feat: enhance reasoning handling in tool calls and change the thinking order when stream=false and exclude reasoning_opaque from token calculation in calculateMessageTokens

Author: caozhiyuan

src/lib/tokenizer.ts

@@ -73,6 +73,9 @@ const calculateMessageTokens = (
   const tokensPerName = 1
   let tokens = tokensPerMessage
   for (const [key, value] of Object.entries(message)) {
+    if (key === "reasoning_opaque") {
+      continue
+    }
     if (typeof value === "string") {
       tokens += encoder.encode(value).length
     }

src/routes/messages/non-stream-translation.ts

@@ -287,7 +287,7 @@ export function translateToAnthropic(
     )
     const toolUseBlocks = getAnthropicToolUseBlocks(choice.message.tool_calls)
 
-    assistantContentBlocks.push(...textBlocks, ...thingBlocks, ...toolUseBlocks)
+    assistantContentBlocks.push(...thingBlocks, ...textBlocks, ...toolUseBlocks)
 
     // Use the finish_reason from the first choice, or prioritize tool_calls
     if (choice.finish_reason === "tool_calls" || stopReason === "stop") {
@@ -320,7 +320,7 @@ export function translateToAnthropic(
 function getAnthropicTextBlocks(
   messageContent: Message["content"],
 ): Array<AnthropicTextBlock> {
-  if (typeof messageContent === "string") {
+  if (typeof messageContent === "string" && messageContent.length > 0) {
     return [{ type: "text", text: messageContent }]
   }
 
@@ -337,16 +337,16 @@ function getAnthropicThinkBlocks(
   reasoningText: string | null | undefined,
   reasoningOpaque: string | null | undefined,
 ): Array<AnthropicThinkingBlock> {
-  if (reasoningText) {
+  if (reasoningText && reasoningText.length > 0) {
     return [
       {
         type: "thinking",
         thinking: reasoningText,
-        signature: "",
+        signature: reasoningOpaque || "",
       },
     ]
   }
-  if (reasoningOpaque) {
+  if (reasoningOpaque && reasoningOpaque.length > 0) {
     return [
       {
         type: "thinking",

src/routes/messages/stream-translation.ts

@@ -62,6 +62,8 @@ function handleFinish(
         index: state.contentBlockIndex,
       })
       state.contentBlockOpen = false
+      state.contentBlockIndex++
+      handleReasoningOpaque(choice.delta, events, state)
     }
 
     events.push(
@@ -96,7 +98,9 @@ function handleToolCalls(
   events: Array<AnthropicStreamEventData>,
 ) {
   if (delta.tool_calls && delta.tool_calls.length > 0) {
-    closeThinkingBlockIfOpen(delta, state, events)
+    closeThinkingBlockIfOpen(state, events)
+
+    handleReasoningOpaqueInToolCalls(state, events, delta)
 
     for (const toolCall of delta.tool_calls) {
       if (toolCall.id && toolCall.function?.name) {
@@ -150,13 +154,29 @@ function handleToolCalls(
   }
 }
 
+function handleReasoningOpaqueInToolCalls(
+  state: AnthropicStreamState,
+  events: Array<AnthropicStreamEventData>,
+  delta: Delta,
+) {
+  if (state.contentBlockOpen) {
+    events.push({
+      type: "content_block_stop",
+      index: state.contentBlockIndex,
+    })
+    state.contentBlockIndex++
+    state.contentBlockOpen = false
+  }
+  handleReasoningOpaque(delta, events, state)
+}
+
 function handleContent(
   delta: Delta,
   state: AnthropicStreamState,
   events: Array<AnthropicStreamEventData>,
 ) {
   if (delta.content && delta.content.length > 0) {
-    closeThinkingBlockIfOpen(delta, state, events)
+    closeThinkingBlockIfOpen(state, events)
 
     if (isToolBlockOpen(state)) {
       // A tool block was open, so close it before starting a text block.
@@ -260,6 +280,7 @@ function handleReasoningOpaque(
         index: state.contentBlockIndex,
       },
     )
+    state.contentBlockIndex++
   }
 }
 
@@ -312,7 +333,6 @@ function handleThinkingText(
 }
 
 function closeThinkingBlockIfOpen(
-  delta: Delta,
   state: AnthropicStreamState,
   events: Array<AnthropicStreamEventData>,
 ): void {
@@ -334,7 +354,6 @@ function closeThinkingBlockIfOpen(
     state.contentBlockIndex++
     state.thinkingBlockOpen = false
   }
-  handleReasoningOpaque(delta, events, state)
 }
 
 export function translateErrorToAnthropicErrorEvent(): AnthropicStreamEventData {