Generator Servant — ruling 1

If the mana is spent on two different creature spells, each of those spells (and resulting creatures) will gain haste until end of turn.

Generator Servant — ruling 2

If a creature spell has generic mana only in its alternative or additional cost, the creature will still gain haste.

Generator Servant — ruling 3

An instant or sorcery spell is not a creature spell, even if that spell creates creature tokens.

Generator Servant — ruling 4

If the mana is spent on a noncreature spell that becomes a creature later in the turn, that creature won't have haste.

Generator Servant : règles, fonctionnement et interactions (MTG)

Generator Servant is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

, Sacrifice this creature: Add . If any of that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and as soon as it comes under your control.)

How it works : Generator Servant

Original English text — Wizards of the Coast / Scryfall

#1December 7, 2018· Wizards of the Coast
If the mana is spent on two different creature spells, each of those spells (and resulting creatures) will gain haste until end of turn.
No other card is named in this ruling.
#2December 7, 2018· Wizards of the Coast
If a creature spell has generic mana only in its alternative or additional cost, the creature will still gain haste.
No other card is named in this ruling.
#3December 7, 2018· Wizards of the Coast
An instant or sorcery spell is not a creature spell, even if that spell creates creature tokens.
No other card is named in this ruling.
#4December 7, 2018· Wizards of the Coast
If the mana is spent on a noncreature spell that becomes a creature later in the turn, that creature won't have haste.
No other card is named in this ruling.