Limitations

Current core and adapter constraints include:

• Ruby code is compiled and embedded at build time.
• Available Ruby features are those implemented by mruby/edge and initialized crates, not the full CRuby standard library.
• Native CRuby extensions cannot be loaded into the Wasm runtime.
• Query parsing does not currently perform URL decoding.
• JSON and form parsing require exact supported content-type values.
• Response headers use 16-bit lengths and response bodies use a 32-bit length in the transport format.
• Platform service APIs are adapter-specific and often require a feature overlay.
• The Cloudflare adapter has its own configurable encoded-request limit and currently text-decodes response bodies.

See the selected platform guide for build tools, bindings, and host-specific constraints.