From 6a37adaee05c89941a11f937d1bf7bd5ed1e24e9 Mon Sep 17 00:00:00 2001
From: cpf <cuipengfei2008@gmail.com>
Date: Sat, 23 Aug 2025 20:59:16 +0800
Subject: [PATCH 1/2] feat: update usage structure in message events and chat
 completion types

---
 src/routes/messages/anthropic-types.ts          | 5 ++++-
 src/routes/messages/stream-translation.ts       | 7 ++++---
 src/services/copilot/create-chat-completions.ts | 8 ++++++++
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/routes/messages/anthropic-types.ts b/src/routes/messages/anthropic-types.ts
index 31c6e86e..7abf70bd 100644
--- a/src/routes/messages/anthropic-types.ts
+++ b/src/routes/messages/anthropic-types.ts
@@ -157,7 +157,10 @@ export interface AnthropicMessageDeltaEvent {
     stop_reason?: AnthropicResponse["stop_reason"]
     stop_sequence?: string | null
   }
-  usage?: { output_tokens: number }
+  usage?: {
+    input_tokens?: number
+    output_tokens: number
+  }
 }
 
 export interface AnthropicMessageStopEvent {
diff --git a/src/routes/messages/stream-translation.ts b/src/routes/messages/stream-translation.ts
index 55af6cbd..5536e060 100644
--- a/src/routes/messages/stream-translation.ts
+++ b/src/routes/messages/stream-translation.ts
@@ -42,8 +42,8 @@ export function translateChunkToAnthropicEvents(
         stop_reason: null,
         stop_sequence: null,
         usage: {
-          input_tokens: 1,
-          output_tokens: 1, // Anthropic requires this to be > 0
+          input_tokens: chunk.usage?.prompt_tokens ?? 0,
+          output_tokens: 0, // Will be updated in message_delta when finished
         },
       },
     })
@@ -152,7 +152,8 @@ export function translateChunkToAnthropicEvents(
           stop_sequence: null,
         },
         usage: {
-          output_tokens: 1,
+          input_tokens: chunk.usage?.prompt_tokens ?? 0,
+          output_tokens: chunk.usage?.completion_tokens ?? 0,
         },
       },
       {
diff --git a/src/services/copilot/create-chat-completions.ts b/src/services/copilot/create-chat-completions.ts
index 1f76cca0..fe18a893 100644
--- a/src/services/copilot/create-chat-completions.ts
+++ b/src/services/copilot/create-chat-completions.ts
@@ -55,6 +55,14 @@ export interface ChatCompletionChunk {
   model: string
   choices: Array<Choice>
   system_fingerprint?: string
+  usage?: {
+    prompt_tokens: number
+    completion_tokens: number
+    total_tokens: number
+    prompt_tokens_details?: {
+      cached_tokens: number
+    }
+  }
 }
 
 interface Delta {

From 1b8c9d427112078cb12cdb32053a4795dcc1af93 Mon Sep 17 00:00:00 2001
From: cpf <cuipengfei2008@gmail.com>
Date: Sat, 23 Aug 2025 21:15:02 +0800
Subject: [PATCH 2/2] feat: add cache token details to usage and completion
 token structures

---
 src/routes/messages/anthropic-types.ts          | 2 ++
 src/routes/messages/stream-translation.ts       | 5 +++++
 src/services/copilot/create-chat-completions.ts | 4 ++++
 3 files changed, 11 insertions(+)

diff --git a/src/routes/messages/anthropic-types.ts b/src/routes/messages/anthropic-types.ts
index 7abf70bd..881fffcc 100644
--- a/src/routes/messages/anthropic-types.ts
+++ b/src/routes/messages/anthropic-types.ts
@@ -160,6 +160,8 @@ export interface AnthropicMessageDeltaEvent {
   usage?: {
     input_tokens?: number
     output_tokens: number
+    cache_creation_input_tokens?: number
+    cache_read_input_tokens?: number
   }
 }
 
diff --git a/src/routes/messages/stream-translation.ts b/src/routes/messages/stream-translation.ts
index 5536e060..c8c20a07 100644
--- a/src/routes/messages/stream-translation.ts
+++ b/src/routes/messages/stream-translation.ts
@@ -154,6 +154,11 @@ export function translateChunkToAnthropicEvents(
         usage: {
           input_tokens: chunk.usage?.prompt_tokens ?? 0,
           output_tokens: chunk.usage?.completion_tokens ?? 0,
+          ...(chunk.usage?.prompt_tokens_details?.cached_tokens
+            !== undefined && {
+            cache_read_input_tokens:
+              chunk.usage.prompt_tokens_details.cached_tokens,
+          }),
         },
       },
       {
diff --git a/src/services/copilot/create-chat-completions.ts b/src/services/copilot/create-chat-completions.ts
index fe18a893..5d38bb45 100644
--- a/src/services/copilot/create-chat-completions.ts
+++ b/src/services/copilot/create-chat-completions.ts
@@ -62,6 +62,10 @@ export interface ChatCompletionChunk {
     prompt_tokens_details?: {
       cached_tokens: number
     }
+    completion_tokens_details?: {
+      accepted_prediction_tokens: number
+      rejected_prediction_tokens: number
+    }
   }
 }