webui: Move static build output from repo code to HF Bucket

[allozaur]

Overview

Close #17207

Move WebUI static build output files from the repository to a versioned Hugging Face Bucket, with automatic local/HF Bucket fallback during build.

Additional information

Build cases

CMake option	Local files	HF Bucket	Result
LLAMA_BUILD_WEBUI=ON (default)	exists	ignored	Uses local tools/server/public/
LLAMA_BUILD_WEBUI=ON + LLAMA_USE_PREBUILT_WEBUI=ON (default)	not exists	available	Downloads from HF Bucket
LLAMA_BUILD_WEBUI=ON + LLAMA_USE_PREBUILT_WEBUI=ON	not exists	not available	Builds without WebUI (warning)
LLAMA_BUILD_WEBUI=OFF	-	-	Builds without WebUI

Runtime behavior while http server is not ready yet:

• Built with WebUI: loading.html served to browsers (HTTP requests to / or .html), JSON 503 to APIs
• Built without WebUI: JSON 503 for all requests

CMake examples

  # Default build (WebUI enabled, uses local or HF Bucket)
  cmake -B build

  # Force local WebUI (requires `npm run build` in tools/server/webui)
  cmake -B build -DLLAMA_BUILD_WEBUI=ON -DLLAMA_USE_PREBUILT_WEBUI=OFF

  # Disable WebUI entirely
  cmake -B build -DLLAMA_BUILD_WEBUI=OFF

  # Skip HF Bucket download, fail if local not available
  cmake -B build -DLLAMA_USE_PREBUILT_WEBUI=OFF

CI/CD changes

WebUI build output is no longer committed to the repo, so CI builds and distributes it as a reusable artifact:

New reusable workflows

• webui-build.yml: Builds WebUI from source (Node.js + npm), generates SHA256 checksums, uploads as webui-build artifact
• webui-publish.yml: Publishes the built WebUI to a versioned HF Bucket path, accepts version_tag input and hf_token secret

Modified workflows

• release.yml: All build jobs now depend on webui-build artifact, download it via actions/download-artifact instead of relying on committed files. Added webui-publish job for release publishing
• server.yml / server-self-hosted.yml: Build jobs now depend on webui-build artifact
• server-webui.yml: Simplified to call webui-build.yml instead of building WebUI directly

Changes

• Deleted: tools/server/public/{bundle.js,bundle.css,index.html,loading.html}
• CMake (tools/server/CMakeLists.txt): Added local-first + HF Bucket download fallback
• CI workflows: New webui-build.yml, changed to artifact download in release/build jobs
• Server (server-http.cpp): Loading page logic preserved under #ifdef LLAMA_BUILD_WEBUI
• Config: Updated .gitignore, removed .gitattributes and editorconfig rules for removed tools/server/public files from the repo

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Moves the WebUI static build output out of the repo and into a versioned Hugging Face Bucket, adding build-time fallback logic (local → HF download → no WebUI), plus CI workflow updates to build/distribute WebUI as an artifact.

Changes:

• Add CMake logic to embed WebUI assets from local tools/server/public/ or download prebuilt assets from an HF Bucket.
• Restructure GitHub Actions workflows to build WebUI once and reuse it across server/release jobs via artifacts.
• Rename/rebrand WebUI identifiers/docs from llama.cpp/llama-server-webui to llama-ui.

Reviewed changes

Copilot reviewed 27 out of 31 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
tools/server/webui/vite.config.ts	Removes custom esbuild settings from WebUI build config
tools/server/webui/tests/stories/Introduction.mdx	Updates Storybook intro naming/wording
tools/server/webui/svelte.config.js	Renames SvelteKit app version name
tools/server/webui/src/routes/(chat)/chat/[id]/+page.svelte	Uses APP_NAME in page title and adjusts constants import
tools/server/webui/src/lib/services/chat.service.ts	Updates service docstring to new server naming
tools/server/webui/src/lib/constants/ui.ts	Changes default app name to llama-ui
tools/server/webui/src/lib/components/app/server/ServerLoadingSplash.svelte	Updates loading splash default message
tools/server/webui/scripts/install-git-hooks.sh	Stops staging generated tools/server/public/ output in pre-commit
tools/server/webui/scripts/dev.sh	Updates script header/comment formatting
tools/server/webui/package.json	Renames package to llama-ui
tools/server/webui/README.md	Renames and updates WebUI README wording
tools/server/server-http.cpp	Adjusts “server not ready” middleware behavior for WebUI/non-WebUI builds
tools/server/public/loading.html	Deletes committed static asset (moved out of repo)
tools/server/public/index.html	Deletes committed static asset (moved out of repo)
tools/server/README.md	Removes legacy Web UI/extension documentation section
tools/server/CMakeLists.txt	Adds local-first + HF Bucket download fallback for WebUI assets
grammars/README.md	Removes reference to legacy WebUI JS grammar tool path
common/common.h	Makes common_params.webui default depend on compile-time macro
CMakeLists.txt	Adds LLAMA_USE_PREBUILT_WEBUI option and formats option block
.gitignore	Ignores tools/server/public directory now that it’s generated/downloaded
.github/workflows/webui-build.yml	New reusable workflow to build and upload WebUI artifacts
.github/workflows/server.yml	Adds dependency on WebUI build artifact for server jobs
.github/workflows/server-webui.yml	Refactors to call reusable WebUI build workflow and reorganizes tests
.github/workflows/server-self-hosted.yml	Adds dependency on WebUI build artifact for self-hosted server builds
.github/workflows/release.yml	Adds dependency on WebUI build artifact for release jobs and sets LLAMA_BUILD_TAG
.github/labeler.yml	Removes tools/server/public/** from label rules
.gitattributes	Removes diff suppression for deleted generated WebUI file
.editorconfig	Removes formatting overrides for deleted tools/server/public/** files

Files not reviewed (1)

• tools/server/webui/package-lock.json: Language not supported

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[ngxson]

Nice job! It seamlessly run the npm build in my test, so I suppose that should be good enough

[ 98%] Building/provisioning WebUI assets (npm build → HF Bucket fallback)
-- WebUI: building from source in /Users/ngxson/work/llama.cpp/tools/server/webui
-- WebUI: local npm build succeeded

Just leaving some small comments

[ngxson]

replace unicode arrow with ascii

Suggested change

	COMMENT "Building/provisioning WebUI assets (npm build → HF Bucket fallback)"
	COMMENT "Building/provisioning WebUI assets (npm build -> HF Bucket fallback)"

[ngxson]

I couldn't trigger this branch to test it, but seems like this should log the URL source to be downloaded, right?