Level 3: Bookish, Gold Scale, Sensitive to Magic
Level 9: Disarm Magic, Minor Magic, Slow Fall (from the Monk class)
Level 13: Evade Magic, Foiling Magic, Reading Magic Scrolls
Level 17: Stash, Undetectable
Starting at 3rd level, you can read any written language enough to roughly know what is being said. Books are very valuable, and you know it.
Starting at 3rd level, you can use an action or bonus action to know the approximate value of any object you can see within 1 foot of your eyes.
Starting at 3rd level, as a bonus action, until the end of your turn, you can sense magic sources around you, as per the Detect Magic spell, but you do not learn which school of magic it belongs to.
Starting at 9th level, with the use of your Thieves' Tools, you can now disarm magical traps (as per the Dispel Magic spell) if your Thieves' Tools check is higher than 10 + the Spell Level (if the trap has no spell level, use the DC of Investigation or Perception check needed to discover the trap).
Starting at 9th level, you acquire the Mage Hand and Minor Illusions cantrips. If you already have one of them, choose another cantrip that doesn't deal damage from the Wizard spell list.
Your spellcasting ability for those cantrips is Dexterity. Also, using Minor Illusions, you can now change the value of a Tiny object for 1 minute.
Starting at 13th level, you have advantage to your saving throw against spells and magical effects.
Starting at 13th level, you can cast at will the Nystul's Magic Aura spell without spell slots or components.
Starting at 13th level, you can now read magic scrolls and cast the spells they contain as if you had access to the appropriate spell list. However, you must use the appropriate spellcasting ability (Wisdom for Cleric spells, Intelligence for Wizard spells, Charisma for Sorcerer spells, and so on).
Starting at 17th level, you can open a small portal 6 inches across if you use a bonus action or 2 feet across if you use an action. You can close it as a reaction. The portal lead to a specific point in space that you must first designate.
If you spend 8 hours within 6 inches of a spot and intricately weave some magic rituals you've learned somewhere you don't remember, you can designate that spot as the receiving end of the portal. Once set, this spot can only be moved by going through this process again, but it is automatically destroyed by a Dispel Magic spell.
Anything living going through the portal dies immediately and you don't know why.
Starting at 17th level, you are so smooth that you are now hidden from Divination magic when hiding or moving stealthily.