---
title: "2026-09-18 Histo domain representation v2 interface inspection"
description: "Inspected the current public inference API, model loading, input and output contracts, and packaging constraints."
image: "https://docs.virdx.dev/img/virdx-social-card.png"
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.virdx.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# 2026-09-18 Histo domain representation v2 interface inspection

## Work Done

- Fetched the `virdx/histo` refs and inspected `origin/main` at `d27ead6d` without changing its worktree.
- Documented the public `histo.domain_representation` imports and exact signatures for settings, model loading, and scan processing.
- Confirmed that the pipeline consumes a WSI or preprocessed HistoScan plus an optional foreground mask, not an existing domain representation.
- Documented model references, device and dtype behavior, output Zarr layout, run records, and release identifiers.
- Identified an integration constraint: Hydra configuration lives outside `src/histo` and is not included in the wheel.

## Lessons Learned: Pitfalls

- The worktree branch was behind its remote and contained unrelated untracked files. Reading `origin/main:<path>` avoided conflating local state with the current interface.
- Package version `0.0.127`, pipeline version `v2.0`, and Git tag `histo-v0.0.127` are distinct identifiers and must not be treated as interchangeable.

## Lessons Learned: Improvements

- Add packaged default configuration or a public `default_settings()` helper so installed-package adapters do not depend on a repository checkout.
- Add a short integration contract that states explicitly that `process_scan` writes maps as side effects and returns a run-record dictionary rather than a representation object.

Source: https://docs.virdx.dev/knowledge/inbox/2026-09-18-histo-domain-representation-v2-interface/index.mdx