SAIL-Recon is a feed-forward Transformer-based system for large-scale Structure-from-Motion (SfM) and visual localization. It processes input images or video to estimate camera poses, depth maps, and generate 3D point clouds without iterative optimization. The architecture combines a Vision Transformer backbone with an alternating attention aggregator for temporal modeling and specialized heads for camera, depth, and track predictions. The system includes both command-line and Gradio-based demo interfaces for end-to-end 3D reconstruction, along with evaluation scripts for standard benchmarks (TUM, 7Scenes, Tank&Temple, etc.). While research-oriented, it is packaged as a usable application with clear entry points and modular components.