diff --git a/package-lock.json b/package-lock.json
index 99846ac..d1896a6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -134,6 +134,11 @@
       "resolved": "https://registry.npmjs.org/assert-plus/-/assert-plus-1.0.0.tgz",
       "integrity": "sha1-8S4PPF13sLHN2RRpQuTpbB5N1SU="
     },
+    "async-limiter": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/async-limiter/-/async-limiter-1.0.1.tgz",
+      "integrity": "sha512-csOlWGAcRFJaI6m+F2WKdnMKr4HhdhFVBk0H/QbJFMCr+uO2kwohwXQPxw/9OCxp05r5ghVBFSyioixx3gfkNQ=="
+    },
     "asynckit": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
@@ -494,6 +499,14 @@
         }
       }
     },
+    "express-ws": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/express-ws/-/express-ws-4.0.0.tgz",
+      "integrity": "sha512-KEyUw8AwRET2iFjFsI1EJQrJ/fHeGiJtgpYgEWG3yDv4l/To/m3a2GaYfeGyB3lsWdvbesjF5XCMx+SVBgAAYw==",
+      "requires": {
+        "ws": "^5.2.0"
+      }
+    },
     "extend": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/extend/-/extend-3.0.2.tgz",
@@ -1555,6 +1568,14 @@
       "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
       "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8="
     },
+    "ws": {
+      "version": "5.2.2",
+      "resolved": "https://registry.npmjs.org/ws/-/ws-5.2.2.tgz",
+      "integrity": "sha512-jaHFD6PFv6UgoIVda6qZllptQsMlDEJkTQcybzzXDYM1XO9Y8em691FGMPmM46WGyLU4z9KMgQN+qrux/nhlHA==",
+      "requires": {
+        "async-limiter": "~1.0.0"
+      }
+    },
     "xpc-connection": {
       "version": "0.1.4",
       "resolved": "https://registry.npmjs.org/xpc-connection/-/xpc-connection-0.1.4.tgz",
diff --git a/package.json b/package.json
index 915a3ef..84e6f50 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
   "license": "ISC",
   "dependencies": {
     "express": "^4.17.1",
+    "express-ws": "^4.0.0",
     "iconsole-bike-client": "^0.1.3",
     "sqlite3": "^4.1.0",
     "underscore": "^1.9.1"
diff --git a/src/api/workout.js b/src/api/workout.js
index c0a19ed..83a86a7 100644
--- a/src/api/workout.js
+++ b/src/api/workout.js
@@ -174,5 +174,45 @@ module.exports = function workoutRouter(repo) {
     }
   });
 
+  router.ws("/:id/subscribe", (ws, req) => {
+    console.log("HELLO!")
+
+    const workout = workouts.find(w => w.id === req.params.id);
+    if (workout == null) {
+      ws.send(JSON.stringify({error: "workout not found"}));
+      ws.close();
+    }
+
+    workout.listMeasurements().then((list) => {
+      ws.send(JSON.stringify({workoutStatusBackfill: list}));
+    }).catch(err => {
+      ws.send(JSON.stringify({error: `could not list measurements: ${err.message || err}`}));
+      ws.close();
+    });
+
+    const handler = (workotuStatus) => {
+      workotuStatus = {...workotuStatus};
+      delete workotuStatus.id;
+    
+      ws.send(JSON.stringify({workotuStatus}))
+    }
+    
+    workout.events.on("workoutStatus", handler);
+
+    ws.onclose = () => {
+      workout.events.removeListener("workoutStatus", handler);
+      ws.removeAllListeners();
+    };
+
+    ws.send(JSON.stringify({
+      workout: {
+        id: workout.id,
+        bike: workout.bike,
+        program: workout.program,
+        date: workout.date,
+      },
+    }));
+  })
+
   return router;
 }
\ No newline at end of file
diff --git a/src/server.js b/src/server.js
index 1c4ee9b..439c4e4 100644
--- a/src/server.js
+++ b/src/server.js
@@ -1,4 +1,6 @@
-const express = require('express');
+const express = require("express");
+const expressWs = require("express-ws");
+
 const SQLite3Repository = require("./repositories/sqlite3");
 
 const repo = new SQLite3Repository("stuff.db");
@@ -11,6 +13,7 @@ repo.setup().catch(err => {
 });
 
 const app = express();
+expressWs(app);
 
 app.use(express.json({strict: false}));
 
diff --git a/src/systems/workout.js b/src/systems/workout.js
index dfcd29e..42dc93c 100644
--- a/src/systems/workout.js
+++ b/src/systems/workout.js
@@ -85,7 +85,7 @@ class Workout {
 
     this.repo.insertMeasurement({...ws, workoutId: this.id});
 
-    this.events.emit("workoutStatus", ws);
+    this.events.emit("workoutStatus", {...ws});
   }
 
   /**
@@ -95,7 +95,14 @@ class Workout {
    */
   static async create(repo, bikeId, programId) {
     const bike = await repo.findBike(bikeId);
+    if (bike == null) {
+      throw new Error("bike not found");
+    }
     const program = await repo.findProgram(programId);
+    if (program == null) {
+      throw new Error("program not found");
+    }
+
     const date = new Date();
     const id = await repo.insertWorkout({
       bikeId: bike.id,
@@ -115,7 +122,7 @@ class Workout {
     const bike = await repo.findBike(data.bikeId);
     const program = await repo.findWorkout(data.workoutId);
 
-    const workout = new Workout(repo, parseInt(id), bike, program, new Date(data.date));
+    const workout = new Workout(repo, id, bike, program, new Date(data.date));
 
     const list = await repo.listMeasurements(id);
     if (list.length > 0) {