MetaObjects

Metamodel reference

Metamodel — field types

Each section below is one field.<subType>. The Attributes table lists the subtype's own + concern-contributed attributes (provider-tagged); universal documentation attributes are omitted here (see providers.md). Allowed children lists the structural child rules with their cardinality (min..max, * = unbounded).

field.base

Abstract base field — the shared root subtype that concrete field subtypes specialize. Carries the attrs common to every field but binds no concrete data type of its own (falls back to string). Not authored directly: a field.base node fails to load (ERR_ABSTRACT_SUBTYPE_AUTHORED) — this subtype is a registry anchor concrete subtypes inherit from, never a node in a document.

Owning provider: metaobjects-core-types

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.boolean

True/false flag. Binds to the native boolean type; DB column is BOOLEAN.

Owning provider: metaobjects-core-types

When to use: A true/false flag.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.currency

Stores money as integer minor units (cents). Binds to long; the client formats via @currency/@locale. Float arithmetic for money is forbidden.

Owning provider: metaobjects-core-types

Rules: Storage is integer minor units (cents for USD, yen for JPY) — the wire form is unchanged from long. The server never formats currency; all formatting is client-side via Intl.NumberFormat using @currency (ISO 4217) and @locale (BCP 47). Float arithmetic for money is forbidden.

When to use: A column holds money. Use currency so it stores integer minor-units and the client formats it — never floats or hand-rolled cents math.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@currency string no USD metaobjects-core-types ISO 4217 currency code for a currency-subtype field. Storage is integer minor units; defaults to 'USD' when omitted.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.date

Calendar date (no time-of-day). Binds to the native date/temporal type; DB column is DATE.

Owning provider: metaobjects-core-types

When to use: A column is a calendar date with no time-of-day. Use date instead of a string.

Attributes

Attribute Type Required Default Allowed values Provider Description
@autoSet string no onCreate, onUpdate metaobjects-db Auto-set semantics for timestamp-like fields: 'onCreate' stamps on insert, 'onUpdate' stamps on every write.
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.decimal

Precision-exact decimal (use @precision/@scale). Native TS binding is string (lossless); DB column is NUMERIC(p,s); the wire form is a string. Classified DATA_TYPE_STRING so an exact decimal is never silently rounded through a double.

Owning provider: metaobjects-core-types

Rules: The wire and native-TS form is a STRING to stay precision-exact end-to-end (Drizzle pg numeric infers as string; SP-H/ADR-0019). Set @precision (total significant digits) and @scale (digits right of the point) to drive NUMERIC(p,s).

When to use: A value needs exact precision (money amounts, rates, quantities). Use decimal with @precision/@scale — never double, which loses precision.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@precision int no metaobjects-core-types Total number of significant digits for decimal-typed fields.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@scale int no metaobjects-core-types Number of digits to the right of the decimal point for decimal-typed fields.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.double

Double-precision (64-bit) IEEE-754 floating point. Binds to the native double/number type; DB column is DOUBLE PRECISION. Not for money — use field.currency or field.decimal.

Owning provider: metaobjects-core-types

When to use: An approximate floating-point number where exactness is not required. For money/precision use decimal.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.enum

String-backed enumeration constrained to a closed set of member symbols (@values). Each member is its own stored string with no name/value divergence.

Owning provider: metaobjects-core-types

Rules: Required @values is a non-empty, duplicate-free set; each member must match ^[A-Za-z_][A-Za-z0-9_]*$ so symbol == stored string in every target language. Optional FR-010/FR-011 overlays add tolerant-extract aliasing (@enumAlias), per-member docs (@enumDoc), an uncoercible-value fallback (@coerceDefault, must be one of @values), and ASCII normalization mode (@normalize).

When to use: A field is a fixed, closed set of string values. Set @values so the union type, DB CHECK, and validation are generated — don't hand-roll constants + checks.

Attributes

Attribute Type Required Default Allowed values Provider Description
@coerceDefault string no metaobjects-prompt Fallback enum member used by tolerant extract when a present value cannot be coerced; must be one of the field's @values.
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@enumAlias properties no metaobjects-prompt Map of alternate/off-vocabulary tokens to canonical enum members; feeds the FR-010 tolerant extract alias-fold.
@enumDoc properties no metaobjects-prompt Map of enum member to a human-readable description; shown per-member in the FR-010 'guide'-style prompt fragment.
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@intValueMap intMap no metaobjects-core-types Optional per-member int values ({member: int}) switching this enum field's DB persistence from string+CHECK to integer+CHECK. Keys must exactly match @values; values must be unique integers. The generated native type and wire format are unchanged in every language.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@normalize string no strip none, collapse, strip metaobjects-prompt ASCII normalization mode for tolerant enum extract (none|collapse|strip, default strip). On field.enum it is per-field; on object.value it is the default for the object's enum fields.
@provided boolean no metaobjects-core-types FR-019: marks an abstract package-level field.enum as externally provided — codegen references the type (resolved via per-port codegen config) instead of materializing it. Default false. Not a field attr — it lives on the type declaration.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@values string[] yes metaobjects-core-types Member symbols of an enum-subtype field. Declaration order is significant; each is a legal identifier and its own stored string.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.float

Single-precision floating point. Binds to the native double/number type (TS has no distinct float); DB column is REAL. Not for money.

Owning provider: metaobjects-core-types

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.inet

An IP-address string (IPv4 or IPv6) (ADR-0036/0037 — a concept with a native type + behavior, so a subtype not a @stringFormat). Binds to TS string (TS has no native IP type, same as field.uuid); other ports bind to their native IP type (Java java.net.InetAddress, C# System.Net.IPAddress, Python ipaddress, Kotlin java.net.InetAddress). DB column is the Postgres-native inet type. Codegen emits an IPv4-or-IPv6 literal validator (a Zod regex union in TS — z.string().ip() was removed in Zod 4 — native IP-type parsing in the other ports); add @lenient to bind a plain string with no validator. v1 ships WITHOUT @kind — the native type subsumes ipv4/ipv6; @kind is reserved for a later ipv4|ipv6 value-constraint.

Owning provider: metaobjects-core-types

When to use: A field holds an IPv4 or IPv6 address. Use it for a native Postgres inet column + IP validation instead of a plain string.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@lenient boolean no metaobjects-core-types #234: opt this field out of strict well-formedness enforcement. When true, codegen binds a plain string (no URL/IP validator, no native URI/InetAddress type; field.inet uses a text column, not the native inet type) so a not-strictly-valid value round-trips unchanged. Default (absent/false) is strict: an absolute-scheme URI / an IPv4-or-IPv6 literal.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.int

32-bit signed integer. Binds to the native int type; DB column is INTEGER.

Owning provider: metaobjects-core-types

When to use: A whole number within +/-2^31. Use long instead if values can exceed that.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.long

64-bit signed integer. Binds to the native long/bigint type; DB column is BIGINT.

Owning provider: metaobjects-core-types

When to use: A whole number that may exceed 32 bits (ids, counters, epoch millis).

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.map

An open-keyed map (Record<string,V> / dict[str,V]) stored in a single jsonb column. Keys are always strings (the JSON object constraint); the value type is set by @valueType (a scalar field subtype) or @objectRef (a value-object).

Owning provider: metaobjects-core-types

Rules: Keys are always strings. Set exactly one of @valueType (a scalar value subtype: string/int/long/double/float/decimal/boolean/date/time/timestamp/uuid) or @objectRef (a value-object name or FQN). Stored as a single jsonb column holding the JSON object — never a native array; isArray does not apply.

When to use: A field is an open-keyed map of values (Record<string,V>). Use it for dynamic keys instead of an untyped jsonb string.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@objectRef string no metaobjects-core-types Name (or FQN) of the value-object for a value-object-valued map. Mutually exclusive with @valueType; exactly one of the two must be set.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@valueType string no metaobjects-core-types Scalar value subtype for a scalar-valued map (string/int/long/double/float/decimal/boolean/date/time/timestamp/uuid). Mutually exclusive with @objectRef; exactly one of the two must be set.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.object

A nested structured value (set @objectRef to the target object). Storage is governed by @storage: flattened (prefixed columns), jsonb (single jsonb column, supports isArray), or subdocument (document-store hint).

Owning provider: metaobjects-core-types

Rules: Set @objectRef to the nested object's name (or FQN). @storage selects physical layout — flattened expands into prefixed parent columns (isArray must be false), jsonb stores the structured value (or array when isArray=true) in one jsonb column, subdocument emits no Postgres column. Defaults to single-jsonb-column when @storage is absent.

When to use: A field holds a nested structured value (or an array of them). Set @objectRef + @storage so the shape is typed and persisted (flattened/jsonb) instead of an untyped blob.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@objectRef string no metaobjects-core-types Name (or FQN) of the target object an object-typed field nests — drives nested-object (de)serialization.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@storage string no flattened, jsonb, subdocument metaobjects-db Storage strategy for an object-typed field (set with @objectRef). "flattened" expands the nested value into prefixed columns on the parent table. "jsonb" stores the structured value in a single jsonb column (supports isArray=true for arrays of values). "subdocument" is a hint for document-store codegen targets and emits no Postgres column.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.string

Variable-length text. Binds to the native string type; DB column is VARCHAR/TEXT (use @maxLength for VARCHAR(n)).

Owning provider: metaobjects-core-types

When to use: Plain variable-length text. Set @maxLength to size the column. The default for textual data.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@maxLength int no metaobjects-core-types Maximum character length for string-typed fields (drives VARCHAR(n)).
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@stringFormat string no email, hostname metaobjects-core-types ADR-0036/0037: a closed validation format for a plain string field that has NO native type or behavior of its own — email | hostname. The field stays a plain string (native binding + DB column unchanged); codegen emits the matching validator (Zod z.email() / a hostname check; PG CHECK where appropriate). The canonical matcher per format lives in each port's codegen, NOT author validator.regex (cross-language regex engines diverge). Named @stringFormat (not @format) to avoid colliding with template.* @format (output format). Concepts WITH a native type or behavior are subtypes instead (uuid → field.uuid, url/uri → field.uri, ip → field.inet).
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.time

Time-of-day (no calendar date). Binds to the native date/temporal type; DB column is TIME.

Owning provider: metaobjects-core-types

Attributes

Attribute Type Required Default Allowed values Provider Description
@autoSet string no onCreate, onUpdate metaobjects-db Auto-set semantics for timestamp-like fields: 'onCreate' stamps on insert, 'onUpdate' stamps on every write.
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.timestamp

Date + time-of-day instant (optionally with timezone). Binds to the native date/temporal type; DB column is TIMESTAMP(TZ). Pair with @autoSet for created/updated stamping.

Owning provider: metaobjects-core-types

When to use: A column records an instant (created/updated at). Use timestamp so it serializes ISO-8601 with timezone consistently.

Attributes

Attribute Type Required Default Allowed values Provider Description
@autoSet string no onCreate, onUpdate metaobjects-db Auto-set semantics for timestamp-like fields: 'onCreate' stamps on insert, 'onUpdate' stamps on every write.
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@localTime boolean no metaobjects-db When true, the timestamp is a naive wall-clock value with no timezone (Postgres timestamp without time zone); absent/false (the default) = an absolute instant (timestamptz). ADR-0036 Wave 2 — replaces the retired @dbColumnType: timestamp_with_tz escape hatch.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.uri

A URI/URL string (ADR-0036/0037 — a concept with a native type + behavior, so a subtype not a @stringFormat). Binds to TS string (TS has no native URI type, same as field.uuid); other ports bind to their native URI type (Java java.net.URI, C# System.Uri, Python urllib.parse, Kotlin java.net.URI) and parse scheme/authority/path. DB column is text (Postgres has no uri type). Codegen emits a URL/URI validator (TS Zod z.string().url()). v1 ships WITHOUT @kind — the native type subsumes url/urn; @kind is reserved for a later url|urn value-constraint.

Owning provider: metaobjects-core-types

When to use: A field holds a URL or URI. Use it for a typed URI column + URL validation instead of a plain string.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@lenient boolean no metaobjects-core-types #234: opt this field out of strict well-formedness enforcement. When true, codegen binds a plain string (no URL/IP validator, no native URI/InetAddress type; field.inet uses a text column, not the native inet type) so a not-strictly-valid value round-trips unchanged. Default (absent/false) is strict: an absolute-scheme URI / an IPv4-or-IPv6 literal.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children

field.uuid

Logical UUID identity scalar. A bare scalar (no required attrs, no loader value-validation) — binds to TS string (no native UUID type); DB column is Postgres-native uuid.

Owning provider: metaobjects-core-types

When to use: A key or external identifier is a UUID. Use it for a typed UUID column instead of a plain string.

Attributes

Attribute Type Required Default Allowed values Provider Description
@column string no metaobjects-db Physical column name for this field on an rdb source. Defaults to the field name via columnNamingStrategy.
@db.indexed boolean no metaobjects-db When true, suppress the @filterable-without-index Loader warning (the field is indexed by other means).
@dbColumnType string no uuid, jsonb metaobjects-db Physical DB column-type override (ADR-0013 escape hatch). Legal values are uuid | jsonb, both on field.string (uuid = native Postgres uuid column over a string-typed field; jsonb = genuinely-open JSON column). The logical field type and its native binding are unchanged. Native SQL arrays (uuid[]/text[]) are NOT declared here — they are derived from a field subtype + isArray (ADR-0036 Wave 1). The retired timestamp_with_tz value is gone — timezone-awareness lives in field.timestamp (instant by default) + @localTime (the naive opt-out), per ADR-0036 Wave 2.
@default any no metaobjects-core-types Default value applied to the column when no value is supplied. Its type follows the field's own subtype (string / boolean / number / ...). Converted at consumption time via MetaField.defaultValue().
@example string no metaobjects-prompt FR-010: an example value for this field, shown in the generated output-format prompt fragment.
@filterable boolean no metaobjects-ui When true, the field is exposed in generated CRUD filter allowlists (Project D filter layer).
@formExclude boolean no metaobjects-ui When true, the field is omitted from generated forms. Inert on fields for which no form is generated (e.g. projection/derived fields).
@instruction string no metaobjects-prompt FR-010: a short instruction for this field, shown in the generated output-format prompt fragment.
@mutability string no readWrite, writeOnce, readOnly metaobjects-core-types FR-037 R1: who may write this field, and when. 'readWrite' (the default when absent) — the caller may set it on create and change it on update. 'writeOnce' — the caller sets it on create; it is excluded from the update shape thereafter, so a value presented on PATCH is ignored rather than rejected. 'readOnly' — nobody writes it: codegen emits no setter / writable property, the persistence layer skips the column on INSERT/UPDATE, and Zod/Pydantic/class-validator schemas omit it from input variants; the value is populated by the database (computed column, default expression, trigger), by replication, or by another external owner. The three are mutually exclusive modes of ONE axis — who may write, and when — so the illegal pair is unrepresentable and inheritance has a total order: a subtype may TIGHTEN an inherited mode (readWrite < writeOnce < readOnly) and never loosen it (ERR_MUTABILITY_DOWNGRADE). Pairing a non-readWrite mode with @autoSet is ERR_MUTABILITY_AUTOSET_CONFLICT: @autoSet already says the SERVER supplies the value, which is a different axis from who may write it.
@required boolean no metaobjects-core-types When true, the field is NOT NULL. Equivalent to attaching a validator.required child. On a non-array string, generated wire-tier input validation (create/patch) additionally rejects the empty string by default — whitespace is accepted — unless an explicit validator.length @min: 0 opts back to presence-only. In-process read models never enforce this at construction.
@sortable boolean no metaobjects-ui When true, the field is exposed in generated CRUD sort allowlists. Inherits from @filterable by default; set false to opt out.
@sortableDefaultOrder string no asc, desc metaobjects-ui Direction a sort takes when it names this field but omits the order: a ?sort= with no :order, and a layout.dataGrid whose @defaultSortField names it with no @defaultSortOrder. Defaults to 'asc'.
@unique boolean no metaobjects-core-types When true, the field gets a column-level UNIQUE constraint.
@xmlText boolean no metaobjects-prompt When true, this field receives its element's XML TEXT CONTENT during tolerant extract (JAXB @XmlValue / Jackson @JacksonXmlText / .NET [XmlText]) instead of a same-named child. No effect when the eliciting prompt's @responseFormat is json.

Allowed children