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💰 Asset Pricing & Metadata Architecture

The Asset system in LibreFolio manages financial instruments (Stocks, ETFs, Bonds, Crypto, etc.), fetches their prices from external providers, and maintains their metadata.

🧱 Core Components

1️⃣ AssetSourceProvider (Plugin Base Class)

Abstract base class for all asset pricing plugins. Each provider auto-registers via @register_provider(AssetProviderRegistry).

Property / Method Required Default Description
provider_code ✅ — Unique identifier (e.g., "yfinance")
provider_name ✅ — Human-readable name
test_cases ✅ — Test data for automated testing
test_search_query ✅ — Search query for tests (None if search unsupported)
get_current_value() ✅ — Fetch latest price → FACurrentValue
get_history_value() ✅ — Fetch historical OHLCV → FAHistoricalData
validate_params() ✅ no-op Validate provider-specific configuration
params_schema — [] Schema for dynamic form generation in the frontend
get_asset_url() — None URL to the provider's page for this asset
accepted_identifier_types — [TICKER, ISIN] Input types accepted by this provider
supports_history — True False for current-price-only providers
search() — raises NOT_SUPPORTED Search for assets by name/ticker/ISIN
fetch_asset_metadata() — None Fetch asset metadata (type, sector, identifiers)
provider_help_url — None URL to the provider's documentation page

supports_search heuristic

The list_providers endpoint determines search support via instance.test_search_query is not None — a local property check, not an HTTP call. This avoids cold-start latency on GET /assets/provider.

2️⃣ AssetSourceManager

Central service that coordinates all asset-related operations:

  • Provider Assignment: Link an asset to a provider (e.g., "AAPL" → "yfinance").
  • Price Sync: 3-phase pipeline: PREPARE → FETCH → PERSIST (see Data Flow below).
  • Price Query: DB-only bulk query with backward-fill via POST /assets/prices/query.
  • Current Price (new): Bulk live-price endpoint via POST /assets/prices/current. Calls each asset's provider get_current_value() with DB fallback. Used by the LiveTicker component.
  • Event Sync: Persist asset events from providers into the asset_events table, filtered by provider_assignment_id (manual events survive sync).
  • Probe: Dry-run provider config testing via probe_provider_config().
  • Metadata: Delegate to AssetMetadataService for classification merging.

3️⃣ AssetMetadataService

Manages descriptive information about assets:

  • Classification: sector_area and geographic_area distributions.
  • Merging: Merges metadata from providers with existing user-defined data.
  • Patching: Supports partial updates to asset metadata.

4️⃣ AssetProviderRegistry

Uses the Registry Pattern for auto-discovery of provider plugins.

5️⃣ AssetEvent Table

Stores asset-level events produced by providers or created manually by users. Events are distinct from portfolio transactions:

  • Events describe what happens to the asset globally (DIVIDEND, INTEREST, SPLIT, etc.)
  • Transactions describe what happens in a user's portfolio (BUY, SELL)

Dedup strategy: Events with a provider_assignment_id (auto-generated) are deduped via DELETE+INSERT filtered by (asset_id, provider_assignment_id) during sync. Events with provider_assignment_id = NULL are user-created manual events and are never auto-deleted.

See Asset Events for full details.

🔄 Data Flow: Sync Pipeline

When the user triggers a sync (or the scheduler does), bulk_refresh_prices() executes a 3-phase pipeline:

graph TD
    API["POST /assets/prices/sync"] --> Manager["AssetSourceManager.bulk_refresh_prices()"]

    subgraph "Phase 1 — PREPARE"
        Manager --> DB1[(Database)]
        DB1 -- "Provider assignments" --> Manager
        Manager --> Registry["AssetProviderRegistry"]
        Registry -- "Provider instances" --> Manager
    end

    subgraph "Phase 2 — FETCH (parallel)"
        Manager -- "get_history_value()" --> P1["Provider A"]
        Manager -- "get_history_value()" --> P2["Provider B"]
        P1 -- "FAHistoricalData" --> Manager
        P2 -- "FAHistoricalData" --> Manager
    end

    subgraph "Phase 3 — PERSIST"
        Manager -- "Upsert prices" --> DB2[(Database)]
        Manager -- "Upsert events" --> DB2
    end

    DB2 -- "FABulkRefreshResponse" --> API

    style P1 fill:#e3f2fd,stroke:#1565c0
    style P2 fill:#e3f2fd,stroke:#1565c0
    style DB1 fill:#f3e5f5,stroke:#7b1fa2
    style DB2 fill:#f3e5f5,stroke:#7b1fa2

Phase 2 uses asyncio.Semaphore to limit concurrent HTTP requests. Each provider fetch includes:

  • Price points (OHLCV)
  • Asset events (if supports_events = True)

Phase 3 upserts prices and events in a single transaction. Event sync respects provider_assignment_id — only auto-generated events for that provider are replaced.

📊 Data Flow: Price Query

POST /assets/prices/query is the primary read endpoint for price data. It reads directly from the database (no provider calls) and applies backward-fill for gaps.

graph LR
    FE["Frontend"] -- "POST /assets/prices/query" --> API["API Endpoint"]
    API --> Manager["AssetSourceManager.get_prices_bulk()"]
    Manager -- "Single SQL query" --> DB[(Database)]
    DB -- "Raw prices" --> Manager
    Manager -- "Backward-fill gaps" --> Manager
    Manager -- "FAPriceQueryResponse" --> FE

    style DB fill:#f3e5f5,stroke:#7b1fa2

Each query item can request:

  • include_price: true — price history with backward-fill
  • include_events: true — asset events in the date range

🧪 Provider Probe

POST /assets/provider/probe allows dry-run testing of a provider configuration without persisting anything.

Operations (selectable per request):

Operation What it tests
current_price Fetches latest price → validates provider can reach the asset
history Fetches last 30 days of data → validates historical data availability
metadata Fetches asset metadata → validates identifier resolution

Each operation returns success, execution_time_ms, and operation-specific data. The probe is used by the frontend "Test Configuration" button in the provider assignment section.

📊 Backward Fill Logic

Financial markets are closed on weekends and holidays. To provide a continuous price series for charts, LibreFolio uses a backward-fill strategy.

If a price is requested for a date where no data exists (e.g., Sunday), the system looks back to find the most recent available price (e.g., Friday's close) and uses that. The backward_fill_info field in FAPricePoint indicates the actual date and staleness (days_back).

⚡ Cache & Performance

  • NamedCache: generic TTL-based in-memory cache used across services. Each cache instance has a name, max TTL, and automatic eviction. Used by _asset_current_cache for current-price lookups.
  • _asset_current_cache: caches get_current_prices_bulk() results keyed by (asset_id, provider_id). Prevents redundant provider calls during UI refresh storms (e.g., scrolling through the asset list).
  • Provider Pre-warm: _prewarm_provider_caches() runs asynchronously in main.py lifespan — instantiates all registered providers at startup to prime internal caches (JustETF ETF list, yfinance search cache, etc.).
  • supports_search check: Uses test_search_query is not None (local property), avoiding cold-start HTTP calls on GET /assets/provider.
  • Bulk queries: get_prices_bulk() uses a single SQL query for all requested assets, not N+1.

🌐 API Endpoints Summary

Endpoint Method Description
POST /api/v1/assets POST Bulk create assets
PATCH /api/v1/assets PATCH Bulk update assets
GET /api/v1/assets GET Bulk read by IDs (with metadata)
GET /api/v1/assets/all GET All active assets
GET /api/v1/assets/query GET Filtered list (search, type, currency, active)
DELETE /api/v1/assets DELETE Bulk delete (cascade provider+prices)
GET /api/v1/assets/provider GET List providers (with params_schema)
GET /api/v1/assets/provider/search GET Multi-provider parallel search
GET /api/v1/assets/provider/search/stream GET SSE streaming search results
POST /api/v1/assets/provider/probe POST Dry-run provider config test
POST /api/v1/assets/provider POST Bulk assign providers
DELETE /api/v1/assets/provider DELETE Bulk remove providers
GET /api/v1/assets/provider/assignments GET Read provider assignments
POST /api/v1/assets/provider/refresh POST Refresh metadata from provider
POST /api/v1/assets/prices POST Bulk upsert prices
DELETE /api/v1/assets/prices DELETE Bulk delete price ranges
POST /api/v1/assets/prices/query POST Bulk price query (DB-only, backward-fill)
POST /api/v1/assets/prices/sync POST Bulk refresh prices from provider