diff --git a/Cargo.lock b/Cargo.lock
index d67943c..862fba0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -718,6 +718,12 @@ version = "0.4.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
 
+[[package]]
+name = "md5"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae960838283323069879657ca3de837e9f7bbb4c7bf6ea7f1b290d5e9476d2e0"
+
 [[package]]
 name = "memchr"
 version = "2.7.5"
@@ -1098,10 +1104,12 @@ dependencies = [
  "digest",
  "flate2",
  "hmac-sha256",
+ "md5",
  "nyquest",
  "serde",
  "serde_json",
  "snafu",
+ "strum 0.27.2",
 ]
 
 [[package]]
@@ -1205,8 +1213,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "15bf745ed831fe29ec1ff6cc8dfb443721c08e895c9a08fcaa1e2c6f09ec020d"
 dependencies = [
  "nom",
- "strum",
- "strum_macros",
+ "strum 0.24.1",
+ "strum_macros 0.24.3",
  "thiserror 1.0.69",
 ]
 
@@ -1260,7 +1268,16 @@ version = "0.24.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
 dependencies = [
- "strum_macros",
+ "strum_macros 0.24.3",
+]
+
+[[package]]
+name = "strum"
+version = "0.27.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af23d6f6c1a224baef9d3f61e287d2761385a5b88fdab4eb4c6f11aeb54c4bcf"
+dependencies = [
+ "strum_macros 0.27.2",
 ]
 
 [[package]]
@@ -1276,6 +1293,18 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "strum_macros"
+version = "0.27.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7695ce3845ea4b33927c055a39dc438a45b059f7c1b3d91d38d10355fb8cbca7"
+dependencies = [
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.104",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.109"
diff --git a/sdgb-api/Cargo.toml b/sdgb-api/Cargo.toml
index 2fbac9a..2c0b7be 100644
--- a/sdgb-api/Cargo.toml
+++ b/sdgb-api/Cargo.toml
@@ -11,12 +11,18 @@ snafu = { workspace = true }
 digest = "0.10.7"
 hmac-sha256 = { version = "1.1.12", features = ["digest010", "traits010"] }
 
+# other utils
 chrono = "0.4.41"
+strum = { version = "0.27.2", features = ["derive"] }
 
+# network request
 nyquest = { version = "0.2.0", features = ["async", "json"] }
 
+# (de)serialization
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.141"
+
 flate2 = "1.1.2"
 cbc = "0.1.2"
 aes = "0.8.4"
+md5 = "0.8.0"
diff --git a/sdgb-api/src/title/error/mod.rs b/sdgb-api/src/title/error/mod.rs
index edc6120..991bb95 100644
--- a/sdgb-api/src/title/error/mod.rs
+++ b/sdgb-api/src/title/error/mod.rs
@@ -7,9 +7,14 @@ pub enum ApiError {
     PadError { error: PadError },
     #[snafu(display("unpad data: {error}"))]
     UnpadError { error: UnpadError },
+
     #[snafu(display("io error: {source}"))]
     #[snafu(context(false))]
     IOError { source: std::io::Error },
+
+    #[snafu(display("json error: {source}"))]
+    #[snafu(context(false))]
+    JSONError { source: serde_json::Error },
 }
 
 impl From<UnpadError> for ApiError {
diff --git a/sdgb-api/src/title/methods/mod.rs b/sdgb-api/src/title/methods/mod.rs
new file mode 100644
index 0000000..129e141
--- /dev/null
+++ b/sdgb-api/src/title/methods/mod.rs
@@ -0,0 +1,63 @@
+#[derive(strum::IntoStaticStr)]
+pub enum APIMethod {
+    GetGameChargeApi,
+    GetGameEventApi,
+    GetGameNgMusicIdApi,
+    GetGameNgWordListApi,
+    GetGameRankingApi,
+    GetGameSettingApi,
+    GetGameTournamentInfoApi,
+    GetTransferFriendApi,
+    GetUserActivityApi,
+    GetUserCardApi,
+    GetUserCharacterApi,
+    GetUserChargeApi,
+    GetUserCourseApi,
+    GetUserDataApi,
+    GetUserExtendApi,
+    GetUserFavoriteApi,
+    GetUserFavoriteItemApi,
+    GetUserFriendSeasonRankingApi,
+    GetUserGhostApi,
+    GetUserItemApi,
+    GetUserLoginBonusApi,
+    GetUserMapApi,
+    GetUserMusicApi,
+    GetUserOptionApi,
+    GetUserPortraitApi,
+    GetUserPreviewApi,
+    GetUserRatingApi,
+    GetUserRecommendRateMusicApi,
+    GetUserRecommendSelectMusicApi,
+    GetUserRegionApi,
+    GetUserScoreRankingApi,
+    Ping,
+    UploadUserPhotoApi,
+    UploadUserPlaylogApi,
+    UploadUserPortraitApi,
+    UpsertClientBookkeepingApi,
+    UpsertClientSettingApi,
+    UpsertClientTestmodeApi,
+    UpsertClientUploadApi,
+    UpsertUserAllApi,
+    UpsertUserChargelogApi,
+    UserLoginApi,
+    UserLogoutApi,
+}
+
+#[cfg(test)]
+mod _test {
+    use crate::title::{MaiVersionExt, Sdgb1_50, methods::APIMethod};
+
+    #[test]
+    fn test_obfuscate_1_50() {
+        assert_eq!(
+            Sdgb1_50::api_hash(APIMethod::Ping),
+            "250b3482854e7697de7d8eb6ea1fabb1"
+        );
+        assert_eq!(
+            Sdgb1_50::api_hash(APIMethod::GetUserPreviewApi),
+            "004cf848f96d393a5f2720101e30b93d"
+        );
+    }
+}
diff --git a/sdgb-api/src/title/mod.rs b/sdgb-api/src/title/mod.rs
index 267229a..2b0f58b 100644
--- a/sdgb-api/src/title/mod.rs
+++ b/sdgb-api/src/title/mod.rs
@@ -1,17 +1,67 @@
-use crate::title::error::ApiError;
+use std::fmt::Display;
+
+use crate::title::methods::APIMethod;
 
 pub mod encryption;
+pub mod methods;
+pub mod model;
+
 mod error;
+pub use error::ApiError;
+use nyquest::{
+    Body,
+    r#async::Request,
+    header::{ACCEPT_ENCODING, CONTENT_ENCODING, EXPECT, USER_AGENT},
+};
+use serde::Serialize;
 
 pub trait MaiVersion {
     const AES_KEY: &[u8; 32];
     const AES_IV: &[u8; 16];
-    const OBFUSECATE_PARAM: &str;
+    const OBFUSECATE_SUFFIX: &str;
+    const VERSION: &str;
 }
 
 pub trait MaiVersionExt: MaiVersion {
     fn encode(data: impl AsRef<[u8]>) -> Result<Vec<u8>, ApiError>;
     fn decode(data: impl AsMut<[u8]>) -> Result<Vec<u8>, ApiError>;
+
+    fn api_hash(api: APIMethod) -> String {
+        let api_name: &str = api.into();
+
+        let mut md5 = md5::Context::new();
+        md5.consume(api_name);
+        md5.consume(Self::OBFUSECATE_SUFFIX);
+        let digest = md5.finalize();
+
+        format!("{digest:x}")
+    }
+
+    fn api_request<D>(
+        api: APIMethod,
+        agent_extra: impl Display,
+        data: D,
+    ) -> Result<Request, ApiError>
+    where
+        D: Serialize,
+    {
+        let json = serde_json::to_vec(&data)?;
+        let payload = Self::encode(json)?;
+
+        let api_hash = Self::api_hash(api);
+        let req = Request::post(format!(
+            "https://maimai-gm.wahlap.com:42081/Maimai2Servlet/{api_hash}"
+        ))
+        .with_body(Body::json_bytes(payload))
+        .with_header(USER_AGENT, format!("{api_hash}#{agent_extra}"))
+        .with_header("Mai-Encoding", Self::VERSION)
+        .with_header(ACCEPT_ENCODING, "")
+        .with_header("Charset", "UTF-8")
+        .with_header(CONTENT_ENCODING, "deflate")
+        .with_header(EXPECT, "100-continue");
+
+        Ok(req)
+    }
 }
 
 pub struct Sdgb1_40;
@@ -20,10 +70,14 @@ pub struct Sdgb1_50;
 impl MaiVersion for Sdgb1_40 {
     const AES_KEY: &[u8; 32] = b"n7bx6:@Fg_:2;5E89Phy7AyIcpxEQ:R@";
     const AES_IV: &[u8; 16] = b";;KjR1C3hgB1ovXa";
-    const OBFUSECATE_PARAM: &str = "BEs2D5vW";
+    const OBFUSECATE_SUFFIX: &str = "MaimaiChnBEs2D5vW";
+
+    const VERSION: &str = "1.40";
 }
 impl MaiVersion for Sdgb1_50 {
     const AES_KEY: &[u8; 32] = b"a>32bVP7v<63BVLkY[xM>daZ1s9MBP<R";
     const AES_IV: &[u8; 16] = b"d6xHIKq]1J]Dt^ue";
-    const OBFUSECATE_PARAM: &str = "B44df8yT";
+    const OBFUSECATE_SUFFIX: &str = "MaimaiChnB44df8yT";
+
+    const VERSION: &str = "1.50";
 }
diff --git a/sdgb-api/src/title/model/mod.rs b/sdgb-api/src/title/model/mod.rs
new file mode 100644
index 0000000..00bfb10
--- /dev/null
+++ b/sdgb-api/src/title/model/mod.rs
@@ -0,0 +1,4 @@
+use serde::Serialize;
+
+#[derive(Serialize)]
+pub struct Ping;
diff --git a/sdgb-cli/src/commands.rs b/sdgb-cli/src/commands.rs
index 0674eed..2ce8f23 100644
--- a/sdgb-cli/src/commands.rs
+++ b/sdgb-cli/src/commands.rs
@@ -10,6 +10,7 @@ pub struct Cli {
 
 #[derive(Subcommand)]
 pub enum Commands {
+    Ping,
     /// Login with QRCode from wechat
     QRLogin {
         /// content of the qrcode, only the last 64 characters were used
diff --git a/sdgb-cli/src/main.rs b/sdgb-cli/src/main.rs
index 444aa8e..f0f72be 100644
--- a/sdgb-cli/src/main.rs
+++ b/sdgb-cli/src/main.rs
@@ -1,6 +1,9 @@
 use nyquest_preset::nyquest::ClientBuilder;
 use palc::Parser;
-use sdgb_api::all_net::QRCode;
+use sdgb_api::{
+    all_net::QRCode,
+    title::{MaiVersionExt, Sdgb1_50, methods::APIMethod, model::Ping},
+};
 use spdlog::{error, info};
 
 use crate::commands::Cli;
@@ -15,6 +18,12 @@ async fn main() -> Result<(), Box<dyn snafu::Error>> {
     let client = ClientBuilder::default().build_async().await?;
 
     match cmd.command {
+        commands::Commands::Ping => {
+            let req = Sdgb1_50::api_request(APIMethod::Ping, "", Ping)?;
+            let data = client.request(req).await?.bytes().await?;
+            let decoded = Sdgb1_50::decode(data)?;
+            info!("resp: {:?}", String::from_utf8_lossy(&decoded));
+        }
         commands::Commands::QRLogin { ref qrcode_content } => {
             let qrcode = QRCode { qrcode_content };
             match qrcode.login(&client).await {