Mixins

File location: schema/mixins/<name>.yaml

Defining a mixin

mixin: timestamps
columns:
  - name: created_at
    type: timestamptz
    nullable: false
    default: now()
  - name: updated_at
    type: timestamptz
    nullable: false
    default: now()
indexes:
  - columns: [created_at]
triggers:
  - name: set_{table}_updated_at
    timing: BEFORE
    events: [UPDATE]
    function: update_timestamp
    for_each: ROW
checks:
  - name: chk_{table}_dates
    expression: 'updated_at >= created_at'
rls: true
force_rls: true
policies:
  - name: '{table}_owner_policy'
    for: ALL
    to: app_user
    using: 'owner_id = current_user_id()'
grants:
  - to: app_readonly
    privileges: [SELECT]

Using a mixin

Tables reference mixins by name:

table: orders
mixins:
  - timestamps
columns:
  - name: id
    type: uuid
    primary_key: true
  # timestamps columns, indexes, triggers, checks, policies, grants merged automatically

What mixins can contribute

Property	Description
columns	Added before table’s own columns
indexes	Merged into table indexes
checks	Merged into table checks
triggers	Merged into table triggers
policies	Merged into table policies
grants	Merged into table grants
rls	Enables RLS on consuming table
force_rls	Forces RLS on consuming table

{table} placeholder

The {table} placeholder in any mixin string value is replaced with the consuming table’s name. This ensures unique constraint/trigger/policy names across tables.

# In the mixin:
triggers:
  - name: set_{table}_updated_at

# Applied to table "orders", becomes:
triggers:
  - name: set_orders_updated_at

Merge rules

• Columns: Mixin columns come first. If a table defines a column with the same name as a mixin column, the table’s definition wins.
• Multiple mixins: Applied in order. Later mixins can override earlier ones.
• All other properties: Concatenated (indexes, checks, triggers, policies, grants).