diff --git a/README.md b/README.md
index d4db2bd..5dd6c52 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,6 @@
 [![Pytest](https://github.com/Arcadia822/codedog/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/Arcadia822/codedog/actions/workflows/test.yml)
 [![Coverage](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/Arcadia822/ce38dae58995aeffef42065093fcfe84/raw/codedog_master.json)](https://github.com/Arcadia822/codedog/actions/workflows/test.yml)
 
-
 Review your Github/Gitlab PR with ChatGPT
 
 ![Design](docs/design.png)
@@ -19,18 +18,18 @@ poetry install --with dev
 
 settings:
 
-| 环境变量                | 是否必要 | 默认值                 | 说明                                |
-| ----------------------- | -------- | ---------------------- | ----------------------------------- |
-| CODEDOG_WORKER_NUM      | 否       | 1                      | 服务线程数                          |
-| CODEDOG_ENV             | 否       | "unknown"              | 表明 codedog 实例所属环境           |
-| DATADOG_METRIC          | 否       |                        | 值为 True 时向 datadog 发送统计指标 |
-| DATADOG_AGENT_HOST      | 否       | localhost              | datadog agent host                  |
-| DATADOG_DOGSTATSD_PORT  | 否       | 8125                   | datadog agent dogstatsd port        |
-| GITHUB_TOKEN            | 否       |                        | 用于连接 github 和评论              |
-| GITHUB_APP_ID           | 否       | 0                      | 用于配置 github app id              |
-| GITHUB_PRIVATE_KEY_PATH | 否       | "/app/private_key.pem" | 用于生成 github app jwt token       |
-| OPENAI_API_KEY          | 是       |                        | 调用 OPENAI 的 API KEY              |
-| OPENAI_PROXY            | 否       |                        | 设置到 openai.proxy                 |
+| 环境变量               | 是否必要 | 默认值    | 说明                                |
+| ---------------------- | -------- | --------- | ----------------------------------- |
+| CODEDOG_WORKER_NUM     | 否       | 1         | 服务线程数                          |
+| CODEDOG_ENV            | 否       | "unknown" | 表明 codedog 实例所属环境           |
+| DATADOG_METRIC         | 否       |           | 值为 True 时向 datadog 发送统计指标 |
+| DATADOG_AGENT_HOST     | 否       | localhost | datadog agent host                  |
+| DATADOG_DOGSTATSD_PORT | 否       | 8125      | datadog agent dogstatsd port        |
+| GITHUB_TOKEN           | 否       |           | 用于连接 github 和评论              |
+| GITHUB_APP_ID          | 否       | 0         | 用于配置 github app id              |
+| GITHUB_APP_PRIVATE_KEY | 否       | ""        | 用于认证 github app                 |
+| OPENAI_API_KEY         | 是       |           | 调用 OPENAI 的 API KEY              |
+| OPENAI_PROXY           | 否       |           | 设置到 openai.proxy                 |
 
 ## Start Server
 
@@ -42,5 +41,4 @@ poetry run start
 
 ### Github
 
-
 ### Gitlab
diff --git a/codedog/adapters/github_adapter.py b/codedog/adapters/github_adapter.py
index 1107732..4b7e05d 100644
--- a/codedog/adapters/github_adapter.py
+++ b/codedog/adapters/github_adapter.py
@@ -25,7 +25,6 @@
     get_jwt_token,
     get_sha256,
     get_ttl_hash,
-    load_private_key,
 )
 
 logger = logging.getLogger(__name__)
@@ -38,7 +37,7 @@
 
 # used for github app
 github_app_id = env.get("GITHUB_APP_ID", 0)
-github_private_key = load_private_key(env.get("GITHUB_PRIVATE_KEY_PATH", "/app/private_key.pem"))
+github_private_key = env.get("GITHUB_APP_PRIVATE_KEY", "")
 
 
 issue_pattern = re.compile(r"#[0-9]+")
diff --git a/codedog/utils.py b/codedog/utils.py
index bb68935..c163866 100644
--- a/codedog/utils.py
+++ b/codedog/utils.py
@@ -8,8 +8,6 @@
 
 import jwt
 import requests
-from cryptography.hazmat.backends import default_backend
-from cryptography.hazmat.primitives import serialization
 
 # -- Logging ------------------------------------------------------------------
 
@@ -103,10 +101,3 @@ def get_access_token_by_installation_id(installation_id: int, jwt_token: str):
     response.raise_for_status()
     token_info = response.json()
     return token_info["token"]
-
-
-def load_private_key(filename):
-    # 从文件中读取你的私钥
-    with open(filename, "rb") as key_file:
-        private_key = serialization.load_pem_private_key(key_file.read(), password=None, backend=default_backend())
-    return private_key
diff --git a/examples/github/github_app.py b/examples/github/github_app.py
index b9b9a78..6e45afa 100644
--- a/examples/github/github_app.py
+++ b/examples/github/github_app.py
@@ -1,17 +1,14 @@
 from github import Github
 
-from codedog.utils import (
-    get_access_token_by_installation_id,
-    get_jwt_token,
-    load_private_key,
-)
+from codedog.utils import get_access_token_by_installation_id, get_jwt_token
 
 YOUR_APP_ID = 363842
 installation_id = 39837873
 
-private_key = load_private_key('codedogassistant.private-key.pem')
-
-print(private_key)
+private_key = """
+-----BEGIN RSA PRIVATE KEY-----
+-----END RSA PRIVATE KEY-----
+"""
 
 jwt_token = get_jwt_token(private_key, YOUR_APP_ID)
 
diff --git a/poetry.lock b/poetry.lock
index 9b2b143..cbcf27d 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -4740,4 +4740,4 @@ reference = "Tsinghua"
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.10"
-content-hash = "11cbae8557aa42ce94fa0069290b6e55ebdb363a43f86f4450149ec3d53ac34a"
+content-hash = "0ec293bfc3f44a7b5bdb25e5ca69e3d212246ef6e93b93b1867e5f63ed0d5b54"
diff --git a/pyproject.toml b/pyproject.toml
index 7013028..895a881 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,6 @@ uvicorn = "^0.21.1"
 pygithub = "^1.58.2"
 unidiff = "^0.7.5"
 pyjwt = "^2.8.0"
-cryptography = "^41.0.2"
 
 [tool.poetry.group.dev]
 optional = true