diff --git a/open-sse/config/credentialLoader.ts b/open-sse/config/credentialLoader.ts
index 0f6cbd8eeb..5cd2a06ac4 100644
--- a/open-sse/config/credentialLoader.ts
+++ b/open-sse/config/credentialLoader.ts
@@ -16,6 +16,7 @@
 
 import { readFileSync, existsSync } from "fs";
 import { join } from "path";
+import { resolveDataDir } from "../../src/lib/dataPaths";
 
 // Fields that can be overridden per provider
 const CREDENTIAL_FIELDS = ["clientId", "clientSecret", "tokenUrl", "authUrl", "refreshUrl"];
@@ -30,8 +31,7 @@ let cachedProviders = null;
  * Priority: DATA_DIR env → ./data (project root)
  */
 function resolveCredentialsPath() {
-  const dataDir = process.env.DATA_DIR || join(process.cwd(), "data");
-  return join(dataDir, "provider-credentials.json");
+  return join(resolveDataDir(), "provider-credentials.json");
 }
 
 /**
@@ -93,7 +93,11 @@ export function loadProviderCredentials(providers) {
       `[CREDENTIALS] ${isReload ? "Reloaded" : "Loaded"} external credentials: ${overrideCount} field(s) from ${credPath}`
     );
   } catch (err) {
-    console.log(`[CREDENTIALS] Error reading credentials file: ${err.message}. Using defaults.`);
+    const reason =
+      err instanceof SyntaxError
+        ? "Invalid JSON format"
+        : (err as NodeJS.ErrnoException).code || "read error";
+    console.log(`[CREDENTIALS] Error reading credentials file (${reason}). Using defaults.`);
   }
 
   cachedProviders = providers;
diff --git a/open-sse/services/autoCombo/persistence.ts b/open-sse/services/autoCombo/persistence.ts
index c940c0032b..7dae3521a9 100644
--- a/open-sse/services/autoCombo/persistence.ts
+++ b/open-sse/services/autoCombo/persistence.ts
@@ -7,6 +7,7 @@
 
 import fs from "fs";
 import path from "path";
+import { resolveDataDir } from "../../../src/lib/dataPaths";
 
 export interface AdaptationState {
   comboId: string;
@@ -23,7 +24,7 @@ export interface AdaptationState {
   lastUpdated: string;
 }
 
-const PERSISTENCE_DIR = path.join(process.cwd(), "data");
+const PERSISTENCE_DIR = resolveDataDir();
 const STATE_FILE = path.join(PERSISTENCE_DIR, "auto_combo_state.json");
 
 let stateCache = new Map<string, AdaptationState>();
diff --git a/open-sse/transformer/responsesTransformer.ts b/open-sse/transformer/responsesTransformer.ts
index 0d20255682..29d1dc9b9b 100644
--- a/open-sse/transformer/responsesTransformer.ts
+++ b/open-sse/transformer/responsesTransformer.ts
@@ -1,5 +1,6 @@
 import * as fs from "fs";
 import * as path from "path";
+import { resolveDataDir } from "../../src/lib/dataPaths";
 /**
  * Responses API Transformer
  * Converts OpenAI Chat Completions SSE to Codex Responses API SSE format
@@ -39,7 +40,7 @@ export function createResponsesLogger(model, logsDir = null) {
 
   const timestamp = new Date().toISOString().replace(/[:.]/g, "").slice(0, 15);
   const uniqueId = Math.random().toString(36).slice(2, 8);
-  const baseDir = logsDir || (typeof process !== "undefined" ? process.cwd() : ".");
+  const baseDir = logsDir || resolveDataDir();
   const logDir = path.join(baseDir, "logs", `responses_${model}_${timestamp}_${uniqueId}`);
 
   try {
diff --git a/open-sse/utils/requestLogger.ts b/open-sse/utils/requestLogger.ts
index 9b83b0431b..be4f7e91ce 100644
--- a/open-sse/utils/requestLogger.ts
+++ b/open-sse/utils/requestLogger.ts
@@ -16,10 +16,8 @@ async function ensureNodeModules() {
   try {
     fs = await import("fs");
     path = await import("path");
-    LOGS_DIR = path.join(
-      typeof process !== "undefined" && process.cwd ? process.cwd() : ".",
-      "logs"
-    );
+    const { resolveDataDir } = await import("../../src/lib/dataPaths");
+    LOGS_DIR = path.join(resolveDataDir(), "logs");
   } catch {
     // Running in non-Node environment (Worker, Browser, etc.)
   }