MarkItDown Reference Notes

Source reviewed: Microsoft markitdown, official repository and README.

Useful Patterns

Keep conversion and extraction units narrow. MarkItDown separates accepts() from convert(), which maps well to this engine's separation between candidate selection, locator verification, replay, and failure records.
Prefer a registry-style extraction pipeline when multiple strategies may apply. MarkItDown registers specific converters before generic HTML/plain-text fallbacks; a future topology engine can use the same pattern for snapshot extraction strategies without becoming a generic crawler.
Preserve machine-friendly output over high-fidelity rendering. MarkItDown targets Markdown for LLM/text pipelines, not perfect visual reproduction. This matches this project's graph-artifact boundary.
Normalize output centrally. MarkItDown trims trailing line whitespace and collapses excessive blank lines after converter execution; this project now uses graph summaries and JSON Schema validation as artifact-level normalization checks.
Keep security boundaries explicit. MarkItDown warns that URI/file conversion performs I/O with current process privileges and recommends narrow conversion APIs. This project should keep navigation scopes, timeouts, and risk policy explicit rather than adding broad fetch/convert behavior.

Do not add MarkItDown as a runtime dependency for v0.2.2.
Do not emit Markdown as the primary artifact. Markdown can be future evidence or summaries, but the project contract remains TopologyGraph.
Do not add LLM/OCR/cloud conversion plugins to this repository.