Count & Autonumber Fields

Two columns the engine fills in — a count of related records, and a sequence the database allocates.

Neither of these takes a value from a user. count is derived from a relationship; autonumber is allocated by the database on insert.

`count`

Counts the records linked through a relationship field in the same table — a rollup narrowed to the one aggregation everybody wants.

Path	Kind	Values	Description
`id`	number		Unique identifier for a field within a table. Examples: 1, 2, 3, 100
`name`	string		Internal identifier for the field: the database column name, and the key used in API payloads and formulas. Use `label` for the name end users read.
`label`	string		External display name shown to end users, in place of the internal `name`. Resolution order on every surface: surface-level override, then this label, then the raw `name` verbatim.
`description`	string		Author-written guidance rendered beside the field (under the control on a form, beside the value in a drawer) and associated with the control via aria-describedby. Unlike a placeholder it persists once the user starts typing.
`required`	boolean		Rejects a record whose value for this field is missing or empty, both through the API and in any generated form.
`unique`	boolean		Rejects a record whose value for this field is already used by another record in the same table.
`indexed`	boolean		Adds a database index on this field, so filtering and sorting on it stay fast as the table grows, at the cost of slightly slower writes.
`type`	enum	`count`	Constant value 'count' for type discrimination in discriminated unions
`relationshipField`	string		Name of the relationship field in the same table to count linked records from

`filters`

Path	Kind	Description
`filters`	object	Filters to apply when counting linked records
`filters.field`	string	Field the condition is evaluated against.
`filters.operator`	string	How the field value is compared, such as `equals`, `greaterThan` or `contains`.
`filters.value`	unknown	Value compared against, when the operator needs one. `isEmpty` and `isNotEmpty` need none; `in` and `notIn` take a list.
`filters.and`	array	Conditions that must ALL hold for a record to be kept.
`filters.and[]`	object (truncated)	A filter condition or a logical group (and/or) of filter nodes.
`filters.or`	array	Conditions of which at least one must hold for a record to be kept.
`filters.or[]`	object (truncated)	A filter condition or a logical group (and/or) of filter nodes.

app.yaml

- {
    id: 2,
    name: completed_task_count,
    type: count,
    relationshipField: tasks,
    filters: { field: status, operator: equals, value: completed },
  }

relationshipField must name an actual relationship field on the same table. That is checked when the configuration is decoded, so a typo or a reference to a field of another type stops the boot rather than counting nothing forever.

filters narrows what is counted, using the same condition grammar a view's filters use. Without it, every linked record counts — except a soft-deleted one, which never counts. Trashing a linked record lowers the count immediately, and restoring it raises the count again.

`autonumber`

A database-assigned auto-incrementing integer — the field type behind invoice and order references. The column is a sequence, so the value is allocated by the database on insert and is never supplied by the client.

Path	Kind	Values	Description
`id`	number		Unique identifier for a field within a table. Examples: 1, 2, 3, 100
`name`	string		Internal identifier for the field: the database column name, and the key used in API payloads and formulas. Use `label` for the name end users read.
`label`	string		External display name shown to end users, in place of the internal `name`. Resolution order on every surface: surface-level override, then this label, then the raw `name` verbatim.
`description`	string		Author-written guidance rendered beside the field (under the control on a form, beside the value in a drawer) and associated with the control via aria-describedby. Unlike a placeholder it persists once the user starts typing.
`required`	boolean		Rejects a record whose value for this field is missing or empty, both through the API and in any generated form.
`unique`	boolean		Rejects a record whose value for this field is already used by another record in the same table.
`indexed`	boolean		Adds a database index on this field, so filtering and sorting on it stay fast as the table grows, at the cost of slightly slower writes.
`type`	enum	`autonumber`	Constant value 'autonumber' for type discrimination in discriminated unions

app.yaml

- { id: 3, name: invoice_number, type: autonumber }

That produces 1, 2, 3, and so on. autonumber takes no type-specific options at all: there is no prefix, no starting offset and no zero-padding. For a human-facing reference such as INV-01000, add a formula field that composes the number with the prefix and padding you want. That keeps presentation in one place and leaves the underlying sequence untouched, so the format can change without renumbering anything.

A sequence also does not promise to be gap-free. A transaction that allocates a number and then rolls back has still consumed it, which is correct — reusing it would let two records carry the same reference at different times.

Both recompute rather than store

count recomputes when the links it counts change. autonumber is allocated once and then fixed. Neither is writable through the records API or a form: a write naming one is refused with Cannot write to readonly field '<name>' rather than accepted and discarded, and the refusal names every readonly column the request touched, not just the first.

Behaviour

Count Fields

Computes count of related records
Returns zero when no records are linked
Auto-updates when linked records change
Counts records for multiple relationship fields on the same table
Applies conditions to filter counted records (a single flat filter; nested AND/OR is not asserted)
Rejects a count field when relationshipField does not exist in the same table
Rejects a count field when relationshipField is not a relationship type
Resolves FK column via reciprocalField when foreignKey is omitted
User can complete full count workflow (regression)
Infers the FK column when the child has exactly one relationship back to the parent (no foreignKey, no reciprocalField)
Rejects the config at validation time when the child has two relationships back to the parent, naming the candidates
Exposes a count as a JSON-serialisable scalar, a string on Postgres and a number on SQLite
Developer counts linked records without declaring a foreignKey

Autonumber Fields

Creates PostgreSQL SERIAL/BIGSERIAL column
Auto-increments on each new record
Is immutable after creation: a manual UPDATE is silently reverted, never raised
Is always NOT NULL (automatically generated)
Creates a unique index automatically
User can complete full autonumber workflow (regression)

Last updated September 23, 2026

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This documentation was written with AI, so errors or outdated content are possible. Sovrium is in beta. Contributions and corrections are welcome.