Search to Find the promises of God

This search worked for me - promise:* INTERSECTS reference:person:God

Others may have better insight and varying options

You can also search the Public Documents for Passage Lists of God's Promises to have another option.

Documents Tab - Select Public - Filter to Passage List - Search Promises

There seems to be some tag for this, but I'm not sure how to find it and then search for it. Anyone?

Right click in the passage reveals tag for search. Figured it out.

Try: speaker:God propositionalOutline:Promise

Note: You did not provide a definition of what you mean by "promises", therefore I would argue none of us know the answer.

@Frank Sauer assumes you trust the Logos label tagging as described in Thompson, Jeremy. Promises in the Bible Dataset Documentation. Bellingham, WA: Faithlife, 2018.

This search worked for me - promise:* INTERSECTS reference:person:God

@Mark Smith assumes you trust the direct speech tagging and the discourse analysis

Try: speaker:God propositionalOutline:Promise

Or I might assume you want a bibliography something like this:

Publishing, Barbour, Inc. The Bible Promise Book - Catholic Edition. Uhrichsville, OH: Barbour Books, 2013.
Publishing, Barbour. The Bible Promise Book: One Thousand Promises from God’s Word. Uhrichsville, OH: Barbour Books, 2006.
Zondervan. Bible Promises for You: From the New International Version. Grand Rapids, MI: Zondervan, 2009.
Water, Mark. Bible Promises Made Easy. The Made Easy Series. Alresford, Hampshire: John Hunt Publishers Ltd, 2001.
Richards, Larry. Every Promise in the Bible. Nashville: T. Nelson Publishers, 1998.
Lucado, Max, and Terri A. Gibbs. God’s Inspirational Promises. Nashville, TN: J. Countryman, 2001.
Beaumont, Mike, and Martin Manser. The Handbook of Bible Promises, 2020.

Each of these answers will give you different results.

I guess what I'm looking for is what has God "promised" (future tense—"will") He will do for His people. So I wonder if maybe a search where God is the subject of a future tense verb might start to get at it?

Some might buy that definition - but the prophet Jonah did only to feel mistreated when God changed His mind. On the other hand, Abraham took such "promises" to be negotiable. 😎

Tenses are complicated, but I think we can basically do what you are talking about here with a clause search.
For the Old Testament

subject:God AND verb-morph:V?I

For the New Testament

(subject:God OR subject:Jesus OR subject:Holy Spirit) AND verb-morph:V[FT]

Although, it is not uninteresting to go the simplest route and do a Bible search
"I will" IN (speaker:God OR speaker:Jesus)