Smart 404

What This Plugin Adds

Smart 404 is an Available, No schema impact Capell package in the Capell Search & SEO product group. It ships as capell-app/smart-404 and extends these surfaces: admin, frontend, console.

Smart 404 turns missing-page dead ends into a short list of deterministic, site-scoped public URL suggestions.

Frontend and static 404 documents keep their 404 status while similar links and nearby hierarchy are available with or without JavaScript.

Evidence: src/Actions/ResolveSmart404SuggestionsAction.php, resources/views/widget.blade.php, routes/web.php, resources/dist/smart-404.js, src/Support/RenderHooks/RegisterSmart404Hook.php, tests/Unit/Actions/ResolveSmart404SuggestionsActionTest.php.

Status details:

• Status: Available
• Tier: premium
• Bundle: search-seo
• Composer package: capell-app/smart-404
• Namespace: Capell\Smart404
• Theme key: not applicable

Why It Matters

For developers: The resolver uses the shared registry, a fixed similarity threshold, safe relative URLs, and a bounded public endpoint rather than application-specific queries in Blade.

For teams: Visitors get useful next steps without redirects, visitor tracking, AI services, or exposing unpublished content.

Evidence: src/Actions/ResolveSmart404SuggestionsAction.php, src/Http/Controllers/Smart404SuggestionsController.php, config/capell-smart-404.php, resources/views/widget.blade.php, src/Health/Smart404HealthCheck.php.

Screens And Workflow

Screenshot contract: docs/screenshots.json.

• Smart 404 suggestions on a missing public page (desktop) (frontend, required evidence).
• Smart 404 suggestions on a missing public page (mobile) (frontend, required evidence).
• Smart 404 settings (admin, required evidence).

Technical Shape

• Service providers: Capell\Smart404\Providers\Smart404ServiceProvider, Capell\Smart404\Providers\AdminServiceProvider.
• Config files: packages/smart-404/config/capell-smart-404.php.
• Settings migrations: packages/smart-404/database/settings/2026_08_08_000001_create_smart_404_settings.php.
• Settings classes: Smart404Settings.
• Filament classes: Smart404SettingsSchema.
• Route files: packages/smart-404/routes/web.php.
• Actions: InstallSmart404PackageAction, ResolveSmart404SuggestionsAction.
• Data objects: Smart404PublicUrlEntryData, Smart404SuggestionData.
• Manifest action API: install: Capell\Smart404\Actions\InstallSmart404PackageAction, resolveSuggestions: Capell\Smart404\Actions\ResolveSmart404SuggestionsAction.
• Manifest contributions: frontend-component: Capell\Smart404\Manifest\Smart404WidgetContribution, health-check: Capell\Smart404\Manifest\Smart404HealthContribution, route: Capell\Smart404\Manifest\Smart404FrontendRoutesContribution, setting: Capell\Smart404\Manifest\Smart404SettingsContribution.
• Health checks: Capell\Smart404\Health\Smart404HealthCheck.
• Blade views: packages/smart-404/resources/views/widget.blade.php.
• Cache tags: smart-404.

Data Model

• Required tables: settings, pages, sites.
• Migration impact: run host migrations through the package install flow before opening package surfaces.
• Deletion/retention behaviour: Docs gap: migrations and manifest contributions do not prove a cascade, pruning command, or timed retention policy.

Install Impact

• Required packages: capell-app/admin, capell-app/core, capell-app/discovery-foundation, capell-app/frontend.
• Admin navigation: no admin page or resource contribution is declared.
• Admin/editor extensions: none declared.
• Permissions: none declared in capell.json.
• Public routes: loads routes/web.php; registers Smart404FrontendRoutesContribution.
• Database changes: no package migrations declared.
• Config: config/capell-smart-404.php.
• Settings: Capell\Smart404\Settings\Smart404Settings.
• Queues or schedules: none declared.
• Cache tags: smart-404.
• Commands: none declared.

Common Pitfalls

• Keep required Capell packages on compatible v4 releases: capell-app/admin, capell-app/core, capell-app/discovery-foundation, capell-app/frontend.
• Review package configuration before production-like verification: config/capell-smart-404.php, Capell\Smart404\Settings\Smart404Settings.
• Review middleware, throttling, signatures, and public-output safety in routes/web.php before exposing routes.
• Keep public Blade and cached HTML free of authoring markers, model IDs, permissions, signed editor URLs, and lazy database queries.
• Custom write integrations must preserve invalidation for smart-404 cache tags.

Troubleshooting

Symptom	Likely cause	Check	Fix
Package surface is missing after install	Provider or manifest is not loaded	Confirm capell.json, package composer.json, and provider registration	Reinstall the package, refresh Composer autoload, and clear host caches
Route returns unexpected output	Route cache, middleware, or signed URL setup does not match the package route file	Check the route files listed in Technical Shape	Clear route cache and verify middleware before exposing public routes
Public output leaks unexpected state	Render data, cache variation, or authoring boundary has regressed	Check public Blade, cache tags, and public-output safety tests	Move data loading out of Blade and rerun the package public-output tests

Quick Start

1. Install the package: composer require capell-app/smart-404.
2. Review config/capell-smart-404.php before enabling the package.
3. Open the package admin surface at /extensions and confirm Smart 404 is available.

Next Steps

• Package docs
• Overview
• Configuration files: config/capell-smart-404.php.
• Troubleshooting
• Screenshot contract
• Capell content language plan
• Capell documentation design system
• Capell and package ERD notes
• Related packages: Discovery Foundation, Site Discovery.
• Focused tests: vendor/bin/pest packages/smart-404/tests --configuration=phpunit.xml.