diff --git a/Sources/Services/Feishu/FeishuAuthService.swift b/Sources/Services/Feishu/FeishuAuthService.swift
index ff45cd4..13b3361 100644
--- a/Sources/Services/Feishu/FeishuAuthService.swift
+++ b/Sources/Services/Feishu/FeishuAuthService.swift
@@ -42,20 +42,20 @@ final class FeishuAuthService {
     }
 
     func exchangeCode(_ code: String) async throws -> OAuthTokenData {
-        BuggerLog.info("exchangeCode: start, code len=\(code.count)")
+        print("[BUGGER] exchangeCode: start, code len=\(code.count)")
         let tenantToken = try await tenantAccessToken()
-        BuggerLog.info("exchangeCode: got tenant token, building request...")
+        print("[BUGGER] exchangeCode: got tenantToken=\(tenantToken.prefix(8))..., building request...")
         let url = URL(string: "\(baseURL)/authen/v1/oidc/access_token")!
         var request = URLRequest(url: url)
         request.httpMethod = "POST"
         request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
         request.setValue("Bearer \(tenantToken)", forHTTPHeaderField: "Authorization")
-        BuggerLog.info("exchangeCode: encoding body...")
-        let body: [String: String] = ["grant_type": "authorization_code", "code": code]
-        request.httpBody = try JSONEncoder().encode(body)
-        BuggerLog.info("exchangeCode: body encoded (\(request.httpBody?.count ?? 0)B), sending...")
+        // Use manual JSON to rule out JSONEncoder issues
+        let jsonBody = "{\"grant_type\":\"authorization_code\",\"code\":\"\(code)\"}"
+        request.httpBody = jsonBody.data(using: .utf8)
+        print("[BUGGER] exchangeCode: sending to \(url.absoluteString)...")
         let tokenData: OAuthTokenData = try await send(request)
-        BuggerLog.info("exchangeCode: got token access=\(tokenData.accessToken.prefix(8))... refresh=\(tokenData.refreshToken?.prefix(8) ?? "nil")...")
+        print("[BUGGER] exchangeCode: SUCCESS access=\(tokenData.accessToken.prefix(8))... refresh=\(tokenData.refreshToken?.prefix(8) ?? "nil")...")
         return tokenData
     }
 
@@ -118,35 +118,32 @@ final class FeishuAuthService {
     }
 
     private func send<T: Decodable>(_ request: URLRequest) async throws -> T {
-        BuggerLog.info("→ \(request.httpMethod ?? "?") \(request.url?.absoluteString ?? "?")")
+        print("[BUGGER] → \(request.httpMethod ?? "?") \(request.url?.absoluteString ?? "?")")
         if let body = request.httpBody, let bodyStr = String(data: body, encoding: .utf8) {
-            BuggerLog.info("  body: \(bodyStr)")
-        }
-        if let auth = request.value(forHTTPHeaderField: "Authorization") {
-            BuggerLog.info("  auth: \(auth.prefix(20))...")
+            print("[BUGGER]   body: \(bodyStr)")
         }
 
         let (data, response) = try await session.data(for: request)
         guard let httpResponse = response as? HTTPURLResponse else {
-            BuggerLog.error("← not an HTTP response")
+            print("[BUGGER] ← not an HTTP response")
             throw FeishuError.networkError(nil)
         }
 
         let bodyStr = String(data: data, encoding: .utf8) ?? "<binary \(data.count)B>"
-        BuggerLog.info("← \(httpResponse.statusCode) \(bodyStr.prefix(500))")
+        print("[BUGGER] ← \(httpResponse.statusCode) \(bodyStr.prefix(500))")
 
         if httpResponse.statusCode == 401 {
-            BuggerLog.error("← 401 Unauthorized")
+            print("[BUGGER] ← 401 Unauthorized")
             throw FeishuError.unauthorized
         }
 
         do {
             let decoded = try decoder.decode(T.self, from: data)
-            BuggerLog.info("  decoded as \(T.self) ✓")
+            print("[BUGGER]   decoded as \(T.self) ✓")
             return decoded
         } catch {
-            BuggerLog.error("  decode failed: \(error.localizedDescription)")
-            BuggerLog.error("  raw body: \(bodyStr.prefix(1000))")
+            print("[BUGGER]   decode FAILED: \(error)")
+            print("[BUGGER]   raw body: \(bodyStr.prefix(1000))")
             throw FeishuError.decodingError(error)
         }
     }