diff --git a/src/endpoints.rs b/src/endpoints.rs
index a101acd..f57831a 100644
--- a/src/endpoints.rs
+++ b/src/endpoints.rs
@@ -1,6 +1,7 @@
 use maud::{html, Markup};
 
 pub mod index;
+pub mod tsg;
 
 fn page(head: Markup, body: Markup) -> Markup {
     html! {
diff --git a/src/endpoints/index.rs b/src/endpoints/index.rs
index cb74c6c..a8ca7e1 100644
--- a/src/endpoints/index.rs
+++ b/src/endpoints/index.rs
@@ -26,6 +26,13 @@ pub async fn get() -> Markup {
             form #form {
                 h1 { "Arbeitszeitdokumentationsgenerator" }
 
+                p {
+                    "Want to use "
+                    a href="https://github.com/kit-sdq/TimeSheetGenerator" { "TimeSheetGenerator" }
+                    "-compatible JSON instead? "
+                    a href="/tsg" { "Go here!" }
+                }
+
                 div #header {
                     label #l-month for="i-month" { "Monat / Jahr:" }
                     input #i-month name="month" type="month" placeholder=(month) value=(month) {}
diff --git a/src/endpoints/tsg.css b/src/endpoints/tsg.css
new file mode 100644
index 0000000..ed60750
--- /dev/null
+++ b/src/endpoints/tsg.css
@@ -0,0 +1,31 @@
+:root {
+  font-family: Arial, FreeSans, sans-serif;
+}
+form {
+  max-width: 210mm; /* DIN-A 4 */
+  margin: 0 auto;
+  padding: 0 5mm 5mm;
+  border: 2px solid black;
+  border-radius: 0 8mm 0 8mm;
+}
+h1 {
+  color: #009682;
+  text-align: center;
+}
+textarea {
+  display: block;
+  width: 100%;
+  height: 14lh;
+  margin: 1mm 0;
+}
+button {
+  display: block;
+  margin: 4mm auto 0;
+  font-size: 1.5em;
+}
+#info.success {
+  color: #070;
+}
+#info.error {
+  color: #900;
+}
diff --git a/src/endpoints/tsg.js b/src/endpoints/tsg.js
new file mode 100644
index 0000000..6e8f490
--- /dev/null
+++ b/src/endpoints/tsg.js
@@ -0,0 +1,67 @@
+const form = document.getElementById("form");
+const submit = document.getElementById("submit");
+const info = document.getElementById("info");
+
+function showStatus(msg) {
+  info.classList.remove("success");
+  info.classList.remove("error");
+  info.textContent = msg;
+  info.scrollIntoView();
+}
+
+function showSuccess(msg) {
+  info.classList.add("success");
+  info.classList.remove("error");
+  info.textContent = msg;
+  info.scrollIntoView();
+}
+
+function showError(msg) {
+  info.classList.add("error");
+  info.classList.remove("success");
+  info.textContent = msg;
+  info.scrollIntoView();
+}
+
+submit.addEventListener("click", async () => {
+  const data = new FormData(form);
+  const dataJson = JSON.stringify({
+    global: JSON.parse(data.get("global")),
+    month: JSON.parse(data.get("month")),
+  });
+
+  try {
+    showStatus("Generiere...");
+
+    const response = await fetch("/tsg", {
+      method: "post",
+      headers: { "Content-Type": "application/json" },
+      body: dataJson,
+    });
+
+    if (response.status !== 200) {
+      const reason = await response.text();
+      showError(`Generieren fehlgeschlagen:\n${reason}`);
+      return;
+    }
+
+    let blob = await response.blob();
+
+    const reader = new FileReader();
+    reader.addEventListener("loadend", () => {
+      let element = document.createElement("a");
+      element.setAttribute("href", reader.result);
+      element.setAttribute("download", "Arbeitszeitdokumentation.pdf");
+
+      element.style.display = "none";
+      document.body.appendChild(element);
+      element.click();
+      document.body.removeChild(element);
+
+      showSuccess("Generieren erfolgreich!");
+    });
+    reader.readAsDataURL(blob);
+  } catch (e) {
+    showError(`Generieren fehlgeschlagen:\n${e}`);
+  }
+});
diff --git a/src/endpoints/tsg.rs b/src/endpoints/tsg.rs
new file mode 100644
index 0000000..7f5f019
--- /dev/null
+++ b/src/endpoints/tsg.rs
@@ -0,0 +1,156 @@
+use axum::{
+    http::{header, StatusCode},
+    response::{IntoResponse, Response},
+    Json,
+};
+use maud::{html, Markup, PreEscaped};
+use serde::Deserialize;
+
+use crate::{
+    endpoints::page,
+    render::{self, Entry, Note, Timesheet, WorkingArea},
+};
+
+pub async fn get() -> Markup {
+    page(
+        html! {
+            style { (PreEscaped(include_str!("tsg.css"))) }
+            script type="module" { (PreEscaped(include_str!("tsg.js"))) }
+        },
+        html! {
+            form #form {
+                h1 { "Arbeitszeitdokumentationsgenerator" }
+
+                p {
+                    "Want to use a fancy-looking form instead? "
+                    a href="/" { "Go here!" }
+                }
+
+                textarea name="global" placeholder="Global.json" {}
+                textarea name="month" placeholder="Month.json" {}
+
+                button #submit type="button" { "Arbeitszeitdokumentation generieren" }
+
+                pre #info {}
+            }
+        },
+    )
+}
+
+fn default_vacation() -> bool {
+    false
+}
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct GlobalJson {
+    name: String,
+    staff_id: i64,
+    department: String,
+    working_time: String,
+    wage: f64,
+    working_area: String,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct EntryJson {
+    action: String,
+    day: u32,
+    start: String,
+    end: String,
+    pause: Option<String>,
+    #[serde(default = "default_vacation")]
+    vacation: bool,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct MonthJson {
+    year: u32,
+    month: u32,
+    pred_transfer: Option<String>,
+    entries: Vec<EntryJson>,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct PostJson {
+    global: GlobalJson,
+    month: MonthJson,
+}
+
+fn error_response<S: ToString>(msg: S) -> Response {
+    (StatusCode::BAD_REQUEST, msg.to_string()).into_response()
+}
+
+fn parse_span(span_str: &str) -> Option<u32> {
+    let mut parts = span_str.split(':');
+
+    let hours = parts.next()?.parse::<u32>().ok()?;
+    let minutes = parts.next()?.parse::<u32>().ok()?;
+
+    if parts.next().is_some() {
+        return None;
+    }
+
+    if minutes != 0 {
+        return None;
+    }
+
+    Some(hours)
+}
+
+pub async fn post(json: Json<PostJson>) -> Response {
+    let json = json.0;
+
+    // Parse working area
+    let working_area = match &json.global.working_area as &str {
+        "gf" => WorkingArea::Großforschung,
+        "ub" => WorkingArea::Unibereich,
+        _ => {
+            return error_response(format!(
+                "invalid working area: {:?}",
+                json.global.working_area
+            ))
+        }
+    };
+
+    // Parse working time
+    let Some(monthly_hours) = parse_span(&json.global.working_time) else {
+        return error_response(format!(
+            "invalid working_time: {:?}",
+            json.global.working_time
+        ));
+    };
+
+    let entries = json
+        .month
+        .entries
+        .into_iter()
+        .map(|e| Entry {
+            task: e.action,
+            day: e.day,
+            start: e.start,
+            end: e.end,
+            rest: e.pause,
+            note: if e.vacation { Some(Note::Urlaub) } else { None },
+        })
+        .collect::<Vec<_>>();
+
+    let timesheet = Timesheet {
+        name: json.global.name,
+        staff_id: json.global.staff_id.to_string(),
+        department: json.global.department,
+        working_area,
+        monthly_hours,
+        hourly_wage: json.global.wage.to_string(),
+        validate: true,
+        carry_prev_month: json.month.pred_transfer,
+        year: json.month.year,
+        month: json.month.month,
+        entries,
+    };
+
+    match render::render(timesheet) {
+        Ok(pdf) => ([(header::CONTENT_TYPE, "application/pdf")], pdf).into_response(),
+        Err(errors) => error_response(errors.join("\n")),
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index d5fef89..28a3466 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -14,8 +14,9 @@ struct Args {
 async fn main() -> anyhow::Result<()> {
     let args = Args::parse();
 
-    let app =
-        Router::<()>::new().route("/", get(endpoints::index::get).post(endpoints::index::post));
+    let app = Router::<()>::new()
+        .route("/", get(endpoints::index::get).post(endpoints::index::post))
+        .route("/tsg", get(endpoints::tsg::get).post(endpoints::tsg::post));
     let listener = TcpListener::bind(args.addr).await?;
     axum::serve(listener, app).await?;