---
id: SLICE-0008
type: slice
status: done
parent: NS-0002
title: Surface build-owned template 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 `hemx-build` validation without turning the LSP into a second source of template truth.

## 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

- LSP diagnostics use the same `hemx_build::diagnostics_for_heml_*` path as the CLI/file checks and publish/clear those results through protocol tests.
- LSP completion and hover consume `hemx_build::template_context_facts_for_heml_source` for repo facts instead of maintaining a separate template fact model.
- Cross-file/global completeness remains a build/mount-test concern; editor overlays may surface facts but do not replace build validation.

## Verification

- `cargo test -p hemx-lsp`
- `workledger check`

## 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

Done across commits `6cf800c`, `baf4b15`, `258524f`, and `e77ddd4`, then recorded at `f605c9e`: LSP diagnostics use build-owned diagnostic functions; repo-fact completion/hover tests exercise `template_context_facts_for_heml_source` with the workout template; protocol tests prove publish/clear, completion, hover, and basic request behavior. Verified with `cargo test -p hemx-lsp` and `workledger check`.