log per-call token usage via TOKENS channel

Author: AdamBien

zsmith/src/main/java/airhacks/zsmith/claude/control/Claude.java

@@ -147,16 +147,24 @@ static HttpResponse<String> sendInstrumented(String message, String model, boole
         var event = new ClaudeAPICallEvent();
         event.begin();
         var response = send(message);
+        event.model = model;
+        event.fallback = fallback;
+        event.statusCode = response.statusCode();
+        populateUsage(event, response);
+        logTokens(event);
         if (event.shouldCommit()) {
-            event.model = model;
-            event.fallback = fallback;
-            event.statusCode = response.statusCode();
-            populateUsage(event, response);
             event.commit();
         }
         return response;
     }
 
+    static void logTokens(ClaudeAPICallEvent event) {
+        if (event.statusCode != 200) return;
+        Log.tokens("in=%d out=%d cache_read=%d cache_create=%d".formatted(
+            event.inputTokens, event.outputTokens,
+            event.cacheReadTokens, event.cacheCreationTokens));
+    }
+
     static void populateUsage(ClaudeAPICallEvent event, HttpResponse<String> response) {
         if (response.statusCode() != 200) {
             return;

zsmith/src/main/java/airhacks/zsmith/logging/control/Log.java

@@ -20,7 +20,8 @@ public enum Log {
     MEMORY("🧠", Color.YELLOW, System.out),
     REQUEST("📤", Color.GREEN, System.out, "log.request"),
     RESPONSE("📥", Color.VIOLET, System.out, "log.response"),
-    LLM("🧩", Color.CYAN, System.out, "log.llm");
+    LLM("🧩", Color.CYAN, System.out, "log.llm"),
+    TOKENS("🪙", Color.YELLOW, System.out);
 
     private PrintStream out;
 
@@ -152,6 +153,10 @@ public static void llm(String message) {
         Log.LLM.out(message);
     }
 
+    public static void tokens(String message) {
+        Log.TOKENS.out(message);
+    }
+
     public static void clearScreen() {
         System.out.println("\033c");
     }