How to use Replit Agent to fix fork collisions

Andrew Blumson imported his existing Coastal Drift racing game into Replit after unsuccessful Claude Code debugging. The visible symptom was asymmetric: taking the right fork caused collisions with traffic that appeared safely on the left. The game’s rendering and collision system disagreed about where cars were.

Replit Agent identified two layers. The collision check inferred the player’s fork from the instantaneous sign of a position near zero. A committed-side variable instead latched the chosen branch after a threshold. Separately, the renderer shifted each fork’s center and narrowed its lanes, while collision conversion still used the original road geometry. The agent derived an effective-lane expression incorporating both changes.

Blumson reports that the false-collision asymmetry disappeared on the first Replit attempt. The same account describes another diagnosis: occasional Replit jerkiness came from comparing Vite development mode with Vercel’s production build. A production preview restored smooth behavior.

The owner supplied the project, described and reproduced the symptom, and had already collected logs and visualizations. The useful result is a reported repair of coordinate-contract mismatches, without a controlled comparison proving one agent generally superior.

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Source: LinkedIn · Andrew Blumson