How to Fix Item Duplication From Trusting a Client Crafting Quantity

Your crafting request carries the materials consumed and items produced as fields the client fills in. A cheat client sends a tiny cost and a huge output, and the server obeys. The client should name the recipe; the server should decide what it costs and yields.

How to fix it

1. Send the recipe ID only

Let the client request a recipe by ID. The server looks up the canonical inputs and outputs from its own data, ignoring any amounts the client supplies.

2. Verify and debit server-side

Confirm the player owns the required inputs, debit them, and grant the output in one atomic server transaction, so a client cannot fabricate a cheaper craft.

3. Validate quantities against limits

Bound batch crafting to sane maximums and reject requests that imply impossible inventories, closing oversized-output exploits.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.