Propagate multi-message system prompts and token usage

.gitignore

@@ -1 +1,2 @@
 /target
+/logs

README.md

@@ -94,7 +94,7 @@ CCORP is designed to work seamlessly with Anthropic's Claude Code CLI:
 
    ```bash
    export ANTHROPIC_BASE_URL=http://localhost:3000
-   export ANTHROPIC_AUTH_TOKEN="your_openrouter_api_key"
+   export ANTHROPIC_API_KEY="your_openrouter_api_key"
    ```
 
 3. Run Claude Code as normal:

src/anthropic_to_openai.rs

@@ -18,10 +18,30 @@ pub fn format_anthropic_to_openai(req: AnthropicRequest, settings: &Config) -> O
     let mut openapi_messages = Vec::new();
 
     if let Some(system) = req.system {
-        if let Some(system_str) = system.as_str() {
+        let system_text = if let Some(system_str) = system.as_str() {
+            // Handle string format: "system prompt text"
+            system_str.to_string()
+        } else if let Some(system_array) = system.as_array() {
+            // Handle array format: [{"type": "text", "text": "..."}]
+            system_array
+                .iter()
+                .filter_map(|block| {
+                    if block["type"] == "text" {
+                        block["text"].as_str().map(|s| s.to_string())
+                    } else {
+                        None
+                    }
+                })
+                .collect::<Vec<String>>()
+                .join("\n\n")
+        } else {
+            String::new()
+        };
+
+        if !system_text.is_empty() {
             openapi_messages.push(OpenAIMessage {
                 role: "system".to_string(),
-                content: Some(system_str.to_string()),
+                content: Some(system_text),
                 tool_calls: None,
                 tool_call_id: None,
             });

src/main.rs

@@ -84,6 +84,15 @@ async fn messages_handler(
     headers: HeaderMap,
     Json(payload): Json<AnthropicRequest>,
 ) -> impl IntoResponse {
+    if let Some(path) = state.logging_path.as_ref() {
+        let timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let anthropic_request_path = format!("{path}/{timestamp}-anthropic-request.json");
+        let anthropic_request_json = serde_json::to_string_pretty(&payload).unwrap();
+        std::fs::write(anthropic_request_path, anthropic_request_json).expect("Failed to write anthropic request log");
+    }
     let settings_guard = state.config.read().await;
     let openai_request = anthropic_to_openai::format_anthropic_to_openai(payload, &settings_guard);
 

src/models.rs

@@ -2,6 +2,16 @@ use serde::{Deserialize, Serialize};
 
 // Anthropic API Structs
 
+#[derive(Debug, Serialize, Deserialize)]
+pub struct AnthropicUsage {
+    pub input_tokens: u32,
+    pub output_tokens: u32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub cache_creation_input_tokens: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub cache_read_input_tokens: Option<u32>,
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 pub struct AnthropicMessage {
     pub role: String,
@@ -32,10 +42,19 @@ pub struct AnthropicResponse {
     pub stop_reason: String,
     pub stop_sequence: Option<String>,
     pub model: String,
+    pub usage: AnthropicUsage,
 }
 
 // OpenAI API Structs
 
+#[derive(Debug, Serialize, Deserialize, Clone)]
+pub struct OpenAIUsage {
+    pub prompt_tokens: u32,
+    pub completion_tokens: u32,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub total_tokens: Option<u32>,
+}
+
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct OpenAIMessage {
     pub role: String,
@@ -78,6 +97,7 @@ pub struct OpenAIResponse {
     pub id: String,
     pub choices: Vec<OpenAIChoice>,
     pub model: String,
+    pub usage: OpenAIUsage,
 }
 
 #[derive(Debug, Serialize, Deserialize, Clone)]

src/openai_to_anthropic.rs

@@ -1,4 +1,4 @@
-use crate::models::*;
+use crate::models::{AnthropicResponse, AnthropicUsage, OpenAIResponse};
 use serde_json::json;
 
 pub fn format_openai_to_anthropic(resp: OpenAIResponse) -> AnthropicResponse {
@@ -32,5 +32,11 @@ pub fn format_openai_to_anthropic(resp: OpenAIResponse) -> AnthropicResponse {
         },
         stop_sequence: None,
         model: resp.model,
+        usage: AnthropicUsage {
+            input_tokens: resp.usage.prompt_tokens,
+            output_tokens: resp.usage.completion_tokens,
+            cache_creation_input_tokens: None,
+            cache_read_input_tokens: None,
+        },
     }
 }