diff --git a/tasks.org b/tasks.org
index e1933da..b48e70c 100644
--- a/tasks.org
+++ b/tasks.org
@@ -250,30 +250,57 @@ HistoryScreen.kt observes captureDao.observeAll() as Flow. Status colored green/
 - datetime: [2026-05-18 Sun 17:00]
 
 * milestone 3: android sync
-** TODO implement api client
+** DONE implement api client
 *** acceptance
 - base url configurable in app settings or build config.
 - bearer token configurable in app settings or build config.
 - client can call `/health`.
 - client can post capture payload.
-** TODO implement manual sync
+*** notes
+SynqApiClient in data/api/. OkHttp with 10s timeouts. checkHealth() does GET /health, returns false on any exception so callers never crash. postCapture() maps 401 → failed, non-2xx → failed, already_seen → AlreadySeen, else → Accepted. Uses org.json for request building, kotlinx-serialization for tag decoding.
+*** evidence
+- commit: 2a963d9
+- tests: manual — sync now button, check history screen status
+- datetime: [2026-05-18 Sun 18:00]
+
+** DONE implement manual sync
 *** acceptance
 - sync now posts all pending captures.
 - successful posts mark rows synced.
 - already-seen response marks row synced.
 - failures retain pending/failed status and last error.
-** TODO implement opportunistic workmanager sync
+*** notes
+syncPending() top-level function in data/sync/SyncService.kt — shared by manual sync and WorkManager. CaptureViewModel.syncNow() calls it on Dispatchers.IO, guards with isSyncing flag. Sync icon in top bar shows CircularProgressIndicator while running.
+*** evidence
+- commit: 2a963d9
+- tests: manual — tap sync, verify captures move to synced in history; test with wrong token, verify failed + error message
+- datetime: [2026-05-18 Sun 18:00]
+
+** DONE implement opportunistic workmanager sync
 *** acceptance
 - periodic sync is registered.
 - sync only runs when network is available.
 - worker first checks `/health`.
 - worker does not block capture speed.
-** TODO add simple server reachability settings
+*** notes
+SyncWorker (CoroutineWorker) in data/sync/. Registered in SynqApp.onCreate() as KEEP unique periodic work (15-min interval, NETWORK_CONNECTED constraint). Health check before sync — exits quietly if server unreachable. Does not touch UI thread.
+*** evidence
+- commit: 2a963d9
+- tests: manual — let app sit on WiFi, verify pending captures eventually sync without manual trigger
+- datetime: [2026-05-18 Sun 18:00]
+
+** DONE add simple server reachability settings
 *** acceptance
 - default url can be set to `http://jeeves.mother:8765`.
 - user can change server url.
 - user can change token.
 - invalid settings do not crash app.
+*** notes
+SettingsScreen + SettingsViewModel from milestone 2. DataStore-backed. Default serverUrl is http://jeeves.mother:8765. All network calls wrap exceptions so invalid URL/token never crashes — they just produce PostResult.Failed with the error message.
+*** evidence
+- commit: 19b05a8 (screen), 2a963d9 (wired to sync)
+- tests: manual — set bad URL, tap sync, verify captures stay pending/failed with error; set correct URL + token, sync succeeds
+- datetime: [2026-05-18 Sun 18:00]
 
 * milestone 4: polish and hardening
 ** TODO make launch path fast