Add Function Calling

openai-core/build.gradle.kts

@@ -23,6 +23,7 @@ kotlin {
         val commonMain by getting {
             dependencies {
                 api(libs.okio)
+                api(libs.serialization.json)
                 implementation(libs.serialization.core)
             }
         }

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionFunction.kt

@@ -0,0 +1,22 @@
+package com.aallam.openai.api.chat
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+public data class ChatCompletionFunction(
+    /**
+     * The name of the function to be called. Must be a-z, A-Z, 0-9, or contain underscores and dashes, with a maximum
+     * length of 64.
+     */
+    @SerialName("name") val name: String,
+    /**
+     * The description of what the function does.
+     */
+    @SerialName("description") val description: String? = null,
+    /**
+     * The parameters the functions accepts, described as a JSON Schema object. See the guide for examples and the
+     * JSON Schema reference for documentation about the format.
+     */
+    @SerialName("parameters") val parameters: JsonData? = null,
+)

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionRequest.kt

@@ -85,7 +85,21 @@ public class ChatCompletionRequest(
      * A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse.
      */
     @SerialName("user") public val user: String? = null,
-)
+
+    /**
+     * A list of functions the model may generate JSON inputs for.
+     */
+    @SerialName("functions") public val functions: List<ChatCompletionFunction>? = null,
+
+    /**
+     * Controls how the model responds to function calls. "none" means the model does not call a function, and responds
+     * to the end-user. "auto" means the model can pick between an end-user or calling a function. Specifying a
+     * particular function via {"name":\ "my_function"} forces the model to call that function. "none" is the default
+     * when no functions are present. "auto" is the default if functions are present.
+     */
+    @SerialName("function_call") public val functionCall: FunctionCall? = null,
+
+    )
 
 /**
  * The messages to generate chat completions for.

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatMessage.kt

@@ -19,12 +19,17 @@ public data class ChatMessage(
     /**
      * The contents of the message.
      */
-    @SerialName("content") public val content: String,
+    @SerialName("content") public val content: String? = null,
 
     /**
      * The name of the user in a multi-user chat.
      */
-    @SerialName("name") public val name: String? = null
+    @SerialName("name") public val name: String? = null,
+
+    /**
+     * The name and arguments of a function that should be called, as generated by the model.
+     */
+    @SerialName("function_call") public val functionCall: JsonData? = null
 )
 
 /**

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatRole.kt

@@ -15,5 +15,6 @@ public value class ChatRole(public val role: String) {
         public val System: ChatRole = ChatRole("system")
         public val User: ChatRole = ChatRole("user")
         public val Assistant: ChatRole = ChatRole("assistant")
+        public val Function: ChatRole = ChatRole("function")
     }
 }

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/FunctionCall.kt

@@ -0,0 +1,62 @@
+package com.aallam.openai.api.chat
+
+import com.aallam.openai.api.BetaOpenAI
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.json.JsonPrimitive
+import kotlin.jvm.JvmInline
+
+@BetaOpenAI
+@Serializable(with = FunctionCallSerializer::class)
+public sealed interface FunctionCall {
+    public val name: String
+
+    public companion object {
+        public val Auto: FunctionCall = FunctionCallString("auto")
+        public val None: FunctionCall = FunctionCallString("none")
+        public fun forceCall(name: String): FunctionCall = FunctionCallObject(name)
+    }
+}
+@OptIn(BetaOpenAI::class)
+internal object FunctionCallSerializer: KSerializer<FunctionCall>{
+    override val descriptor: SerialDescriptor = buildClassSerialDescriptor("FunctionCall") {}
+    private val objectSerializer = FunctionCallObject.serializer()
+    override fun deserialize(decoder: Decoder): FunctionCall {
+        if(decoder is JsonDecoder){
+            return when(val json = decoder.decodeJsonElement()){
+                is JsonPrimitive -> FunctionCallString(json.content)
+                is JsonObject -> objectSerializer.deserialize(decoder)
+                else -> throw UnsupportedOperationException("Cannot deserialize Parameters")
+            }
+        }
+        throw UnsupportedOperationException("Cannot deserialize Parameters")
+    }
+
+    override fun serialize(encoder: Encoder, value: FunctionCall) {
+        if(encoder is JsonEncoder){
+            when(value){
+                is FunctionCallString -> encoder.encodeString(value.name)
+                is FunctionCallObject -> objectSerializer.serialize(encoder, value)
+            }
+            return
+        }
+        throw UnsupportedOperationException("Cannot deserialize Parameters")
+    }
+}
+
+@OptIn(BetaOpenAI::class)
+@JvmInline
+@Serializable
+internal value class FunctionCallString(override val name: String): FunctionCall
+
+@OptIn(BetaOpenAI::class)
+@Serializable
+internal data class FunctionCallObject(override val name: String): FunctionCall
+

openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/JsonData.kt

@@ -0,0 +1,50 @@
+package com.aallam.openai.api.chat
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.descriptors.buildClassSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonDecoder
+import kotlinx.serialization.json.JsonElement
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonObjectBuilder
+import kotlinx.serialization.json.buildJsonObject
+import kotlin.jvm.JvmInline
+
+@JvmInline
+@Serializable(with = JsonData.JsonDataSerializer::class)
+public value class JsonData(public val json: JsonElement){
+    public object JsonDataSerializer: KSerializer<JsonData>{
+        override val descriptor: SerialDescriptor = buildClassSerialDescriptor("JsonData") {}
+
+        override fun deserialize(decoder: Decoder): JsonData {
+            if(decoder is JsonDecoder){
+                return JsonData(decoder.decodeJsonElement())
+            }
+            throw UnsupportedOperationException("Cannot deserialize Parameters")
+        }
+
+        override fun serialize(encoder: Encoder, value: JsonData) {
+            if(encoder is JsonEncoder){
+                encoder.encodeJsonElement(value.json)
+                return
+            }
+        }
+    }
+    public companion object{
+        public fun fromString(json: String): JsonData = fromJsonElement(Json.parseToJsonElement(json))
+
+        public fun fromJsonElement(json: JsonElement): JsonData = JsonData(json)
+
+        public fun builder(block: JsonObjectBuilder.() -> Unit): JsonData{
+            val json = buildJsonObject (
+                block
+            )
+            return fromJsonElement(json)
+        }
+
+    }
+}

sample/jvm/src/main/kotlin/com/aallam/openai/sample/jvm/App.kt

@@ -6,6 +6,9 @@ import com.aallam.openai.api.audio.TranslationRequest
 import com.aallam.openai.api.chat.ChatCompletionRequest
 import com.aallam.openai.api.chat.ChatMessage
 import com.aallam.openai.api.chat.ChatRole
+import com.aallam.openai.api.chat.FunctionCall
+import com.aallam.openai.api.chat.ChatCompletionFunction
+import com.aallam.openai.api.chat.JsonData
 import com.aallam.openai.api.completion.CompletionRequest
 import com.aallam.openai.api.file.FileSource
 import com.aallam.openai.api.image.ImageCreation
@@ -22,6 +25,7 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.runBlocking
 import okio.FileSystem
 import okio.Path.Companion.toPath
+import kotlinx.serialization.json.put
 
 @OptIn(BetaOpenAI::class)
 fun main() = runBlocking {
@@ -101,6 +105,71 @@ fun main() = runBlocking {
     )
     openAI.chatCompletion(chatCompletionRequest).choices.forEach(::println)
 
+    println("> Create Chat Completion function call...")
+    val chatCompletionCreateFunctionCall = ChatCompletionRequest(
+        model = ModelId("gpt-3.5-turbo-0613"),
+        messages = listOf(
+            ChatMessage(
+                role = ChatRole.System,
+                content = "You are a helpful assistant that translates English to French."
+            ),
+            ChatMessage(
+                role = ChatRole.User,
+                content = "Translate the following English text to French: “OpenAI is awesome!”"
+            )
+        ),
+        functionCall = FunctionCall.forceCall("translate"),
+        functions = listOf(
+            ChatCompletionFunction(
+                name = "translate",
+                description = "Translate English to French",
+                parameters = JsonData.fromString(
+                   """
+                    {
+                        "type": "object",
+                        "properties": {
+                            "text": {
+                                "type": "string"
+                            }
+                        }
+                    }
+                    """
+                ),
+            )
+        )
+    )
+    openAI.chatCompletion(chatCompletionCreateFunctionCall).choices.forEach(::println)
+    println("> Process Chat Completion function call...")
+    val chatFunctionReturn = ChatCompletionRequest(
+        model = ModelId("gpt-3.5-turbo-0613"),
+        messages = listOf(
+            ChatMessage(
+                role = ChatRole.System,
+                content = "You are a helpful assistant that uses a function to translates English to French.\n" +
+                        "Use only the result of the function call as the response."
+            ),
+            ChatMessage(
+                role = ChatRole.User,
+                content = "Translate the following English text to French: “OpenAI is awesome!”"
+            ),
+            ChatMessage(
+                role = ChatRole.Assistant,
+                content = "None",
+                functionCall = JsonData.builder {
+                    put("name", "translate")
+                    put("arguments", """{"text": "OpenAI is awesome!"}""")
+                }
+
+            ),
+            ChatMessage(
+                role = ChatRole.Function,
+                content = "openai est super !",
+                name = "translate",
+            )
+        ),
+    )
+    openAI.chatCompletion(chatFunctionReturn).choices.forEach(::println)
+
     println("\n>️ Creating chat completions stream...")
     openAI.chatCompletions(chatCompletionRequest)
         .onEach { print(it.choices.first().delta?.content.orEmpty()) }