diff --git a/client/src/components/Table.vue b/client/src/components/Table.vue
index aa5f918..c92b646 100644
--- a/client/src/components/Table.vue
+++ b/client/src/components/Table.vue
@@ -2,13 +2,13 @@
     <table class="table">
         <thead>
             <th>Date</th>
-            <th v-for="track in tracks" :key="track.id">{{ track.icon }}</th>
+            <th v-for="track in state.tracks" :key="track.id">{{ track.icon }}</th>
         </thead>
         <tbody>
             <tr v-for="date in dates" :key="date.valueOf()">
                 <th>{{ dateString(date) }}</th>
-                <td v-for="track in tracks" :key="track.id">
-                    <TickComponent :isSet="track.isSetOn(date)" />
+                <td v-for="track in state.tracks" :key="track.id">
+                    <TickComponent :isSet="track.isSetOn(date)" :trackID="track.id" />
                 </td>
             </tr>
         </tbody>
@@ -16,11 +16,8 @@
 </template>
 
 <script setup lang="ts">
-import { ref } from 'vue';
-import { Track } from '../track'
 import TickComponent from "./TickComponent.vue";
-
-const tracks = ref(new Array<Track>())
+import { state } from "../state";
 
 const today = new Date()
 const ONE_DAY_MS = 86_400_000
@@ -33,6 +30,4 @@ function dateString(date: Date) {
     return date.toISOString().substring(0, 10)
 }
 
-Track.fetchAll().then(result => tracks.value = result)
-
 </script>
\ No newline at end of file
diff --git a/client/src/components/TickComponent.vue b/client/src/components/TickComponent.vue
index 8681322..cd3ffcb 100644
--- a/client/src/components/TickComponent.vue
+++ b/client/src/components/TickComponent.vue
@@ -1,9 +1,23 @@
 <template>
-    <button :class="className()"></button>
+    <button :class="className()" @click="toggle"></button>
 </template>
 
 <script setup lang="ts">
-const props = defineProps<{ isSet: boolean }>()
+import { Ref, ref } from 'vue';
+import { state } from '../state';
+import { Track } from '../track';
+
+const tick: Ref<Tick | undefined> = ref()
+const props = defineProps<{ isSet: boolean, track: Track }>()
 
 const className = () => props.isSet ? "button is-rounded is-info" : "button is-rounded"
+
+async function toggle() {
+    const $tick = tick.value
+    if ($tick) {
+        await state.taskMarkedIncomplete($tick)
+        tick.value = undefined
+    } else
+        tick.value = await state.taskCompleted(props.track)
+}
 </script>
\ No newline at end of file
diff --git a/client/src/state.ts b/client/src/state.ts
new file mode 100644
index 0000000..2b03738
--- /dev/null
+++ b/client/src/state.ts
@@ -0,0 +1,33 @@
+import { reactive } from "vue"
+import { Track } from "./track"
+import { error } from "./error"
+
+export const state = reactive({
+    tracks: new Array<Track>,
+    isPopulating: false,
+    async populate() {
+        if (this.isPopulating) return
+        this.isPopulating = true
+        this.tracks = await Track.fetchAll()
+        this.isPopulating = false
+    },
+    async taskCompleted(track: Track): Promise<Tick> {
+        const result = await fetch(`/api/v1/tracks/${track.id}/ticked`, { method: "PATCH" })
+        const body = await result.text()
+        if (!result.ok) {
+            error(body)
+            throw new Error(`error setting tick for track ${track.id} ("${track.name}"): ${result.status} ${result.statusText}`)
+        }
+        const tick: Tick = JSON.parse(body)
+        track.ticks = track.ticks ?? []
+        track.ticks.push(tick)
+        const tracks = this.tracks.map($track => track.id === $track.id ? track : $track)
+        this.tracks = tracks
+        return tick
+    },
+    async taskMarkedIncomplete(tick: Tick) {
+        const { ok, status, statusText } = await fetch(`/api/v1/ticks/${tick.id}`, { method: 'DELETE' })
+        if (!ok)
+            error(`error deleting tick ${tick.id}: ${statusText} (${status})`)
+    }
+})
\ No newline at end of file
diff --git a/client/src/track.ts b/client/src/track.ts
index 4ce889d..13c2174 100644
--- a/client/src/track.ts
+++ b/client/src/track.ts
@@ -85,7 +85,6 @@ export class Track implements ITrack {
                     console.error(e)
                     console.debug(body)
                 }
-
             } catch (err) {
                 console.error(err)
                 result.text()