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๐Ÿ“… Asset Events

Asset events represent significant occurrences that affect an asset's price or generate distributions. They live in the asset domain, not the portfolio/transaction domain.

๐Ÿ“‹ Event Types

  Event Type Effect on Price Who Generates Description
๐Ÿ’ฐ DIVIDEND Price drops by event value (ex-date) Provider (yfinance, justetf) or manual Cash distribution from equity/ETF
๐Ÿ“ˆ INTEREST Price drops by event value Scheduled Investment (generate_interest) or manual Interest payment from debt/loan. Resets accrued interest
๐Ÿ“Š PRICE_ADJUSTMENT Algebraic change (+/โˆ’) Manual, or listed in a Scheduled Investment schedule Non-cash value change (write-down, haircut)
โœ‚๏ธ SPLIT Changes quantity, not total value Provider (yfinance) or manual Stock/unit split
๐Ÿ MATURITY_SETTLEMENT Final capital return Scheduled Investment (generate_interest) or manual Asset reaches maturity โ€” no further calculations

๐Ÿ—ƒ๏ธ Database Model

erDiagram
    ASSET ||--o{ ASSET_EVENT : "has events"
    ASSET_PROVIDER_ASSIGNMENT ||--o{ ASSET_EVENT : "generates"

    ASSET_EVENT {
        int id PK
        int asset_id FK "โ†’ assets.id"
        date date "Event date"
        enum type "DIVIDEND, INTEREST, PRICE_ADJUSTMENT, SPLIT, MATURITY_SETTLEMENT"
        decimal value "Monetary value"
        string currency "ISO 4217"
        int provider_assignment_id FK "nullable โ€” NULL = manual"
        text notes "nullable"
    }

No UniqueConstraint on (asset_id, date, type) โ€” auto-generated and manual events can coexist on the same date and type. Nothing forbids two rows of the same source on one key either: the upsert below collapses such legacy duplicates when a batch brings fewer events for that key.

Indexes: (asset_id, date), (asset_id, type, date), (provider_assignment_id).

๐Ÿ”„ Dedup Strategy

_upsert_asset_events() (asset_sources/price_store.py) writes both kinds of events in place, one source per call: a sync passes the assignment's id, the manual upsert passes None. It groups the incoming events by (date, type) and matches each key against the stored rows of the same source only (same asset_id and provider_assignment_id, IS NULL for manual events):

# Simplified logic of _upsert_asset_events() and _write_event_group(), for each (date, type) key
stored = rows on the key with this asset_id and provider_assignment_id, ORDER BY id
for row, evt in zip(stored, incoming):  # paired lowest id first: updated, id kept
    row.value, row.currency = evt.value.amount, evt.value.code or default_currency
    row.notes, row.updated_at = evt.notes, now
session.add_all(incoming[len(stored):])  # extra incoming events are inserted
surplus = stored[len(incoming):]  # legacy same-key duplicates of this source
# UPDATE transactions SET asset_event_id = stored[0].id WHERE asset_event_id IN surplus
# DELETE FROM asset_events WHERE id IN surplus

A key thus ends with as many rows as the batch brings, the lowest ids kept, and the transactions of a collapsed duplicate move to the row that stays. Rows of another source on that key are never touched, and a stored key the batch does not mention is kept. Keys are committed in slices of PRICE_UPSERT_CHUNK_SIZE (1,000).

The upsert used to DELETE the stored rows of each key and INSERT the new ones. But transactions.asset_event_id is ON DELETE RESTRICT, so that failed as soon as a transaction realised the event: a provider refresh of such an event reported Event upsert failed, and editing a linked manual event answered HTTP 500. A row updated in place keeps its id, so the transactions linked to it stay linked.

๐Ÿค– Auto-Generated Events (provider_assignment_id IS NOT NULL)

A sync passes the assignment's id. This ensures:

  • An event the provider returns again updates the stored one of the same date and type, which keeps its id: a transaction linked to it stays linked
  • Events from different providers for the same asset are independent, and manual events are never touched
  • A stored event the provider no longer returns is kept: the upsert only touches the date and type pairs of its batch

A parametric provider (Scheduled Investment) derives its whole series from its parameters. When they change, or when the asset leaves it for another provider, provider_management.py deletes the asset's prices and that assignment's events, first unlinking the transactions that pointed to them (asset_event_id = NULL); manual events stay.

The data editor shows these events read-only: the events of POST /assets/prices/query carry is_auto (provider_assignment_id IS NOT NULL). An edit would be overwritten by the next sync, and a deletion lasts only until the provider returns the event again.

โœ‹ Manual Events (provider_assignment_id IS NULL)

POST /api/v1/assets/events (bulk_upsert_events()) takes a list of FAEventUpsert items, {asset_id, events}, whose points are FAEventUpsertPoint: an FAAssetEventPoint with an optional id (schemas/prices.py). For each item:

  • An event with an explicit currency other than the asset's โ†’ HTTP 400 EVENT_CURRENCY_MISMATCH.
  • An event with id edits that manual row in place, every field included (date, type, value and currency, notes), and the row keeps its id. The data editor sends the id of every saved row, so changing the Type of a saved event no longer adds a second event.
  • Events without id go through _upsert_asset_events(provider_assignment_id=None): matched on (date, type) among the manual rows and updated in place, so a manual event still replaces the manual event of the same date and type, now keeping its id.
  • Each item is committed on its own: a refused item writes nothing and ends the request, while the items before it stay stored.

The whole item is checked before anything is written:

Refused Answer
The same id twice in the item HTTP 422 Duplicate event id in one upsert item, from the FAEventUpsert validator: the whole request is refused
An id that is unknown, belongs to another asset, or names a provider event HTTP 400 EVENT_NOT_EDITABLE
An edit that changes its date or type (a mover) landing on a key another edit of the item ends on, or on a key held by a manual row the item does not edit HTTP 400 EVENT_KEY_CONFLICT
An event without id on a key an edit of the item ends on HTTP 400 EVENT_KEY_CONFLICT

Allowed: two edits swapping their keys, edits that keep a shared key (legacy duplicates stay editable), and an event without id on a key a mover vacates. These checks only cover keys an edit ends on: an event without id on the key of a manual row the item does not edit updates that row, and two events without id on one key are both stored. assets.py maps the three codes to HTTP 400; any other AssetSourceError is a 500.

A type change is allowed even when a transaction is linked to the event: the link stays, and the transaction is then read according to the new type. compute_wac_iterative() (portfolio_service.py) counts an ADJUSTMENT as split-linked only while its event is a SPLIT: the type is joined live, and the split-linked set is part of the WAC cache fingerprint. Once the event is retyped to PRICE_ADJUSTMENT, a +qty adjustment becomes an acquisition of unknown cost (the pool cost turns incomplete, the numbers shown do not change) and a โˆ’qty one a plain reduction that takes its share of the cost away (in the test, the total cost halves from 1,500 to 750). Both cases are pinned by the test_*_split_relabelled_as_price_adjustment_* tests in test_scripts/test_api/test_portfolio_wac.py.

Manual events are never deleted by the sync process. They survive provider re-syncs, provider changes, and bulk refreshes. Only an explicit user deletion removes them (DELETE /api/v1/assets/events?ids=โ€ฆ, which reports an event a transaction uses as in_use instead of deleting it), or the market-data wipe of a currency change (POST /api/v1/assets/{asset_id}/market-data/wipe), which deletes every event of the asset.

๐Ÿ”ง Auto-Generated Events

๐Ÿ“ˆ Yahoo Finance: Dividends & Splits

During sync, the Yahoo Finance provider generates:

  • DIVIDEND events from ticker.dividends โ€” ex-dividend dates with the per-share payout value and currency.
  • SPLIT events from ticker.splits โ€” split dates with the split ratio as the event value (e.g., 4.0 for a 4:1 split).

Both are written by the standard _upsert_asset_events() pipeline, scoped by provider_assignment_id.

๐Ÿ” JustETF: Dividends from Chart Data

During sync, the JustETF provider parses dividend data from load_chart() response. Distribution dates and amounts are extracted and stored as DIVIDEND events.

๐Ÿ“Š Scheduled Investment: generate_interest

When a schedule period has generate_interest = True, the Scheduled Investment provider auto-generates:

  1. INTEREST events at each maturation date within the period
  2. After each INTEREST event, accrued interest resets: total_interest = 0, event_adjustment = 0 โ†’ value returns to initial_value

The maturation frequency is controlled by maturation_frequency on each interest rate period (DAILY, WEEKLY, MONTHLY, QUARTERLY, SEMIANNUAL, ANNUAL).

The events entered in the schedule itself (asset_events in the provider parameters, Add Event in the asset form) travel the same way: get_history_value() returns them with the generated ones, so the sync stores them under the assignment and the data editor shows them read-only.

๐Ÿ MATURITY_SETTLEMENT

Auto-generated when:

  • The schedule ends and generate_interest = True on the last period
  • Or late interest is configured with generate_interest = True

After settlement, the engine is "off" โ€” get_current_value() returns the settlement value for all future dates.

๐Ÿ“ Event Impact on Pricing

The Scheduled Investment engine's pricing formula incorporates events:

price(d) = initial_value + accrued_interest - ฮฃ(INTEREST events) + ฮฃ(PRICE_ADJUSTMENT events)
  • Interest is always calculated on initial_value (not running value)
  • INTEREST events subtract from the running price (coupon paid out)
  • PRICE_ADJUSTMENT events are algebraic (can add or subtract)
  • After MATURITY_SETTLEMENT, no further calculations occur