KotlinxGraphQLTransportCodec

kotlinx.serialization-backed implementation of GraphQLTransportCodec.

KotlinxGraphQLTransportCodec serializes GraphQLOperationRequest envelopes and deserializes GraphQLResponse envelopes with kotlinx serialization only inside this module. It is the neutral counterpart of the legacy co.anitrend.retrofit.graphql.serialization.kotlinx.KotlinxGraphQLJson (which moved to :compat with the deprecated GraphConverter flow) and never routes through the generic co.anitrend.retrofit.graphql.model.GraphQLJson seam.

Request encoding

encodeRequest writes the neutral envelope (query, operationName, variables, extensions). Typed variables are encoded through the serializer resolved from the first generic argument of the complete parameterized request Type, falling back to the runtime class of the variables when the type is not parameterized. Absent variables and extensions are written as explicit JSON nulls.

Response decoding

decodeResponse preserves the neutral protocol semantics:

• A missing data key decodes to GraphQLData.Absent, while an explicit data: null decodes to GraphQLData.Present with a null value.

• Error message is required: missing, null, or non-string messages fail with GraphQLResponseDecodingException.

• Error path segments decode to GraphQLPathSegment.Field for strings and GraphQLPathSegment.Index for integral numbers; non-integral or non-scalar segments fail.

• Top-level and error extensions decode to GraphQLValue.ObjectValue with exact java.math.BigDecimal precision for numbers.

• Explicit JSON nulls for optional errors/extensions fields are treated as absent.

Exception policy

Every failure is wrapped in GraphQLRequestEncodingException or GraphQLResponseDecodingException with the operation or response type context; backend exceptions never leak.

Parameters

See also