medusajs/medusa · warning

'fields' property at the

Error message

'fields' property at the ${j} index of the 'forms' property is malformed. The 'fields' property must be an object.

What it means

The getConfig equivalent of the fields-shape check: fieldsObject.value must be an ObjectExpression. Arrays, identifiers, calls, or any other node type cause this warning and the entry is skipped.

Solutions

1. Make 'fields' an inline object literal keyed by field name
2. Inline any imported map
3. Remove helper-call indirection

Example fix

// before
forms: [{ zone: 'general', fields: sharedFields }]
// after
forms: [{ zone: 'general', fields: { myField: { ... } } }]

if (Array.isArray(f.fields) || typeof f.fields !== 'object') {
  throw new Error('fields must be an inline object literal')
}

const isFieldsObject = (v: unknown): v is Record<string, unknown> =>
  typeof v === 'object' && v !== null && !Array.isArray(v)

When it happens

Trigger: fields: [ ... ] array syntax, fields: importedFields variable, or fields: buildFields().

Common situations: Assuming an array like 'forms', or attempting to share/reuse field maps via imports (not possible with static analysis).

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• 'forms' property at the
• The 'fields' property at the
• The 'forms' property is malformed. The 'forms' property…
• 'defaultValue' property is missing at the
• 'fields' property is missing from the

AI-assisted analysis of medusajs/medusa@5e06e544a2 (2026-08-27). Data as JSON: /api/errors/46b06630bd62e59b. Report an issue: GitHub.

Appendix: source

Thrown at packages/admin/admin-vite-plugin/src/custom-fields/generate-custom-field-forms.ts:584

      return
    }

    const fieldsObject = element.properties.find(
      (p) => isObjectProperty(p) && isIdentifier(p.key, { name: "fields" })
    ) as ObjectProperty | undefined

    if (!fieldsObject) {
      logger.warn(
        `'fields' property is missing from the ${j} entry in the 'forms' property in ${file}.`,
        { file }
      )
      return
    }

    const fields: CustomFieldConfigField[] = []

    if (!isObjectExpression(fieldsObject.value)) {
      logger.warn(
        `'fields' property at the ${j} index of the 'forms' property is malformed. The 'fields' property must be an object.`,
        { file }
      )
      return
    }

    fieldsObject.value.properties.forEach((field) => {
      if (!isObjectProperty(field) || !isIdentifier(field.key)) {
        return
      }

      const name = field.key.name

      if (
        !isObjectExpression(field.value) &&
        !(
          isCallExpression(field.value) &&
          isMemberExpression(field.value.callee) &&

View on GitHub (pinned to 5e06e544a2)