__tests__/**/*.ts",
       "eslint.config.mjs",
-      "vitest.*.config.ts",
-      "vitest.*.setup.ts",
+      "vitest.config.ts",
+      "vitest.setup.ts",
+      "vitest.otel.js",
       "coverage",
       "out",
       "dist",
diff --git a/packages/client-web/package.json b/packages/client-web/package.json
index dec875f8f..23e67c4d3 100644
--- a/packages/client-web/package.json
+++ b/packages/client-web/package.json
@@ -25,11 +25,19 @@
   },
   "scripts": {
     "pack": "npm pack",
-    "prepack": "cp ../../README.md ../../LICENSE .",
+    "prepack": "cp ../../LICENSE .",
     "typecheck": "tsc --noEmit",
     "lint": "eslint --max-warnings=0 .",
     "lint:fix": "eslint . --fix",
-    "build": "rm -rf dist; tsc"
+    "build": "rm -rf dist; tsc",
+    "test:unit": "CLICKHOUSE_TEST_SKIP_INIT=1 TEST_MODE=unit vitest",
+    "test:integration": "TEST_MODE=integration vitest",
+    "test:integration:dist": "npm --prefix ../.. run build && TEST_TARGET=dist TEST_MODE=integration vitest",
+    "test:integration:local_cluster": "CLICKHOUSE_TEST_ENVIRONMENT=local_cluster TEST_MODE=integration vitest",
+    "test:integration:cloud": "CLICKHOUSE_TEST_ENVIRONMENT=cloud TEST_MODE=integration vitest",
+    "test:integration:cloud:jwt": "CLICKHOUSE_TEST_ENVIRONMENT=cloud TEST_MODE=jwt vitest",
+    "test:all": "TEST_MODE=all vitest",
+    "test:coverage": "VITEST_COVERAGE=true TEST_MODE=all vitest"
   },
   "dependencies": {}
 }
diff --git a/packages/client-web/src/index.ts b/packages/client-web/src/index.ts
index 958bdd1da..d0030758f 100644
--- a/packages/client-web/src/index.ts
+++ b/packages/client-web/src/index.ts
@@ -92,6 +92,8 @@ import {
   ClickHouseSpanStatusCode as ClickHouseSpanStatusCode_,
   ClickHouseSpanKind as ClickHouseSpanKind_,
   defaultJSONHandling as defaultJSONHandling_,
+  EXCEPTION_TAG_HEADER_NAME as EXCEPTION_TAG_HEADER_NAME_,
+  extractErrorAtTheEndOfChunk as extractErrorAtTheEndOfChunk_,
 } from "./common/index";
 
 export const ClickHouseError = ClickHouseError_;
@@ -120,3 +122,5 @@ export const ClickHouseSpanNames = ClickHouseSpanNames_;
 export const ClickHouseSpanStatusCode = ClickHouseSpanStatusCode_;
 export const ClickHouseSpanKind = ClickHouseSpanKind_;
 export const defaultJSONHandling = defaultJSONHandling_;
+export const EXCEPTION_TAG_HEADER_NAME = EXCEPTION_TAG_HEADER_NAME_;
+export const extractErrorAtTheEndOfChunk = extractErrorAtTheEndOfChunk_;
diff --git a/vitest.web.config.ts b/packages/client-web/vitest.config.ts
similarity index 86%
rename from vitest.web.config.ts
rename to packages/client-web/vitest.config.ts
index a4080bf67..ca515c255 100644
--- a/vitest.web.config.ts
+++ b/packages/client-web/vitest.config.ts
@@ -2,6 +2,11 @@ import { defineConfig } from "vitest/config";
 import { playwright } from "@vitest/browser-playwright";
 import { fileURLToPath } from "node:url";
 
+// Embedded in the web client package, but rooted at the repo so the shared
+// (common) sources and specs are reachable. The node and web packages run the
+// common tests so the common code is exercised and shows up in coverage.
+const root = fileURLToPath(new URL("../..", import.meta.url));
+
 const browser = process.env.BROWSER ?? "chromium";
 if (browser !== "chromium" && browser !== "firefox" && browser !== "webkit") {
   throw new Error(
@@ -14,8 +19,6 @@ if (
   testMode !== "unit" &&
   testMode !== "integration" &&
   testMode !== "jwt" &&
-  testMode !== "common" &&
-  testMode !== "common-integration" &&
   testMode !== "all"
 ) {
   throw new Error(
@@ -57,13 +60,6 @@ const collections = {
     "packages/client-web/__tests__/integration/*.test.ts",
     "packages/client-web/__tests__/jwt/*.test.ts",
   ],
-  common: [
-    "packages/client-common/__tests__/unit/*.test.ts",
-    "packages/client-common/__tests__/utils/*.test.ts",
-  ],
-  "common-integration": [
-    "packages/client-common/__tests__/integration/*.test.ts",
-  ],
   all: [
     "packages/client-common/__tests__/unit/*.test.ts",
     "packages/client-common/__tests__/utils/*.test.ts",
@@ -75,6 +71,7 @@ const collections = {
 };
 
 export default defineConfig({
+  root,
   test: {
     // Increase maxWorkers to speed up integration tests
     // as we're not bound by the CPU here.
@@ -83,7 +80,7 @@ export default defineConfig({
     hookTimeout: 300_000,
     testTimeout: 300_000,
     slowTestThreshold: testMode === "unit" ? 10_000 : undefined,
-    setupFiles: ["vitest.web.setup.ts"],
+    setupFiles: ["packages/client-web/vitest.setup.ts"],
     include: collections[testMode],
     coverage: {
       enabled: process.env.VITEST_COVERAGE === "true",
@@ -124,15 +121,20 @@ export default defineConfig({
           process.env.VITEST_OTEL_ENABLED === "true" &&
           // not set in dependabot PRs
           !!process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
-        sdkPath: "./vitest.node.otel.js",
+        sdkPath: "./packages/client-node/vitest.otel.js",
         // According to testing, runners hang indefinitely when OTEL is enabled in browser tests,
         // and when they don't the exporter visibly slows the tests down (2x-5x).
         // Tests also crash (their iframe?) when the devtools are open in Chrome.
-        // browserSdkPath: './vitest.web.otel.js',
+        // browserSdkPath: './packages/client-web/vitest.otel.js',
       },
     },
     browser: {
       enabled: true,
+      // Run headless by default so the test runner never pops up a browser
+      // window (locally Vitest would otherwise launch a headed browser; it only
+      // defaults to headless in CI). Set BROWSER_HEADED=true to opt back into a
+      // visible browser, e.g. for debugging.
+      headless: process.env.BROWSER_HEADED !== "true",
       provider: playwright(),
       instances: [{ browser }],
     },
@@ -165,18 +167,18 @@ export default defineConfig({
             // intact, and common-origin symbols share the client's one bundle.
             "@clickhouse/client-common": "@clickhouse/client-web",
             "@test": fileURLToPath(
-              new URL("./packages/client-common/__tests__", import.meta.url),
+              new URL("packages/client-common/__tests__", `file://${root}/`),
             ),
           }
         : {
             "@clickhouse/client-common": fileURLToPath(
-              new URL("./packages/client-common/src", import.meta.url),
+              new URL("packages/client-common/src", `file://${root}/`),
             ),
             "@clickhouse/client-web": fileURLToPath(
-              new URL("./packages/client-web", import.meta.url),
+              new URL("packages/client-web", `file://${root}/`),
             ),
             "@test": fileURLToPath(
-              new URL("./packages/client-common/__tests__", import.meta.url),
+              new URL("packages/client-common/__tests__", `file://${root}/`),
             ),
           },
   },
diff --git a/vitest.web.otel.js b/packages/client-web/vitest.otel.js
similarity index 100%
rename from vitest.web.otel.js
rename to packages/client-web/vitest.otel.js
diff --git a/vitest.web.setup.ts b/packages/client-web/vitest.setup.ts
similarity index 100%
rename from vitest.web.setup.ts
rename to packages/client-web/vitest.setup.ts