Refactor oneliner storage to use enum

The oneliner is now stored as `OnelinerState` enum which can represent
three states: `Ready`, `Empty` or `Error`. This allows the client to
differentiate between a case with no medical content and a case where
the oneliner generation failed.

The `OnelinerState` enum is serialized to JSON and stored in
`oneliner.json` file. The `OnelinerEntry` struct has been updated to
reflect this change.

The client-desktop application has been updated to handle the new
`OnelinerState` enum and display appropriate UI elements for each state.

The server-side code has also been updated to read and write the
`OnelinerState` enum, and to handle the new file format.
The `reset_case_artefacts` function in
`server/src/routes/case_actions.rs` has been updated to remove
`oneliner.txt` and create `oneliner.json` instead.

The tests have been updated to reflect these changes.

client-desktop/src/app.rs

@@ -18,6 +18,7 @@ use doctate_client_core::{
     PendingUpload, ServerSync, SnapshotCache, SyncConfig, UploadEvent, WorkerSnapshot, WorkerState,
     pick_footer_status, run_startup_cleanup, write_sidecar,
 };
+use doctate_common::oneliners::OnelinerState;
 use doctate_common::timestamp::{
     extract_hhmm, now_rfc3339, parse_rfc3339, recorded_at_to_filename_stem,
 };
@@ -506,11 +507,12 @@ impl DoctateApp {
                 ui.add_space(4.0);
 
                 let time_str = extract_hhmm(&marker.last_activity_at);
-                let oneliner = marker
-                    .oneliner
-                    .as_deref()
-                    .map(str::to_owned)
-                    .unwrap_or_else(|| "⏳".to_owned());
+                let oneliner = match &marker.oneliner {
+                    Some(OnelinerState::Ready { text, .. }) => text.clone(),
+                    Some(OnelinerState::Empty { .. }) => "∅".to_owned(),
+                    Some(OnelinerState::Error { .. }) => "⚠".to_owned(),
+                    None => "⏳".to_owned(),
+                };
                 let has_pending = pending_ids.contains(&marker.case_id);
                 let line = if has_pending {
                     format!("⬆ {time_str} · {oneliner}")

doctate-client-core/src/case_store.rs

@@ -22,7 +22,7 @@ use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
-use doctate_common::oneliners::OnelinersResponse;
+use doctate_common::oneliners::{OnelinerState, OnelinersResponse};
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 use time::format_description::well_known::Rfc3339;
@@ -48,9 +48,12 @@ pub struct CaseMarker {
     /// (`= false`) markers guard unsent uploads and are never touched by
     /// either — losing one would silently erase a patient recording.
     pub synced_to_server: bool,
-    /// `None` while transcription / oneliner generation is pending; set
-    /// from the server snapshot when available.
-    pub oneliner: Option<String>,
+    /// Persisted oneliner state mirrored from the server snapshot.
+    /// `None` while no state file has been written server-side yet (fresh
+    /// case, nothing transcribed). The variant distinguishes usable text
+    /// from "no medical content" and "generation failed" — clients render
+    /// each case as they see fit.
+    pub oneliner: Option<OnelinerState>,
 }
 
 #[derive(Debug, Error)]
@@ -443,10 +446,24 @@ mod tests {
         OffsetDateTime::parse(s, &Rfc3339).unwrap()
     }
 
+    fn ready(text: &str) -> OnelinerState {
+        OnelinerState::Ready {
+            text: text.to_owned(),
+            generated_at: "2026-04-18T10:00:00Z".into(),
+        }
+    }
+
+    fn text_of(o: &Option<OnelinerState>) -> Option<&str> {
+        match o {
+            Some(OnelinerState::Ready { text, .. }) => Some(text.as_str()),
+            _ => None,
+        }
+    }
+
     fn server_entry(case_id: Uuid, oneliner: Option<&str>, created: &str) -> OnelinerEntry {
         OnelinerEntry {
             case_id: case_id.to_string(),
-            oneliner: oneliner.map(str::to_owned),
+            oneliner: oneliner.map(ready),
             created_at: created.to_owned(),
             last_recording_at: Some(created.to_owned()),
             updated_at: Some(created.to_owned()),
@@ -535,7 +552,7 @@ mod tests {
         let list = store.list().await;
         assert_eq!(list.len(), 1);
         assert_eq!(list[0].case_id, id);
-        assert_eq!(list[0].oneliner.as_deref(), Some("Kniegelenk re."));
+        assert_eq!(text_of(&list[0].oneliner), Some("Kniegelenk re."));
         assert!(list[0].synced_to_server);
     }
 
@@ -559,7 +576,7 @@ mod tests {
         let list = store.list().await;
         assert_eq!(list.len(), 1);
         assert!(list[0].synced_to_server);
-        assert_eq!(list[0].oneliner.as_deref(), Some("Hypertonie"));
+        assert_eq!(text_of(&list[0].oneliner), Some("Hypertonie"));
     }
 
     #[tokio::test]
@@ -604,7 +621,7 @@ mod tests {
         let list = store.list().await;
         assert_eq!(list.len(), 1);
         assert!(list[0].synced_to_server);
-        assert_eq!(list[0].oneliner.as_deref(), Some("old"));
+        assert_eq!(text_of(&list[0].oneliner), Some("old"));
     }
 
     #[tokio::test]
@@ -670,7 +687,7 @@ mod tests {
         // oneliner regenerated just now in a recovery scan.
         let entry = OnelinerEntry {
             case_id: id.to_string(),
-            oneliner: Some("x".into()),
+            oneliner: Some(ready("x")),
             created_at: "2026-04-17T09:00:00Z".into(),
             last_recording_at: Some("2026-04-18T09:30:00Z".into()),
             updated_at: Some("2026-04-18T10:00:00Z".into()),
@@ -694,7 +711,7 @@ mod tests {
         let id = Uuid::new_v4();
         let entry = OnelinerEntry {
             case_id: id.to_string(),
-            oneliner: Some("x".into()),
+            oneliner: Some(ready("x")),
             created_at: "2026-04-17T09:00:00Z".into(),
             last_recording_at: None,
             updated_at: Some("2026-04-18T10:00:00Z".into()),
@@ -724,7 +741,7 @@ mod tests {
         store
             .merge_server_snapshot(&server_snapshot(vec![OnelinerEntry {
                 case_id: old_synced.to_string(),
-                oneliner: Some("old".into()),
+                oneliner: Some(ready("old")),
                 created_at: "2026-04-14T10:00:00Z".into(),
                 last_recording_at: Some("2026-04-14T10:00:00Z".into()),
                 updated_at: Some("2026-04-14T10:00:00Z".into()),
@@ -740,7 +757,7 @@ mod tests {
         store
             .merge_server_snapshot(&server_snapshot(vec![OnelinerEntry {
                 case_id: young_synced.to_string(),
-                oneliner: Some("young".into()),
+                oneliner: Some(ready("young")),
                 created_at: "2026-04-18T10:00:00Z".into(),
                 last_recording_at: Some("2026-04-18T10:00:00Z".into()),
                 updated_at: Some("2026-04-18T10:00:00Z".into()),

doctate-client-core/src/server_sync.rs

@@ -515,12 +515,17 @@ mod tests {
     }
 
     fn oneliner_body(case_id: &str, oneliner: Option<&str>) -> OnelinersResponse {
+        use doctate_common::oneliners::OnelinerState;
+        let state = oneliner.map(|t| OnelinerState::Ready {
+            text: t.to_owned(),
+            generated_at: "2026-04-18T10:00:00Z".into(),
+        });
         OnelinersResponse {
             as_of: "2026-04-18T10:00:00Z".into(),
             window_hours: 72,
             oneliners: vec![OnelinerEntry {
                 case_id: case_id.into(),
-                oneliner: oneliner.map(str::to_owned),
+                oneliner: state,
                 created_at: "2026-04-18T09:30:00Z".into(),
                 last_recording_at: Some("2026-04-18T09:45:00Z".into()),
                 updated_at: Some("2026-04-18T09:45:00Z".into()),

doctate-client-core/src/snapshot_cache.rs

@@ -92,7 +92,7 @@ fn tmp_extension(path: &Path) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use doctate_common::oneliners::OnelinerEntry;
+    use doctate_common::oneliners::{OnelinerEntry, OnelinerState};
     use tempfile::TempDir;
 
     fn sample() -> CachedSnapshot {
@@ -104,7 +104,10 @@ mod tests {
                 window_hours: 72,
                 oneliners: vec![OnelinerEntry {
                     case_id: "550e8400-e29b-41d4-a716-446655440000".into(),
-                    oneliner: Some("Kniegelenk".into()),
+                    oneliner: Some(OnelinerState::Ready {
+                        text: "Kniegelenk".into(),
+                        generated_at: "2026-04-18T10:30:00Z".into(),
+                    }),
                     created_at: "2026-04-18T10:00:00Z".into(),
                     last_recording_at: Some("2026-04-18T10:30:00Z".into()),
                     updated_at: Some("2026-04-18T10:30:00Z".into()),
@@ -123,10 +126,11 @@ mod tests {
         let loaded = cache.load().await.expect("cache present");
         assert_eq!(loaded.etag, s.etag);
         assert_eq!(loaded.response.oneliners.len(), 1);
-        assert_eq!(
-            loaded.response.oneliners[0].oneliner.as_deref(),
-            Some("Kniegelenk")
-        );
+        let text = match &loaded.response.oneliners[0].oneliner {
+            Some(OnelinerState::Ready { text, .. }) => Some(text.as_str()),
+            _ => None,
+        };
+        assert_eq!(text, Some("Kniegelenk"));
     }
 
     #[tokio::test]

doctate-common/src/oneliners.rs

@@ -9,6 +9,40 @@ use serde::{Deserialize, Serialize};
 /// HTTP path of the oneliners endpoint.
 pub const ONELINERS_PATH: &str = "/api/oneliners";
 
+/// Filename used by the server to persist [`OnelinerState`] per case
+/// (inside the case directory). Shared so both writer and readers
+/// agree on the exact path.
+pub const ONELINER_FILENAME: &str = "oneliner.json";
+
+/// Outcome of the LLM oneliner generation for a single case.
+///
+/// Three disjoint outcomes used to collapse onto the same filesystem
+/// representation (missing file). Making them first-class lets the UI
+/// distinguish "LLM said nothing medical" (valid empty result) from
+/// "LLM call errored" (transient failure worth retrying) from "file
+/// simply isn't there yet" (no state persisted).
+///
+/// Serialized as internally-tagged JSON: `{"kind":"ready","text":...}`.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(tag = "kind", rename_all = "lowercase")]
+pub enum OnelinerState {
+    /// LLM produced a usable one-sentence summary.
+    Ready {
+        text: String,
+        /// RFC3339 UTC timestamp of the LLM call that produced this
+        /// text. Diagnostic only — the file mtime drives ETag/sort.
+        generated_at: String,
+    },
+    /// LLM deliberately returned an empty answer — the transcript
+    /// contained no medical content. This is a valid outcome, not a
+    /// failure, and recovery must not retry it.
+    Empty { generated_at: String },
+    /// LLM call failed (timeout, HTTP, parse, …). Details stay in the
+    /// server logs on purpose; the UI surfaces only "error", and
+    /// startup recovery retries this variant.
+    Error { generated_at: String },
+}
+
 /// Full response body of `GET /api/oneliners`.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct OnelinersResponse {
@@ -29,14 +63,14 @@ pub struct OnelinersResponse {
 ///   including addenda). This is the **primary sort key** for clients:
 ///   "when did the doctor last work on this case?". Absent only if the
 ///   case has no recordings at all (shouldn't happen in normal flow).
-/// - `updated_at` — `oneliner.txt` mtime, i.e. when the oneliner text
-///   was last regenerated. Diagnostic only — not for sort or display.
-/// - `oneliner` — the text itself; `None` while transcription / LLM
-///   generation is still pending.
+/// - `updated_at` — `oneliner.json` mtime, i.e. when the oneliner state
+///   was last written. Diagnostic only — not for sort or display.
+/// - `oneliner` — the persisted state; `None` while no state file has
+///   been written yet for this case (fresh case, nothing transcribed).
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct OnelinerEntry {
     pub case_id: String,
-    pub oneliner: Option<String>,
+    pub oneliner: Option<OnelinerState>,
     pub created_at: String,
     pub last_recording_at: Option<String>,
     pub updated_at: Option<String>,

server/src/paths.rs

@@ -1,6 +1,8 @@
 use std::path::{Path, PathBuf};
 
+use doctate_common::oneliners::{ONELINER_FILENAME, OnelinerState};
 use serde::{Deserialize, Serialize};
+use time::OffsetDateTime;
 use uuid::Uuid;
 
 /// Absolute on-disk location of a case directory.
@@ -46,3 +48,36 @@ pub async fn write_delete_marker(case_dir: &Path, marker: &DeleteMarker) -> std:
         .map_err(|e| std::io::Error::other(format!("serialize delete marker: {e}")))?;
     tokio::fs::write(case_dir.join(DELETE_MARKER), bytes).await
 }
+
+/// Read the persisted oneliner state for a case.
+///
+/// Returns `(Some(state), Some(mtime))` when `oneliner.json` exists and
+/// parses. Missing file → `(None, None)`. A file that exists but fails
+/// to parse is treated as missing and logged — the next transcription
+/// job will overwrite it with a well-formed state.
+pub async fn read_oneliner_state(
+    case_dir: &Path,
+) -> (Option<OnelinerState>, Option<OffsetDateTime>) {
+    let path = case_dir.join(ONELINER_FILENAME);
+    let bytes = match tokio::fs::read(&path).await {
+        Ok(b) => b,
+        Err(_) => return (None, None),
+    };
+    let state: OnelinerState = match serde_json::from_slice(&bytes) {
+        Ok(s) => s,
+        Err(e) => {
+            tracing::warn!(
+                path = %path.display(),
+                error = %e,
+                "malformed oneliner.json; treating as missing"
+            );
+            return (None, None);
+        }
+    };
+    let mtime = tokio::fs::metadata(&path)
+        .await
+        .ok()
+        .and_then(|m| m.modified().ok())
+        .map(OffsetDateTime::from);
+    (Some(state), mtime)
+}

server/src/routes/case_actions.rs

@@ -10,6 +10,7 @@ use time::format_description::well_known::Rfc3339;
 use tokio::io::AsyncWriteExt;
 use tracing::{info, warn};
 
+use doctate_common::oneliners::ONELINER_FILENAME;
 use doctate_common::timestamp::{filename_stem_to_recorded_at, now_rfc3339};
 
 use crate::analyze::{
@@ -252,7 +253,7 @@ pub(crate) async fn read_document(case_dir: &Path) -> Option<String> {
 /// `*.m4a.failed` back to `*.m4a` so the transcribe self-heal picks it
 /// up again. Idempotent: missing files are no-ops.
 pub(crate) async fn reset_case_artefacts(case_dir: &Path) -> std::io::Result<()> {
-    for name in [DOCUMENT_FILE, ANALYSIS_INPUT_FILE, "oneliner.txt"] {
+    for name in [DOCUMENT_FILE, ANALYSIS_INPUT_FILE, ONELINER_FILENAME] {
         match tokio::fs::remove_file(case_dir.join(name)).await {
             Ok(_) => {}
             Err(e) if e.kind() == std::io::ErrorKind::NotFound => {}

server/src/routes/oneliners.rs

@@ -2,8 +2,9 @@
 //!
 //! Time window is caller-controlled via `?hours=N` (default 16, clamped
 //! to [1, MAX_HOURS]). Each entry carries the case-id, the oneliner
-//! text (or null if not yet generated), and UTC timestamps for when the
-//! case started and when its oneliner was last written.
+//! state (or null if no state file has been written yet), and UTC
+//! timestamps for when the case started and when its oneliner was last
+//! written.
 //!
 //! Conditional-GET: the response carries a weak ETag
 //! `W/"<fingerprint_hex>-<hours>"`. The fingerprint is a deterministic
@@ -32,6 +33,7 @@ use tracing::warn;
 
 use crate::auth::AuthenticatedUser;
 use crate::error::AppError;
+use crate::paths;
 
 const DEFAULT_HOURS: u32 = 16;
 const MAX_HOURS: u32 = 168;
@@ -154,7 +156,7 @@ async fn scan_cases(user_data_dir: &Path, since: OffsetDateTime) -> ScanResult {
             continue;
         }
 
-        let (oneliner_text, updated_at) = read_oneliner(&case_dir).await;
+        let (oneliner_state, updated_at) = paths::read_oneliner_state(&case_dir).await;
         let Ok(created_at_str) = created_at.format(&Rfc3339) else {
             warn!(case = %case_dir.display(), "format created_at failed");
             continue;
@@ -168,7 +170,7 @@ async fn scan_cases(user_data_dir: &Path, since: OffsetDateTime) -> ScanResult {
 
         entries.push(OnelinerEntry {
             case_id: case_id.to_owned(),
-            oneliner: oneliner_text,
+            oneliner: oneliner_state,
             created_at: created_at_str,
             last_recording_at: last_recording_at_str,
             updated_at: updated_at_str,
@@ -274,23 +276,3 @@ async fn m4a_mtime_range(case_dir: &Path) -> Option<(SystemTime, SystemTime)> {
         _ => None,
     }
 }
-
-/// Read `oneliner.txt` (trimmed, non-empty) plus its mtime. Missing file
-/// yields `(None, None)`.
-async fn read_oneliner(case_dir: &Path) -> (Option<String>, Option<OffsetDateTime>) {
-    let path = case_dir.join("oneliner.txt");
-    let text = tokio::fs::read_to_string(&path)
-        .await
-        .ok()
-        .map(|s| s.trim().to_string())
-        .filter(|s| !s.is_empty());
-    if text.is_none() {
-        return (None, None);
-    }
-    let mtime = tokio::fs::metadata(&path)
-        .await
-        .ok()
-        .and_then(|m| m.modified().ok())
-        .map(OffsetDateTime::from);
-    (text, mtime)
-}

server/src/routes/user_web.rs

@@ -5,6 +5,7 @@ use std::sync::atomic::Ordering;
 use askama::Template;
 use axum::extract::State;
 use axum::response::Html;
+use doctate_common::oneliners::OnelinerState;
 use tracing::{info, warn};
 
 use time::{Date, OffsetDateTime, format_description::well_known::Rfc3339};
@@ -18,10 +19,34 @@ use crate::case_id::{CaseId, CaseIdPath};
 use crate::config::Config;
 use crate::error::AppError;
 use crate::events::EventSender;
+use crate::paths;
 use crate::routes::case_actions::read_document;
 use crate::routes::web::{RecordingView, scan_recordings};
 use crate::transcribe::recovery as transcribe_recovery;
 
+/// UI-layer oneliner status for the case list. Combines the persisted
+/// [`OnelinerState`] with derived transit states that only make sense
+/// in the list context (transcription still pending, or no state file
+/// despite completed transcription).
+///
+/// Kept local to the server — not part of the public API DTO, which
+/// exposes the raw [`OnelinerState`] and lets each client decide how
+/// to render transit states.
+enum OnelinerDisplay {
+    Ready(String),
+    Empty,
+    Error,
+    /// No state file on disk + at least one non-failed recording is
+    /// still awaiting its transcript. The oneliner will appear once
+    /// transcription finishes.
+    Pending,
+    /// No state file on disk and no pending transcription. Rare in
+    /// practice — the worker writes a state at the end of every job —
+    /// but possible right after a server crash between transcript and
+    /// oneliner write.
+    Missing,
+}
+
 struct UserCaseView {
     case_id: String,
     most_recent: String,
@@ -34,7 +59,7 @@ struct UserCaseView {
     /// render it in the doctor's actual timezone (which may differ from
     /// the server's, e.g. server on Bahamas, doctor in Germany).
     recorded_at_iso: String,
-    oneliner: Option<String>,
+    oneliner: OnelinerDisplay,
     recordings_count: usize,
     analyzing: bool,
     has_document: bool,
@@ -307,11 +332,7 @@ pub async fn handle_case_page(
         .map(|md| crate::analyze::render::md_to_html(&md));
 
     let recordings = scan_recordings(&case_dir).await;
-    let oneliner = tokio::fs::read_to_string(case_dir.join("oneliner.txt"))
-        .await
-        .ok()
-        .map(|s| s.trim().to_string())
-        .filter(|s| !s.is_empty());
+    let oneliner = ready_text(&case_dir).await;
 
     let a_busy = pipeline.analyze_busy.0.load(Ordering::Acquire);
     let flags = compute_flags(&case_dir, &recordings, config.llm_configured(), a_busy).await;
@@ -371,11 +392,7 @@ pub async fn handle_case_recordings(
     info!(slug = %user.slug, case_id = %case_id, "case recordings viewed");
 
     let recordings = scan_recordings(&case_dir).await;
-    let oneliner = tokio::fs::read_to_string(case_dir.join("oneliner.txt"))
-        .await
-        .ok()
-        .map(|s| s.trim().to_string())
-        .filter(|s| !s.is_empty());
+    let oneliner = ready_text(&case_dir).await;
 
     let t_busy = pipeline.transcribe_busy.0.load(Ordering::Acquire);
     let case_id_short = case_id_str.chars().take(8).collect();
@@ -509,11 +526,14 @@ async fn compute_case_view(
             .filter(|r| !r.failed)
             .all(|r| r.transcript.is_some());
 
-    let oneliner = tokio::fs::read_to_string(case_path.join("oneliner.txt"))
-        .await
-        .ok()
-        .map(|s| s.trim().to_string())
-        .filter(|s| !s.is_empty());
+    let (state, _) = paths::read_oneliner_state(case_path).await;
+    let oneliner = match state {
+        Some(OnelinerState::Ready { text, .. }) => OnelinerDisplay::Ready(text),
+        Some(OnelinerState::Empty { .. }) => OnelinerDisplay::Empty,
+        Some(OnelinerState::Error { .. }) => OnelinerDisplay::Error,
+        None if !all_transcribed => OnelinerDisplay::Pending,
+        None => OnelinerDisplay::Missing,
+    };
 
     let has_document = any_document_exists(case_path).await;
     let analyzing = !has_document && worker_busy && any_analysis_input_exists(case_path).await;
@@ -533,3 +553,14 @@ async fn compute_case_view(
         can_analyze,
     })
 }
+
+/// Extract only the text from a `Ready` state; other states (Empty,
+/// Error, missing file) collapse to `None`. Used by single-case pages
+/// whose headings simply fall back to a generic placeholder — they do
+/// not need the full five-state UI treatment.
+async fn ready_text(case_dir: &Path) -> Option<String> {
+    match paths::read_oneliner_state(case_dir).await.0 {
+        Some(OnelinerState::Ready { text, .. }) => Some(text),
+        _ => None,
+    }
+}

server/src/transcribe/recovery.rs

@@ -1,11 +1,13 @@
 use std::path::{Path, PathBuf};
 
+use doctate_common::oneliners::OnelinerState;
 use tracing::{info, warn};
 
 use super::{TranscribeJob, TranscribeSender};
 use crate::config::Config;
 use crate::events::EventSender;
 use crate::gazetteer::Gazetteer;
+use crate::paths;
 /// Walk `data_path/*/` and enqueue every recording pending transcription for
 /// every user. Intended for startup; the same primitive backs the per-user
 /// self-heal triggered by web handlers.
@@ -83,10 +85,18 @@ pub async fn enqueue_pending_for_user(
 }
 
 /// Walk `data_path/*/*` and return every case directory that has at least
-/// one non-empty `*.transcript.txt` but no `oneliner.txt`, paired with the
-/// user-slug (parent directory name). Pure filesystem scan, no LLM calls —
-/// separated from the regeneration wrapper so it can be unit-tested without
-/// mocking Ollama.
+/// one non-empty `*.transcript.txt` and whose persisted oneliner state
+/// warrants (re-)generation, paired with the user-slug (parent directory
+/// name). Pure filesystem scan, no LLM calls — separated from the
+/// regeneration wrapper so it can be unit-tested without mocking Ollama.
+///
+/// Retry policy by persisted state:
+/// - missing file → retry (first generation, or crash before write)
+/// - [`OnelinerState::Error`] → retry (transient LLM failure last time)
+/// - [`OnelinerState::Ready`] or [`OnelinerState::Empty`] → do **not**
+///   retry; `Empty` is a valid outcome and `Ready` is already correct.
+///   A fresh transcript write will trigger regeneration through the
+///   normal worker path.
 pub(crate) async fn cases_needing_oneliner(data_path: &Path) -> Vec<(PathBuf, String)> {
     let mut out: Vec<(PathBuf, String)> = Vec::new();
     let Ok(mut users) = tokio::fs::read_dir(data_path).await else {
@@ -105,10 +115,15 @@ pub(crate) async fn cases_needing_oneliner(data_path: &Path) -> Vec<(PathBuf, St
         };
         while let Ok(Some(case_entry)) = cases.next_entry().await {
             let case_dir = case_entry.path();
-            if !case_dir.is_dir() || crate::paths::is_deleted(&case_dir).await {
+            if !case_dir.is_dir() || paths::is_deleted(&case_dir).await {
                 continue;
             }
-            if case_dir.join("oneliner.txt").exists() {
+            let (state, _) = paths::read_oneliner_state(&case_dir).await;
+            let needs_retry = match state {
+                None | Some(OnelinerState::Error { .. }) => true,
+                Some(OnelinerState::Ready { .. } | OnelinerState::Empty { .. }) => false,
+            };
+            if !needs_retry {
                 continue;
             }
             if has_non_empty_transcript(&case_dir).await {
@@ -141,10 +156,11 @@ async fn has_non_empty_transcript(case_dir: &Path) -> bool {
     false
 }
 
-/// Regenerate `oneliner.txt` for every case that has transcripts but no
-/// oneliner (crash between transcript-write and oneliner-write). Called at
-/// startup after `scan_and_enqueue`. Sequential on purpose — the oneliner
-/// model is light, but spamming it in parallel is not worth it.
+/// Regenerate `oneliner.json` for every case that has transcripts but no
+/// state file (crash between transcript-write and oneliner-write) or a
+/// previously-errored state. Called at startup after `scan_and_enqueue`.
+/// Sequential on purpose — the oneliner model is light, but spamming it
+/// in parallel is not worth it.
 pub async fn regenerate_missing_oneliners(
     data_path: &Path,
     client: &reqwest::Client,
@@ -180,21 +196,72 @@ mod tests {
         assert_eq!(got, vec![(case, "user".to_owned())]);
     }
 
+    async fn write_state(case: &Path, state: &OnelinerState) {
+        let bytes = serde_json::to_vec(state).unwrap();
+        tokio::fs::write(case.join("oneliner.json"), bytes)
+            .await
+            .unwrap();
+    }
+
     #[tokio::test]
-    async fn cases_needing_oneliner_skips_cases_with_oneliner() {
+    async fn cases_needing_oneliner_skips_ready_state() {
         let data = tempdir().unwrap();
         let case = data.path().join("user").join("case1");
         tokio::fs::create_dir_all(&case).await.unwrap();
         tokio::fs::write(case.join("2026-04-16T10-00-00Z.transcript.txt"), "content")
             .await
             .unwrap();
-        tokio::fs::write(case.join("oneliner.txt"), "Existing")
-            .await
-            .unwrap();
+        write_state(
+            &case,
+            &OnelinerState::Ready {
+                text: "Existing".into(),
+                generated_at: "2026-04-16T10:01:00Z".into(),
+            },
+        )
+        .await;
 
         assert!(cases_needing_oneliner(data.path()).await.is_empty());
     }
 
+    #[tokio::test]
+    async fn cases_needing_oneliner_skips_empty_state() {
+        let data = tempdir().unwrap();
+        let case = data.path().join("user").join("case1");
+        tokio::fs::create_dir_all(&case).await.unwrap();
+        tokio::fs::write(case.join("2026-04-16T10-00-00Z.transcript.txt"), "content")
+            .await
+            .unwrap();
+        write_state(
+            &case,
+            &OnelinerState::Empty {
+                generated_at: "2026-04-16T10:01:00Z".into(),
+            },
+        )
+        .await;
+
+        assert!(cases_needing_oneliner(data.path()).await.is_empty());
+    }
+
+    #[tokio::test]
+    async fn cases_needing_oneliner_retries_error_state() {
+        let data = tempdir().unwrap();
+        let case = data.path().join("user").join("case1");
+        tokio::fs::create_dir_all(&case).await.unwrap();
+        tokio::fs::write(case.join("2026-04-16T10-00-00Z.transcript.txt"), "content")
+            .await
+            .unwrap();
+        write_state(
+            &case,
+            &OnelinerState::Error {
+                generated_at: "2026-04-16T10:01:00Z".into(),
+            },
+        )
+        .await;
+
+        let got = cases_needing_oneliner(data.path()).await;
+        assert_eq!(got, vec![(case, "user".to_owned())]);
+    }
+
     #[tokio::test]
     async fn cases_needing_oneliner_skips_cases_with_only_empty_transcripts() {
         let data = tempdir().unwrap();

server/src/transcribe/worker.rs

@@ -2,6 +2,9 @@ use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
 
+use doctate_common::oneliners::{ONELINER_FILENAME, OnelinerState};
+use time::OffsetDateTime;
+use time::format_description::well_known::Rfc3339;
 use tracing::{error, info, warn};
 
 use super::{TranscribeReceiver, ffmpeg, ollama, whisper};
@@ -178,13 +181,14 @@ async fn write_duration_sidecar(audio_path: &Path, probe_path: &Path) {
     }
 }
 
-/// Regenerate `case_dir/oneliner.txt` from **all** non-empty transcripts in
-/// the case, joined chronologically. Called after every successful transcript
-/// write so later recordings can correct earlier ones (mirror of the
-/// analyze-LLM rule "later recordings override"). Overwrites any existing
-/// oneliner on success; LLM errors are non-fatal and leave the previous
-/// oneliner (if any) untouched. Silent case (no non-empty transcript) is a
-/// no-op — next transcript write retries.
+/// Regenerate `case_dir/oneliner.json` from **all** non-empty transcripts
+/// in the case, joined chronologically. Called after every successful
+/// transcript write so later recordings can correct earlier ones (mirror
+/// of the analyze-LLM rule "later recordings override"). Every outcome —
+/// generated text, deliberate empty ("no medical content"), or call error
+/// — is persisted as an [`OnelinerState`] variant, overwriting any
+/// previous state. Silent case (no non-empty transcript) is a no-op; the
+/// next transcript write retries.
 pub(crate) async fn update_oneliner(
     case_dir: &Path,
     user_slug: &str,
@@ -193,14 +197,16 @@ pub(crate) async fn update_oneliner(
     vocab: &Gazetteer,
     events_tx: &EventSender,
 ) {
-    let path = case_dir.join("oneliner.txt");
-
     let transcript = match all_transcripts_joined(case_dir).await {
         Some(t) => t,
         None => return,
     };
 
-    match ollama::generate_oneliner(
+    let generated_at = OffsetDateTime::now_utc()
+        .format(&Rfc3339)
+        .unwrap_or_default();
+
+    let state = match ollama::generate_oneliner(
         client,
         &config.ollama_url,
         &config.ollama_model,
@@ -211,34 +217,50 @@ pub(crate) async fn update_oneliner(
     .await
     {
         Ok(line) => {
-            let line = vocab.replace(&line);
-            if let Err(e) = tokio::fs::write(&path, &line).await {
-                error!(path = %path.display(), error = %e, "writing oneliner failed");
-            } else {
-                info!(
-                    user = %user_slug,
-                    path = %path.display(),
-                    chars = line.chars().count(),
-                    "Oneliner updated"
-                );
-                events::emit(
-                    events_tx,
-                    user_slug,
-                    events::case_id_of(case_dir),
-                    CaseEventKind::OnelinerUpdated,
-                );
-            }
+            let text = vocab.replace(&line);
+            info!(
+                user = %user_slug,
+                case = %case_dir.display(),
+                chars = text.chars().count(),
+                "Oneliner ready"
+            );
+            OnelinerState::Ready { text, generated_at }
         }
         Err(ollama::OllamaError::EmptyResponse) => {
             warn!(
                 case = %case_dir.display(),
-                "oneliner skipped — model returned empty (no medical keyword in transcript)"
+                "oneliner empty — model returned nothing (no medical keyword in transcript)"
             );
+            OnelinerState::Empty { generated_at }
         }
         Err(e) => {
             error!(case = %case_dir.display(), error = %e, "oneliner generation failed");
+            OnelinerState::Error { generated_at }
         }
+    };
+
+    if let Err(e) = write_oneliner_state(case_dir, &state).await {
+        error!(case = %case_dir.display(), error = %e, "writing oneliner.json failed");
+        return;
     }
+    events::emit(
+        events_tx,
+        user_slug,
+        events::case_id_of(case_dir),
+        CaseEventKind::OnelinerUpdated,
+    );
+}
+
+/// Write `state` atomically to `case_dir/oneliner.json` via
+/// `write(tmp) + rename(tmp, final)`. Rename is atomic within a single
+/// filesystem, so concurrent readers never see a half-serialized JSON
+/// document.
+async fn write_oneliner_state(case_dir: &Path, state: &OnelinerState) -> std::io::Result<()> {
+    let final_path = case_dir.join(ONELINER_FILENAME);
+    let tmp_path = case_dir.join(format!("{ONELINER_FILENAME}.tmp"));
+    let payload = serde_json::to_vec(state).expect("OnelinerState is infallibly serializable");
+    tokio::fs::write(&tmp_path, &payload).await?;
+    tokio::fs::rename(&tmp_path, &final_path).await
 }
 
 /// Return true if `case_dir` contains at least one `.m4a` recording

server/templates/my_cases.html

@@ -11,6 +11,7 @@ section { margin: 1.5em 0; }
 section h2 { font-size: 1.1em; color: #555; border-bottom: 1px solid #ddd; padding-bottom: 0.2em; display: flex; justify-content: space-between; align-items: baseline; gap: 1em; }
 section h2 .count { font-weight: normal; font-size: 0.85em; color: #888; }
 .empty { color: #888; font-style: italic; }
+.pending { color: #888; font-style: italic; }
 
 .case-list { list-style: none; padding: 0; margin: 0; }
 .case-row { display: grid; grid-template-columns: auto 1fr auto; gap: 0.6em 1em; align-items: center; padding: 0.7em 1em; border: 1px solid #ccc; border-radius: 4px; margin: 0.5em 0; }
@@ -85,7 +86,7 @@ try {
 <div class="check"><input type="checkbox" name="case_id" value="{{ case.case_id }}"></div>
 <div class="body">
 <a href="/web/cases/{{ case.case_id }}">
-<div class="line1"><span class="time"><time datetime="{{ case.recorded_at_iso }}">{{ case.time_hms_utc }}</time></span>{% match case.oneliner %}{% when Some with (t) %} — {{ t }}{% when None %} — <span class="empty">kein Oneliner</span>{% endmatch %}</div>
+<div class="line1"><span class="time"><time datetime="{{ case.recorded_at_iso }}">{{ case.time_hms_utc }}</time></span>{% match case.oneliner %}{% when OnelinerDisplay::Ready with (t) %} — {{ t }}{% when OnelinerDisplay::Empty %} — <span class="empty">kein medizinischer Inhalt</span>{% when OnelinerDisplay::Error %} — <span class="empty">Oneliner-Fehler</span>{% when OnelinerDisplay::Pending %} — <span class="pending">wird transkribiert …</span>{% when OnelinerDisplay::Missing %} — <span class="empty">unbenannt</span>{% endmatch %}</div>
 <div class="line2">{{ case.recordings_count }} Aufnahmen{% if case.has_document %} — <span class="status-badge done">ausgewertet</span>{% else %} — <span class="status-badge open">offen</span>{% endif %}{% if case.analyzing %} <span class="label analyzing">wird analysiert</span>{% endif %}</div>
 {% if is_admin %}<div class="uuid admin-only">{{ case.case_id }}</div>{% endif %}
 </a>

server/tests/analyze_test.rs

@@ -837,7 +837,11 @@ async fn reset_case_clears_derived_and_unfails_audio() {
     // A failed recording: raw audio written, but filename carries `.failed`.
     std::fs::write(dir.join("2026-04-15T09-05-00Z.m4a.failed"), b"audio-bytes").unwrap();
     // Derived artefacts the reset must wipe.
-    std::fs::write(dir.join("oneliner.txt"), "Knie re.").unwrap();
+    std::fs::write(
+        dir.join("oneliner.json"),
+        br#"{"kind":"ready","text":"Knie re.","generated_at":"2026-04-18T10:00:00Z"}"#,
+    )
+    .unwrap();
     std::fs::write(dir.join("document.md"), "# Doc\n").unwrap();
     std::fs::write(dir.join("analysis_input.json"), "{}").unwrap();
 
@@ -854,7 +858,7 @@ async fn reset_case_clears_derived_and_unfails_audio() {
     assert!(!dir.join("2026-04-15T09-05-00Z.m4a.failed").exists());
     // Derived artefacts gone.
     assert!(!dir.join("2026-04-15T09-00-00Z.transcript.txt").exists());
-    assert!(!dir.join("oneliner.txt").exists());
+    assert!(!dir.join("oneliner.json").exists());
     assert!(!dir.join("document.md").exists());
     assert!(!dir.join("analysis_input.json").exists());
 }

server/tests/case_page_test.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 
 use axum::body::Body;
 use axum::http::{Request, StatusCode, header};
+use doctate_common::oneliners::OnelinerState;
 use doctate_server::config::{Config, User};
 use tower::util::ServiceExt;
 
@@ -32,7 +33,17 @@ fn make_admin(slug: &str) -> User {
 }
 
 fn seed_oneliner(case_dir: &Path, text: &str) {
-    std::fs::write(case_dir.join("oneliner.txt"), text).unwrap();
+    let state = OnelinerState::Ready {
+        text: text.to_owned(),
+        generated_at: "2026-04-18T10:00:00Z".into(),
+    };
+    let bytes = serde_json::to_vec(&state).unwrap();
+    std::fs::write(case_dir.join("oneliner.json"), bytes).unwrap();
+}
+
+fn seed_oneliner_state(case_dir: &Path, state: &OnelinerState) {
+    let bytes = serde_json::to_vec(state).unwrap();
+    std::fs::write(case_dir.join("oneliner.json"), bytes).unwrap();
 }
 
 fn config_with_llm_users(data_path: PathBuf, llm_url: String, users: Vec<User>) -> Arc<Config> {
@@ -326,6 +337,34 @@ async fn case_page_uses_oneliner_as_h1_when_present() {
     );
 }
 
+#[tokio::test]
+async fn case_page_falls_back_to_generic_title_for_empty_state() {
+    // An `Empty` state (LLM deliberately returned no medical content) is
+    // not a text; the H1 must fall back to the generic "Fall" label, not
+    // leak the kind string or crash the template.
+    let config = config_with_llm(unique_tmp("cp-empty"));
+    let case_id = "22222222-2222-2222-2222-222222222222";
+    let case_dir = seed_case(&config.data_path, "dr_a", case_id);
+    seed_oneliner_state(
+        &case_dir,
+        &OnelinerState::Empty {
+            generated_at: "2026-04-18T10:00:00Z".into(),
+        },
+    );
+
+    let app = doctate_server::create_router(config);
+    let cookie = login(app.clone(), "dr_a").await;
+
+    let resp = app.oneshot(get_page(case_id, &cookie, "")).await.unwrap();
+    let body = body_string(resp).await;
+
+    assert!(body.contains("Fall"), "expected generic 'Fall' fallback");
+    assert!(
+        !body.contains("\"kind\""),
+        "must not leak JSON kind discriminator into HTML"
+    );
+}
+
 #[tokio::test]
 async fn case_page_admin_sees_admin_view_toggle() {
     let data_path = unique_tmp("cp-toggle");

server/tests/oneliners_api_test.rs

@@ -8,6 +8,7 @@ use axum::http::{Request, StatusCode};
 use filetime::FileTime;
 use tower::util::ServiceExt;
 
+use doctate_common::oneliners::OnelinerState;
 use doctate_server::config::{Config, User};
 
 const TEST_KEY: &str = "test-key-oneliners";
@@ -50,13 +51,29 @@ async fn seed_case(
     filetime::set_file_mtime(&m4a, FileTime::from_system_time(target_mtime)).unwrap();
 
     if let Some(text) = oneliner_text {
-        tokio::fs::write(case_dir.join("oneliner.txt"), text)
-            .await
-            .unwrap();
+        write_ready_state(&case_dir, text).await;
     }
     case_dir
 }
 
+async fn write_ready_state(case_dir: &Path, text: &str) {
+    let state = OnelinerState::Ready {
+        text: text.to_owned(),
+        generated_at: "2026-04-18T10:00:00Z".into(),
+    };
+    let bytes = serde_json::to_vec(&state).unwrap();
+    tokio::fs::write(case_dir.join("oneliner.json"), bytes)
+        .await
+        .unwrap();
+}
+
+async fn write_state(case_dir: &Path, state: &OnelinerState) {
+    let bytes = serde_json::to_vec(state).unwrap();
+    tokio::fs::write(case_dir.join("oneliner.json"), bytes)
+        .await
+        .unwrap();
+}
+
 async fn mark_deleted(case_dir: &Path) {
     tokio::fs::write(case_dir.join(".deleted"), "{}")
         .await
@@ -155,7 +172,8 @@ async fn recent_case_with_oneliner_shows_up() {
     let arr = body["oneliners"].as_array().unwrap();
     assert_eq!(arr.len(), 1);
     assert_eq!(arr[0]["case_id"], case_id);
-    assert_eq!(arr[0]["oneliner"], "Kniegelenk re., V.a. Meniskus");
+    assert_eq!(arr[0]["oneliner"]["kind"], "ready");
+    assert_eq!(arr[0]["oneliner"]["text"], "Kniegelenk re., V.a. Meniskus");
     assert!(arr[0]["created_at"].is_string());
     assert!(arr[0]["updated_at"].is_string());
 
@@ -365,8 +383,8 @@ async fn multiple_cases_sorted_newest_first() {
     let body = body_json(app.oneshot(get("/api/oneliners")).await.unwrap()).await;
     let arr = body["oneliners"].as_array().unwrap();
     assert_eq!(arr.len(), 2);
-    assert_eq!(arr[0]["oneliner"], "newer");
-    assert_eq!(arr[1]["oneliner"], "older");
+    assert_eq!(arr[0]["oneliner"]["text"], "newer");
+    assert_eq!(arr[1]["oneliner"]["text"], "older");
 
     let _ = std::fs::remove_dir_all(&dp);
 }
@@ -398,9 +416,7 @@ async fn sorts_by_last_recording_not_created() {
         FileTime::from_system_time(SystemTime::now() - Duration::from_secs(60)),
     )
     .unwrap();
-    tokio::fs::write(dir_a.join("oneliner.txt"), "A (fresh addendum)")
-        .await
-        .unwrap();
+    write_ready_state(&dir_a, "A (fresh addendum)").await;
 
     // Case B: single recording 10h ago — created_at newer than A's, but
     // last_recording_at older than A's fresh addendum.
@@ -421,3 +437,58 @@ async fn sorts_by_last_recording_not_created() {
 
     let _ = std::fs::remove_dir_all(&dp);
 }
+
+#[tokio::test]
+async fn empty_state_serializes_as_kind_empty() {
+    let (config, dp) = test_config();
+    let case_dir = seed_case(
+        &dp,
+        "550e8400-e29b-41d4-a716-000000000030",
+        Duration::from_secs(60),
+        None,
+    )
+    .await;
+    write_state(
+        &case_dir,
+        &OnelinerState::Empty {
+            generated_at: "2026-04-18T10:00:00Z".into(),
+        },
+    )
+    .await;
+    let app = doctate_server::create_router(config);
+
+    let body = body_json(app.oneshot(get("/api/oneliners")).await.unwrap()).await;
+    let arr = body["oneliners"].as_array().unwrap();
+    assert_eq!(arr.len(), 1);
+    assert_eq!(arr[0]["oneliner"]["kind"], "empty");
+    assert!(arr[0]["oneliner"].get("text").is_none());
+
+    let _ = std::fs::remove_dir_all(&dp);
+}
+
+#[tokio::test]
+async fn error_state_serializes_as_kind_error() {
+    let (config, dp) = test_config();
+    let case_dir = seed_case(
+        &dp,
+        "550e8400-e29b-41d4-a716-000000000031",
+        Duration::from_secs(60),
+        None,
+    )
+    .await;
+    write_state(
+        &case_dir,
+        &OnelinerState::Error {
+            generated_at: "2026-04-18T10:00:00Z".into(),
+        },
+    )
+    .await;
+    let app = doctate_server::create_router(config);
+
+    let body = body_json(app.oneshot(get("/api/oneliners")).await.unwrap()).await;
+    let arr = body["oneliners"].as_array().unwrap();
+    assert_eq!(arr.len(), 1);
+    assert_eq!(arr[0]["oneliner"]["kind"], "error");
+
+    let _ = std::fs::remove_dir_all(&dp);
+}