The runtime starts with structure
A GGUF file carries the information a runtime needs to locate and interpret model data. That includes metadata, tensor shapes, tensor types, offsets, and the alignment of the binary data block.
What the parser establishes
The Flatline parser memory-maps the file, validates the GGUF magic and supported version, reads metadata and tensor headers, resolves the aligned data offset, and associates each tensor with its mapped data. It then groups layer-specific tensors so the engine can reason about execution order.
The broader lesson
Model integration is systems work. A provider API hides most of this surface area; local inference exposes it. The same discipline applies to hosted systems too: make model capabilities, constraints, token accounting, and evaluation data explicit before wiring them into a product.