---
id: SLICE-0008
type: slice
status: ready
parent: NS-0002
title: Surface cross-file facts without replacing build validation
refs:
  - REQUIREMENTS.md
  - docs/editor-support.md
  - docs/diagnostics.md
  - hemx-build/src/lib.rs
  - hemx-lsp/src/main.rs
---

## Objective

Define and prove the handoff between editor-visible template facts and `cargo check`/`hemx-build` completeness checks for template/handler references.

## Authority

`REQUIREMENTS.md` `check/001`, `check/003`, `diagnostics/004`, and `diagnostics/005` require cross-file references visible to build validation to fail at `cargo check` with useful spans, while editor overlays remain optional glue.

## Close when

- A test fixture demonstrates a template/handler reference that editor diagnostics can surface and `cargo check`/build validation also rejects.
- The LSP path reports useful spans without becoming the global source of truth.
- Global completeness boundaries remain component-scoped unless mount/tests are needed.

## Verification

- `cargo test -p hemx-lsp`
- `cargo check --workspace` or a focused compile-fail/build fixture when build validation changes.

## Non-goals

- Do not make the LSP own Rust type checking.
- Do not create a persistent project index unless a later slice proves it is required.

## Evidence

`docs/diagnostics.md` and `hemx-build` diagnostics define the authority boundary that editor support must reflect.