Add completion_tokens_details with reasoning_tokens to OpenAi Usage

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiApi.java

@@ -929,12 +929,28 @@ public record TopLogProbs(// @formatter:off
 	 * @param promptTokens Number of tokens in the prompt.
 	 * @param totalTokens Total number of tokens used in the request (prompt +
 	 * completion).
+	 * @param completionTokenDetails Breakdown of tokens used in a completion
 	 */
 	@JsonInclude(Include.NON_NULL)
 	public record Usage(// @formatter:off
 			@JsonProperty("completion_tokens") Integer completionTokens,
 			@JsonProperty("prompt_tokens") Integer promptTokens,
-			@JsonProperty("total_tokens") Integer totalTokens) {// @formatter:on
+			@JsonProperty("total_tokens") Integer totalTokens,
+			@JsonProperty("completion_tokens_details") CompletionTokenDetails completionTokenDetails) {// @formatter:on
+
+		public Usage(Integer completionTokens, Integer promptTokens, Integer totalTokens) {
+			this(completionTokens, promptTokens, totalTokens, null);
+		}
+
+		/**
+		 * Breakdown of tokens used in a completion
+		 *
+		 * @param reasoningTokens Number of tokens generated by the model for reasoning.
+		 */
+		@JsonInclude(Include.NON_NULL)
+		public record CompletionTokenDetails(// @formatter:off
+				@JsonProperty("reasoning_tokens") Integer reasoningTokens) {// @formatter:on
+		}
 
 	}
 

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/metadata/OpenAiUsage.java

@@ -58,6 +58,12 @@ public Long getGenerationTokens() {
 		return generationTokens != null ? generationTokens.longValue() : 0;
 	}
 
+	public Long getReasoningTokens() {
+		OpenAiApi.Usage.CompletionTokenDetails completionTokenDetails = getUsage().completionTokenDetails();
+		Integer reasoningTokens = completionTokenDetails != null ? completionTokenDetails.reasoningTokens() : null;
+		return reasoningTokens != null ? reasoningTokens.longValue() : 0;
+	}
+
 	@Override
 	public Long getTotalTokens() {
 		Integer totalTokens = getUsage().totalTokens();

models/spring-ai-openai/src/test/java/org/springframework/ai/openai/metadata/OpenAiUsageTests.java

@@ -54,4 +54,28 @@ void whenTotalTokensIsNull() {
 		assertThat(usage.getTotalTokens()).isEqualTo(300);
 	}
 
+	@Test
+	void whenCompletionTokenDetailsIsNull() {
+		OpenAiApi.Usage openAiUsage = new OpenAiApi.Usage(100, 200, 300, null);
+		OpenAiUsage usage = OpenAiUsage.from(openAiUsage);
+		assertThat(usage.getTotalTokens()).isEqualTo(300);
+		assertThat(usage.getReasoningTokens()).isEqualTo(0);
+	}
+
+	@Test
+	void whenReasoningTokensIsNull() {
+		OpenAiApi.Usage openAiUsage = new OpenAiApi.Usage(100, 200, 300,
+				new OpenAiApi.Usage.CompletionTokenDetails(null));
+		OpenAiUsage usage = OpenAiUsage.from(openAiUsage);
+		assertThat(usage.getReasoningTokens()).isEqualTo(0);
+	}
+
+	@Test
+	void whenCompletionTokenDetailsIsPresent() {
+		OpenAiApi.Usage openAiUsage = new OpenAiApi.Usage(100, 200, 300,
+				new OpenAiApi.Usage.CompletionTokenDetails(50));
+		OpenAiUsage usage = OpenAiUsage.from(openAiUsage);
+		assertThat(usage.getReasoningTokens()).isEqualTo(50);
+	}
+
 }