Limitations

A migration and build integration#

Simpcn uploads existing local assets and rewrites supported production references. It does not provision buckets, set access policies, create CDNs, optimize images, purge caches, or process arbitrary runtime URLs.

Original files remain in place. Migration is not an instruction to remove public/, and the adapters do not disable framework public-file serving. Unsupported references can continue to use local assets.

Framework and syntax boundaries#

The verified versions are Next.js 16.4 with webpack/Turbopack and Vite 8. Other versions and custom loader combinations need testing. Next.js CSS/PostCSS rewriting is not implemented.

Vite support does not mean automatic Vue or Svelte template rewriting. Dynamic strings, JSON/API values, custom component props, and uploaded raw stylesheet contents need explicit handling. See the support matrix.

Automatic next/image delivery uses unoptimized; it preserves conflicting explicit settings and leaves those cases unchanged with diagnostics. Dynamic references need an explicit helper.

Expo is experimental#

React Native with Expo has implemented static PNG/JPEG sources, default image imports, iOS/Android variants and density selection. Packed installation and real Android/iOS exports are tested.

Device rendering and downloads, offline/cache behavior, native/EAS builds, and OTA updates/rollback still require validation. Use immutable release namespaces and retain old objects for installed apps. Expo web, bare React Native, .native families, fonts/media, app icons, splash screens, custom wrappers, and dynamic asset expressions are outside current automatic delivery. Read the Expo guide →

Verification has a point in time#

Production builds validate local deployment records against current assets and storage target. Those records do not prove that objects are still present, anonymously readable, or fresh in CDN caches. Check the delivery URL and use plan --check-remote when remote state may have changed.

Changed assets must be migrated and the application rebuilt. Changing a URL or uploading after deployment does not update the already compiled mapping. Builds intentionally perform no storage network operations.

Storage and upload limits#

The adapter is integration-tested against local MinIO. AWS S3 and R2 have configuration presets but have not been verified against live services in the repository tests. Validate any chosen provider’s conditional-upload and metadata behavior.

Uploads above 5 GiB are rejected; multipart is not implemented. Removed local files are never deleted remotely. Existing conflicting keys require explicit --overwrite. Storage ownership and cleanup remain with the application owner.

Current evidence#

Repository tests cover local scanning, reconciliation, MinIO migration, transforms, and real Next.js/Vite production builds. Next.js tests use a separate local asset-origin server, not a live CDN, and exercise server-rendered pages and ISR after build-time state is removed.

This is not complete proof of browser hydration, every third-party loader stack, standalone packaging, or real CDN cache behavior. Report a reproducible gap on GitHub issues.