I'm about to start a game playing a Battle Smith and realized I was unsure of what cantrips I should take.  I'm planning to stick primarily with using infused weapons for offense so I figured that I didn't really need damage-dealing cantrips, but I was wondering what else would be good?  Mending is pretty much essential, any other ones to really look out for?  I was thinking Guidance for my second, but I wanted to see what other people had to say.

Mage hand is still pretty good and staple. Lightning Lure would also be pretty good to pull enemies closer to you. Light is also viable since you can cast it on your Steel Defender or an item on it and have it lead the way while you go through dark caves. 

Guidance is the usual answer, although I think it's a bit overrated if used as written (how often do you really know ahead of time that there's a skill check coming in the next minute?).

Sword Burst can outpace weapons for damage if you're surrounded, and doesn't make the boom that Thunderclap does.

Thorn Whip can be useful for control, especially since you're one of the few melee classes that gets it.

Worth considering that Battle Smith melee output falls off in double-digit levels, but they're always a great utility class, so lean into that role with your later cantrip choices.

I agree with rat, Guidance is essential, and Battlesmiths love spells that move the target around, for defender shenanigans.

If you decide to go melee by probably riding your defender into battle with a spear or similar, Booming Blade/Green-flame Blade are quite good.  Neither has any synergy if you instead go ranged.

Thorn Whip + Create Bonfire is great for shenanigans, and scales well if your party has STR-based members willing to Shove your enemies around.  Thorn Whip is radically better if you can Fly, and your defender can't base, but that's a potentially solvable problem in the future.

Spare the Dying has excellent synergy with a familiar, if you have the Homunculus Servant and/or Spellwrought Tattoo infusions.  I don't really like doing this, but you can also take Shocking Grasp if you want.  Remember, using a minion's Move+Reaction won't hurt your action economy at all.

Myself I took Light and Mending as my Artificer is a Tortle without Darkvision, but yes you can do so much. I took mending as I have the Homunculus Servant infusion just haven't had a chance to use it yet, as I am using the Enhanced Defence on my shield and Enhanced Weapon on my Warhammer. Strength is my dump stat but did good on rolling stats but what the heck right :)

If you want to use melee weapons mainly, I think firebolt is a good backup cantrip for when you can’t reach your enemies 

My go to are Create Bonfire and Guidance. Create bonfire can start adding up when you have a way to move mobs back into it, like telekineticist  feat. 

Hm.  A little late, but some words from my own experience for whatever they may be worth.

I took Guidance and Mending for my artificer cantrips on Star, my (currently) 8/1 BS/Wizard.  I figured those were the blind smack-obvious choices, and I specifically wanted to play a character with no combative cantrips so even the wizard choices were all utility.  

I've used Mending maybe three times in the whole eighteen-ass months we've been running this game, and Guidance comes up so infrequently it has not even slightly earned its pick.  Admittedly, I'm stricter on myself than many users of Guidance are - I cast the spell only when I know someone may need a boost, and only on tasks that could be successfully completed within the one-minute duration of the spell.  But still.  There are plenty of times where I wish I'd taken Message instead, or unbent enough to have a magical attack to combat my weaknesses.

There are games where we get a lot more out of Mending than what typically happens in Grave of Saints, but even then.  The one-minute casting time limits it heavily.  I'd still probably take Mending, just in case - especially in games where the DM favors a larger number of smaller attacks a steel defender might live through, distinctly unlike Grave - but Guidance is by no means mandatory.  A ranged battlesmith using bows or guns could definitely benefit from Shocking Grasp to allow them to both retaliate against and escape from melee threats, and a melee battlesmith with an infused weapon (or shield) could use a ranged poke they get to Warcaster with.

Another curious possibility (and perhaps the only truly valid use of an otherwise absolutely awful spell) is taking Magic Stone specifically to arm your Steel Defender with a ranged attack.  The Defender can huck a stone (either with a hand if it has one, or you can use your artifice to rig up a small catapult/similar throwing mechanism on your defender - remember, the defender can now take 'some other action' and Magic Stone doesn't specify a humanoid needs to throw it) using your spell attack modifier, to a range of 60 feet, for 1d6 +INT bludgeoning damage.  Battlesmiths not looking to 'waste' an infusion on the Homunculus and who spend most of their time fighting in tandem with the Defender can, with a bit of forethought and/or bonus action juggling, grant their critter three chances to shoot something with a magic rock if it's outside the Defender's reach.

I don't think it's a great choice, there's usually better things for the Defender to be doing...but it's a cute one, and the sort of thing that could make for great table moments depending on how your Defender goes about hucking magic rocks.

So the game has started and I've gone with Message and Thorn Whip.  And since I was able to start with a bonus feat I picked up Mending as well.

Quote from Yurei1453 >>

Hm.  A little late, but some words from my own experience for whatever they may be worth.

I took Guidance and Mending for my artificer cantrips on Star, my (currently) 8/1 BS/Wizard.  I figured those were the blind smack-obvious choices, and I specifically wanted to play a character with no combative cantrips so even the wizard choices were all utility.  

I've used Mending maybe three times in the whole eighteen-ass months we've been running this game, and Guidance comes up so infrequently it has not even slightly earned its pick.  Admittedly, I'm stricter on myself than many users of Guidance are - I cast the spell only when I know someone may need a boost, and only on tasks that could be successfully completed within the one-minute duration of the spell.  But still.  There are plenty of times where I wish I'd taken Message instead, or unbent enough to have a magical attack to combat my weaknesses.

There are games where we get a lot more out of Mending than what typically happens in Grave of Saints, but even then.  The one-minute casting time limits it heavily.  I'd still probably take Mending, just in case - especially in games where the DM favors a larger number of smaller attacks a steel defender might live through, distinctly unlike Grave - but Guidance is by no means mandatory.  A ranged battlesmith using bows or guns could definitely benefit from Shocking Grasp to allow them to both retaliate against and escape from melee threats, and a melee battlesmith with an infused weapon (or shield) could use a ranged poke they get to Warcaster with.

Another curious possibility (and perhaps the only truly valid use of an otherwise absolutely awful spell) is taking Magic Stone specifically to arm your Steel Defender with a ranged attack.  The Defender can huck a stone (either with a hand if it has one, or you can use your artifice to rig up a small catapult/similar throwing mechanism on your defender - remember, the defender can now take 'some other action' and Magic Stone doesn't specify a humanoid needs to throw it) using your spell attack modifier, to a range of 60 feet, for 1d6 +INT bludgeoning damage.  Battlesmiths not looking to 'waste' an infusion on the Homunculus and who spend most of their time fighting in tandem with the Defender can, with a bit of forethought and/or bonus action juggling, grant their critter three chances to shoot something with a magic rock if it's outside the Defender's reach.

I don't think it's a great choice, there's usually better things for the Defender to be doing...but it's a cute one, and the sort of thing that could make for great table moments depending on how your Defender goes about hucking magic rocks.

Did you not take the homunculus infusion or a spellwrought tattoo for a familiar?  Once guidance can be cast at range, in any context in which a single player is making ability checks on behalf of the entire party - such as a party scout or face - you should be nowhere nearby spamming guidance every round and waiting to get word that you can stop (this is significantly easier with a real familiar, both the cast - which the probably owl will let you make without seeing the target, since the owl counts as the caster - and knowing when to stop). 

Magic Stone is excellent paired with Tiny Servant - what you need are minions that don't consume your action economy for their actions.  Tiny Servants can throw stones on their own, like Animate Dead skeletons can.

Quote from 6thLyranGuard >>

So the game has started and I've gone with Message and Thorn Whip.  And since I was able to start with a bonus feat I picked up Mending as well.

Thorn Whip without Create Bonfire is a bold and interesting choice, sounds interesting!

I can pick up CB later.  I took it mostly to let me pull enemies away from more vulnerable teammates since the group is caster-heavy.

For a battle smith I'd say that Guidance and Mending are probably the best all-round cantrips. You can probably manage without guidance until level 6 though if you want to pick up something else. I'd go for a cantrip with the best range personally but thorn whip is not a bad choice. Bonus points if it suits thematically. :)

I was going to get Guidance but there are two other PCs in the party that already have it, so I figured that I could safely pass on it.