diff --git a/.codegraph/.gitignore b/.codegraph/.gitignore
new file mode 100644
index 0000000..d20c0fe
--- /dev/null
+++ b/.codegraph/.gitignore
@@ -0,0 +1,5 @@
+# CodeGraph data files — local to each machine, not for committing.
+# Ignore everything in .codegraph/ except this file itself, so transient
+# files (the database, daemon.pid, sockets, logs) never show up in git.
+*
+!.gitignore
diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..08041c9
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,8 @@
+# md-vector-db 环境变量配置
+# 复制此文件为 .env 并填入实际值
+
+# 嵌入 API 密钥 (embed.mode=api 时使用)
+EMBED_API_KEY=sk-your-key-here
+
+# HTTP API 认证密钥 (不设置则跳过认证)
+MD_VECTOR_API_KEY=your-secret-key
diff --git a/pyproject.toml b/pyproject.toml
index eb62690..4f49cc5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,6 +11,7 @@ dependencies = [
     "pyyaml>=6.0",
     "markdown-it-py>=3.0.0",
     "typer>=0.12.0",
+    "python-dotenv>=1.2.2",
 ]
 
 [project.scripts]
diff --git a/src/core/config.py b/src/core/config.py
index 6f46c4d..ff7cd99 100644
--- a/src/core/config.py
+++ b/src/core/config.py
@@ -5,8 +5,13 @@ import os
 from dataclasses import dataclass, field
 from pathlib import Path
 
+from dotenv import load_dotenv
+
 import yaml
 
+# 加载 .env 文件 (若存在)
+load_dotenv()
+
 # 默认配置文件路径
 DEFAULT_CONFIG_PATH = "config.yaml"
 
diff --git a/uv.lock b/uv.lock
index fda2d1c..35656b5 100644
--- a/uv.lock
+++ b/uv.lock
@@ -873,6 +873,7 @@ dependencies = [
     { name = "chromadb" },
     { name = "fastapi" },
     { name = "markdown-it-py" },
+    { name = "python-dotenv" },
     { name = "pyyaml" },
     { name = "sentence-transformers" },
     { name = "typer" },
@@ -892,6 +893,7 @@ requires-dist = [
     { name = "httpx", marker = "extra == 'dev'", specifier = ">=0.27.0" },
     { name = "markdown-it-py", specifier = ">=3.0.0" },
     { name = "pytest", marker = "extra == 'dev'", specifier = ">=8.0" },
+    { name = "python-dotenv", specifier = ">=1.2.2" },
     { name = "pyyaml", specifier = ">=6.0" },
     { name = "sentence-transformers", specifier = ">=3.0.0" },
     { name = "typer", specifier = ">=0.12.0" },