* ui: add conversation compaction Add a compaction action that asks the model to summarize the conversation so far and stores the summary in a new compaction node appended to the branch. Later requests slice the branch at the last compaction node, keeping the system prefix and continuing from the summary instead of the full history, which frees up context while the complete history stays visible and navigable in the UI. The slice is applied once at the request funnel, covering the plain send, the agentic flow and the KV cache pre-encode, plus the continue path that bypasses it. The summary request is a one-shot outside the SSE replay machinery, streamed live into the node with a full rollback on abort, error or empty result. The action is exposed as a /compact slash command and a Compact button in the context gauge popup, with an overridable summarization prompt in the settings. * ui: pre-fill KV cache and refresh context gauge after compaction Once the summary is stored, pre-encode the compacted branch and stamp the returned prompt timings on the compaction node: re-encoding the reduced prefix is part of the compaction itself, so the server KV cache and the context gauge reflect the summary right away. The summary stream is registered under a prefixed identity (compact::convId), so the visibility kick and byte-offset resume protect it through tab switches while the reload probe never reattaches it as a chat turn. The stamped node becomes the shared context truth for the gauge and the processing state restore, and the stale live state that kept the gauge full is cleared. * chore: format * ui: allow a dedicated model for conversation compaction An opt-in setting reveals a model selector whose options come from the live router model list. The chosen model writes the summary and is loaded on demand when it is not resident, while the default path keeps resolving to the conversation's own model. * ui: align the compaction model field with project conventions * ui: fix the model option helpers import path The compaction model selector pulls filterModelOptions and groupModelOptions from the models component folder, where they no longer live, so the build fails to resolve the module. Point the import at the navigation folder, which now owns them. Missed during the rebase: the helpers moved in a commit that does not touch any compaction file, so nothing conflicted. * ui: import the model option helpers from models/utils * ui: follow the moved models selector in the compaction model field The models manager moved ModelsSelectorList under ModelsSelector and the model option helpers to /utils, where groupModelOptions takes the options alone. Drop the stale copy the rebase kept and read the helpers from their new home. * ui: drop the dedicated compaction model A summary written by another model loses the prefix the conversation model cached, so the whole history is prefilled again, and the model then resumes from text it did not write. The conversation model always writes its own summary. * ui: keep the last steps of a compacted conversation A compaction now folds the steps the model reads but the last ones, a step being a user message or an assistant message with its tool results, and stores how many it kept on the compaction node. The model then reads the system prefix, the summary, the kept steps and what follows. The summary request is the request the chat sends, with its options, tools and message shaping, cut before the preserved steps: the server reuses the prefix it cached and only the instruction is new. The number of preserved steps is a setting, 10 by default. * ui: run every compaction summary through one path Three callers needed the same thing - the automatic pre-encode pass, the action in the context gauge, and re-running a summary from the block - and each of them had grown its own copy of the request, the streaming and the storing. There is one path now: a summarization owns a node, streams into it, and reports itself through a ledger the rest of the app reads (`isCompacting`, which node belongs to which conversation). Re-running a summary is the same call on an existing node, so the two entry points cannot drift apart again. * ui: give the compaction row its own summary UI The summary was a line of text in a tool-call-shaped collapsible, which is how a compaction reads as a side note rather than as the thing the rest of the conversation now stands on. The row is its own block: a divider that names the boundary, and the summary inside it with the model that wrote it, its statistics, and the same actions an assistant turn has - copy, edit, fork, regenerate and delete all apply to the summary, and it collapses to the divider once a summary is in, because the shrunk context is the headline and the prose is the detail. The divider is a variant of the shared collapsible block, which also needed the toggle and the title split into snippets so a caller can lay them out without copying the markup. The action icons no longer take a role: they render what a message offers, and a compaction offers the same as any other stored message. * ui: report compaction progress on the row The row owns the run, so the row says how it is going: the prompt progress in the header while the context is being read, the phase once the summary starts streaming, and the token count once it is in. Before the first summary token there is nothing to collapse, so the header stands on its own instead of offering an empty block. * ui: keep the summarized turns quiet while a compaction runs The turns being summarized used to keep their own "Processing..." indicator and live reading stats while the summary streamed, so the conversation said the same thing twice in two places. The row reports the run, so the turns it replaces stay silent until it is done. * ui: hand the compact action to the context gauge Compacting is a decision about the context, so the action belongs with the numbers that show the context filling up rather than inside the form: it sits at the bottom of both the hover card and the drawer, under the breakdown it acts on, quiet enough to stay a footnote and disabled - with the row's own spinner - while a summary is already running. * ui: follow the bottom, otherwise leave the view alone The screen scrolled itself with a controller of observers, intervals, direction heuristics and landing timers, and still managed to move the view while the reader was reading: any mutation that grew the branch was treated as a reason to keep following. The page is the scroller, so it follows when the reader sits at the bottom, and stays where it is otherwise. A resize observer plus native scroll anchoring does the rest, and `pointerdown` buys the reader a moment of grace to be caught mid-drag. * ui: expand collapsible bodies with a height transition Expanding a block snapped it open: the body was mounted the moment `open` flipped, so a tall block moved the conversation around it in one frame. The body now goes through the same region the models table uses. The height interpolates and the visibility follows it, so a body is unmounted once the collapse has finished rather than the moment it starts - a closed block still costs nothing while tokens stream past it. * ui: open a compaction summary at the top of the screen Toggling a summary left the reader wherever they were, so a conversation that had just compacted showed the divider at the bottom of the screen and read down from there. A toggle now scrolls the page once and lands the divider a breath under the tabs, both ways: the summary is read from its beginning, and closing it returns to the same boundary instead of wherever the page happens to come to rest. The scroll waits for the body to reach its height, because before that the page is too short to scroll the divider up there and the call would clamp. That wait is the shared collapse duration rather than a transition event: an engine without `interpolate-size` animates the region's grid row instead of its height, so a listener on `height` would never fire there and the page would not move at all. * ui: spin the compaction icon while the summary runs The divider reported the phase in its title while the icon still showed a finished block, so a run in progress and a summary that had landed looked the same in the one place the eye reads first. The icon spins while the summary is running and folds back once it is in. * ui: let the compaction summary speak without the reasoning trimmings The summary is the thing the conversation now stands on, not a note beside it, and the conversation model always writes it, so the body drops the reasoning block's rule and indent (`flushBody` keeps them for the blocks that borrow them) and the model selector under the summary is gone - there is nothing left to swap. * ui: drop the model override from the compaction path The summary row no longer offers a model selector, so nothing hands regenerateCompaction a model anymore. Remove the parameter from the whole path, with the on-demand load of another model it carried: the summary always comes from the model the request funnel resolves. * ui: let the compaction summary think as the chat does The summary request forced thinking off, overriding the reasoning effort the user chose. The summary is the text the conversation resumes from, the task where reasoning helps the most, so the request now carries the very options of the chat. * ui: pre-encode the compacted branch as the next turn reads it The post-compaction pre-encode sent the branch without tools, while the tools render ahead of the messages, so it warmed a prefix the next turn never reads and that turn prefilled the whole compacted context again. The pre-encode now sends the tools, message shaping and reasoning handling of the chat, so the next turn only prefills its new message. * ui: pre-encode the branch the next turn actually reads The per-turn pre-encode sent the messages of the request plus one assistant message holding the streamed text, without tools. With tools on, it replaced the slot the next turn extends with a prefix nobody reads again, and after an agentic turn its history did not match the stored calls and results. Without agentic, it never ran. Both pre-encodes now read the stored branch up to its leaf, cut at the last compaction, and send it with the tools, message shaping and reasoning handling of the chat. The plain completion path triggers it too. * ui: refuse a compaction summary the output limit cut The stream handler read every chunk but dropped the finish reason, so a summary cut by max_tokens folded the conversation into half a text. The handlers now hand the finish reason to onComplete, and a summary that ends on length rolls the compaction back with an error. The summary was framed through a replacement string, so $& or 32560 in it changed the text the model read; it is framed as written now. * ui: wait for the collapse transition in the tool call tests The collapsible body now unmounts once its collapse animation ends rather than as soon as the block closes, so the "folds back" assertions ran before the body was gone. Wait out COLLAPSIBLE_TRANSITION_MS first. Assisted-by: Claude (Opus 5.5 Medium) --------- Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>
30 KiB
llama-ui
A modern, feature-rich web interface for llama-server built with SvelteKit. This UI provides an intuitive chat interface with advanced file handling, conversation management, and comprehensive model interaction capabilities.
Llama UI supports two server operation modes:
- MODEL mode - Single model operation (standard llama-server)
- ROUTER mode - Multi-model operation with dynamic model loading/unloading
Table of Contents
- Features
- Getting Started
- Tech Stack
- Build Pipeline
- Architecture
- Data Flows
- Architectural Patterns
- Testing
Features
Chat Interface
- Streaming responses with real-time updates
- Reasoning content - Support for models with thinking/reasoning blocks
- Dark/light theme with system preference detection
- Responsive design for desktop and mobile
File Attachments
- Images - JPEG, PNG, GIF, WebP, SVG (with PNG conversion)
- Documents - PDF (text extraction or image conversion for vision models)
- Audio - MP3, WAV for audio-capable models
- Text files - Source code, markdown, and other text formats
- Drag-and-drop and paste support with rich previews
Conversation Management
- Branching - Branch messages conversations at any point by editing messages or regenerating responses, navigate between branches
- Regeneration - Regenerate responses with optional model switching (ROUTER mode)
- Import/Export - JSON format for backup and sharing
- Search - Find conversations by title or content
Advanced Rendering
- Syntax highlighting - Code blocks with language detection
- Math formulas - KaTeX rendering for LaTeX expressions
- Markdown - Full GFM support with tables, lists, and more
Multi-Model Support (ROUTER mode)
- Models manager - one table for every model the server can serve, split into loaded, downloading, favorites, local and hidden sections, with search, context/capability/modality filters, sorting, load/unload, delete from disk and hide. It opens from the sidebar, from a model row or from the selector.
- Model selector with Loaded/Available groups
- Automatic loading - Models load on selection
- Modality validation - Prevents sending images to non-vision models
- LRU unloading - Server auto-manages model cache
- Downloads - In-flight downloads stay visible above the selector and can be paused, resumed or cancelled from the manager
- Hub metadata - Avatars, context length and chat template come from the Hugging Face Hub only while the
Use Hugging Face Hub API for models metadatasetting is on. It is off by default, and the UI then shows what the server reports for/v1/models
Keyboard Shortcuts
| Shortcut | Action |
|---|---|
Shift+Ctrl/Cmd+O |
New chat |
Shift+Ctrl/Cmd+E |
Edit conversation |
Shift+Ctrl/Cmd+D |
Delete conversation |
Ctrl/Cmd+K |
Search conversations |
Ctrl/Cmd+B |
Toggle sidebar |
Developer Experience
- Request tracking - Monitor token generation with
/slotsendpoint - Storybook - Component library with visual testing
- Hot reload - Instant updates during development
Getting Started
Prerequisites
- Node.js 18+ (20+ recommended)
- npm 9+
- llama-server running locally (for API access)
1. Install Dependencies
cd tools/ui
npm ci
2. Start llama-server
In a separate terminal, start the backend server:
# Single model (MODEL mode)
./llama-server -m model.gguf
# Multi-model (ROUTER mode)
./llama-server --models-dir /path/to/models
3. Start Development Servers
npm run dev
This starts:
- Vite dev server at
http://localhost:5173- The main UI frontend app - Storybook at
http://localhost:6006- Component documentation
The Vite dev server proxies API requests to SERVER_ORIGIN (with fallback to default llama-server 9931 port):
// vite.config.ts proxy configuration
proxy: {
'/v1': SERVER_ORIGIN,
'/props': SERVER_ORIGIN,
'/models': SERVER_ORIGIN,
'/tools': SERVER_ORIGIN,
'/slots': SERVER_ORIGIN,
'/cors-proxy': SERVER_ORIGIN
},
Development Workflow
- Open
http://localhost:5173in your browser - Make changes to
.svelte,.ts, or.cssfiles - Changes hot-reload instantly
- Use Storybook at
http://localhost:6006for isolated component development
Tech Stack
| Layer | Technology | Purpose |
|---|---|---|
| Framework | SvelteKit + Svelte 5 | Reactive UI with runes ($state, $derived, $effect) |
| UI Components | shadcn-svelte + bits-ui | Accessible, customizable component library |
| Drawers | vaul-svelte | Draggable drawer overlays (mobile pickers, model pane) |
| Styling | TailwindCSS 4 | Utility-first CSS with design tokens |
| Database | IndexedDB (Dexie) | Client-side storage for conversations and messages |
| Build | Vite | Fast bundling with static adapter |
| Testing | Playwright + Vitest + Storybook | E2E, unit, and visual testing |
| Markdown | remark + rehype | Markdown processing with KaTeX and syntax highlighting |
Key Dependencies
{
"svelte": "^5.0.0",
"bits-ui": "^2.8.11",
"dexie": "^4.0.11",
"pdfjs-dist": "^5.4.54",
"highlight.js": "^11.11.1",
"rehype-katex": "^7.0.1"
}
Build Pipeline
Development Build
npm run dev
Runs Vite in development mode with:
- Hot Module Replacement (HMR)
- Source maps
- Proxy to llama-server
Production Build
npm run build
The build process:
- Vite Build - Bundles all TypeScript, Svelte, and CSS
- Static Adapter - Outputs to
../../build/tools/ui/dist(llama-server's static file directory) - Post-Build Script - Cleans up intermediate files
- Custom Plugin - Creates
index.htmlwith:- Inlined favicon as base64
- GZIP compression (level 9)
- Deterministic output (zeroed timestamps)
tools/ui/ → build → build/tools/ui/dist/
├── src/ ├── index.html (served by llama-server)
├── static/ └── (favicon inlined)
└── ...
SvelteKit Configuration
// svelte.config.js
adapter: adapter({
pages: '../../build/tools/ui/dist', // Output directory
assets: '../../build/tools/ui/dist', // Static assets
fallback: 'index.html', // SPA fallback
strict: true
}),
output: {
bundleStrategy: 'inline' // Single-file bundle
}
Integration with llama-server
llama-ui is embedded directly into the llama-server binary:
npm run buildoutputsindex.htmltobuild/tools/ui/dist/- llama-server compiles this into the binary at build time
- When accessing
/, llama-server serves the bundled HTML
This results in a single portable binary with the full Llama UI included.
Architecture
Llama UI follows a layered architecture with unidirectional data flow:
Routes → Components → Hooks → Stores → Services → Storage/API
High-Level Architecture
flowchart TB
subgraph Routes["📍 Routes"]
R1["/ (Welcome)"]
R2["/chat/[id]"]
R3["/mcp-servers"]
R4["/search"]
R5["/settings"]
RL["+layout.svelte"]
end
subgraph Components["🧩 Components"]
C_Screen["ChatScreen"]
C_Form["ChatForm"]
C_Messages["ChatMessages"]
C_Sidebar["ChatSidebar"]
C_Models["ModelsSelector"]
C_Settings["ChatSettings"]
C_Mcp["McpServers"]
end
subgraph Hooks["🔌 Hooks"]
H1["use-chat-screen-active-model"]
H2["use-processing-state"]
H3["use-context-gauge"]
H4["use-models-selector"]
H5["use-tools-panel"]
end
subgraph Stores["🗄️ Stores"]
S1["chatStore"]
S2["conversationsStore"]
S3["modelsStore"]
S4["mcpStore"]
S5["agenticStore"]
S6["serverStore"]
S7["settingsStore"]
S8["toolsStore"]
end
subgraph Services["⚙️ Services"]
SV1["ChatService"]
SV2["ModelsService"]
SV3["PropsService"]
SV4["DatabaseService"]
SV5["MCPService"]
SV6["ToolsService"]
SV7["SandboxService"]
end
subgraph Storage["💾 Storage"]
ST1["IndexedDB"]
ST2["LocalStorage"]
end
subgraph APIs["🌐 llama-server"]
API1["/v1/chat/completions"]
API2["/props"]
API3["/models/*"]
API4["/tools"]
end
R1 & R2 --> C_Screen
RL --> C_Sidebar
C_Screen --> C_Form & C_Messages & C_Settings
C_Screen --> H1 & H2 & H3
C_Models --> H4
C_Mcp --> S4
C_Screen --> S1 & S2 & S3
C_Models --> S3
H1 --> S3
S1 --> SV1 & SV4
S2 --> SV4
S3 --> SV2 & SV3
S4 --> SV5
S5 --> SV1 & SV5 & SV6 & SV7
SV4 --> ST1
SV1 --> API1
SV2 --> API3
SV3 --> API2
SV6 --> API4
Layer Breakdown
Routes (src/routes/)
/- Welcome screen, creates new conversation/chat/[id]- Active chat interface/mcp-servers- MCP server management/search- Conversation search/settings- Settings (optional[[section]])+layout.svelte- Sidebar, navigation, global initialization
Components (src/lib/components/)
Components are organized in app/ (application-specific) and ui/ (shadcn-svelte primitives).
Chat Components (app/chat/):
| Component | Responsibility |
|---|---|
ChatScreen/ |
Main chat container, coordinates message list, input form, and attachments |
ChatForm/ |
Message input textarea with file upload, paste handling, keyboard shortcuts |
ChatMessages/ |
Message list with branch navigation, regenerate/continue/edit actions |
ChatAttachments/ |
File attachment previews, drag-and-drop, PDF/image/audio handling |
ChatSettings/ |
Parameter sliders (temperature, top-p, etc.) with server default sync |
ChatSidebar/ |
Conversation list, search, import/export, navigation |
Dialog Components (app/dialogs/):
| Component | Responsibility |
|---|---|
DialogChatSettings |
Full-screen settings configuration |
DialogManageModels |
Models manager: browse, load, download and delete models |
DialogModelInformation |
Model details (context size, modalities, parallel slots) |
DialogChatAttachmentsPreview |
Full preview for images, PDFs (text or page view), code |
DialogConfirmation |
Generic confirmation for destructive actions |
DialogConversationRename |
Edit conversation title |
Server/Model Components (app/server/, app/models/):
| Component | Responsibility |
|---|---|
ServerErrorSplash |
Error display when server is unreachable |
ModelsSelector/ |
Model dropdown and mobile sheet: favorites, loaded and local sections, rows windowed and folded into families |
ModelsManager/ |
Models manager table and model pane: sections, filters, sorting, quants folded per repo, downloads |
ModelAvatar |
Org avatar of a model, with the quantizer badge; follows the family grouping of the list |
ModelId, ModelBadge |
Model name, aliases, tags, quantization and draft sidecar badges |
ModelContext, ModelCapabilities |
Context window and capability icons, filled from the Hub when it is enabled |
Shared UI Components (app/misc/):
| Component | Responsibility |
|---|---|
MarkdownContent |
Markdown rendering with KaTeX, syntax highlighting, copy buttons |
SyntaxHighlightedCode |
Code blocks with language detection and highlighting |
ActionIcon, DropdownMenuActions |
Reusable action button and action menu |
BadgesModality, BadgeInfo |
Status and capability badges |
CollapsibleSection, CollapsibleRegion |
Section header with a trigger that expands in place |
GroupedList |
Grouped rows with foldable groups, per-group windows and show-more rows |
ScrollCarousel, TruncatedText |
Horizontal scroll strip and single-line truncation with tooltip |
Hooks (src/lib/hooks/)
Hooks are the thin view-layer between components and stores: they own UI concerns (scroll, drag-and-drop, keyboard shortcuts, pickers, selection) and translate store state into view state.
| Hook | Responsibility |
|---|---|
use-chat-screen-active-model |
Active model resolution + modality capability detection |
use-processing-state |
View over chatStore.processing for streaming progress/tokens |
use-context-gauge |
View over contextStatsStore for the context usage gauge |
use-models-selector |
Model selector state: hidden models, family grouping, windowed rows, selection and load on pick |
use-tools-panel |
Tools panel state |
use-reasoning-menu |
Reasoning-effort menu state |
use-attachment-menu |
Attachment menu + modality flags |
use-draft-messages |
Per-chat draft message/files persistence |
use-chat-form-pickers |
Chat form pickers (commands, mentions) |
use-debounced-search |
Shared debounced async search for pickers |
use-picker-navigation |
Picker keyboard navigation |
use-chat-message-edit-context |
Message edit context (content + extras) |
use-chat-screen-drag-and-drop |
Drag-and-drop state machine |
use-chat-screen-file-upload |
File upload queue + capability validation |
use-stick-to-bottom |
Follows new content while the reader sits at the bottom of a scroller |
use-marquee-selection |
Shift+click / marquee range selection |
use-keyboard-shortcuts |
Global keyboard shortcuts |
use-settings-navigation |
Settings section navigation |
use-pwa |
PWA install/update + version mismatch detection |
Stores (src/lib/stores/)
Stores own reactive application state as Svelte 5 runes. Larger stores are split into directories and compose focused sub-stores behind a narrow host interface (see Architectural Patterns).
| Store | Responsibility |
|---|---|
chatStore |
Chat lifecycle, streaming, abort control, error handling; composes processing, activity, streams, flows |
conversationsStore |
Conversation CRUD, message branching, navigation, import/export; composes preferences |
modelsStore |
Model list, selection, loading/unloading (ROUTER), recent picks, favorites, hidden models and list open state; composes props, status |
mcpStore |
MCP host role: multi-server lifecycle, tool routing, server icons; composes health, resources |
agenticStore |
Multi-turn agentic loop orchestration, tool execution; composes gates |
serverStore |
Server connection state, /props, role detection, modalities |
settingsStore |
User preferences, theme, parameter sync with server defaults |
toolsStore |
Tool registry: server + MCP tools, enabled set for the LLM |
permissionsStore |
Persisted tool permission grants |
contextStatsStore |
Context window usage for the active conversation |
draftMessagesStore |
Per-chat draft message/files |
deviceStore |
Browser environment signals (mobile, OS, theme) |
versionStore |
Build version information |
Services (src/lib/services/)
Services are a stateless protocol layer: static methods, pure I/O, no reactive state. Stores consume them for all API and storage access.
| Service | Responsibility |
|---|---|
ChatService |
/v1/chat/completions streaming + SSE parsing, message format conversion |
ModelsService |
/models, /models/load, /models/unload |
PropsService |
/props, /props?model= |
HuggingFaceService |
Hugging Face Hub metadata: model details, avatars, README and file tree, cached per repo and off unless the Hub setting is on |
DatabaseService |
IndexedDB operations via Dexie |
MCPService |
MCP protocol: transports, connect, list/execute tools, prompts, resources |
ToolsService |
Server tool list/execute/stream (/tools) |
SandboxService |
Browser JS execution in a sandboxed worker |
ParameterSyncService |
Syncs settings with server defaults |
ConversationTransferService |
Conversation import/export JSONL + ZIP format |
MigrationService |
Non-destructive localStorage/IndexedDB migrations |
RouterService |
Dynamic route URL construction |
Data Flows
MODEL Mode (Single Model)
sequenceDiagram
participant User
participant UI
participant Stores
participant DB as IndexedDB
participant API as llama-server
Note over User,API: Initialization
UI->>Stores: initStores() (awaited by route loads)
Stores->>Stores: run migrations
Stores->>DB: load conversations (background)
Stores->>API: GET /props
API-->>Stores: server config
Stores->>API: GET /v1/models
API-->>Stores: single model (auto-selected)
Note over User,API: Chat Flow
User->>UI: send message
Stores->>DB: save user message
Stores->>API: POST /v1/chat/completions (stream)
loop streaming
API-->>Stores: SSE chunks
Stores-->>UI: reactive update
end
Stores->>DB: save assistant message
ROUTER Mode (Multi-Model)
sequenceDiagram
participant User
participant UI
participant Stores
participant API as llama-server
Note over User,API: Initialization
Stores->>API: GET /props
API-->>Stores: {role: "router"}
Stores->>API: GET /models
API-->>Stores: models[] with status
Note over User,API: Model Selection
User->>UI: select model
alt model not loaded
Stores->>API: POST /models/load
loop poll status
Stores->>API: GET /models
end
Stores->>API: GET /props?model=X
end
Stores->>Stores: validate modalities
Note over User,API: Chat Flow
Stores->>API: POST /v1/chat/completions {model: X}
loop streaming
API-->>Stores: SSE chunks + model info
end
Architectural Patterns
1. Reactive State with Svelte 5 Runes
All stores use Svelte 5's fine-grained reactivity:
// Store with reactive state
class ChatStore {
#isLoading = $state(false);
#currentResponse = $state('');
// Derived values auto-update
get isStreaming() {
return $derived(this.#isLoading && this.#currentResponse.length > 0);
}
}
// Exported reactive accessors
export const isLoading = () => chatStore.isLoading;
export const currentResponse = () => chatStore.currentResponse;
2. Unidirectional Data Flow
Data flows in one direction, making state predictable:
flowchart LR
subgraph UI["UI Layer"]
A[User Action] --> B[Component]
end
subgraph State["State Layer"]
B --> C[Store Method]
C --> D[State Update]
end
subgraph IO["I/O Layer"]
C --> E[Service]
E --> F[API / IndexedDB]
F -.->|Response| D
end
D -->|Reactive| B
Components dispatch actions to stores, stores coordinate with services for I/O, and state updates reactively propagate back to the UI.
3. Per-Conversation State
Enables concurrent streaming across multiple conversations. Loading is tracked
per conversation by the activity ledger (chatStore.activity), while streaming
state and abort controllers live in per-conversation maps:
class ChatStore {
chatStreamingStates = new SvelteMap<string, { response: string; messageId: string }>();
abortControllers = new SvelteMap<string, AbortController>();
}
4. Message Branching with Tree Structure
Conversations are stored as a tree, not a linear list:
interface DatabaseMessage {
id: string;
parent: string | null; // Points to parent message
children: string[]; // List of child message IDs
// ...
}
interface DatabaseConversation {
currentNode: string; // Currently viewed branch tip
// ...
}
Navigation between branches updates currentNode without losing history.
5. Layered Service Architecture
Stores handle state; services handle I/O:
┌─────────────────┐
│ Stores │ Business logic, state management
├─────────────────┤
│ Services │ API calls, database operations
├─────────────────┤
│ Storage/API │ IndexedDB, LocalStorage, HTTP
└─────────────────┘
6. Server Role Abstraction
Single codebase handles both MODEL and ROUTER modes:
// serverStore.ts
get isRouterMode() {
return this.role === ServerRole.ROUTER;
}
// Components conditionally render based on mode
{#if isRouterMode()}
<ModelsSelector />
{/if}
7. Modality Validation
Prevents sending attachments to incompatible models. The
use-chat-screen-active-model hook derives the active model's capabilities
from modelsStore.props:
// use-chat-screen-active-model hook
const hasVisionModality = $derived.by(() => modelsStore.props.modelSupportsVision(activeModelId));
const hasAudioModality = $derived.by(() => modelsStore.props.modelSupportsAudio(activeModelId));
8. Persistent Storage Strategy
Data is persisted across sessions using two storage mechanisms:
flowchart TB
subgraph Browser["Browser Storage"]
subgraph IDB["IndexedDB (Dexie)"]
C[Conversations]
M[Messages]
end
subgraph LS["LocalStorage"]
S[Settings Config]
O[User Overrides]
T[Theme Preference]
end
end
subgraph Stores["Svelte Stores"]
CS[conversationsStore] --> C
CS --> M
SS[settingsStore] --> S
SS --> O
SS --> T
end
- IndexedDB: Conversations and messages (large, structured data)
- LocalStorage: Settings, user parameter overrides, theme, model favorites, recent picks, hidden models and model list open state (small key-value data)
- Memory only: Server props, model list (fetched fresh on each session), Hugging Face Hub details (cached per repo for the session)
9. Remote Assets Under Cross-Origin Isolation
llama-server serves the UI with Cross-Origin-Embedder-Policy: require-corp and Cross-Origin-Opener-Policy: same-origin, so a cross-origin subresource has to be allowed by the target origin. The UI handles that per asset kind:
- Hub avatars are requested in CORS mode (
crossorigin="anonymous"), which the Hub allows - Hub metadata is fetched with
fetch(), which is a CORS request by default, and only while the Hub setting is on - MCP server icons and web-search result favicons have no CORS guarantee, so they go through the server's
/cors-proxywhen the user started llama-server with--ui-mcp-proxy; without it they fall back to the bundled glyph - Per-row Hub lookups wait until the row is near the viewport (the
nearViewportaction), so a long model list does not fire one request per row on mount
Testing
Test Types
| Type | Tool | Location | Command |
|---|---|---|---|
| Unit | Vitest | tests/unit/ |
npm run test:unit |
| UI/Visual | Storybook + Vitest | tests/stories/ |
npm run test:ui |
| E2E | Playwright | tests/e2e/ |
npm run test:e2e |
| Client | Vitest | tests/client/. |
npm run test:unit |
Running Tests
# All tests
npm run test
# Individual test suites
npm run test:e2e # End-to-end (requires llama-server)
npm run test:client # Client-side unit tests
npm run test:server # Server-side unit tests
npm run test:ui # Storybook visual tests
Storybook Development
npm run storybook # Start Storybook dev server on :6006
npm run build-storybook # Build static Storybook
Linting and Formatting
npm run lint # Check code style
npm run format # Auto-format with Prettier
npm run check # TypeScript type checking
Project Structure
tools/ui/
├── src/
│ ├── lib/
│ │ ├── components/ # UI components (app/, ui/)
│ │ ├── hooks/ # Svelte hooks
│ │ ├── stores/ # State management
│ │ ├── services/ # API and database services
│ │ ├── types/ # TypeScript interfaces
│ │ └── utils/ # Utility functions
│ ├── routes/ # SvelteKit routes
│ └── styles/ # Global styles
├── static/ # Static assets
├── tests/ # Test files
└── .storybook/ # Storybook configuration
Related Documentation
- llama.cpp Server README - Full server documentation
- Multimodal Documentation - Image and audio support
- Function Calling - Tool use capabilities