# Internals
Most downstream implementers should not need internals.
Use this section when debugging `tidu` itself or when integrating a runtime that
must inspect lower-level graph storage.
Key implementation areas:
- `linearize` walks a resolved graph and asks primitive JVP rules to emit
tangent graph structure.
- `linear_transpose` walks linear graph structure in reverse and asks primitive
transpose rules to emit cotangent graph structure.
- `tidu::eager` stores recorded graph invocation traces, linearizes those
graphs during backward, and delegates concrete execution to
`BackwardExecutor`.
The public tutorials intentionally avoid these implementation details until they
are needed.