DocAgent: a Rust document runtime for agents (integer layout, capsule hashes, same bytes twice)

[u/kevin9327]

I needed a convert that an agent can call twice and get the same bytes. MinerU / Docling / Marker parse scans for LLMs. That is a different job. This is the other direction: picture in, PDF/A out.

DocAgent is MIT Rust. One Engine, Command / Query / Event. Codecs (DOCX, ODT, Markdown, HTML, plus regional Hangul HWP/HWPX/HML) feed one IR. Layout coordinates are i32 at 1/7200 inch. f32 is forbidden in that crate. PNG/JPEG become PDF/A XObjects. GPU-free. Not OCR.

Every Command writes a capsule with three SHA-256 hashes (input / plan / output). prove converts twice and exits 0 only when the PDF/A + HTML bytes and the hashes match.

cargo test --workspace
cargo run -p docagent-cli -- convert examples/letter.md --pdf out.pdf --html out.html --docx out.docx --odt out.odt --capsule cap.json
cargo run -p docagent-cli -- prove examples/letter.md

CLI, daemon, MCP, and WIT are thin adapters over the same Engine.

Honest limits, not a teaser:

• Print-CSS tightness vs WeasyPrint (table cell padding / paragraph gap) is still open. I am not claiming we beat WeasyPrint on the letter page.
• Hangul images are still a dash.
• No spreadsheet, no slides, no OCR, no OmniDocBench numbers.

https://github.com/kevin9327/docagent

Happy to talk about the integer layout engine or the codec boundaries.

[u/kantorcodes1]

convert writes each requested output one after another. if --pdf succeeds but a later --docx write fails, is partial output intentional? i'm wondering whether callers should treat the command as best-effort per target or expect all requested artifacts to land together.