Hi everyone, Credian team here. We are exploring how to make AI agent payment decisions explainable after the fact, and I would love a knowledge graph perspective. If you needed to reconstruct why an agent was allowed to make a payment, how would you model the relationship between the human who delegated authority, the agent, the active policy, the approval, and the final transaction? Would you treat each policy decision as an immutable event node, or derive it from versioned entities and relationships? Our sandbox is still under construction, so I am mainly looking for the modeling tradeoffs. More context is at credian.io.
Interesting question! After some brain teasing I can share my two cents on the trade-offs: 1. immutable event nodes
Pros: freezes live signals (trust score, balance, fraud flags) that overwrite themselves and can never > be recovered later. Instant lookup. Self-proving in a dispute.
Cons: you must anticipate upfront what to capture, and anything you didn't record is gone forever. > Weak at "what if" questions across history.
2. versioned Es and Rs
Pros: compact, single source of truth for rules, and lets you ask questions nobody anticipated (eg > "which past approvals would fail under the new policy?").
Cons: can't recover anything that was never an entity, so live scores are unrecoverable. And you're trusting replay code written years after the fact (would need to maintain an additional software code).
If I had to make a decision: I would do both, with a clear split. The event record because live signals like AI agent's trust score are ephemeral (among many other things). The versioned entities because you will need to answer questions nobody has thought of yet (you keep scalability intact). But the bigger win is making decisions replayable rather than merely recorded, because a receipt is a claim and a replay is a proof. Hope this makes sense! Best, Lokesh
Lokesh S. Would you be willing to test the product when our sandbox is ready?
Sure. I can try to find sometime for it.