diff --git a/.github/scripts/schema_guard.py b/.github/scripts/schema_guard.py
index 4051259..4d8a184 100755
--- a/.github/scripts/schema_guard.py
+++ b/.github/scripts/schema_guard.py
@@ -14,9 +14,32 @@
 """
 
 import sys
+import json
+import re
 import pathlib
 import yaml
 
+# Every lerd since the package layer fetches each entry of the index's
+# `packages` on `lerd update` and refuses a name composer could not publish, so
+# an entry that is not a composer name fails a refresh on every install. Other
+# package kinds take an index key of their own, which those versions never read.
+COMPOSER_NAME = re.compile(r"^[a-z0-9][a-z0-9._-]*/[a-z0-9][a-z0-9._-]*$")
+
+
+def index_failures(candidate_dir):
+    path = pathlib.Path(candidate_dir) / "frameworks" / "index.json"
+    try:
+        index = json.loads(path.read_text(encoding="utf-8"))
+    except (OSError, ValueError):
+        return []
+    return [
+        f"frameworks/index.json: `{entry.get('name')}` under `packages` is not a composer name; "
+        "every lerd since the package layer fetches each entry there on update and refuses it. "
+        "List other package kinds under their own key, such as `npm_packages`"
+        for entry in index.get("packages", [])
+        if not COMPOSER_NAME.match(str(entry.get("name", "")))
+    ]
+
 # A key whose published values number no more than this across the whole store
 # is treated as a closed set, so a value outside it is worth a second look.
 CLOSED_SET_MAX = 8
@@ -97,7 +120,7 @@ def main():
     candidate = profile(candidate_dir, pattern)
     enums = closed_sets(published)
 
-    failures, warnings = [], []
+    failures, warnings = index_failures(candidate_dir), []
 
     for rel, entry in published.items():
         if rel not in candidate:
diff --git a/README.md b/README.md
index 0ca2b79..cffddd5 100644
--- a/README.md
+++ b/README.md
@@ -222,7 +222,11 @@ list meaning every framework. The package wins a name collision with the version
 file, which is what lets an entry move here without being shadowed by the copy
 it left behind. List the package under `packages` in `frameworks/index.json` as
 `{"name": "vendor/package"}`, which is where lerd reads the set from; a file
-nothing lists is never fetched.
+nothing lists is never fetched. Only composer names belong there: every lerd
+since the package layer fetches each entry of `packages` on `lerd update` and
+refuses a name composer could not publish, so anything else, an npm package
+say, gets an index key of its own that those versions never read. The schema
+guard refuses a non-composer name under `packages`.
 
 A capture seam names a method the Debug window should report, for a library
 whose own call is the event rather than the start of one. It belongs to the
@@ -263,6 +267,33 @@ removes:
   doctor: [horizon_supervisor]
 ```
 
+#### Browser events
+
+A frontend library reports what goes wrong through DOM events of its own, which
+lerd's browser capture records once it knows their names. The package that ships
+the library declares them in a `browser:` block, and lerd offers them as a preset
+for any project that requires the package:
+
+```yaml
+package: "@inertiajs/vue3"
+type: npm                  # optional: composer (the default) or npm
+browser:
+  preset: inertia          # packages sharing a preset are offered as one
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response          # where in the event the message is
+```
+
+An npm package lives in `packages/npm-<scope>-<name>.yaml`, its scope's `@`
+dropped (`npm-inertiajs-vue3.yaml`, `npm-vite.yaml`), and is listed in the index
+under `npm_packages` rather than `packages`: a lerd that predates npm packages
+fetches every entry of `packages` on `lerd update` and would count an npm name
+as a failure, while it never reads a key it does not know. It also reads a
+composer package's file without the keys it does not know, so a `browser:`
+block reaches only the versions that use it.
+
 The copies a package was lifted out of stay in the version files that already
 shipped them: an install whose binary predates the package layer still reads
 those, and deleting them would take the worker away from it. The package file is
diff --git a/frameworks/index.json b/frameworks/index.json
index 62007a4..1ee55e7 100644
--- a/frameworks/index.json
+++ b/frameworks/index.json
@@ -190,10 +190,21 @@
     {"name": "symfony/panther"},
     {"name": "symfony/redis-messenger"},
     {"name": "symfony/scheduler"},
+    {"name": "symfony/ux-turbo"},
     {"name": "tempest/command-bus"},
     {"name": "tempest/database"},
     {"name": "typesense/typesense-php"},
     {"name": "typo3/cms-scheduler"},
     {"name": "vladimir-yuldashev/laravel-queue-rabbitmq"}
+  ],
+  "npm_packages": [
+    {"name": "@hotwired/turbo"},
+    {"name": "@hotwired/turbo-rails"},
+    {"name": "@inertiajs/inertia"},
+    {"name": "@inertiajs/react"},
+    {"name": "@inertiajs/svelte"},
+    {"name": "@inertiajs/vue3"},
+    {"name": "htmx.org"},
+    {"name": "vite"}
   ]
 }
diff --git a/packages/inertiajs-inertia-laravel.yaml b/packages/inertiajs-inertia-laravel.yaml
index 20c697b..a32de58 100644
--- a/packages/inertiajs-inertia-laravel.yaml
+++ b/packages/inertiajs-inertia-laravel.yaml
@@ -15,3 +15,14 @@ workers:
     # exists once someone has run it.
     check:
       file: bootstrap/ssr/ssr.js
+
+browser:
+  preset: inertia
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response
+    - event: inertia:exception
+      label: Inertia exception
+      message: detail.exception.message
diff --git a/packages/npm-hotwired-turbo-rails.yaml b/packages/npm-hotwired-turbo-rails.yaml
new file mode 100644
index 0000000..fc2fb56
--- /dev/null
+++ b/packages/npm-hotwired-turbo-rails.yaml
@@ -0,0 +1,13 @@
+package: "@hotwired/turbo-rails"
+type: npm
+
+browser:
+  preset: turbo
+  label: Hotwire Turbo
+  events:
+    - event: turbo:fetch-request-error
+      label: Turbo request failed
+      message: detail.error.message
+    - event: turbo:frame-missing
+      label: Turbo frame missing
+      message: detail.response.status
diff --git a/packages/npm-hotwired-turbo.yaml b/packages/npm-hotwired-turbo.yaml
new file mode 100644
index 0000000..080225b
--- /dev/null
+++ b/packages/npm-hotwired-turbo.yaml
@@ -0,0 +1,13 @@
+package: "@hotwired/turbo"
+type: npm
+
+browser:
+  preset: turbo
+  label: Hotwire Turbo
+  events:
+    - event: turbo:fetch-request-error
+      label: Turbo request failed
+      message: detail.error.message
+    - event: turbo:frame-missing
+      label: Turbo frame missing
+      message: detail.response.status
diff --git a/packages/npm-htmx.org.yaml b/packages/npm-htmx.org.yaml
new file mode 100644
index 0000000..6b24b3d
--- /dev/null
+++ b/packages/npm-htmx.org.yaml
@@ -0,0 +1,14 @@
+package: "htmx.org"
+type: npm
+
+browser:
+  preset: htmx
+  label: htmx
+  events:
+    - event: htmx:responseError
+      label: htmx error response
+      message: detail.xhr.status
+    - event: htmx:sendError
+      label: htmx request not sent
+    - event: htmx:swapError
+      label: htmx swap failed
diff --git a/packages/npm-inertiajs-inertia.yaml b/packages/npm-inertiajs-inertia.yaml
new file mode 100644
index 0000000..37efa6f
--- /dev/null
+++ b/packages/npm-inertiajs-inertia.yaml
@@ -0,0 +1,13 @@
+package: "@inertiajs/inertia"
+type: npm
+
+browser:
+  preset: inertia
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response
+    - event: inertia:exception
+      label: Inertia exception
+      message: detail.exception.message
diff --git a/packages/npm-inertiajs-react.yaml b/packages/npm-inertiajs-react.yaml
new file mode 100644
index 0000000..2ccbead
--- /dev/null
+++ b/packages/npm-inertiajs-react.yaml
@@ -0,0 +1,13 @@
+package: "@inertiajs/react"
+type: npm
+
+browser:
+  preset: inertia
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response
+    - event: inertia:exception
+      label: Inertia exception
+      message: detail.exception.message
diff --git a/packages/npm-inertiajs-svelte.yaml b/packages/npm-inertiajs-svelte.yaml
new file mode 100644
index 0000000..e2e9828
--- /dev/null
+++ b/packages/npm-inertiajs-svelte.yaml
@@ -0,0 +1,13 @@
+package: "@inertiajs/svelte"
+type: npm
+
+browser:
+  preset: inertia
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response
+    - event: inertia:exception
+      label: Inertia exception
+      message: detail.exception.message
diff --git a/packages/npm-inertiajs-vue3.yaml b/packages/npm-inertiajs-vue3.yaml
new file mode 100644
index 0000000..fceb01c
--- /dev/null
+++ b/packages/npm-inertiajs-vue3.yaml
@@ -0,0 +1,13 @@
+package: "@inertiajs/vue3"
+type: npm
+
+browser:
+  preset: inertia
+  label: Inertia.js
+  events:
+    - event: inertia:invalid
+      label: Inertia invalid response
+      message: detail.response
+    - event: inertia:exception
+      label: Inertia exception
+      message: detail.exception.message
diff --git a/packages/npm-vite.yaml b/packages/npm-vite.yaml
new file mode 100644
index 0000000..e61cf1a
--- /dev/null
+++ b/packages/npm-vite.yaml
@@ -0,0 +1,10 @@
+package: "vite"
+type: npm
+
+browser:
+  preset: vite
+  label: Vite
+  events:
+    - event: vite:preloadError
+      label: Vite chunk failed to load
+      message: payload.message
diff --git a/packages/symfony-ux-turbo.yaml b/packages/symfony-ux-turbo.yaml
new file mode 100644
index 0000000..2944c1c
--- /dev/null
+++ b/packages/symfony-ux-turbo.yaml
@@ -0,0 +1,12 @@
+package: symfony/ux-turbo
+
+browser:
+  preset: turbo
+  label: Hotwire Turbo
+  events:
+    - event: turbo:fetch-request-error
+      label: Turbo request failed
+      message: detail.error.message
+    - event: turbo:frame-missing
+      label: Turbo frame missing
+      message: detail.response.status