• joi version: 14.0

What are you trying to achieve or the steps to reproduce ?

1. Use Number.MAX_SAFE_INTEGER.

if (isNumber) {
            if (!this._flags.unsafe &&
                (value >= Number.MAX_SAFE_INTEGER || value <= Number.MIN_SAFE_INTEGER)) {
                result.errors = this.createError('number.unsafe', { value }, state, options);
            }
        }

joi/lib/types/number/index.js

Which result you had ?

1. Obtain error that number unsafe.

What did you expect ?

1. Expect that value Number.MAX_SAFE_INTEGER is the safe integer.
   Number.isSafeInteger(Number.MAX_SAFE_INTEGER);
   // true