diff --git a/.github/workflows/pr-testbox-windows.yml b/.github/workflows/pr-testbox-windows.yml
new file mode 100644
index 00000000000..5706db45c24
--- /dev/null
+++ b/.github/workflows/pr-testbox-windows.yml
@@ -0,0 +1,58 @@
+name: Blacksmith PR Testbox Windows
+
+on:
+  workflow_dispatch:
+    inputs:
+      testbox_id:
+        type: string
+        description: "Testbox session ID"
+        required: true
+
+permissions:
+  contents: read
+
+jobs:
+  pr-testbox-windows:
+    runs-on: blacksmith-4vcpu-windows-2025
+
+    steps:
+      - name: Begin Testbox
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        uses: useblacksmith/begin-testbox@233448af4bfdc6fca509a7f0974411ac6d8a8043 # v2
+        with:
+          testbox_id: ${{ inputs.testbox_id }}
+
+      - name: ⬇️ Checkout repo
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - name: ⎔ Setup pnpm
+        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5.0.0
+        with:
+          version: 10.33.2
+
+      - name: ⎔ Setup node
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: 20.20.2
+
+      - name: 📥 Download CLI deps
+        run: pnpm install --frozen-lockfile --filter trigger.dev...
+
+      - name: 📀 Generate Prisma Client
+        run: pnpm run generate
+
+      - name: 🔧 Build v3 cli monorepo dependencies
+        run: pnpm run build --filter trigger.dev^...
+
+      - name: 🔧 Build worker template files
+        run: pnpm --filter trigger.dev run --if-present build:workers
+
+      - name: Enable corepack
+        run: corepack enable
+
+      - name: Run Testbox
+        uses: useblacksmith/run-testbox@5ca05834db1d3813554d1dd109e5f2087a8d7cbc # v2
+        if: ${{ always() && github.event_name == 'workflow_dispatch' }}
diff --git a/.github/workflows/pr-testbox.yml b/.github/workflows/pr-testbox.yml
new file mode 100644
index 00000000000..32b0d6a28be
--- /dev/null
+++ b/.github/workflows/pr-testbox.yml
@@ -0,0 +1,127 @@
+name: Blacksmith PR Testbox
+
+on:
+  workflow_dispatch:
+    inputs:
+      testbox_id:
+        type: string
+        description: "Testbox session ID"
+        required: true
+
+permissions:
+  contents: read
+
+jobs:
+  pr-testbox:
+    runs-on: blacksmith-8vcpu-ubuntu-2404
+    env:
+      DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
+
+    steps:
+      - name: Begin Testbox
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        uses: useblacksmith/begin-testbox@233448af4bfdc6fca509a7f0974411ac6d8a8043 # v2
+        with:
+          testbox_id: ${{ inputs.testbox_id }}
+
+      - name: 🔧 Disable IPv6
+        run: |
+          sudo sysctl -w net.ipv6.conf.all.disable_ipv6=1
+          sudo sysctl -w net.ipv6.conf.default.disable_ipv6=1
+          sudo sysctl -w net.ipv6.conf.lo.disable_ipv6=1
+
+      - name: 🔧 Configure docker address pool
+        run: |
+          CONFIG='{
+            "default-address-pools" : [
+              {
+                "base" : "172.17.0.0/12",
+                "size" : 20
+              },
+              {
+                "base" : "192.168.0.0/16",
+                "size" : 24
+              }
+            ]
+          }'
+          sudo mkdir -p /etc/docker
+          echo "$CONFIG" | sudo tee /etc/docker/daemon.json
+
+      - name: 🔧 Restart docker daemon
+        run: sudo systemctl restart docker
+
+      - name: ⬇️ Checkout repo
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - name: ⎔ Setup pnpm
+        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5.0.0
+        with:
+          version: 10.33.2
+
+      - name: ⎔ Setup Node 22 for SDK compatibility checks
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: 22.12
+
+      - name: ⎔ Setup active Node 20
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6.4.0
+        with:
+          node-version: 20.20.2
+          cache: "pnpm"
+
+      - name: 🥟 Setup Bun
+        uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2.2.0
+        with:
+          bun-version: latest
+
+      - name: 🦕 Setup Deno
+        uses: denoland/setup-deno@667a34cdef165d8d2b2e98dde39547c9daac7282 # v2.0.4
+        with:
+          deno-version: v2.x
+
+      - name: 🐳 Login to DockerHub
+        if: ${{ env.DOCKERHUB_USERNAME }}
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee # v4.2.0
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: 🐳 Skipping DockerHub login (no secrets available)
+        if: ${{ !env.DOCKERHUB_USERNAME }}
+        run: echo "DockerHub login skipped because secrets are not available."
+
+      - name: 🐳 Pre-pull testcontainer images
+        if: ${{ env.DOCKERHUB_USERNAME }}
+        run: |
+          pull() {
+            for attempt in 1 2 3; do
+              docker pull "$1" && return 0
+              echo "::warning::docker pull $1 failed (attempt ${attempt}/3); retrying in 10s"
+              sleep 10
+            done
+            echo "::error::docker pull $1 failed after 3 attempts"
+            return 1
+          }
+
+          echo "Pre-pulling Docker images with authenticated session..."
+          pull postgres:14
+          pull clickhouse/clickhouse-server:26.2.19.43-alpine@sha256:c6ad6a7eb2fb5999df3adfb8b69a0c7222c68fa9b8f6b04a088564ebbc959251
+          pull redis:7.2
+          pull testcontainers/ryuk:0.11.0
+          pull testcontainers/ryuk:0.14.0
+          pull electricsql/electric:1.2.4
+          pull minio/minio:latest
+          echo "Image pre-pull complete"
+
+      - name: 📥 Download deps
+        run: pnpm install --frozen-lockfile
+
+      - name: 📀 Generate Prisma Client
+        run: pnpm run generate
+
+      - name: Run Testbox
+        uses: useblacksmith/run-testbox@5ca05834db1d3813554d1dd109e5f2087a8d7cbc # v2
+        if: ${{ always() && github.event_name == 'workflow_dispatch' }}
diff --git a/scripts/blacksmith.md b/scripts/blacksmith.md
new file mode 100644
index 00000000000..691e930edba
--- /dev/null
+++ b/scripts/blacksmith.md
@@ -0,0 +1,63 @@
+# Blacksmith Testboxes
+
+Use Testboxes to validate changes in CI-like runners instead of running tests locally.
+
+Always run `blacksmith testbox` commands from the repository root:
+
+```bash
+cd "$(git rev-parse --show-toplevel)"
+```
+
+## PR checks Testbox
+
+The Linux PR Testbox covers the normal Linux PR checks: format, lint, typecheck, exports, unit test shards, webapp e2e, Linux CLI e2e, and SDK compatibility checks.
+
+Warm it up:
+
+```bash
+blacksmith testbox warmup pr-testbox.yml --idle-timeout 60
+```
+
+Run the PR checks against your current working tree:
+
+```bash
+blacksmith testbox run --id <linux-testbox-id> "scripts/test-pr-check.sh"
+```
+
+## Windows PR checks Testbox
+
+The Windows PR Testbox covers the Windows CLI v3 e2e matrix row.
+
+Warm it up:
+
+```bash
+blacksmith testbox warmup pr-testbox-windows.yml --idle-timeout 60
+```
+
+Run the Windows checks against your current working tree:
+
+```bash
+blacksmith testbox run --id <windows-testbox-id> "pwsh -NoProfile -ExecutionPolicy Bypass -File scripts/test-pr-check-windows.ps1"
+```
+
+## Running both
+
+```bash
+linux_id=<linux-testbox-id>
+windows_id=<windows-testbox-id>
+
+blacksmith testbox run --id "$linux_id" "scripts/test-pr-check.sh"
+blacksmith testbox run --id "$windows_id" "pwsh -NoProfile -ExecutionPolicy Bypass -File scripts/test-pr-check-windows.ps1"
+```
+
+## Notes
+
+- The workflow files must be merged before GitHub can dispatch them via `workflow_dispatch`.
+- `blacksmith testbox run` syncs your local tracked and unignored files before running the command.
+- If you change dependency manifests, the scripts run `pnpm install` again inside the Testbox.
+- The Linux Testbox intentionally does not cover the Windows CLI row; use the Windows Testbox for that.
+- Stop Testboxes when you are finished:
+
+```bash
+blacksmith testbox stop --id <testbox-id>
+```
diff --git a/scripts/test-pr-check-windows.ps1 b/scripts/test-pr-check-windows.ps1
new file mode 100644
index 00000000000..79948177815
--- /dev/null
+++ b/scripts/test-pr-check-windows.ps1
@@ -0,0 +1,74 @@
+$ErrorActionPreference = "Stop"
+
+Set-Location (git rev-parse --show-toplevel)
+
+function Start-Section {
+  param([Parameter(Mandatory = $true)][string]$Title)
+
+  Write-Host ""
+  Write-Host "::group::$Title"
+}
+
+function Stop-Section {
+  Write-Host "::endgroup::"
+}
+
+function Invoke-Native {
+  param(
+    [Parameter(Mandatory = $true)][string]$Command,
+    [Parameter(ValueFromRemainingArguments = $true)][string[]]$Arguments
+  )
+
+  & $Command @Arguments
+  if ($LASTEXITCODE -ne 0) {
+    throw "Command failed with exit code ${LASTEXITCODE}: $Command $($Arguments -join ' ')"
+  }
+}
+
+function Invoke-Section {
+  param(
+    [Parameter(Mandatory = $true)][string]$Title,
+    [Parameter(Mandatory = $true)][scriptblock]$ScriptBlock
+  )
+
+  Start-Section $Title
+  try {
+    & $ScriptBlock
+  } finally {
+    Stop-Section
+  }
+}
+
+Invoke-Section "Install CLI dependencies" {
+  Invoke-Native pnpm install --frozen-lockfile --filter trigger.dev...
+}
+
+Invoke-Section "Generate Prisma client" {
+  Invoke-Native pnpm run generate
+}
+
+Invoke-Section "Build CLI monorepo dependencies" {
+  Invoke-Native pnpm run build --filter trigger.dev^...
+}
+
+Invoke-Section "Build worker template files" {
+  Invoke-Native pnpm --filter trigger.dev run --if-present build:workers
+}
+
+Invoke-Section "Enable corepack" {
+  Invoke-Native corepack enable
+}
+
+Invoke-Section "CLI v3 E2E tests (npm)" {
+  $env:LOG = "debug"
+  $env:PM = "npm"
+  Invoke-Native pnpm --filter trigger.dev run test:e2e
+}
+
+Invoke-Section "CLI v3 E2E tests (pnpm)" {
+  $env:LOG = "debug"
+  $env:PM = "pnpm"
+  Invoke-Native pnpm --filter trigger.dev run test:e2e
+}
+
+Write-Host "Windows PR checks completed."
diff --git a/scripts/test-pr-check.sh b/scripts/test-pr-check.sh
new file mode 100755
index 00000000000..7ea105e2f92
--- /dev/null
+++ b/scripts/test-pr-check.sh
@@ -0,0 +1,171 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd "$(git rev-parse --show-toplevel)"
+
+section() {
+  local title="$1"
+  echo ""
+  echo "::group::${title}"
+}
+
+end_section() {
+  echo "::endgroup::"
+}
+
+run_section() {
+  local title="$1"
+  shift
+  section "$title"
+
+  local status=0
+  if bash -euo pipefail -c '"$@"' bash "$@"; then
+    status=0
+  else
+    status=$?
+  fi
+
+  end_section
+  return "${status}"
+}
+
+find_node_bin() {
+  local version_prefix="$1"
+
+  if [[ ! -d /opt/hostedtoolcache/node ]]; then
+    return 0
+  fi
+
+  find /opt/hostedtoolcache/node -maxdepth 3 -type d -path "*/${version_prefix}*/x64/bin" 2>/dev/null | sort -V | tail -n 1
+}
+
+with_node() {
+  local node_bin="$1"
+  shift
+
+  if [[ -n "${node_bin}" ]]; then
+    PATH="${node_bin}:${PATH}" "$@"
+  else
+    "$@"
+  fi
+}
+
+run_webapp_unit_tests() {
+  for shard in {1..10}; do
+    echo "Running webapp unit test shard ${shard}/10"
+    SHARD_INDEX="${shard}" SHARD_TOTAL="10" pnpm run test:webapp --reporter=default --shard="${shard}/10" --passWithNoTests
+  done
+}
+
+run_package_unit_tests() {
+  for shard in {1..3}; do
+    echo "Running package unit test shard ${shard}/3"
+    SHARD_INDEX="${shard}" SHARD_TOTAL="3" pnpm run test:packages --reporter=default --shard="${shard}/3" --passWithNoTests
+  done
+}
+
+run_internal_unit_tests() {
+  for shard in {1..12}; do
+    echo "Running internal unit test shard ${shard}/12"
+    SHARD_INDEX="${shard}" SHARD_TOTAL="12" pnpm run test:internal --reporter=default --shard="${shard}/12" --passWithNoTests
+  done
+}
+
+run_webapp_e2e_tests() {
+  pnpm run build --filter webapp
+  (cd apps/webapp && WEBAPP_TEST_VERBOSE="1" pnpm exec vitest run --config vitest.e2e.config.ts --reporter=default)
+}
+
+run_cli_e2e_tests() {
+  pnpm run build --filter trigger.dev^...
+  pnpm --filter trigger.dev run --if-present build:workers
+  corepack enable
+
+  LOG=debug PM=npm pnpm --filter trigger.dev run test:e2e
+  LOG=debug PM=pnpm pnpm --filter trigger.dev run test:e2e
+
+  echo "Skipped the PR workflow's Windows CLI matrix row; this Testbox is Linux only."
+}
+
+run_sdk_node_compat_tests() {
+  local node_bin="$1"
+  local label="$2"
+
+  with_node "${node_bin}" node --version
+  with_node "${node_bin}" pnpm install --frozen-lockfile
+  with_node "${node_bin}" pnpm run generate
+  with_node "${node_bin}" pnpm run build --filter '@trigger.dev/sdk^...'
+  with_node "${node_bin}" pnpm run build --filter '@trigger.dev/sdk'
+  with_node "${node_bin}" pnpm --filter @internal/sdk-compat-tests test
+
+  echo "Completed SDK Node compatibility checks for ${label}."
+}
+
+run_sdk_runtime_compat_tests() {
+  local node20_bin="$1"
+
+  with_node "${node20_bin}" pnpm run build --filter '@trigger.dev/sdk^...'
+  with_node "${node20_bin}" pnpm run build --filter '@trigger.dev/sdk'
+
+  (cd internal-packages/sdk-compat-tests/src/fixtures/bun && bun run test.ts)
+
+  (
+    cd internal-packages/sdk-compat-tests/src/fixtures/deno
+    if [[ ! -e node_modules && ! -L node_modules ]]; then
+      ln -s ../../../../../node_modules node_modules
+    fi
+    deno run --allow-read --allow-env --allow-sys test.ts
+  )
+
+  (
+    cd internal-packages/sdk-compat-tests/src/fixtures/cloudflare-worker
+    pnpm install
+    npx wrangler deploy --dry-run --outdir dist
+  )
+}
+
+export -f find_node_bin
+export -f with_node
+export -f run_webapp_unit_tests
+export -f run_package_unit_tests
+export -f run_internal_unit_tests
+export -f run_webapp_e2e_tests
+export -f run_cli_e2e_tests
+export -f run_sdk_node_compat_tests
+export -f run_sdk_runtime_compat_tests
+
+export DATABASE_URL="${DATABASE_URL:-postgresql://postgres:postgres@localhost:5432/postgres}"
+export DIRECT_URL="${DIRECT_URL:-postgresql://postgres:postgres@localhost:5432/postgres}"
+export SESSION_SECRET="${SESSION_SECRET:-secret}"
+export MAGIC_LINK_SECRET="${MAGIC_LINK_SECRET:-secret}"
+export ENCRYPTION_KEY="${ENCRYPTION_KEY:-dummy-encryption-keeeey-32-bytes}"
+export DEPLOY_REGISTRY_HOST="${DEPLOY_REGISTRY_HOST:-docker.io}"
+export CLICKHOUSE_URL="${CLICKHOUSE_URL:-http://default:password@localhost:8123}"
+export NODE_OPTIONS="${NODE_OPTIONS:---max-old-space-size=8192}"
+
+NODE20_BIN="${NODE20_BIN:-$(find_node_bin 20.20)}"
+NODE22_BIN="${NODE22_BIN:-$(find_node_bin 22.12)}"
+
+run_section "Install dependencies" pnpm install --frozen-lockfile
+run_section "Generate Prisma client" pnpm run generate
+
+run_section "Format check" pnpm exec oxfmt --check .
+run_section "Lint" pnpm exec oxlint .
+run_section "Typecheck" pnpm run typecheck
+run_section "Check exports" pnpm run check-exports
+
+run_section "Webapp unit tests" run_webapp_unit_tests
+run_section "Package unit tests" run_package_unit_tests
+run_section "Internal unit tests" run_internal_unit_tests
+run_section "Webapp E2E tests" run_webapp_e2e_tests
+run_section "CLI v3 E2E tests" run_cli_e2e_tests
+
+run_section "SDK Node 20 compatibility tests" run_sdk_node_compat_tests "${NODE20_BIN}" "Node 20.20"
+if [[ -n "${NODE22_BIN}" ]]; then
+  run_section "SDK Node 22 compatibility tests" run_sdk_node_compat_tests "${NODE22_BIN}" "Node 22.12"
+else
+  echo "::warning::Node 22.12 was not found in /opt/hostedtoolcache; skipping SDK Node 22 compatibility tests."
+fi
+run_section "SDK Bun/Deno/Cloudflare compatibility tests" run_sdk_runtime_compat_tests "${NODE20_BIN}"
+
+echo "All Linux PR checks completed."