A journal is an internal accounting artifact created by the runtime from a business event. Journals are not the main application-facing API; applications publish business events.

Statuses

• draft — built but not yet posted
• validated — passed invariant validation
• posted — immutable, persisted, executed by the ledger backend
• reversed — fully reversed by a later reversal journal
• rejected — preserved for audit

Fields

• id — integer() — primary key

• event_id — String.t() | nil — the originating business event id

• external_id — String.t() | nil

• source_system / source_type / source_id — String.t() | nil — provenance

• selected_policy — String.t() | nil — e.g. "cash_deposit"

• selected_template — String.t() | nil

• description — String.t() | nil

• status — String.t() — one of statuses/0 (default "draft")

• effective_date — Date.t() | nil

• posted_at — DateTime.t() | nil — set when posted

• reversed_at — DateTime.t() | nil — set when reversed

• reversal_of_id — integer() | nil — self-reference for reversals

• idempotency_key — String.t() | nil — unique; prevents duplicate posting

• explanation — map() | nil — full knowledge-layer explanation

• metadata — map()
• postings — [Posting.t()] — has_many association
• inserted_at / updated_at — DateTime.t()

Rules

• posted journals are immutable
• rejected journals are preserved for audit
• reversals create a new journal that exactly negates the original postings
• the idempotency key prevents duplicate posting

Example

%Logistiki.Accounting.Journal{
  id: 1,
  event_id: "evt_001",
  selected_policy: "cash_deposit",
  status: "posted",
  effective_date: ~D[2026-07-07],
  posted_at: ~U[2026-07-07 12:00:00Z],
  idempotency_key: "evt:evt_001:policy:cash_deposit"
}