feat: Implement DeepSeek integration, refactor model adapters for streaming and tool calls, enhance admin and account management, and introduce new UI features for settings, API testing, and Vercel sync.

api/chat-stream/token_usage.js

@@ -0,0 +1,51 @@
+'use strict';
+
+function buildUsage(prompt, thinking, output) {
+  const promptTokens = estimateTokens(prompt);
+  const reasoningTokens = estimateTokens(thinking);
+  const completionTokens = estimateTokens(output);
+  return {
+    prompt_tokens: promptTokens,
+    completion_tokens: reasoningTokens + completionTokens,
+    total_tokens: promptTokens + reasoningTokens + completionTokens,
+    completion_tokens_details: {
+      reasoning_tokens: reasoningTokens,
+    },
+  };
+}
+
+function estimateTokens(text) {
+  const t = asString(text);
+  if (!t) {
+    return 0;
+  }
+  let asciiChars = 0;
+  let nonASCIIChars = 0;
+  for (const ch of Array.from(t)) {
+    if (ch.charCodeAt(0) < 128) {
+      asciiChars += 1;
+    } else {
+      nonASCIIChars += 1;
+    }
+  }
+  const n = Math.floor(asciiChars / 4) + Math.floor((nonASCIIChars * 10 + 7) / 13);
+  return n < 1 ? 1 : n;
+}
+
+function asString(v) {
+  if (typeof v === 'string') {
+    return v.trim();
+  }
+  if (Array.isArray(v)) {
+    return asString(v[0]);
+  }
+  if (v == null) {
+    return '';
+  }
+  return String(v).trim();
+}
+
+module.exports = {
+  buildUsage,
+  estimateTokens,
+};