Extend deepseek-r1 support

src/api/transform/r1-format.ts

@@ -0,0 +1,98 @@
+import { Anthropic } from "@anthropic-ai/sdk"
+import OpenAI from "openai"
+
+type ContentPartText = OpenAI.Chat.ChatCompletionContentPartText
+type ContentPartImage = OpenAI.Chat.ChatCompletionContentPartImage
+type UserMessage = OpenAI.Chat.ChatCompletionUserMessageParam
+type AssistantMessage = OpenAI.Chat.ChatCompletionAssistantMessageParam
+type Message = OpenAI.Chat.ChatCompletionMessageParam
+type AnthropicMessage = Anthropic.Messages.MessageParam
+
+/**
+ * Converts Anthropic messages to OpenAI format while merging consecutive messages with the same role.
+ * This is required for DeepSeek Reasoner which does not support successive messages with the same role.
+ *
+ * @param messages Array of Anthropic messages
+ * @returns Array of OpenAI messages where consecutive messages with the same role are combined
+ */
+export function convertToR1Format(messages: AnthropicMessage[]): Message[] {
+	return messages.reduce<Message[]>((merged, message) => {
+		const lastMessage = merged[merged.length - 1]
+		let messageContent: string | (ContentPartText | ContentPartImage)[] = ""
+		let hasImages = false
+
+		// Convert content to appropriate format
+		if (Array.isArray(message.content)) {
+			const textParts: string[] = []
+			const imageParts: ContentPartImage[] = []
+
+			message.content.forEach((part) => {
+				if (part.type === "text") {
+					textParts.push(part.text)
+				}
+				if (part.type === "image") {
+					hasImages = true
+					imageParts.push({
+						type: "image_url",
+						image_url: { url: `data:${part.source.media_type};base64,${part.source.data}` },
+					})
+				}
+			})
+
+			if (hasImages) {
+				const parts: (ContentPartText | ContentPartImage)[] = []
+				if (textParts.length > 0) {
+					parts.push({ type: "text", text: textParts.join("\n") })
+				}
+				parts.push(...imageParts)
+				messageContent = parts
+			} else {
+				messageContent = textParts.join("\n")
+			}
+		} else {
+			messageContent = message.content
+		}
+
+		// If last message has same role, merge the content
+		if (lastMessage?.role === message.role) {
+			if (typeof lastMessage.content === "string" && typeof messageContent === "string") {
+				lastMessage.content += `\n${messageContent}`
+			}
+			// If either has image content, convert both to array format
+			else {
+				const lastContent = Array.isArray(lastMessage.content)
+					? lastMessage.content
+					: [{ type: "text" as const, text: lastMessage.content || "" }]
+
+				const newContent = Array.isArray(messageContent)
+					? messageContent
+					: [{ type: "text" as const, text: messageContent }]
+
+				if (message.role === "assistant") {
+					const mergedContent = [...lastContent, ...newContent] as AssistantMessage["content"]
+					lastMessage.content = mergedContent
+				} else {
+					const mergedContent = [...lastContent, ...newContent] as UserMessage["content"]
+					lastMessage.content = mergedContent
+				}
+			}
+		} else {
+			// Add as new message with the correct type based on role
+			if (message.role === "assistant") {
+				const newMessage: AssistantMessage = {
+					role: "assistant",
+					content: messageContent as AssistantMessage["content"],
+				}
+				merged.push(newMessage)
+			} else {
+				const newMessage: UserMessage = {
+					role: "user",
+					content: messageContent as UserMessage["content"],
+				}
+				merged.push(newMessage)
+			}
+		}
+
+		return merged
+	}, [])
+}