Claude 4.5 Speculative Tooling: Why Your Java Backend Needs Idempotency or It’s Dead Claude 4.5's speculative tool execution is a double-edged sword that slashes latency but will wreck your database if your idempotency logic is still stuck in the past. If your services aren't built for "maybe" invocations, you're one hallucinated pre-computation away from a production nightmare. Heads up: if you want to see these patterns applied to real interview problems, javalld.com has full machine coding solutions with traces. Why Most Developers Get This Wrong Treating AI tool calls as deterministic RPCs: Developers assume every tool call from Claude is a "final" intent, ignoring that speculative branches are frequently pruned and discarded. Relying on DB-level auto-increment IDs: Using sequential IDs for tool-call correlation is a recipe for disaster when the AI fires three parallel "guesses" for the same user action.…