diff --git a/Cargo.lock b/Cargo.lock
index 86d564e..2c32ed1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -457,6 +457,26 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "crabtime"
+version = "1.1.3"
+source = "git+https://github.com/wdanilo/crabtime.git?rev=2ed856f5#2ed856f5f8b85a1e81598d64a36305a1d3f17d01"
+dependencies = [
+ "crabtime-internal",
+]
+
+[[package]]
+name = "crabtime-internal"
+version = "1.1.3"
+source = "git+https://github.com/wdanilo/crabtime.git?rev=2ed856f5#2ed856f5f8b85a1e81598d64a36305a1d3f17d01"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "rustc_version",
+ "syn 2.0.104",
+ "toml",
+]
+
 [[package]]
 name = "crc32fast"
 version = "1.5.0"
@@ -1433,6 +1453,7 @@ dependencies = [
  "chrono",
  "cipher",
  "compio",
+ "crabtime",
  "digest",
  "flate2",
  "hmac-sha256",
@@ -1503,6 +1524,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde_spanned"
+version = "0.6.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf41e0cfaf7226dca15e8197172c295a782857fcb97fad1808a166870dee75a3"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -1755,11 +1785,26 @@ dependencies = [
  "syn 2.0.104",
 ]
 
+[[package]]
+name = "toml"
+version = "0.8.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc1beb996b9d83529a9e75c17a1686767d148d70663143c7854d8b4a09ced362"
+dependencies = [
+ "serde",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_edit",
+]
+
 [[package]]
 name = "toml_datetime"
 version = "0.6.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
+dependencies = [
+ "serde",
+]
 
 [[package]]
 name = "toml_edit"
@@ -1768,10 +1813,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
 dependencies = [
  "indexmap",
+ "serde",
+ "serde_spanned",
  "toml_datetime",
+ "toml_write",
  "winnow",
 ]
 
+[[package]]
+name = "toml_write"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
+
 [[package]]
 name = "tracing"
 version = "0.1.41"
diff --git a/sdgb-api/Cargo.toml b/sdgb-api/Cargo.toml
index 2a7cff3..3a76a81 100644
--- a/sdgb-api/Cargo.toml
+++ b/sdgb-api/Cargo.toml
@@ -39,3 +39,6 @@ cbc = { version = "0.1.2", features = ["alloc"] }
 aes = "0.8.4"
 cipher = { version = "0.4.4", features = ["block-padding"] }
 bincode = { version = "2.0.1", optional = true }
+
+# magic macro
+crabtime = { git = "https://github.com/wdanilo/crabtime.git", rev = "2ed856f5" }
diff --git a/sdgb-api/src/title/methods/mod.rs b/sdgb-api/src/title/methods/mod.rs
index 9a3f2da..4ef1164 100644
--- a/sdgb-api/src/title/methods/mod.rs
+++ b/sdgb-api/src/title/methods/mod.rs
@@ -1,3 +1,5 @@
+use serde::{Deserialize, Serialize};
+
 #[derive(strum::IntoStaticStr)]
 pub enum APIMethod {
     GetGameChargeApi,
@@ -45,6 +47,36 @@ pub enum APIMethod {
     UserLogoutApi,
 }
 
+pub trait APIExt {
+    const METHOD: APIMethod;
+    type Payload: Serialize + Send + 'static;
+    type Output: for<'de> Deserialize<'de>;
+}
+
+#[crabtime::function]
+fn api_implement(api_names: Vec<String>) {
+    for api_name in api_names {
+        let api_name = api_name;
+        crabtime::output!(
+            pub struct {{api_name}};
+
+            impl APIExt for {{api_name}} {
+                const METHOD: APIMethod = APIMethod::{{api_name}};
+                type Payload = crate::title::model::{{api_name}};
+                type Output  = crate::title::model::{{api_name}}Resp;
+            }
+        );
+    }
+}
+
+api_implement!([
+    "Ping",
+    "UserLoginApi",
+    "UserLogoutApi",
+    "GetUserDataApi",
+    "GetUserPreviewApi",
+]);
+
 #[cfg(test)]
 mod _test {
     use crate::title::{MaiVersionExt, Sdgb1_50, methods::APIMethod};
diff --git a/sdgb-api/src/title/mod.rs b/sdgb-api/src/title/mod.rs
index 619eda0..24e579d 100644
--- a/sdgb-api/src/title/mod.rs
+++ b/sdgb-api/src/title/mod.rs
@@ -1,6 +1,6 @@
 use std::fmt::Display;
 
-use crate::title::methods::APIMethod;
+use crate::title::methods::{APIExt, APIMethod};
 
 pub mod encryption;
 pub mod methods;
@@ -107,6 +107,14 @@ pub trait MaiVersionExt: MaiVersion {
             Ok(serde_json::from_slice(&raw_data)?)
         }
     }
+
+    fn request_ext<M: APIExt>(
+        client: &AsyncClient,
+        data: M::Payload,
+        agent_extra: impl Display + Send + 'static,
+    ) -> impl Future<Output = Result<M::Output, ApiError>> {
+        Self::request(client, M::METHOD, agent_extra, data)
+    }
 }
 
 pub struct Sdgb1_40;