Derives OpenAI function-tool schemas from serialization descriptors, turning sealed request hierarchies into SDK tool declarations and decoding model function calls into typed request objects.
kotlin-openai-schemas is a Kotlin Multiplatform helper library for deriving OpenAI function-tool
schemas from kotlinx.serialization descriptors.
It is designed for applications that model tool calls as typed Kotlin request classes and want the
same model to produce OpenAI SDK Tool declarations and decode model FunctionCall values.
repositories {
mavenCentral()
}
dependencies {
implementation("one.wabbit:kotlin-openai-schemas:0.1.0")
}
The library depends on kotlinx.serialization, one.wabbit:kotlin-data-ref, and the Aallam
OpenAI Kotlin SDK types used for chat tools.
Each sealed subtype becomes one OpenAI function tool. Use @SerialName values without package dots,
because subtype names become OpenAI function names.
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.JsonPrimitive
import kotlinx.serialization.json.JsonArray
val request = FunctionSchema.parseFunctionCall(
serializer = ToolRequest.serializer(),
name = "GenerateMeme",
arguments = JsonObject(
mapOf(
"templateName" to JsonPrimitive("classic"),
"boxText" to JsonArray(listOf(JsonPrimitive("top"), JsonPrimitive("bottom"))),
)
),
)
check(request is ToolRequest.GenerateMeme)
parseFunctionCall injects the function name as the sealed "type" discriminator before decoding
with kotlinx.serialization.
FunctionSchema.TypeDef is an intermediate schema tree derived from SerialDescriptor values. It
supports primitive values, enums, lists, maps, inline/value-class aliases, objects, nullable fields,
and sealed request hierarchies.
For OpenAI function parameters, nullable object fields are omitted from the generated required
list. The current JSON Schema lowering does not emit an explicit "null" union for nullable field
types.
This library is early and intentionally narrow. It is useful for typed sealed request hierarchies, but it is not a complete JSON Schema generator. Open polymorphism, contextual serializers, and direct sealed-type JSON Schema lowering are not currently implemented.
Generated API docs can be built locally with Dokka. See API reference notes for the command.
This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0) for open source use.
For commercial use, contact Wabbit Consulting Corporation at wabbit@wabbit.one.
Before contributions can be merged, contributors need to agree to the repository CLA.
import kotlinx.serialization.SerialName
import kotlinx.serialization.Serializable
import one.wabbit.openaischemas.FunctionSchema
import one.wabbit.openaischemas.FunctionSchema.Doc
sealed interface ToolRequest {
data class GenerateMeme(
val templateName: String,
val boxText: List<String>,
) : ToolRequest
}
val tools = FunctionSchema.makeFunctions(ToolRequest.serializer().descriptor)
check(tools.single().compiledToolSchema.function.name == "GenerateMeme")
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