Scalar Types

Note: Firebase Data Connect is in Public Preview. Data Connect will be subject to the "Pre-GA Offerings Terms" in the Service Specific Terms section of the Google Cloud Platform Terms of Service. Pre-GA features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

Scalar types define the basic data types used for individual fields or arguments in a GraphQL schema.

Data Connect Defined

scalar Any

Specification: https://www.json.org/json-en.html

The Any scalar type accommodates any valid JSON value (e.g., numbers, strings, booleans, arrays, objects). PostgreSQL efficiently stores this data as jsonb, providing flexibility for schemas with evolving structures.

Caution: JSON doesn't distinguish Int and Float.

Example:

Schema

type Movie @table {
  name: String!
  metadata: Any!
}

Mutation

Insert a movie with name and metadata from JSON literal.

mutation InsertMovie {
  movie_insert(
    data: {
      name: "The Dark Knight"
      metadata: {
        release_year: 2008
        genre: ["Action", "Adventure", "Superhero"]
        cast: [
          { name: "Christopher Bale", age: 31 }
          { name: "Heath Ledger", age: 28 }
        ]
        director: "Christopher Nolan"
      }
    }
  )
}

Insert a movie with name and metadata that's constructed from a few GQL variables.

mutation InsertMovie($name: String!, $releaseDate: Date!, $genre: [String], $cast: [Any], $director: String!, $boxOfficeInUSD: Int) {
  movie_insert(data: {
    name: $name,
    release_date: $releaseDate,
    genre: $genre,
    cast: $cast,
    director: $director,
    box_office: $boxOfficeInUSD
  })
}

Note:

• A mix of non-null and nullable variables can be provided.

• Date! can be passed into scalar Any as well! It's stored as string.

• $cast is a nested array. [Any] can represent an array of arbitrary types, but it won't enforce the input shape.

Query

Since metadata field has scalar Any type, it would return the full JSON in the response.

Note: You can't define selection set to scalar based on GraphQL spec.

query GetAllMovies {
  movies {
    name
    metadata
  }
}

scalar Any_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression whose return type is unspecified.

Limitation: Only a limited set of expressions are currently supported for each type.

Example	Description
auth.uid	The ID of the currently logged in user in Firebase Auth. (Errors if not logged in.)
uuidV4()	Generates a new random UUID version 4 (formatted as 32 lower-case hex digits without delimiters if result type is String).
request.time	The timestamp when the request is received (with microseconds precision).

scalar Any_SQL

Specification: https://www.postgresql.org/docs/current/sql-expressions.html

A PostgreSQL value expression whose return type is unspecified.

scalar Boolean_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression that returns a boolean at runtime.

This expression can reference the auth variable, which is null when Firebase Auth is not used. When Firebase Auth is used, the following fields are available:

• auth.uid: The current user ID.
• auth.token: A map containing all token fields (e.g., claims).

Example	Description
auth != null	Allow only if a Firebase Auth user is present.

scalar Date

Specification: https://scalars.graphql.org/andimarek/local-date.html

Date is a string in the YYYY-MM-DD format representing a local-only date.

See the description for Timestamp for range and limitations.

As a FDC-specific extension, inputs that includes time portions (as specified by the Timestamp scalar) are accepted but only the date portion is used. In other words, only the part before "T" is used and the rest discarded. This effectively truncates it to the local date in the specified time-zone.

Outputs will always be in the canonical YYYY-MM-DD format.

In the PostgreSQL table, it's stored as date.

scalar Date_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression that returns a Timestamp at runtime, which is then truncated to UTC date only. The time-of-day parts are discarded.

Limitation: Right now, only a few expressions are supported.

Example	Description
request.time	The UTC date on which the request is received.

scalar Int64

Int64 is a scalar that represents a 64-bit signed integer.

In the PostgreSQL table, it's stored as bigint.

On the wire, it's encoded as string because 64-bit integer exceeds the range of JSON number.

scalar String_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression that returns a string at runtime.

Limitation: Currently, only a limited set of expressions are supported.

Example	Description
auth.uid	The ID of the currently logged in user in Firebase Auth. (Errors if not logged in.)
uuidV4()	Generates a new random UUID (version 4) string, formatted as 32 lower-case hex digits without delimiters.

scalar Timestamp

Specification: https://scalars.graphql.org/andimarek/date-time

Timestamp is a RFC 3339 string that represents an exact point in time.

The serialization format follows https://scalars.graphql.org/andimarek/date-time except the "Non-optional exact milliseconds" Section. As a FDC-specific extension, inputs and outputs may contain 0, 3, 6, or 9 fractional digits.

Specifically, output precision varies by server-side factors such as data source support and clients must not rely on an exact number of digits. Clients may truncate extra digits as fit, with the caveat that there may be information loss if the truncated value is subsequently sent back to the server.

FDC only supports year 1583 to 9999 (inclusive) and uses the ISO-8601 calendar system for all date-time calculations. Notably, the expanded year representation (+/-YYYYY) is rejected and Year 1582 and before may either be rejected or cause undefined behavior.

In the PostgreSQL table, it's stored as timestamptz.

scalar Timestamp_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression that returns a Timestamp at runtime.

Limitation: Right now, only a few expressions are supported.

Example	Description
request.time	The timestamp when the request is received (with microseconds precision).

scalar True

The True scalar type only accepts the boolean value true.

An optional field/argument typed as True may either be set to true or omitted (not provided at all). The values false or null are not accepted.

Example	Description
true	The only allowed value.

scalar UUID

Specification: https://tools.ietf.org/html/rfc4122

UUID is a string of hexadecimal digits representing an RFC4122-compliant UUID.

UUIDs are always output as 32 lowercase hexadecimal digits without delimiters or curly braces. Inputs in the following formats are also accepted (case insensitive):

• xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
• urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
• {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}

In the PostgreSQL table, it's stored as uuid.

scalar UUID_Expr

Specification: https://github.com/google/cel-spec

A Common Expression Language (CEL) expression that returns a UUID string at runtime.

Limitation: Currently, only a limited set of expressions are supported.

Example	Description
uuidV4()	Generates a new random UUID (version 4) every time.

scalar Vector

Vector is an array of single-precision floating-point numbers, serialized as a JSON array. All elements must be finite (no NaN, Infinity or -Infinity).

Example: [1.1, 2, 3.3]

In the PostgreSQL table, it's stored as pgvector.

See Vector_Embed for how to generate text embeddings in query and mutations.

scalar Vector_Embed_Model

Specification: https://cloud.google.com/vertex-ai/generative-ai/docs/learn/model-versioning

The Vertex AI model version that is required in input Vector_Embed.

It is recommended to use the latest stable model version: textembedding-gecko@003.

View all supported Vertex AI Text embeddings APIs.

Example	Description
textembedding-gecko@003	A stable version of the textembedding-gecko model
textembedding-gecko@001	An older version of the textembedding-gecko model
text-embedding-004	Another text embedding model

scalar Void

The Void scalar type represents the absence of any value. It is typically used in operations where no value is expected in return.

Data Connect Generated

scalar BasicTable_KeyOutput

✨ BasicTable_KeyOutput returns the primary key fields of table type BasicTable.

It has the same format as BasicTable_Key, but is only used as mutation return value.

scalar JoinTable_KeyOutput

✨ JoinTable_KeyOutput returns the primary key fields of table type JoinTable.

It has the same format as JoinTable_Key, but is only used as mutation return value.

scalar LeftTable_KeyOutput

✨ LeftTable_KeyOutput returns the primary key fields of table type LeftTable.

It has the same format as LeftTable_Key, but is only used as mutation return value.

scalar ManyTable_KeyOutput

✨ ManyTable_KeyOutput returns the primary key fields of table type ManyTable.

It has the same format as ManyTable_Key, but is only used as mutation return value.

scalar MaybeTable_KeyOutput

✨ MaybeTable_KeyOutput returns the primary key fields of table type MaybeTable.

It has the same format as MaybeTable_Key, but is only used as mutation return value.

scalar OneTable_KeyOutput

✨ OneTable_KeyOutput returns the primary key fields of table type OneTable.

It has the same format as OneTable_Key, but is only used as mutation return value.

scalar RightTable_KeyOutput

✨ RightTable_KeyOutput returns the primary key fields of table type RightTable.

It has the same format as RightTable_Key, but is only used as mutation return value.

Built In

scalar Boolean

The Boolean scalar type represents true or false.

scalar Float

The Float scalar type represents signed double-precision fractional values as specified by IEEE 754.

scalar ID

The ID scalar type represents a unique identifier, often used to refetch an object or as key for a cache. The ID type appears in a JSON response as a String; however, it is not intended to be human-readable. When expected as an input type, any string (such as "4") or integer (such as 4) input value will be accepted as an ID.

scalar Int

The Int scalar type represents non-fractional signed whole numeric values. Int can represent values between -(2^31) and 2^31 - 1.

scalar String

The String scalar type represents textual data, represented as UTF-8 character sequences. The String type is most often used by GraphQL to represent free-form human-readable text.