diff --git a/CHANGELOG.md b/CHANGELOG.md
index 49f9f1a..f368c3b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixed
+
+- Install built-in Svelte, Solid, and Tailwind runtimes from package-owned npm_ex lockfiles, and include each lock digest in the named runtime signature.
+
 ## 0.17.10 - 2026-07-17
 
 ### Added
diff --git a/lib/volt/js/runtime.ex b/lib/volt/js/runtime.ex
index c9274b4..3a50936 100644
--- a/lib/volt/js/runtime.ex
+++ b/lib/volt/js/runtime.ex
@@ -267,12 +267,24 @@ defmodule Volt.JS.Runtime do
 
   defp runtime_signature(opts) do
     opts
-    |> Keyword.take([:packages, :install_dir, :entry, :bundle])
+    |> Keyword.take([:packages, :install_dir, :entry, :bundle, :lockfile])
+    |> digest_lockfile()
     |> Enum.sort()
     |> :erlang.term_to_binary()
     |> :erlang.md5()
   end
 
+  defp digest_lockfile(opts) do
+    case Keyword.fetch(opts, :lockfile) do
+      {:ok, path} when is_binary(path) ->
+        digest = path |> File.read!() |> then(&:crypto.hash(:sha256, &1))
+        Keyword.put(opts, :lockfile, {:sha256, digest})
+
+      _ ->
+        opts
+    end
+  end
+
   defp maybe_put(opts, _key, nil), do: opts
   defp maybe_put(opts, key, value), do: Keyword.put(opts, key, value)
 end
diff --git a/lib/volt/js/runtime/package_set.ex b/lib/volt/js/runtime/package_set.ex
new file mode 100644
index 0000000..ad690d9
--- /dev/null
+++ b/lib/volt/js/runtime/package_set.ex
@@ -0,0 +1,43 @@
+defmodule Volt.JS.Runtime.PackageSet do
+  @moduledoc false
+
+  alias Volt.JS.Runtime.Installer
+
+  @enforce_keys [:app, :name, :packages]
+  defstruct [:app, :name, :packages]
+
+  @type t :: %__MODULE__{
+          app: atom(),
+          name: atom(),
+          packages: %{required(String.t()) => String.t()}
+        }
+
+  @spec bundled(atom(), atom(), map()) :: t()
+  def bundled(app, name, packages)
+      when is_atom(app) and is_atom(name) and is_map(packages) do
+    %__MODULE__{app: app, name: name, packages: packages}
+  end
+
+  @spec install!(t(), keyword()) :: %{install_dir: String.t(), node_modules: String.t()}
+  def install!(%__MODULE__{} = set, opts \\ []) do
+    Installer.install!(set.packages, lock_opts(set, opts))
+  end
+
+  @spec runtime_opts(t(), keyword()) :: keyword()
+  def runtime_opts(%__MODULE__{} = set, opts \\ []) do
+    set
+    |> lock_opts(opts)
+    |> Keyword.put(:packages, set.packages)
+  end
+
+  @spec lockfile_path(t()) :: String.t()
+  def lockfile_path(%__MODULE__{app: app, name: name}) do
+    Volt.Priv.path({app, "npm"}, "#{name}.lock")
+  end
+
+  defp lock_opts(set, opts) do
+    opts
+    |> Keyword.delete(:packages)
+    |> Keyword.put(:lockfile, lockfile_path(set))
+  end
+end
diff --git a/lib/volt/plugin/solid.ex b/lib/volt/plugin/solid.ex
index 509d06c..91162f8 100644
--- a/lib/volt/plugin/solid.ex
+++ b/lib/volt/plugin/solid.ex
@@ -11,10 +11,13 @@ defmodule Volt.Plugin.Solid do
 
   @behaviour Volt.Plugin
 
+  alias Volt.JS.Runtime.PackageSet
+
   @runtime_packages %{
-    "@babel/standalone" => "^7.0.0",
-    "babel-preset-solid" => "^1.9.0"
+    "@babel/standalone" => "7.29.8",
+    "babel-preset-solid" => "1.9.12"
   }
+  @runtime_package_set PackageSet.bundled(:volt, :solid, @runtime_packages)
 
   @runtime_name __MODULE__.Runtime
   @jsx_exts ~w(.jsx .tsx)
@@ -61,12 +64,13 @@ defmodule Volt.Plugin.Solid do
   def prebundle_entry(_specifier), do: nil
 
   def runtime_packages, do: @runtime_packages
+  def runtime_package_set, do: @runtime_package_set
 
   defp do_compile(source, filename, opts, plugin_opts) do
     runtime =
-      Volt.JS.Runtime.ensure!(
+      PackageSet.runtime_opts(
+        @runtime_package_set,
         name: @runtime_name,
-        packages: @runtime_packages,
         apis: [:browser, :node],
         entry: {:volt_asset, "compilers/solid.ts"},
         bundle: true,
@@ -75,6 +79,7 @@ defmodule Volt.Plugin.Solid do
         ],
         max_stack_size: 32 * 1024 * 1024
       )
+      |> Volt.JS.Runtime.ensure!()
 
     compile_options =
       filename
diff --git a/lib/volt/plugin/svelte.ex b/lib/volt/plugin/svelte.ex
index a5e8cbe..d3d5cb2 100644
--- a/lib/volt/plugin/svelte.ex
+++ b/lib/volt/plugin/svelte.ex
@@ -5,7 +5,10 @@ defmodule Volt.Plugin.Svelte do
 
   @behaviour Volt.Plugin
 
-  @runtime_packages %{"svelte" => "^5.0.0"}
+  alias Volt.JS.Runtime.PackageSet
+
+  @runtime_packages %{"svelte" => "5.56.8"}
+  @runtime_package_set PackageSet.bundled(:volt, :svelte, @runtime_packages)
   @runtime_name __MODULE__.Runtime
   @resolve_extensions Volt.JS.Extensions.node_resolvable()
 
@@ -37,7 +40,7 @@ defmodule Volt.Plugin.Svelte do
   def resolve(_, _), do: nil
 
   defp resolve_svelte(specifier, _importer) do
-    install = Volt.JS.Runtime.Installer.install!(@runtime_packages)
+    install = PackageSet.install!(@runtime_package_set)
 
     case NPM.Resolution.PackageResolver.resolve(specifier, install.install_dir,
            extensions: @resolve_extensions,
@@ -77,17 +80,19 @@ defmodule Volt.Plugin.Svelte do
   end
 
   def runtime_packages, do: @runtime_packages
+  def runtime_package_set, do: @runtime_package_set
 
   defp do_compile(path, source, opts, plugin_opts) do
     runtime =
-      Volt.JS.Runtime.ensure!(
+      PackageSet.runtime_opts(
+        @runtime_package_set,
         name: @runtime_name,
-        packages: @runtime_packages,
         apis: [:browser, :node],
         entry: {:volt_asset, "compilers/svelte.ts"},
         bundle: true,
         max_stack_size: 16 * 1024 * 1024
       )
+      |> Volt.JS.Runtime.ensure!()
 
     compile_options =
       path
diff --git a/lib/volt/tailwind.ex b/lib/volt/tailwind.ex
index 2339fbc..d162271 100644
--- a/lib/volt/tailwind.ex
+++ b/lib/volt/tailwind.ex
@@ -76,8 +76,8 @@ defmodule Volt.Tailwind do
 
   defp ensure_runtime(%{runtime: nil} = state) do
     runtime =
-      Volt.JS.Runtime.ensure!(
-        packages: Volt.Tailwind.Loader.runtime_packages(),
+      Volt.JS.Runtime.PackageSet.runtime_opts(
+        Volt.Tailwind.Loader.runtime_package_set(),
         apis: [:browser, :node],
         handlers: fn runtime -> Volt.Tailwind.Loader.handlers(runtime.node_modules) end,
         define: fn runtime ->
@@ -88,6 +88,7 @@ defmodule Volt.Tailwind do
         end,
         entry: {:volt_asset, "compilers/tailwind.ts"}
       )
+      |> Volt.JS.Runtime.ensure!()
 
     %{state | runtime: runtime, scanner: build_scanner(state.sources)}
   end
diff --git a/lib/volt/tailwind/loader.ex b/lib/volt/tailwind/loader.ex
index 7b211a1..2a8a723 100644
--- a/lib/volt/tailwind/loader.ex
+++ b/lib/volt/tailwind/loader.ex
@@ -1,16 +1,18 @@
 defmodule Volt.Tailwind.Loader do
   @moduledoc "Handles Tailwind module loading, prebundling CJS graphs via OXC, and stylesheet resolution."
 
+  alias Volt.JS.Runtime.PackageSet
   alias Volt.JS.Transforms.Specifiers
   alias Volt.Tailwind.Resolver
 
-  @tailwind_install_spec "^4.3.0"
   @tailwind_runtime_deps %{
-    "tailwindcss" => @tailwind_install_spec,
-    "@tailwindcss/typography" => "*"
+    "tailwindcss" => "4.3.3",
+    "@tailwindcss/typography" => "0.5.20"
   }
+  @runtime_package_set PackageSet.bundled(:volt, :tailwind, @tailwind_runtime_deps)
 
   def runtime_packages, do: @tailwind_runtime_deps
+  def runtime_package_set, do: @runtime_package_set
 
   def handlers(runtime_node_modules) do
     %{
diff --git a/priv/npm/solid.lock b/priv/npm/solid.lock
new file mode 100644
index 0000000..97ce82f
--- /dev/null
+++ b/priv/npm/solid.lock
@@ -0,0 +1,126 @@
+{
+  "lockfileVersion": 1,
+  "packages": {
+    "@babel/helper-module-imports": {
+      "dependencies": {
+        "@babel/types": "^7.18.6"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-0NFvs3VkuSYbFi1x2Vd6tKrywq+z/cLeYC/RJNFrIX/30Bf5aiGYbtvGXolEktzJH8o5E5KJ3tT+nkxuuZFVlA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/helper-module-imports/-/helper-module-imports-7.18.6.tgz",
+      "version": "7.18.6"
+    },
+    "@babel/helper-plugin-utils": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-G7sHYigPY17oO5SYWnfD/0MTBwVR781S/JI643e/JhUYgVgWE/61SoW3NH9KWUKyKq5LVh3npif99Wkt6j86Jw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.29.7.tgz",
+      "version": "7.29.7"
+    },
+    "@babel/helper-string-parser": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-Pb5ijPrZ89GDH8223L4UP8i6QApWxs04RbPQJTeWDV0/keR2E36MeKnyr6LYmUUvqRRI+Iv87SuF1W6ErINzYw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/helper-string-parser/-/helper-string-parser-7.29.7.tgz",
+      "version": "7.29.7"
+    },
+    "@babel/helper-validator-identifier": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-qehxGkRj55h/ff8EMaJ+cYhyaKlHIxqYDn682wQD7RNp9UujOQsHog2uS0r2vzr4pW+sXf90NeeayjcNaX3fFg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/helper-validator-identifier/-/helper-validator-identifier-7.29.7.tgz",
+      "version": "7.29.7"
+    },
+    "@babel/plugin-syntax-jsx": {
+      "dependencies": {
+        "@babel/helper-plugin-utils": "^7.29.7"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-TSu8+mHCoEaaCDEZ0I3+6mvTBYR4PCxQwf2z9/r5Tbztv6NaLR3B9thGTTxX2WGuGHJqRiAbKPeGTJ5XWXVg6A==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/plugin-syntax-jsx/-/plugin-syntax-jsx-7.29.7.tgz",
+      "version": "7.29.7"
+    },
+    "@babel/standalone": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-XgbPNz+u6JzB7cKGnPDoS1U24J5td8yp3HFWbT/6f4/ASZ0PqaQGIvts1o5v5AI+f6i3jdVB/L/o2CYLCv101A==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/standalone/-/standalone-7.29.8.tgz",
+      "version": "7.29.8"
+    },
+    "@babel/types": {
+      "dependencies": {
+        "@babel/helper-string-parser": "^7.29.7",
+        "@babel/helper-validator-identifier": "^7.29.7"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-Vj1jF3cPfxg7OAfoI7QnVKLoILlm2JF9pnVHrX8qx7AHMiYWT+NDAA7jChlNgRS4WTLc/fD1lXLmPixluj+3Gg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@babel/types/-/types-7.29.8.tgz",
+      "version": "7.29.8"
+    },
+    "babel-plugin-jsx-dom-expressions": {
+      "dependencies": {
+        "@babel/helper-module-imports": "7.18.6",
+        "@babel/plugin-syntax-jsx": "^7.18.6",
+        "@babel/types": "^7.20.7",
+        "html-entities": "2.3.3",
+        "parse5": "^7.1.2"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-/O6JWUmjv03OI9lL2ry9bUjpD5S3PclM55RRJEyCdcFZ5W2SEA/59d+l2hNsk3gI6kiWRdRPdOtqZmsQzFN1pQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/babel-plugin-jsx-dom-expressions/-/babel-plugin-jsx-dom-expressions-0.40.7.tgz",
+      "version": "0.40.7"
+    },
+    "babel-preset-solid": {
+      "dependencies": {
+        "babel-plugin-jsx-dom-expressions": "^0.40.6"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-LLqnuKVDlKpyBlMPcH6qEvs/wmS9a+NczppxJ3ryS/c0O5IiSFOIBQi9GzyiGDSbcJpx4Gr87jyFTos1MyEuWg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/babel-preset-solid/-/babel-preset-solid-1.9.12.tgz",
+      "version": "1.9.12"
+    },
+    "entities": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-aN97NXWF6AWBTahfVOIrB/NShkzi5H7F9r1s9mD3cDj4Ko5f2qhhVoYMibXF7GlLveb/D2ioWay8lxI97Ven3g==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/entities/-/entities-6.0.1.tgz",
+      "version": "6.0.1"
+    },
+    "html-entities": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-DV5Ln36z34NNTDgnz0EWGBLZENelNAtkiFA4kyNOG2tDI6Mz1uSWiq1wAKdyjnJwyDiDO7Fa2SO1CTxPXL8VxA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/html-entities/-/html-entities-2.3.3.tgz",
+      "version": "2.3.3"
+    },
+    "parse5": {
+      "dependencies": {
+        "entities": "^6.0.0"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-IInvU7fabl34qmi9gY8XOVxhYyMyuH2xUNpb2q8/Y+7552KlejkRvqvD19nMoUW/uQGGbqNpA6Tufu5FL5BZgw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/parse5/-/parse5-7.3.0.tgz",
+      "version": "7.3.0"
+    }
+  },
+  "policy": {
+    "allow_registry_redirects": false,
+    "allowed_registries": [
+      "https://registry.npmjs.org"
+    ],
+    "block_exotic_subdeps": true,
+    "exotic_deps": []
+  }
+}
diff --git a/priv/npm/svelte.lock b/priv/npm/svelte.lock
new file mode 100644
index 0000000..78620ec
--- /dev/null
+++ b/priv/npm/svelte.lock
@@ -0,0 +1,205 @@
+{
+  "lockfileVersion": 1,
+  "packages": {
+    "@jridgewell/gen-mapping": {
+      "dependencies": {
+        "@jridgewell/sourcemap-codec": "^1.5.0",
+        "@jridgewell/trace-mapping": "^0.3.24"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-2kkt/7niJ6MgEPxF0bYdQ6etZaA+fQvDcLKckhy1yIQOzaoKjBBjSj63/aLVjYE3qhRt5dvM+uUyfCg6UKCBbA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.13.tgz",
+      "version": "0.3.13"
+    },
+    "@jridgewell/remapping": {
+      "dependencies": {
+        "@jridgewell/gen-mapping": "^0.3.5",
+        "@jridgewell/trace-mapping": "^0.3.24"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-LI9u/+laYG4Ds1TDKSJW2YPrIlcVYOwi2fUC6xB43lueCjgxV4lffOCZCtYFiH6TNOX+tQKXx97T4IKHbhyHEQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@jridgewell/remapping/-/remapping-2.3.5.tgz",
+      "version": "2.3.5"
+    },
+    "@jridgewell/resolve-uri": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-bRISgCIjP20/tbWSPWMEi54QVPRZExkuD9lJL+UIxUKtwVJA8wW1Trb1jMs1RFXo1CBTNZ/5hpC9QvmKWdopKw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.1.2.tgz",
+      "version": "3.1.2"
+    },
+    "@jridgewell/sourcemap-codec": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-cYQ9310grqxueWbl+WuIUIaiUaDcj7WOq5fVhEljNVgRfOUhY9fy2zTvfoqWsnebh8Sl70VScFbICvJnLKB0Og==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.5.5.tgz",
+      "version": "1.5.5"
+    },
+    "@jridgewell/trace-mapping": {
+      "dependencies": {
+        "@jridgewell/resolve-uri": "^3.1.0",
+        "@jridgewell/sourcemap-codec": "^1.4.14"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-zzNR+SdQSDJzc8joaeP8QQoCQr8NuYx2dIIytl1QeBEZHJ9uW6hebsrYgbz8hJwUQao3TWCMtmfV8Nu1twOLAw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@jridgewell/trace-mapping/-/trace-mapping-0.3.31.tgz",
+      "version": "0.3.31"
+    },
+    "@sveltejs/acorn-typescript": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-J1jNYG23QWd67UfrQSFHtjhV37r9mVi0gdc12A3MWPldOjRK35Xk+um+qACPVjgw3AleiqoyEAhok8Wm3q46NA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@sveltejs/acorn-typescript/-/acorn-typescript-1.0.12.tgz",
+      "version": "1.0.12"
+    },
+    "@types/estree": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-GhdPgy1el4/ImP05X05Uw4cw2/M93BCUmnEvWZNStlCzEKME4Fkk+YpoA5OiHNQmoS7Cafb8Xa3Pya8m1Qrzeg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
+      "version": "1.0.9"
+    },
+    "@types/trusted-types": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@types/trusted-types/-/trusted-types-2.0.7.tgz",
+      "version": "2.0.7"
+    },
+    "acorn": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-lGq+9yr1/GuAWaVYIHRjvvySG5/4VfKIvC8EWxStPdcDh/Ka7FG3twP6v4d5BkravUilhIAsG4Qj83t02LWUPQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/acorn/-/acorn-8.18.0.tgz",
+      "version": "8.18.0"
+    },
+    "aria-query": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-Z/ZeOgVl7bcSYZ/u/rh0fOpvEpq//LZmdbkXyc7syVzjPAhfOa9ebsdTSjEBDU4vs5nC98Kfduj1uFo0qyET3g==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/aria-query/-/aria-query-5.3.1.tgz",
+      "version": "5.3.1"
+    },
+    "axobject-query": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-qIj0G9wZbMGNLjLmg1PT6v2mE9AH2zlnADJD/2tC6E00hgmhUOfEB6greHPAfLRSufHqROIUTkw6E+M3lH0PTQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/axobject-query/-/axobject-query-4.1.0.tgz",
+      "version": "4.1.0"
+    },
+    "clsx": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-eYm0QWBtUrBWZWG0d386OGAw16Z995PiOVo2B7bjWSbHedGl5e0ZWaq65kOGgUSNesEIDkB9ISbTg/JK9dhCZA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/clsx/-/clsx-2.1.1.tgz",
+      "version": "2.1.1"
+    },
+    "devalue": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-RWrqdArjvPbsATEhOPUo6Wndc/iWnkWKlhIrdlF3zMMYo/c3CVtoaVAyLtWxz5h8nSlkHzxnzV2uLydPXmtF+A==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/devalue/-/devalue-5.9.0.tgz",
+      "version": "5.9.0"
+    },
+    "esm-env": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-Epxrv+Nr/CaL4ZcFGPJIYLWFom+YeV1DqMLHJoEd9SYRxNbaFruBwfEX/kkHUJf55j2+TUbmDcmuilbP1TmXHA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/esm-env/-/esm-env-1.2.2.tgz",
+      "version": "1.2.2"
+    },
+    "esrap": {
+      "dependencies": {
+        "@jridgewell/sourcemap-codec": "^1.4.15"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-40GyiEJevYKXzYTHtZkFqAgTjLOuFcaXMao8TPyOlnWTlkHDlvZ6mPMJaJyOqVwrVCgomEG1WhJd81w0X+IcCw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/esrap/-/esrap-2.3.2.tgz",
+      "version": "2.3.2"
+    },
+    "is-reference": {
+      "dependencies": {
+        "@types/estree": "^1.0.6"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-ixkJoqQvAP88E6wLydLGGqCJsrFUnqoH6HnaczB8XmDH1oaWU+xxdptvikTgaEhtZ53Ky6YXiBuUI2WXLMCwjw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/is-reference/-/is-reference-3.0.3.tgz",
+      "version": "3.0.3"
+    },
+    "locate-character": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-SW13ws7BjaeJ6p7Q6CO2nchbYEc3X3J6WrmTTDto7yMPqVSZTUyY5Tjbid+Ab8gLnATtygYtiDIJGQRRn2ZOiA==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/locate-character/-/locate-character-3.0.0.tgz",
+      "version": "3.0.0"
+    },
+    "magic-string": {
+      "dependencies": {
+        "@jridgewell/sourcemap-codec": "^1.5.5"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
+      "version": "0.30.21"
+    },
+    "svelte": {
+      "dependencies": {
+        "@jridgewell/remapping": "^2.3.4",
+        "@jridgewell/sourcemap-codec": "^1.5.0",
+        "@sveltejs/acorn-typescript": "^1.0.10",
+        "@types/estree": "^1.0.5",
+        "@types/trusted-types": "^2.0.7",
+        "acorn": "^8.12.1",
+        "aria-query": "5.3.1",
+        "axobject-query": "^4.1.0",
+        "clsx": "^2.1.1",
+        "devalue": "^5.8.1",
+        "esm-env": "^1.2.1",
+        "esrap": "^2.2.12",
+        "is-reference": "^3.0.3",
+        "locate-character": "^3.0.0",
+        "magic-string": "^0.30.11",
+        "zimmerframe": "^1.1.2"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-PY8LOw7xP6c8IOiVqdo0sbbZVYhXRSfklOQLAUyGBKqjTX0wx/z4l/9J+PmBpmlLnxzEb1NqltxQ5/wZme/Cmg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/svelte/-/svelte-5.56.8.tgz",
+      "version": "5.56.8"
+    },
+    "zimmerframe": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-B58NGBEoc8Y9MWWCQGl/gq9xBCe4IiKM0a2x7GZdQKOW5Exr8S1W24J6OgM1njK8xCRGvAJIL/MxXHf6SkmQKQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/zimmerframe/-/zimmerframe-1.1.4.tgz",
+      "version": "1.1.4"
+    }
+  },
+  "policy": {
+    "allow_registry_redirects": false,
+    "allowed_registries": [
+      "https://registry.npmjs.org"
+    ],
+    "block_exotic_subdeps": true,
+    "exotic_deps": []
+  }
+}
diff --git a/priv/npm/tailwind.lock b/priv/npm/tailwind.lock
new file mode 100644
index 0000000..0f67f46
--- /dev/null
+++ b/priv/npm/tailwind.lock
@@ -0,0 +1,58 @@
+{
+  "lockfileVersion": 1,
+  "packages": {
+    "@tailwindcss/typography": {
+      "dependencies": {
+        "postcss-selector-parser": "6.0.10"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-hwbzQuNUfcPvbegQFatVPl/MY/tcM9KLl963hQ5laJKPh81TEZ1+dNG9PirGvcaDBkp+BCshExAyKVPW91dozw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/@tailwindcss/typography/-/typography-0.5.20.tgz",
+      "version": "0.5.20"
+    },
+    "cssesc": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-/Tb/JcjK111nNScGob5MNtsntNM1aCNUDipB/TkwZFhyDrrE47SOx/18wF2bbjgc3ZzCSKW1T5nt5EbFoAz/Vg==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/cssesc/-/cssesc-3.0.0.tgz",
+      "version": "3.0.0"
+    },
+    "postcss-selector-parser": {
+      "dependencies": {
+        "cssesc": "^3.0.0",
+        "util-deprecate": "^1.0.2"
+      },
+      "has_install_script": false,
+      "integrity": "sha512-IQ7TZdoaqbT+LCpShg46jnZVlhWD2w6iQYAcYXfHARZ7X1t/UGhhceQDs5X0cGqKvYlHNOuv7Oa1xmb0oQuA3w==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/postcss-selector-parser/-/postcss-selector-parser-6.0.10.tgz",
+      "version": "6.0.10"
+    },
+    "tailwindcss": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-gOhV3P7ufE62QDGg1zVaTgCR+EtPv92k2nIhVcVKcLmxT1sUBsQGhnZj175j+MqRt4zLF7ic+sCYjfhxMxj7YQ==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-4.3.3.tgz",
+      "version": "4.3.3"
+    },
+    "util-deprecate": {
+      "dependencies": {},
+      "has_install_script": false,
+      "integrity": "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw==",
+      "optional_dependencies": {},
+      "tarball": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz",
+      "version": "1.0.2"
+    }
+  },
+  "policy": {
+    "allow_registry_redirects": false,
+    "allowed_registries": [
+      "https://registry.npmjs.org"
+    ],
+    "block_exotic_subdeps": true,
+    "exotic_deps": []
+  }
+}
diff --git a/scripts/update_runtime_locks.exs b/scripts/update_runtime_locks.exs
new file mode 100644
index 0000000..bab34b3
--- /dev/null
+++ b/scripts/update_runtime_locks.exs
@@ -0,0 +1,62 @@
+Logger.configure(level: :warning)
+
+alias Volt.JS.Runtime.Installer
+
+sets = [
+  Volt.Plugin.Svelte.runtime_package_set(),
+  Volt.Plugin.Solid.runtime_package_set(),
+  Volt.Tailwind.Loader.runtime_package_set()
+]
+
+{opts, args} = OptionParser.parse!(System.argv(), strict: [only: :keep])
+
+if args != [] do
+  raise ArgumentError, "unexpected arguments: #{Enum.join(args, " ")}"
+end
+
+requested = opts |> Keyword.get_values(:only) |> MapSet.new()
+
+selected =
+  if MapSet.size(requested) == 0 do
+    sets
+  else
+    Enum.filter(sets, &MapSet.member?(requested, Atom.to_string(&1.name)))
+  end
+
+found = selected |> Enum.map(&Atom.to_string(&1.name)) |> MapSet.new()
+missing = MapSet.difference(requested, found)
+
+if MapSet.size(missing) > 0 do
+  raise ArgumentError,
+        "unknown runtime package sets: #{missing |> Enum.sort() |> Enum.join(", ")}"
+end
+
+tmp_dir =
+  Path.join(
+    System.tmp_dir!(),
+    "volt-runtime-locks-#{System.unique_integer([:positive])}"
+  )
+
+File.mkdir_p!(tmp_dir)
+
+try do
+  Enum.each(selected, fn set ->
+    install =
+      Installer.install!(set.packages,
+        install_dir: Path.join(tmp_dir, Atom.to_string(set.name)),
+        force: true
+      )
+
+    generated = Path.join(install.install_dir, "npm.lock")
+    target = Path.expand("../priv/npm/#{set.name}.lock", __DIR__)
+    File.mkdir_p!(Path.dirname(target))
+    File.cp!(generated, target)
+
+    digest =
+      target |> File.read!() |> then(&:crypto.hash(:sha256, &1)) |> Base.encode16(case: :lower)
+
+    Mix.shell().info("Updated #{Path.relative_to_cwd(target)} (sha256: #{digest})")
+  end)
+after
+  File.rm_rf!(tmp_dir)
+end
diff --git a/test/volt/js/runtime/package_set_test.exs b/test/volt/js/runtime/package_set_test.exs
new file mode 100644
index 0000000..39fe869
--- /dev/null
+++ b/test/volt/js/runtime/package_set_test.exs
@@ -0,0 +1,60 @@
+defmodule Volt.JS.Runtime.PackageSetTest do
+  use ExUnit.Case, async: true
+
+  alias Volt.JS.Runtime.PackageSet
+
+  @runtime_modules [Volt.Plugin.Svelte, Volt.Plugin.Solid, Volt.Tailwind.Loader]
+
+  test "built-in package sets ship exact direct versions in valid npm_ex locks" do
+    Enum.each(@runtime_modules, fn module ->
+      set = module.runtime_package_set()
+      lockfile_path = PackageSet.lockfile_path(set)
+
+      assert File.regular?(lockfile_path)
+      assert NPM.Lockfile.version(lockfile_path) == 1
+      assert {:ok, lockfile} = NPM.Lockfile.read(lockfile_path)
+      assert {:ok, policy} = NPM.Lockfile.read_policy(lockfile_path)
+      assert NPM.Lockfile.policy_matches?(policy)
+
+      Enum.each(set.packages, fn {package, exact_version} ->
+        assert %{version: ^exact_version} = Map.fetch!(lockfile, package)
+      end)
+    end)
+  end
+
+  test "runtime opts cannot replace a package set's packages or lockfile" do
+    set = PackageSet.bundled(:volt, :fixture, %{"fixture" => "1.0.0"})
+
+    opts =
+      PackageSet.runtime_opts(set,
+        packages: %{"other" => "2.0.0"},
+        lockfile: "/tmp/other.lock",
+        bundle: true
+      )
+
+    assert opts[:packages] == %{"fixture" => "1.0.0"}
+    assert opts[:lockfile] == PackageSet.lockfile_path(set)
+    assert opts[:bundle]
+  end
+
+  @tag :integration
+  @tag :tmp_dir
+  test "built-in package sets install their packaged locks without re-resolving", %{
+    tmp_dir: tmp_dir
+  } do
+    Enum.each(@runtime_modules, fn module ->
+      set = module.runtime_package_set()
+      source_lock = PackageSet.lockfile_path(set)
+
+      install =
+        PackageSet.install!(set,
+          install_dir: Path.join(tmp_dir, Atom.to_string(set.name)),
+          force: true
+        )
+
+      installed_lock = Path.join(install.install_dir, "npm.lock")
+
+      assert File.read!(installed_lock) == File.read!(source_lock)
+    end)
+  end
+end
diff --git a/test/volt/js/runtime_test.exs b/test/volt/js/runtime_test.exs
index 7bf73d9..deac552 100644
--- a/test/volt/js/runtime_test.exs
+++ b/test/volt/js/runtime_test.exs
@@ -8,7 +8,12 @@ defmodule Volt.JS.RuntimeTest do
     tmp_dir = Path.join(System.tmp_dir!(), Atom.to_string(name))
 
     on_exit(fn ->
-      if pid = GenServer.whereis(name), do: Runtime.stop(pid)
+      try do
+        if pid = GenServer.whereis(name), do: Runtime.stop(pid)
+      catch
+        :exit, _reason -> :ok
+      end
+
       File.rm_rf!(tmp_dir)
     end)
 
@@ -27,4 +32,34 @@ defmodule Volt.JS.RuntimeTest do
       Runtime.ensure!(name: name, packages: %{}, install_dir: second_dir)
     end
   end
+
+  test "named runtimes include package-owned lock contents in their signature", %{
+    name: name,
+    tmp_dir: tmp_dir
+  } do
+    install_dir = Path.join(tmp_dir, "runtime")
+    lockfile = Path.join(tmp_dir, "npm.lock")
+    File.mkdir_p!(tmp_dir)
+    :ok = NPM.Lockfile.write(%{}, lockfile)
+
+    runtime =
+      Runtime.ensure!(
+        name: name,
+        packages: %{},
+        lockfile: lockfile,
+        install_dir: install_dir
+      )
+
+    assert is_pid(runtime.pid)
+    File.write!(lockfile, File.read!(lockfile) <> "\n")
+
+    assert_raise ArgumentError, ~r/already started with different options/, fn ->
+      Runtime.ensure!(
+        name: name,
+        packages: %{},
+        lockfile: lockfile,
+        install_dir: install_dir
+      )
+    end
+  end
 end