'model' is invalid. The 'model' property must be a string li

Error message

'model' is invalid. The 'model' property must be a string literal, e.g. 'product' or 'customer'.

What it means

The admin-vite-plugin statically parses custom field configs and requires the `model` property to be a string literal AST node. If it is an identifier, a variable reference, a member expression, or any other non-literal node, the plugin cannot determine the model name at build time and skips the config with this warning.

Source

Thrown at packages/admin/admin-vite-plugin/src/custom-fields/helpers.ts:46

  const modelProperty = configArgument.properties.find(
    (p) => isObjectProperty(p) && isIdentifier(p.key, { name: "model" })
  ) as ObjectProperty | undefined

  if (!modelProperty) {
    return null
  }

  if (isTemplateLiteral(modelProperty.value)) {
    logger.warn(
      `'model' property cannot be a template literal (e.g. \`product\`).`,
      { file }
    )
    return null
  }

  if (!isStringLiteral(modelProperty.value)) {
    logger.warn(
      `'model' is invalid. The 'model' property must be a string literal, e.g. 'product' or 'customer'.`,
      { file }
    )
    return null
  }

  const model = modelProperty.value.value.trim()

  if (!isValidCustomFieldModel(model)) {
    logger.warn(
      `'model' is invalid, received: ${model}. The 'model' property must be set to a valid model, e.g. 'product' or 'customer'.`,
      { file }
    )
    return null
  }

  return model
}

View on GitHub (pinned to 5e06e544a2)

Solutions

Inline the model name as a string literal: model: "product"
Do not reference variables, imports, or computed values for the model property
Restart the dev server to regenerate

Example fix

// before
import { myModel } from "./model"
export default defineCustomFieldConfig({ model: myModel })

// after
export default defineCustomFieldConfig({ model: "product" })

Defensive patterns

Strategy: type-guard

Type guard

// config values must be inline literals for the vite plugin
// (checked by the plugin; nothing to guard at runtime)

Prevention

Never reference variables or imports in admin codegen configs — inline string literals only
Keep config.ts files tiny and free of logic

When it happens

Trigger: Passing a variable instead of a literal in the config: `model: myModelVar` or `model: someObject.model`, or omitting quotes entirely.

Common situations: Developer imports a model constant and references it in the config; or reuses a shared config object built programmatically.

Related errors

AI-assisted analysis of medusajs/medusa@5e06e544a2 (2026-08-27). Data as JSON: /api/errors/e23642321e7227de. Report an issue: GitHub.