feat(chat): add logprob and topLogprobs (#328)

openai-client/src/commonTest/kotlin/com/aallam/openai/client/TestChatCompletions.kt

@@ -126,4 +126,43 @@ class TestChatCompletions : TestOpenAI() {
         assertNotNull(answer.question)
         assertNotNull(answer.response)
     }
+
+    @Test
+    fun logprobs() = test {
+        val request = chatCompletionRequest {
+            model = ModelId("gpt-3.5-turbo-0125")
+            messages {
+                message {
+                    role = ChatRole.User
+                    content = "What's the weather like in Boston?"
+                }
+            }
+            logprobs = true
+        }
+        val response = openAI.chatCompletion(request)
+        val logprobs = response.choices.first().logprobs
+        assertNotNull(logprobs)
+        assertEquals(response.usage!!.completionTokens, logprobs.content!!.size)
+    }
+
+    @Test
+    fun top_logprobs() = test {
+        val expectedTopLogProbs = 5
+        val request = chatCompletionRequest {
+            model = ModelId("gpt-3.5-turbo-0125")
+            messages {
+                message {
+                    role = ChatRole.User
+                    content = "What's the weather like in Boston?"
+                }
+            }
+            logprobs = true
+            topLogprobs = expectedTopLogProbs
+        }
+        val response = openAI.chatCompletion(request)
+        val logprobs = response.choices.first().logprobs
+        assertNotNull(logprobs)
+        assertEquals(response.usage!!.completionTokens, logprobs.content!!.size)
+        assertEquals(logprobs.content!![0].topLogprobs?.size, expectedTopLogProbs)
+    }
 }

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

@@ -1,6 +1,5 @@
-package com.aallam.openai.api.chat;
+package com.aallam.openai.api.chat
 
-import com.aallam.openai.api.BetaOpenAI
 import com.aallam.openai.api.core.FinishReason
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
@@ -20,9 +19,12 @@ public data class ChatChoice(
      * The generated chat message.
      */
     @SerialName("message") public val message: ChatMessage,
-
     /**
      * The reason why OpenAI stopped generating.
      */
     @SerialName("finish_reason") public val finishReason: FinishReason? = null,
+    /**
+     * Log probability information for the choice.
+     */
+    @SerialName("logprobs") public val logprobs: Logprobs? = null,
 )

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

@@ -1,6 +1,5 @@
 package com.aallam.openai.api.chat
 
-import com.aallam.openai.api.BetaOpenAI
 import com.aallam.openai.api.core.Usage
 import com.aallam.openai.api.model.ModelId
 import kotlinx.serialization.SerialName

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

@@ -146,6 +146,18 @@ public class ChatCompletionRequest(
      */
     @property:BetaOpenAI
     @SerialName("seed") public val seed: Int? = null,
+
+    /**
+     * Whether to return log probabilities of the output tokens or not. If true,
+     * returns the log probabilities of each output token returned in the content of message.
+     */
+    @SerialName("logprobs") public val logprobs: Boolean? = null,
+
+    /**
+     * An integer between 0 and 20 specifying the number of most likely tokens to return at each token position,
+     * each with an associated log probability. logprobs must be set to true if this parameter is used.
+     */
+    @SerialName("top_logprobs") public val topLogprobs: Int? = null,
 )
 
 /**
@@ -282,6 +294,18 @@ public class ChatCompletionRequestBuilder {
      */
     public var toolChoice: ToolChoice? = null
 
+    /**
+     * Whether to return log probabilities of the output tokens or not. If true,
+     * returns the log probabilities of each output token returned in the content of message.
+     */
+    public var logprobs: Boolean? = null
+
+    /**
+     * An integer between 0 and 20 specifying the number of most likely tokens to return at each token position,
+     * each with an associated log probability. logprobs must be set to true if this parameter is used.
+     */
+    public var topLogprobs: Int? = null
+
     /**
      * The messages to generate chat completions for.
      */
@@ -323,7 +347,9 @@ public class ChatCompletionRequestBuilder {
         functionCall = functionCall,
         responseFormat = responseFormat,
         toolChoice = toolChoice,
-        tools = tools
+        tools = tools,
+        logprobs = logprobs,
+        topLogprobs = topLogprobs
     )
 }
 

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

@@ -0,0 +1,17 @@
+package com.aallam.openai.api.chat
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * An object containing log probability information for the choice.
+ *
+ * [documentation](https://platform.openai.com/docs/api-reference/chat/object)
+ */
+@Serializable
+public data class Logprobs(
+    /**
+     * A list of message content tokens with log probability information.
+     */
+    @SerialName("content") public val content: List<LogprobsContent>? = null,
+)

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

@@ -0,0 +1,33 @@
+package com.aallam.openai.api.chat
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * An object containing logprobs for a single token
+ *
+ * [documentation](https://platform.openai.com/docs/api-reference/chat/object)
+ */
+@Serializable
+public data class LogprobsContent(
+    /**
+     * The token.
+     */
+    @SerialName("token") public val token: String,
+    /**
+     * The log probability of this token, if it is within the top 20 most likely tokens.
+     * Otherwise, the value -9999.0 is used to signify that the token is very unlikely.
+     */
+    @SerialName("logprob") public val logprob: Double,
+    /**
+     * A list of integers representing the UTF-8 bytes representation of the token. Useful in instances where
+     * characters are represented by multiple tokens and their byte representations must be combined to generate
+     * the correct text representation. Can be `null` if there is no bytes representation for the token.
+     */
+    @SerialName("bytes") public val bytes: List<Int>? = null,
+    /**
+     * List of the most likely tokens and their log probability, at this token position.
+     * In rare cases, there may be fewer than the number of requested top_logprobs returned.
+     */
+    @SerialName("top_logprobs") public val topLogprobs: List<TopLogprob>,
+)

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

@@ -0,0 +1,28 @@
+package com.aallam.openai.api.chat
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * An object containing a token and their log probability.
+ *
+ * [documentation](https://platform.openai.com/docs/api-reference/chat/object)
+ */
+@Serializable
+public data class TopLogprob(
+    /**
+     * The token
+     */
+    @SerialName("token") public val token: String,
+    /**
+     * The log probability of this token, if it is within the top 20 most likely tokens.
+     * Otherwise, the value `-9999.0` is used to signify that the token is very unlikely.
+     */
+    @SerialName("logprob") public val logprob: Double,
+    /**
+     * A list of integers representing the UTF-8 bytes representation of the token. Useful in instances where
+     * characters are represented by multiple tokens and their byte representations must be combined to generate
+     * the correct text representation. Can be `null` if there is no bytes representation for the token.
+     */
+    @SerialName("bytes") public val bytes: List<Int>? = null,
+)