Morph Error Reference

Every error and warning reported by morph check and morph build has a stable rule code starting with mx-. When a diagnostic fires, the terminal shows the code, what went wrong, a hint, a code frame, and a Learn more link that opens the matching page in this reference:

error : mx-tag : Unknown tag <vidio>
  hint: Did you mean <video>?
  Learn more: https://morph.levizr.com/docs/errors/mx-tag

How to use this reference

1. Copy the mx-* code from your terminal output.
2. Open the page below — each page explains why the rule exists (Morph compiles .mx files to native C++, so browser-only patterns cannot pass through), shows the broken code, the fixed code, and how to tune the rule.
3. Errors block morph build and dev-mode reloads until fixed. Warnings are reported and never block — but they describe real bugs (missing key, stub elements), so fix them too.

Pages marked (rule) document a real constraint that morph check does not report yet — violations surface as build failures or silently ignored code instead of a labeled diagnostic. The cause and fix on those pages still apply when you hit the underlying problem. Only implemented, triggerable checks are listed here: there is no page for a feature that does not exist.

Rule severity

Severity is per-code with a documented default (see lint configuration). You can turn a rule off or change its severity in morph.config.json:

{
  "lint": {
    "disable": ["mx-list-key"],
    "severities": { "mx-tag-stub": "error" }
  }
}

All error codes

Structure

• mx-export — missing or duplicate default-export component
• mx-component-unknown — unknown component tag
• mx-component-prop — unknown prop on a component
• mx-component-required — missing required prop

Window

• mx-window-missing — no window created
• mx-windowconfig-key (rule) — invalid windowConfig key
• mx-windowconfig-type (rule) — invalid windowConfig value type

Elements and props

• mx-tag — unknown element tag
• mx-tag-stub — registered but unimplemented element
• mx-prop — invalid or misspelled prop
• mx-img-src (rule) — <img> without src
• mx-event-value (rule) — event handler is not a function
• mx-key-misuse (rule) — key used outside a list
• mx-dup-class (rule) — class and className used together

Styles

• mx-style-prop (rule) — unsupported inline style property
• mx-style-value (rule) — invalid inline style value
• mx-tailwind-class (rule) — unresolvable Tailwind class
• mx-css-prop (rule) — unsupported CSS file property
• mx-css-file-missing (rule) — imported CSS file not found
• mx-css-load-deprecated — CSS.load() is deprecated

Imports and names

• mx-import-morph (rule) — bad import from 'morph'
• mx-no-morph-import — Morph API used without import
• mx-undefined — name is not defined or imported
• mx-import-type (rule) — unsupported import type
• mx-naming — invalid module file or directory name

State and effects

• mx-state-scope — morphState outside a component
• mx-shared-scope — morphShared not at exported module scope
• mx-event-scope — morphEvent not at exported module scope
• mx-api-removed — removed string-key API in use
• mx-state-pattern (rule) — morphState not destructured as pair
• mx-effect-cb (rule) — morphEffect first argument is not a function
• mx-effect-deps (rule) — effect dependency is not state

JavaScript support

• mx-transpile (rule) — JavaScript that cannot compile to C++
• mx-js-global — browser global with no native counterpart
• mx-js-member (rule) — unsupported builtin member access
• mx-js-method (rule) — method the runtime types do not implement
• mx-js-op (rule) — operator the translator cannot emit
• mx-js-syntax (rule) — syntax construct the translator cannot handle
• mx-list-key — list item without key

Routes

• mx-route-unknown — unknown route id
• mx-route-no-export — route file without default export
• mx-route-state — route helper reads mount state from module scope