.env.example

@@ -139,3 +139,31 @@ CLIP_REQUEST_TIMEOUT_SEC=60
 # ── RAG / search ────────────────────────────────────────────────────────
 # Set to `1` to enable cross-encoder reranking on /search results.
 SEARCH_RAG_RERANK=0
+
+# ── Nightly reel pre-generation (Phase 3+) ──────────────────────────────
+# Set to `1` to enable the scheduler. Disabled by default.
+# REEL_PREGEN_ENABLED=1
+# Hour (0-23) when the nightly batch fires. Default 3 AM.
+# REEL_PREGEN_HOUR=3
+# Day of week for weekly reels (0=Sun, 1=Mon, …). Default Monday.
+# REEL_PREGEN_WEEK_DOW=1
+# Timezone offset in minutes from UTC (e.g., -480 = PST). Defaults to
+# the server's local timezone.
+# REEL_PREGEN_TZ_OFFSET_MINUTES=
+# Fixed timezone offset — overrides auto-detect to avoid DST shifts.
+# When set, both the DB fallback and env fallback use this value.
+# REEL_PREGEN_TZ_FIXED_MINUTES=-480
+# Voice ID for narration (e.g., "grandma"). Falls back to the value
+# stored in the user_ai_prefs DB row when set.
+# REEL_PREGEN_VOICE=
+# Library filter: a library id (e.g. "1") or "all" for every library.
+# REEL_PREGEN_LIBRARY=all
+# Max agentic tool iterations for pre-gen scripter. Default 8.
+# REEL_PREGEN_MAX_TOOL_ITERS=8
+#
+# On-disk reel cache sweep (runs every 24h, independent of pre-gen). Removes
+# reel MP4s with no ledger row + no live job that are older than the max age —
+# i.e. the on-demand cache, which otherwise grows forever. Set to 0 to disable.
+# REEL_CACHE_SWEEP_ENABLED=1
+# Age (days) before an unreferenced reel MP4 is swept. Default 7.
+# REEL_CACHE_MAX_AGE_DAYS=7

Cargo.lock

@@ -2051,7 +2051,7 @@ dependencies = [
 
 [[package]]
 name = "image-api"
-version = "1.3.0"
+version = "1.4.0"
 dependencies = [
  "actix",
  "actix-cors",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "image-api"
-version = "1.3.0"
+version = "1.4.0"
 authors = ["Cameron Cordes <cameronc.dev@gmail.com>"]
 edition = "2024"
 

migrations/2026-06-13-000000_add_precomputed_reels/down.sql

@@ -0,0 +1,2 @@
+DROP INDEX IF EXISTS idx_precomputed_reels_span_library;
+DROP TABLE IF EXISTS precomputed_reels;

migrations/2026-06-13-000000_add_precomputed_reels/up.sql

@@ -0,0 +1,14 @@
+CREATE TABLE precomputed_reels (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    span TEXT NOT NULL,
+    library_key TEXT NOT NULL,
+    cache_key TEXT NOT NULL,
+    output_path TEXT NOT NULL,
+    title TEXT NOT NULL,
+    media_count INT NOT NULL,
+    render_version INT NOT NULL DEFAULT 1,
+    tz_offset_minutes INT NOT NULL,
+    voice TEXT,
+    generated_at BIGINT NOT NULL
+);
+CREATE INDEX idx_precomputed_reels_span_library ON precomputed_reels(span, library_key, generated_at DESC);

migrations/2026-06-13-000010_add_user_ai_prefs/down.sql

@@ -0,0 +1 @@
+DROP TABLE IF EXISTS user_ai_prefs;

migrations/2026-06-13-000010_add_user_ai_prefs/up.sql

@@ -0,0 +1,7 @@
+CREATE TABLE user_ai_prefs (
+    id INTEGER PRIMARY KEY CHECK(id=1),
+    voice TEXT,
+    tz_offset_minutes INTEGER,
+    library TEXT,
+    updated_at BIGINT NOT NULL
+);

src/ai/handlers.rs

@@ -120,7 +120,7 @@ pub async fn generation_status_handler(
     }
 
     if let Some(ref fp) = query.path {
-        let library = libraries::resolve_library_param(&app_state, query.library.as_deref())
+        let library = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
             .ok()
             .flatten()
             .unwrap_or_else(|| app_state.primary_library());
@@ -218,10 +218,11 @@ pub async fn cancel_generation_handler(
     }
 
     if let Some(ref fp) = request.file_path {
-        let library = libraries::resolve_library_param(&app_state, request.library.as_deref())
+        let library =
-            .ok()
+            libraries::resolve_library_param_state(&app_state, request.library.as_deref())
-            .flatten()
+                .ok()
-            .unwrap_or_else(|| app_state.primary_library());
+                .flatten()
+                .unwrap_or_else(|| app_state.primary_library());
         let normalized = normalize_path(fp);
 
         // Get active job ids first, then cancel in DB, then abort tasks
@@ -580,7 +581,7 @@ pub async fn get_insight_handler(
 
     // Expand to rel_paths sharing content so an insight generated under
     // library 1 still shows when the same photo is viewed from library 2.
-    let library = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());
@@ -1218,15 +1219,16 @@ pub async fn chat_turn_handler(
     let mut span = tracer.start_with_context("http.insights.chat", &parent_context);
     span.set_attribute(KeyValue::new("file_path", request.file_path.clone()));
 
-    let library = match libraries::resolve_library_param(&app_state, request.library.as_deref()) {
+    let library =
-        Ok(Some(lib)) => lib,
+        match libraries::resolve_library_param_state(&app_state, request.library.as_deref()) {
-        Ok(None) => app_state.primary_library(),
+            Ok(Some(lib)) => lib,
-        Err(e) => {
+            Ok(None) => app_state.primary_library(),
-            return HttpResponse::BadRequest().json(serde_json::json!({
+            Err(e) => {
-                "error": format!("invalid library: {}", e)
+                return HttpResponse::BadRequest().json(serde_json::json!({
-            }));
+                    "error": format!("invalid library: {}", e)
-        }
+                }));
-    };
+            }
+        };
 
     // Service-token claims (sub: "service:apollo") fall through to
     // user_id=1 — the operator convention. Mobile/web clients have a
@@ -1344,15 +1346,16 @@ pub async fn chat_rewind_handler(
     request: web::Json<ChatRewindHttpRequest>,
     app_state: web::Data<AppState>,
 ) -> impl Responder {
-    let library = match libraries::resolve_library_param(&app_state, request.library.as_deref()) {
+    let library =
-        Ok(Some(lib)) => lib,
+        match libraries::resolve_library_param_state(&app_state, request.library.as_deref()) {
-        Ok(None) => app_state.primary_library(),
+            Ok(Some(lib)) => lib,
-        Err(e) => {
+            Ok(None) => app_state.primary_library(),
-            return HttpResponse::BadRequest().json(serde_json::json!({
+            Err(e) => {
-                "error": format!("invalid library: {}", e)
+                return HttpResponse::BadRequest().json(serde_json::json!({
-            }));
+                    "error": format!("invalid library: {}", e)
-        }
+                }));
-    };
+            }
+        };
 
     match app_state
         .insight_chat
@@ -1393,7 +1396,7 @@ pub async fn chat_history_handler(
     // cross-library lookup when the scoped one misses, so a photo
     // with no insight in this library but one in another still
     // surfaces (the "show this photo's primary insight" merge case).
-    let library = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());
@@ -1444,15 +1447,16 @@ pub async fn chat_stream_handler(
     request: web::Json<ChatTurnHttpRequest>,
     app_state: web::Data<AppState>,
 ) -> HttpResponse {
-    let library = match libraries::resolve_library_param(&app_state, request.library.as_deref()) {
+    let library =
-        Ok(Some(lib)) => lib,
+        match libraries::resolve_library_param_state(&app_state, request.library.as_deref()) {
-        Ok(None) => app_state.primary_library(),
+            Ok(Some(lib)) => lib,
-        Err(e) => {
+            Ok(None) => app_state.primary_library(),
-            return HttpResponse::BadRequest().json(serde_json::json!({
+            Err(e) => {
-                "error": format!("invalid library: {}", e)
+                return HttpResponse::BadRequest().json(serde_json::json!({
-            }));
+                    "error": format!("invalid library: {}", e)
-        }
+                }));
-    };
+            }
+        };
 
     // Service-token sub falls through to user_id=1 (see chat_turn_handler).
     let user_id = claims.sub.parse::<i32>().unwrap_or(1);
@@ -1589,15 +1593,16 @@ pub async fn turn_async_handler(
     let mut span = tracer.start_with_context("http.insights.chat_turn_async", &parent_context);
     span.set_attribute(KeyValue::new("file_path", request.file_path.clone()));
 
-    let library = match libraries::resolve_library_param(&app_state, request.library.as_deref()) {
+    let library =
-        Ok(Some(lib)) => lib,
+        match libraries::resolve_library_param_state(&app_state, request.library.as_deref()) {
-        Ok(None) => app_state.primary_library(),
+            Ok(Some(lib)) => lib,
-        Err(e) => {
+            Ok(None) => app_state.primary_library(),
-            return HttpResponse::BadRequest().json(serde_json::json!({
+            Err(e) => {
-                "error": format!("invalid library: {}", e)
+                return HttpResponse::BadRequest().json(serde_json::json!({
-            }));
+                    "error": format!("invalid library: {}", e)
-        }
+                }));
-    };
+            }
+        };
 
     let user_id = claims.sub.parse::<i32>().unwrap_or(1);
 

src/ai/insight_generator.rs

@@ -217,6 +217,13 @@ impl InsightGenerator {
         &self.insight_dao
     }
 
+    /// Accessor for the EXIF DAO (used by the reel scheduler to resolve
+    /// GPS enrichment without creating a separate DB connection).
+    #[allow(dead_code)]
+    pub fn exif_dao(&self) -> &Arc<Mutex<Box<dyn ExifDao>>> {
+        &self.exif_dao
+    }
+
     /// Whether the optional Apollo Places integration is wired up. Drives
     /// tool-definition gating (no point offering `get_personal_place_at`
     /// when Apollo is unreachable) — exposed publicly so `insight_chat`
@@ -4497,6 +4504,110 @@ Return ONLY the summary, nothing else."#,
         ))
     }
 
+    /// A read-only agentic tool loop: chat with tools until the model stops
+    /// calling them, then return the final content.
+    ///
+    /// This is the loop body extracted from
+    /// `generate_agentic_insight_for_photo` (lines 4316-4377) so it can be
+    /// reused by the reel-scripter without the photo-specific context
+    /// (image_base64, file_path, persona_id). The photo insight loop still
+    /// has its own copy because it threads image/file context through
+    /// `execute_tool`.
+    ///
+    /// Calls `execute_tool` with empty file/image context; enabled tools
+    /// never read those fields.
+    ///
+    /// Only used by the `reels` module (compiled in `main.rs`, not `lib.rs`),
+    /// so the `#[allow(dead_code)]` suppresses the lib-target warning.
+    #[allow(dead_code)]
+    pub(crate) async fn run_readonly_tool_loop(
+        &self,
+        backend: &ResolvedBackend,
+        mut messages: Vec<ChatMessage>,
+        tools: Vec<Tool>,
+        max_iter: usize,
+    ) -> Result<String> {
+        let mut final_content = String::new();
+
+        for iteration in 0..max_iter {
+            log::info!("Agentic iteration {}/{}", iteration + 1, max_iter);
+
+            let (response, _prompt_tokens, _eval_tokens) = backend
+                .chat()
+                .chat_with_tools(messages.clone(), tools.clone())
+                .await?;
+
+            // Sanitize tool call arguments before pushing back into history.
+            // Some models occasionally return non-object arguments (bool,
+            // string, null) which Ollama rejects when they are re-sent in
+            // a subsequent request.
+            let mut response = response;
+            if let Some(ref mut tool_calls) = response.tool_calls {
+                for tc in tool_calls.iter_mut() {
+                    if !tc.function.arguments.is_object() {
+                        log::warn!(
+                            "Tool '{}' returned non-object arguments ({:?}), normalising to {{}}",
+                            tc.function.name,
+                            tc.function.arguments
+                        );
+                        tc.function.arguments = serde_json::Value::Object(Default::default());
+                    }
+                }
+            }
+
+            messages.push(response.clone());
+
+            if let Some(ref tool_calls) = response.tool_calls
+                && !tool_calls.is_empty()
+            {
+                for tool_call in tool_calls {
+                    log::info!(
+                        "Agentic tool call [{}]: {} {}",
+                        iteration,
+                        tool_call.function.name,
+                        tool_call.function.arguments
+                    );
+                    let result = self
+                        .execute_tool(
+                            &tool_call.function.name,
+                            &tool_call.function.arguments,
+                            backend,
+                            &None,
+                            "",
+                            0,
+                            "",
+                            &opentelemetry::Context::new(),
+                        )
+                        .await;
+                    messages.push(ChatMessage::tool_result(result));
+                }
+                continue;
+            }
+
+            // No tool calls — this is the final answer
+            final_content = response.content;
+            break;
+        }
+
+        // If loop exhausted without final answer, ask for one
+        if final_content.is_empty() {
+            log::info!(
+                "Agentic loop exhausted after {} iterations, requesting final answer",
+                max_iter
+            );
+            messages.push(ChatMessage::user(
+                "Based on the context gathered, please write the final answer. Return ONLY the JSON object, no prose or code fences.",
+            ));
+            let (final_response, _, _) = backend
+                .chat()
+                .chat_with_tools(messages.clone(), vec![])
+                .await?;
+            final_content = final_response.content;
+        }
+
+        Ok(final_content)
+    }
+
     /// Reverse geocode GPS coordinates to human-readable place names
     async fn reverse_geocode(&self, lat: f64, lon: f64) -> Option<String> {
         let url = format!(

src/ai/tts.rs

@@ -23,6 +23,7 @@ use std::time::{Duration, Instant};
 use tokio::sync::Semaphore;
 use uuid::Uuid;
 
+use crate::ai::llamacpp::LlamaCppClient;
 use crate::data::Claims;
 use crate::file_types::{is_audio_file, is_video_file};
 use crate::files::is_valid_full_path;
@@ -473,6 +474,40 @@ pub struct TtsJobStatusResponse {
     pub error: Option<String>,
 }
 
+/// Synthesize speech honoring the global single-GPU serialization
+/// (`TTS_PERMIT`) and the GPU write lease, exactly as the speech-job path does.
+/// Queues on the permit rather than fast-failing, so callers wait their turn
+/// instead of contending. Text is run through the same markdown/emoji cleanup +
+/// pronunciation pipeline as the HTTP handlers. Reused by the memory-reel
+/// pipeline to narrate each segment without racing a user's TTS request on the
+/// Chatterbox GPU.
+pub async fn synthesize_serialized(
+    client: &LlamaCppClient,
+    text: &str,
+    voice: Option<&str>,
+    format: &str,
+    exaggeration: Option<f32>,
+) -> anyhow::Result<Vec<u8>> {
+    let prepared = prepare_for_tts(text);
+    if prepared.is_empty() {
+        anyhow::bail!("nothing to synthesize after cleanup");
+    }
+    // Clamp to Chatterbox's documented range, matching the HTTP handlers
+    // (which clamp before forwarding; this path bypasses them).
+    let exaggeration = exaggeration.map(|x| x.clamp(0.25, 2.0));
+    // Queue rather than fast-fail (mirrors create_speech_job_handler).
+    let _permit = TTS_PERMIT
+        .acquire()
+        .await
+        .map_err(|_| anyhow::anyhow!("TTS permit closed"))?;
+    // Wait for the LLM side to release the GPU before the request timeout
+    // starts (see ai::gpu).
+    let _gpu = crate::ai::gpu::tts_lease().await;
+    client
+        .text_to_speech(&prepared, voice, format, exaggeration, None, None)
+        .await
+}
+
 /// POST /tts/speech/jobs — durable variant of /tts/speech for long syntheses.
 /// Returns 202 + a job id immediately; the synth queues on the single GPU
 /// permit (instead of fast-failing 429) and the client polls the job until
@@ -985,7 +1020,7 @@ pub async fn create_voice_from_library_handler(
     let voice_name =
         append_ref_window(&voice_name, ref_start, ref_duration.round().max(1.0) as u32);
 
-    let library = match libraries::resolve_library_param(&app_state, req.library.as_deref()) {
+    let library = match libraries::resolve_library_param_state(&app_state, req.library.as_deref()) {
         Ok(Some(l)) => l,
         Ok(None) => app_state.primary_library(),
         Err(msg) => {

src/database/mod.rs

@@ -51,10 +51,12 @@ pub mod knowledge_dao;
 pub mod location_dao;
 pub mod models;
 pub mod persona_dao;
+pub mod precomputed_reel_dao;
 pub mod preview_dao;
 pub mod reconcile;
 pub mod schema;
 pub mod search_dao;
+pub mod user_ai_prefs_dao;
 
 pub use calendar_dao::{CalendarEventDao, SqliteCalendarEventDao};
 pub use daily_summary_dao::{DailySummaryDao, InsertDailySummary, SqliteDailySummaryDao};
@@ -66,8 +68,10 @@ pub use knowledge_dao::{
 };
 pub use location_dao::{LocationHistoryDao, SqliteLocationHistoryDao};
 pub use persona_dao::{ImportPersona, PersonaDao, PersonaPatch, SqlitePersonaDao};
+pub use precomputed_reel_dao::{PrecomputedReelDao, SqlitePrecomputedReelDao};
 pub use preview_dao::{PreviewDao, SqlitePreviewDao};
 pub use search_dao::{SearchHistoryDao, SqliteSearchHistoryDao};
+pub use user_ai_prefs_dao::{SqliteUserAiPrefsDao, UserAiPrefsDao};
 
 pub trait UserDao {
     fn create_user(&mut self, user: &str, password: &str) -> Option<User>;

src/database/models.rs

@@ -1,6 +1,7 @@
 use crate::database::schema::{
     entities, entity_facts, entity_photo_links, favorites, image_exif, insight_generation_jobs,
-    libraries, personas, photo_insights, users, video_preview_clips,
+    libraries, personas, photo_insights, precomputed_reels, user_ai_prefs, users,
+    video_preview_clips,
 };
 use serde::Serialize;
 
@@ -505,3 +506,56 @@ pub struct InsightGenerationJob {
     pub result_insight_id: Option<i32>,
     pub error_message: Option<String>,
 }
+
+// --- Precomputed reels -------------------------------------------------------
+
+#[derive(Insertable)]
+#[diesel(table_name = precomputed_reels)]
+pub struct InsertablePrecomputedReel {
+    pub span: String,
+    pub library_key: String,
+    pub cache_key: String,
+    pub output_path: String,
+    pub title: String,
+    pub media_count: i32,
+    pub render_version: i32,
+    pub tz_offset_minutes: i32,
+    pub voice: Option<String>,
+    pub generated_at: i64,
+}
+
+#[derive(Serialize, Queryable, Clone, Debug)]
+pub struct PrecomputedReel {
+    pub id: i32,
+    pub span: String,
+    pub library_key: String,
+    pub cache_key: String,
+    pub output_path: String,
+    pub title: String,
+    pub media_count: i32,
+    pub render_version: i32,
+    pub tz_offset_minutes: i32,
+    pub voice: Option<String>,
+    pub generated_at: i64,
+}
+
+// --- User AI preferences (Section E) ----------------------------------------
+
+#[derive(Queryable, Insertable, Debug, Clone, serde::Deserialize, serde::Serialize)]
+#[diesel(table_name = user_ai_prefs)]
+pub struct UserAiPrefs {
+    pub id: i32,
+    pub voice: Option<String>,
+    pub tz_offset_minutes: Option<i32>,
+    pub library: Option<String>,
+    pub updated_at: i64,
+}
+
+#[derive(Insertable, Debug, Clone, serde::Deserialize, serde::Serialize)]
+#[diesel(table_name = user_ai_prefs)]
+pub struct UpsertUserAiPrefs {
+    pub voice: Option<String>,
+    pub tz_offset_minutes: Option<i32>,
+    pub library: Option<String>,
+    pub updated_at: i64,
+}

src/database/precomputed_reel_dao.rs

@@ -0,0 +1,439 @@
+use diesel::prelude::*;
+use diesel::sqlite::SqliteConnection;
+use std::ops::DerefMut;
+use std::sync::{Arc, Mutex};
+
+use crate::database::models::{InsertablePrecomputedReel, PrecomputedReel};
+use crate::database::schema;
+use crate::database::{DbError, DbErrorKind, connect};
+use crate::otel::trace_db_call;
+
+/// Ledger for precomputed memory reels. The nightly agentic job writes a
+/// row after each successful render; the `GET /reels/precomputed` handler
+/// reads it to gate on freshness and serve the cached MP4.
+pub trait PrecomputedReelDao: Sync + Send {
+    /// Insert a precomputed reel row. Returns the new row's id.
+    /// Written by the nightly agentic job (Section D).
+    #[allow(dead_code)]
+    fn record_reel(
+        &mut self,
+        context: &opentelemetry::Context,
+        row: &InsertablePrecomputedReel,
+    ) -> Result<i32, DbError>;
+
+    /// Find the latest precomputed reel for the given (span, library_key).
+    fn latest_for(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+    ) -> Result<Option<PrecomputedReel>, DbError>;
+
+    /// Return true when a fresh precomputed reel exists for the given
+    /// (span, library_key, render_version) that was generated at or after
+    /// `min_generated_at`. Used as a fast existence gate before falling
+    /// back to `latest_for` (avoids a second query path).
+    fn exists_fresh(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        render_version: i32,
+        min_generated_at: i64,
+    ) -> Result<bool, DbError>;
+
+    /// Delete all but the newest `keep` rows for (span, library_key), returning
+    /// the deleted rows so the caller can unlink their output files. Used by the
+    /// nightly job to retire superseded reels (e.g. yesterday's daily).
+    #[allow(dead_code)]
+    fn prune_superseded(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        keep: usize,
+    ) -> Result<Vec<PrecomputedReel>, DbError>;
+
+    /// Every cache_key currently in the ledger. Used by the on-disk cache sweep
+    /// to protect files a ledger row still points at.
+    #[allow(dead_code)]
+    fn all_cache_keys(&mut self, context: &opentelemetry::Context) -> Result<Vec<String>, DbError>;
+}
+
+pub struct SqlitePrecomputedReelDao {
+    connection: Arc<Mutex<SqliteConnection>>,
+}
+
+impl Default for SqlitePrecomputedReelDao {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SqlitePrecomputedReelDao {
+    pub fn new() -> Self {
+        Self {
+            connection: Arc::new(Mutex::new(connect())),
+        }
+    }
+
+    #[cfg(test)]
+    pub fn from_connection(conn: Arc<Mutex<SqliteConnection>>) -> Self {
+        Self { connection: conn }
+    }
+}
+
+impl PrecomputedReelDao for SqlitePrecomputedReelDao {
+    fn record_reel(
+        &mut self,
+        context: &opentelemetry::Context,
+        row: &InsertablePrecomputedReel,
+    ) -> Result<i32, DbError> {
+        trace_db_call(context, "insert", "record_reel", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            diesel::insert_into(dsl::precomputed_reels)
+                .values(row)
+                .execute(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to insert reel: {}", e))?;
+
+            dsl::precomputed_reels
+                .order(dsl::id.desc())
+                .select(dsl::id)
+                .first::<i32>(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to get reel id: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::InsertError, e))
+    }
+
+    fn latest_for(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+    ) -> Result<Option<PrecomputedReel>, DbError> {
+        trace_db_call(context, "query", "latest_for", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            dsl::precomputed_reels
+                .filter(dsl::span.eq(span))
+                .filter(dsl::library_key.eq(library_key))
+                .order(dsl::generated_at.desc())
+                .first::<PrecomputedReel>(connection.deref_mut())
+                .optional()
+                .map_err(|e| anyhow::anyhow!("Failed to get latest reel: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn exists_fresh(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        render_version: i32,
+        min_generated_at: i64,
+    ) -> Result<bool, DbError> {
+        trace_db_call(context, "query", "exists_fresh", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            let count: i64 = dsl::precomputed_reels
+                .filter(dsl::span.eq(span))
+                .filter(dsl::library_key.eq(library_key))
+                .filter(dsl::render_version.eq(render_version))
+                .filter(dsl::generated_at.ge(min_generated_at))
+                .count()
+                .get_result(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to check fresh reel: {}", e))?;
+
+            Ok(count > 0)
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn prune_superseded(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        keep: usize,
+    ) -> Result<Vec<PrecomputedReel>, DbError> {
+        trace_db_call(context, "delete", "prune_superseded", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            // Newest first; everything past `keep` is superseded. The table
+            // holds at most a handful of rows per (span, library), so loading
+            // and slicing in Rust is cheaper than a correlated subquery.
+            let mut rows: Vec<PrecomputedReel> = dsl::precomputed_reels
+                .filter(dsl::span.eq(span))
+                .filter(dsl::library_key.eq(library_key))
+                .order(dsl::generated_at.desc())
+                .load::<PrecomputedReel>(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to load reels for prune: {}", e))?;
+
+            let stale = rows.split_off(rows.len().min(keep));
+            if !stale.is_empty() {
+                let ids: Vec<i32> = stale.iter().map(|r| r.id).collect();
+                diesel::delete(dsl::precomputed_reels.filter(dsl::id.eq_any(ids)))
+                    .execute(connection.deref_mut())
+                    .map_err(|e| anyhow::anyhow!("Failed to delete superseded reels: {}", e))?;
+            }
+            Ok(stale)
+        })
+        .map_err(|e| DbError::log(DbErrorKind::UpdateError, e))
+    }
+
+    fn all_cache_keys(&mut self, context: &opentelemetry::Context) -> Result<Vec<String>, DbError> {
+        trace_db_call(context, "query", "all_cache_keys", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            dsl::precomputed_reels
+                .select(dsl::cache_key)
+                .load::<String>(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to load cache keys: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use diesel::Connection;
+    use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
+
+    const DB_MIGRATIONS: EmbeddedMigrations = embed_migrations!();
+
+    fn setup_dao() -> SqlitePrecomputedReelDao {
+        let mut conn = SqliteConnection::establish(":memory:")
+            .expect("Unable to create in-memory db connection");
+        conn.run_pending_migrations(DB_MIGRATIONS)
+            .expect("Failure running DB migrations");
+        SqlitePrecomputedReelDao::from_connection(Arc::new(Mutex::new(conn)))
+    }
+
+    fn ctx() -> opentelemetry::Context {
+        opentelemetry::Context::new()
+    }
+
+    fn sample_row() -> InsertablePrecomputedReel {
+        InsertablePrecomputedReel {
+            span: "day".to_string(),
+            library_key: "1".to_string(),
+            cache_key: "abc123".to_string(),
+            output_path: "/tmp/reel.mp4".to_string(),
+            title: "Test Reel".to_string(),
+            media_count: 10,
+            render_version: 1,
+            tz_offset_minutes: 0,
+            voice: Some("default".to_string()),
+            generated_at: 1_000_000,
+        }
+    }
+
+    #[test]
+    fn record_reel_inserts_and_returns_id() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        let row = sample_row();
+
+        let id = dao.record_reel(&ctx, &row).unwrap();
+        assert!(id > 0, "should return a positive id");
+    }
+
+    #[test]
+    fn record_reel_returns_increasing_ids() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        let row = sample_row();
+
+        let id1 = dao.record_reel(&ctx, &row).unwrap();
+        let id2 = dao.record_reel(&ctx, &row).unwrap();
+        assert!(id2 > id1, "each insert should get a higher id");
+    }
+
+    #[test]
+    fn latest_for_returns_latest() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let row1 = InsertablePrecomputedReel {
+            generated_at: 1_000_000,
+            ..sample_row()
+        };
+        let row2 = InsertablePrecomputedReel {
+            generated_at: 2_000_000,
+            ..sample_row()
+        };
+
+        dao.record_reel(&ctx, &row1).unwrap();
+        dao.record_reel(&ctx, &row2).unwrap();
+
+        let latest = dao.latest_for(&ctx, "day", "1").unwrap().unwrap();
+        assert_eq!(latest.generated_at, 2_000_000);
+    }
+
+    #[test]
+    fn latest_for_scoped_by_span_and_library() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let day_row = InsertablePrecomputedReel {
+            span: "day".to_string(),
+            library_key: "1".to_string(),
+            generated_at: 1_000_000,
+            ..sample_row()
+        };
+        let week_row = InsertablePrecomputedReel {
+            span: "week".to_string(),
+            library_key: "1".to_string(),
+            generated_at: 2_000_000,
+            ..sample_row()
+        };
+
+        dao.record_reel(&ctx, &day_row).unwrap();
+        dao.record_reel(&ctx, &week_row).unwrap();
+
+        let day_latest = dao.latest_for(&ctx, "day", "1").unwrap().unwrap();
+        assert_eq!(day_latest.span, "day");
+
+        let week_latest = dao.latest_for(&ctx, "week", "1").unwrap().unwrap();
+        assert_eq!(week_latest.span, "week");
+
+        // Different library returns None
+        let missing = dao.latest_for(&ctx, "day", "99").unwrap();
+        assert!(missing.is_none());
+    }
+
+    #[test]
+    fn latest_for_returns_none_when_no_rows() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let result = dao.latest_for(&ctx, "day", "1").unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn exists_fresh_returns_true_when_present() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        dao.record_reel(&ctx, &sample_row()).unwrap();
+
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap();
+        assert!(exists, "should find the row we just inserted");
+    }
+
+    #[test]
+    fn exists_fresh_returns_false_when_missing() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap();
+        assert!(!exists, "should not find anything in empty table");
+    }
+
+    #[test]
+    fn exists_fresh_respects_min_generated_at() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        dao.record_reel(&ctx, &sample_row()).unwrap();
+
+        // Below the threshold — should exist
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 500_000).unwrap();
+        assert!(exists);
+
+        // Above the threshold — should not exist
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 2_000_000).unwrap();
+        assert!(!exists);
+    }
+
+    #[test]
+    fn exists_fresh_respects_render_version() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let row_v1 = InsertablePrecomputedReel {
+            render_version: 1,
+            ..sample_row()
+        };
+        dao.record_reel(&ctx, &row_v1).unwrap();
+
+        assert!(dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap());
+        assert!(!dao.exists_fresh(&ctx, "day", "1", 2, 900_000).unwrap());
+    }
+
+    #[test]
+    fn prune_superseded_keeps_newest_and_returns_deleted() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        // Three day/lib1 reels at increasing timestamps, plus an unrelated one.
+        for (i, key) in ["k1", "k2", "k3"].iter().enumerate() {
+            dao.record_reel(
+                &ctx,
+                &InsertablePrecomputedReel {
+                    cache_key: key.to_string(),
+                    generated_at: 1_000_000 + i as i64 * 1000,
+                    ..sample_row()
+                },
+            )
+            .unwrap();
+        }
+        let other = InsertablePrecomputedReel {
+            library_key: "2".to_string(),
+            cache_key: "other".to_string(),
+            ..sample_row()
+        };
+        dao.record_reel(&ctx, &other).unwrap();
+
+        // Keep the newest 2 of (day, "1"); k1 (oldest) is superseded.
+        let deleted = dao.prune_superseded(&ctx, "day", "1", 2).unwrap();
+        assert_eq!(deleted.len(), 1);
+        assert_eq!(deleted[0].cache_key, "k1");
+
+        // The newest 2 survive; the other-library row is untouched.
+        let keys = dao.all_cache_keys(&ctx).unwrap();
+        assert_eq!(keys.len(), 3);
+        assert!(keys.contains(&"k2".to_string()));
+        assert!(keys.contains(&"k3".to_string()));
+        assert!(keys.contains(&"other".to_string()));
+        assert!(!keys.contains(&"k1".to_string()));
+    }
+
+    #[test]
+    fn prune_superseded_noop_when_within_keep() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        dao.record_reel(&ctx, &sample_row()).unwrap();
+        let deleted = dao.prune_superseded(&ctx, "day", "1", 2).unwrap();
+        assert!(deleted.is_empty());
+        assert_eq!(dao.all_cache_keys(&ctx).unwrap().len(), 1);
+    }
+}

src/database/schema.rs

@@ -266,6 +266,16 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    user_ai_prefs (id) {
+        id -> Integer,
+        voice -> Nullable<Text>,
+        tz_offset_minutes -> Nullable<Integer>,
+        library -> Nullable<Text>,
+        updated_at -> BigInt,
+    }
+}
+
 diesel::table! {
     video_preview_clips (id) {
         id -> Integer,
@@ -294,6 +304,22 @@ diesel::table! {
     }
 }
 
+diesel::table! {
+    precomputed_reels (id) {
+        id -> Integer,
+        span -> Text,
+        library_key -> Text,
+        cache_key -> Text,
+        output_path -> Text,
+        title -> Text,
+        media_count -> Integer,
+        render_version -> Integer,
+        tz_offset_minutes -> Integer,
+        voice -> Nullable<Text>,
+        generated_at -> BigInt,
+    }
+}
+
 diesel::joinable!(entity_facts -> photo_insights (source_insight_id));
 diesel::joinable!(entity_photo_links -> entities (entity_id));
 diesel::joinable!(entity_photo_links -> libraries (library_id));
@@ -322,9 +348,11 @@ diesel::allow_tables_to_appear_in_same_query!(
     personas,
     persons,
     photo_insights,
+    precomputed_reels,
     search_history,
     tagged_photo,
     tags,
+    user_ai_prefs,
     users,
     video_preview_clips,
 );

src/database/user_ai_prefs_dao.rs

@@ -0,0 +1,206 @@
+use diesel::prelude::*;
+use diesel::sqlite::SqliteConnection;
+use std::ops::DerefMut;
+use std::sync::{Arc, Mutex};
+
+use crate::database::models::{UpsertUserAiPrefs, UserAiPrefs};
+use crate::database::schema;
+use crate::database::{DbError, DbErrorKind, connect};
+use crate::otel::trace_db_call;
+
+/// Generic single-row table that passively mirrors the latest client AI
+/// request parameters (voice, timezone, library). Read by the nightly
+/// pre-generation scheduler (Section D) to pick up user preferences.
+pub trait UserAiPrefsDao: Sync + Send {
+    /// Read the single row; `None` when it hasn't been populated yet.
+    fn get_prefs(
+        &mut self,
+        context: &opentelemetry::Context,
+    ) -> Result<Option<UserAiPrefs>, DbError>;
+
+    /// Upsert the single row (id is always 1).
+    #[allow(dead_code)]
+    fn upsert_prefs(
+        &mut self,
+        context: &opentelemetry::Context,
+        prefs: &UpsertUserAiPrefs,
+    ) -> Result<(), DbError>;
+}
+
+pub struct SqliteUserAiPrefsDao {
+    connection: Arc<Mutex<SqliteConnection>>,
+}
+
+impl Default for SqliteUserAiPrefsDao {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SqliteUserAiPrefsDao {
+    pub fn new() -> Self {
+        Self {
+            connection: Arc::new(Mutex::new(connect())),
+        }
+    }
+
+    #[cfg(test)]
+    pub fn from_connection(conn: Arc<Mutex<SqliteConnection>>) -> Self {
+        Self { connection: conn }
+    }
+}
+
+impl UserAiPrefsDao for SqliteUserAiPrefsDao {
+    fn get_prefs(
+        &mut self,
+        context: &opentelemetry::Context,
+    ) -> Result<Option<UserAiPrefs>, DbError> {
+        trace_db_call(context, "query", "get_prefs", |_span| {
+            use schema::user_ai_prefs::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock UserAiPrefsDao");
+
+            dsl::user_ai_prefs
+                .first::<UserAiPrefs>(connection.deref_mut())
+                .optional()
+                .map_err(|e| anyhow::anyhow!("Failed to get prefs: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn upsert_prefs(
+        &mut self,
+        context: &opentelemetry::Context,
+        prefs: &UpsertUserAiPrefs,
+    ) -> Result<(), DbError> {
+        trace_db_call(context, "upsert", "upsert_prefs", |_span| {
+            use schema::user_ai_prefs::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock UserAiPrefsDao");
+
+            // Single-row table (id=1): one atomic upsert. The explicit id=1
+            // makes the conflict target deterministic so the second call
+            // updates in place rather than tripping the CHECK(id=1) constraint,
+            // and real insert errors surface instead of being swallowed into a
+            // separate update branch. The columns are set explicitly (rather
+            // than via AsChangeset) so a None field overwrites to NULL — the
+            // row mirrors the latest request exactly, not a merge of past ones.
+            diesel::insert_into(dsl::user_ai_prefs)
+                .values((dsl::id.eq(1), prefs))
+                .on_conflict(dsl::id)
+                .do_update()
+                .set((
+                    dsl::voice.eq(&prefs.voice),
+                    dsl::tz_offset_minutes.eq(&prefs.tz_offset_minutes),
+                    dsl::library.eq(&prefs.library),
+                    dsl::updated_at.eq(&prefs.updated_at),
+                ))
+                .execute(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to upsert prefs: {}", e))?;
+            Ok(())
+        })
+        .map_err(|e| DbError::log(DbErrorKind::InsertError, e))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use diesel::Connection;
+    use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
+
+    const DB_MIGRATIONS: EmbeddedMigrations = embed_migrations!();
+
+    fn setup_dao() -> SqliteUserAiPrefsDao {
+        let mut conn = SqliteConnection::establish(":memory:")
+            .expect("Unable to create in-memory db connection");
+        conn.run_pending_migrations(DB_MIGRATIONS)
+            .expect("Failure running DB migrations");
+        SqliteUserAiPrefsDao::from_connection(Arc::new(Mutex::new(conn)))
+    }
+
+    fn ctx() -> opentelemetry::Context {
+        opentelemetry::Context::new()
+    }
+
+    #[test]
+    fn get_prefs_returns_none_when_empty() {
+        let mut dao = setup_dao();
+        let result = dao.get_prefs(&ctx()).unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn upsert_prefs_inserts_row() {
+        let mut dao = setup_dao();
+        let now = 1_700_000_000i64;
+        let prefs = UpsertUserAiPrefs {
+            voice: Some("grandma".to_string()),
+            tz_offset_minutes: Some(-480),
+            library: Some("1".to_string()),
+            updated_at: now,
+        };
+        dao.upsert_prefs(&ctx(), &prefs).unwrap();
+
+        let row = dao.get_prefs(&ctx()).unwrap().unwrap();
+        assert_eq!(row.id, 1);
+        assert_eq!(row.voice, Some("grandma".to_string()));
+        assert_eq!(row.tz_offset_minutes, Some(-480));
+        assert_eq!(row.library, Some("1".to_string()));
+        assert_eq!(row.updated_at, now);
+    }
+
+    #[test]
+    fn upsert_prefs_replaces_existing() {
+        let mut dao = setup_dao();
+        let now1 = 1_700_000_000i64;
+        let now2 = 1_800_000_000i64;
+
+        let prefs1 = UpsertUserAiPrefs {
+            voice: Some("grandma".to_string()),
+            tz_offset_minutes: Some(-480),
+            library: Some("1".to_string()),
+            updated_at: now1,
+        };
+        dao.upsert_prefs(&ctx(), &prefs1).unwrap();
+
+        let prefs2 = UpsertUserAiPrefs {
+            voice: Some("dad".to_string()),
+            tz_offset_minutes: Some(-300),
+            library: None,
+            updated_at: now2,
+        };
+        dao.upsert_prefs(&ctx(), &prefs2).unwrap();
+
+        let row = dao.get_prefs(&ctx()).unwrap().unwrap();
+        assert_eq!(row.voice, Some("dad".to_string()));
+        assert_eq!(row.tz_offset_minutes, Some(-300));
+        assert!(row.library.is_none());
+        assert_eq!(row.updated_at, now2);
+    }
+
+    #[test]
+    fn upsert_partial_fields() {
+        let mut dao = setup_dao();
+        let now = 1_700_000_000i64;
+
+        let prefs = UpsertUserAiPrefs {
+            voice: None,
+            tz_offset_minutes: Some(-480),
+            library: None,
+            updated_at: now,
+        };
+        dao.upsert_prefs(&ctx(), &prefs).unwrap();
+
+        let row = dao.get_prefs(&ctx()).unwrap().unwrap();
+        assert_eq!(row.tz_offset_minutes, Some(-480));
+        assert!(row.voice.is_none());
+        assert!(row.library.is_none());
+    }
+}

src/duplicates.rs

@@ -234,7 +234,7 @@ async fn list_exact_handler(
     let span = global_tracer().start_with_context("duplicates.list_exact", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
 
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);
@@ -265,7 +265,7 @@ async fn list_perceptual_handler(
     let span = global_tracer().start_with_context("duplicates.list_perceptual", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
 
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);
@@ -449,7 +449,7 @@ async fn list_folder_pairs_handler(
     let span = global_tracer().start_with_context("duplicates.list_folder_pairs", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
 
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);

src/faces.rs

@@ -1755,7 +1755,7 @@ async fn stats_handler<D: FaceDao>(
     let span = global_tracer().start_with_context("faces.stats", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
 
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);
@@ -1782,11 +1782,12 @@ async fn list_faces_handler<D: FaceDao>(
     let normalized_path = normalize_path(&query.path);
     // resolve_library_param returns Option<&Library>; clone so the result
     // is owned (matching the primary_library fallback's type).
-    let library: Library = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library: Library =
-        .ok()
+        libraries::resolve_library_param_state(&app_state, query.library.as_deref())
-        .flatten()
+            .ok()
-        .cloned()
+            .flatten()
-        .unwrap_or_else(|| app_state.primary_library().clone());
+            .cloned()
+            .unwrap_or_else(|| app_state.primary_library().clone());
 
     let mut dao = face_dao.lock().expect("face dao lock");
     let hash = match dao.resolve_content_hash(&span_context, library.id, &normalized_path) {
@@ -1870,7 +1871,7 @@ async fn create_face_handler<D: FaceDao>(
     }
 
     let normalized_path = normalize_path(&body.path);
-    let library: Library = match libraries::resolve_library_param(
+    let library: Library = match libraries::resolve_library_param_state(
         &app_state,
         body.library.as_ref().map(|i| i.to_string()).as_deref(),
     ) {
@@ -2192,7 +2193,7 @@ async fn list_persons_handler<D: FaceDao>(
     let span = global_tracer().start_with_context("persons.list", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
 
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);
@@ -2345,7 +2346,7 @@ async fn person_faces_handler<D: FaceDao>(
     let context = extract_context_from_request(&request);
     let span = global_tracer().start_with_context("persons.faces", &context);
     let span_context = opentelemetry::Context::current_with_span(span);
-    let library_id = libraries::resolve_library_param(&app_state, query.library.as_deref())
+    let library_id = libraries::resolve_library_param_state(&app_state, query.library.as_deref())
         .ok()
         .flatten()
         .map(|l| l.id);

src/files.rs

@@ -275,14 +275,14 @@ pub async fn list_photos<TagD: TagDao, FS: FileSystemAccess>(
     // Resolve the optional library filter. Unknown values return 400. A
     // `None` result means "union across all libraries" and downstream
     // walks iterate every configured library root.
-    let library = match crate::libraries::resolve_library_param(&app_state, req.library.as_deref())
+    let library =
-    {
+        match crate::libraries::resolve_library_param_state(&app_state, req.library.as_deref()) {
-        Ok(lib) => lib,
+            Ok(lib) => lib,
-        Err(msg) => {
+            Err(msg) => {
-            log::warn!("Rejecting /photos request: {}", msg);
+                log::warn!("Rejecting /photos request: {}", msg);
-            return HttpResponse::BadRequest().body(msg);
+                return HttpResponse::BadRequest().body(msg);
-        }
+            }
-    };
+        };
 
     let span_context = opentelemetry::Context::current_with_span(span);
 
@@ -1238,7 +1238,7 @@ pub async fn list_exif_summary(
     // Resolve the library filter up front so a bad id/name 400s before we
     // ever take the DAO mutex. None == union across all libraries.
     let library_filter =
-        match crate::libraries::resolve_library_param(&app_state, req.library.as_deref()) {
+        match crate::libraries::resolve_library_param_state(&app_state, req.library.as_deref()) {
             Ok(lib) => lib.map(|l| l.id),
             Err(msg) => {
                 span.set_status(Status::error(msg.clone()));

src/handlers/image.rs

@@ -53,7 +53,7 @@ pub async fn get_image(
 
     // Resolve library from query param; default to primary so clients that
     // don't yet send `library=` continue to work.
-    let library = match libraries::resolve_library_param(&app_state, req.library.as_deref()) {
+    let library = match libraries::resolve_library_param_state(&app_state, req.library.as_deref()) {
         Ok(Some(lib)) => lib,
         Ok(None) => app_state.primary_library(),
         Err(msg) => {
@@ -492,7 +492,7 @@ pub async fn get_file_metadata(
     let span_context =
         opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());
 
-    let library = libraries::resolve_library_param(&app_state, path.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, path.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());
@@ -580,7 +580,7 @@ pub async fn set_image_gps(
     let span_context =
         opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());
 
-    let library = libraries::resolve_library_param(&app_state, body.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, body.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());
@@ -746,7 +746,7 @@ pub async fn get_full_exif(
     let context = extract_context_from_request(&request);
     let mut span = tracer.start_with_context("get_full_exif", &context);
 
-    let library = libraries::resolve_library_param(&app_state, path.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, path.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());
@@ -888,7 +888,8 @@ pub async fn set_image_date(
     let span_context =
         opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());
 
-    let library = match libraries::resolve_library_param(&app_state, body.library.as_deref()) {
+    let library = match libraries::resolve_library_param_state(&app_state, body.library.as_deref())
+    {
         Ok(Some(lib)) => lib,
         Ok(None) => app_state.primary_library(),
         Err(msg) => {
@@ -941,7 +942,8 @@ pub async fn clear_image_date(
     let span_context =
         opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());
 
-    let library = match libraries::resolve_library_param(&app_state, body.library.as_deref()) {
+    let library = match libraries::resolve_library_param_state(&app_state, body.library.as_deref())
+    {
         Ok(Some(lib)) => lib,
         Ok(None) => app_state.primary_library(),
         Err(msg) => {
@@ -1001,7 +1003,7 @@ pub async fn upload_image(
     // Resolve the optional library selector. Absent → primary library
     // (backwards-compatible with clients that don't yet send `library=`).
     let target_library =
-        match libraries::resolve_library_param(&app_state, query.library.as_deref()) {
+        match libraries::resolve_library_param_state(&app_state, query.library.as_deref()) {
             Ok(Some(lib)) => lib,
             Ok(None) => app_state.primary_library(),
             Err(msg) => {

src/handlers/video.rs

@@ -67,10 +67,11 @@ pub async fn generate_video(
     let context = extract_context_from_request(&request);
     let mut span = tracer.start_with_context("generate_video", &context);
 
-    let preferred_library = libraries::resolve_library_param(&app_state, body.library.as_deref())
+    let preferred_library =
-        .ok()
+        libraries::resolve_library_param_state(&app_state, body.library.as_deref())
-        .flatten()
+            .ok()
-        .unwrap_or_else(|| app_state.primary_library());
+            .flatten()
+            .unwrap_or_else(|| app_state.primary_library());
 
     // Try the resolved library first, then fall back to any other library
     // that actually contains the file — handles union-mode requests where

src/libraries.rs

@@ -291,11 +291,11 @@ pub fn seed_or_patch_from_env(conn: &mut SqliteConnection, base_path: &str) {
 }
 
 /// Resolve a library request parameter (accepts numeric id as string or name)
-/// against the configured libraries. Returns `Ok(None)` when the param is
+/// against a list of libraries. Returns `Ok(None)` when the param is
 /// absent, meaning "span all libraries". Returns `Err` when a value is
 /// provided but does not match any library.
 pub fn resolve_library_param<'a>(
-    state: &'a AppState,
+    libs: &'a [Library],
     param: Option<&str>,
 ) -> Result<Option<&'a Library>, String> {
     let Some(raw) = param.map(str::trim).filter(|s| !s.is_empty()) else {
@@ -303,18 +303,29 @@ pub fn resolve_library_param<'a>(
     };
 
     if let Ok(id) = raw.parse::<i32>() {
-        return state
+        return libs
-            .library_by_id(id)
+            .iter()
+            .find(|l| l.id == id)
             .map(Some)
             .ok_or_else(|| format!("unknown library id: {}", id));
     }
 
-    state
+    libs.iter()
-        .library_by_name(raw)
+        .find(|l| l.name == raw)
         .map(Some)
         .ok_or_else(|| format!("unknown library name: {}", raw))
 }
 
+/// Resolve a library request parameter against the AppState's libraries.
+/// Returns `Ok(None)` when the param is absent, meaning "span all libraries".
+/// Returns `Err` when a value is provided but does not match any library.
+pub fn resolve_library_param_state<'a>(
+    state: &'a AppState,
+    param: Option<&str>,
+) -> Result<Option<&'a Library>, String> {
+    resolve_library_param(&state.libraries, param)
+}
+
 /// Health of a library at a point in time. Probed at the top of each
 /// file-watcher tick. The `Stale` state is the "be conservative" signal:
 /// destructive paths (ingest writes, future move-handoff and orphan GC in
@@ -662,12 +673,6 @@ mod tests {
         assert_eq!(abs, PathBuf::from("/tmp/media/2024/photo.jpg"));
     }
 
-    fn state_with_libraries(libs: Vec<Library>) -> AppState {
-        let mut state = AppState::test_state();
-        state.libraries = libs;
-        state
-    }
-
     fn sample_libraries() -> Vec<Library> {
         vec![
             Library {
@@ -687,52 +692,52 @@ mod tests {
         ]
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_absent_is_union() {
+    fn resolve_library_param_absent_is_union() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        assert!(matches!(resolve_library_param(&state, None), Ok(None)));
+        assert!(matches!(resolve_library_param(&libs, None), Ok(None)));
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_empty_or_whitespace_is_union() {
+    fn resolve_library_param_empty_or_whitespace_is_union() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        assert!(matches!(resolve_library_param(&state, Some("")), Ok(None)));
+        assert!(matches!(resolve_library_param(&libs, Some("")), Ok(None)));
         assert!(matches!(
-            resolve_library_param(&state, Some("   ")),
+            resolve_library_param(&libs, Some("   ")),
             Ok(None)
         ));
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_numeric_id_matches() {
+    fn resolve_library_param_numeric_id_matches() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        let lib = resolve_library_param(&state, Some("7"))
+        let lib = resolve_library_param(&libs, Some("7"))
             .expect("valid id")
             .expect("some library");
         assert_eq!(lib.id, 7);
         assert_eq!(lib.name, "archive");
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_name_matches() {
+    fn resolve_library_param_name_matches() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        let lib = resolve_library_param(&state, Some("main"))
+        let lib = resolve_library_param(&libs, Some("main"))
             .expect("valid name")
             .expect("some library");
         assert_eq!(lib.id, 1);
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_unknown_id_errs() {
+    fn resolve_library_param_unknown_id_errs() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        let err = resolve_library_param(&state, Some("999")).unwrap_err();
+        let err = resolve_library_param(&libs, Some("999")).unwrap_err();
         assert!(err.contains("unknown library id"));
     }
 
-    #[actix_rt::test]
+    #[test]
-    async fn resolve_library_param_unknown_name_errs() {
+    fn resolve_library_param_unknown_name_errs() {
-        let state = state_with_libraries(sample_libraries());
+        let libs = sample_libraries();
-        let err = resolve_library_param(&state, Some("missing")).unwrap_err();
+        let err = resolve_library_param(&libs, Some("missing")).unwrap_err();
         assert!(err.contains("unknown library name"));
     }
 

src/main.rs

@@ -62,6 +62,7 @@ mod knowledge;
 mod memories;
 mod otel;
 mod personas;
+mod reels;
 mod service;
 #[cfg(test)]
 mod testhelpers;
@@ -266,6 +267,11 @@ fn main() -> std::io::Result<()> {
             }
         }
 
+        // Spawn the nightly pre-generation scheduler (Section D).
+        reels::spawn_pregen_scheduler(app_state.clone()).await;
+        // Spawn the on-disk reel-cache sweeper (bounds pre-gen + on-demand reels).
+        reels::spawn_reel_cache_sweeper(app_state.clone()).await;
+
         HttpServer::new(move || {
             let user_dao = SqliteUserDao::new();
             let favorites_dao = SqliteFavoriteDao::new();
@@ -344,6 +350,11 @@ fn main() -> std::io::Result<()> {
                 .service(handlers::image::clear_image_date)
                 .service(handlers::image::get_full_exif)
                 .service(memories::list_memories)
+                .service(reels::create_reel_handler)
+                .service(reels::reel_status_handler)
+                .service(reels::reel_video_handler)
+                .service(reels::precomputed_reel_handler)
+                .service(reels::precomputed_video_handler)
                 .service(ai::generate_insight_handler)
                 .service(ai::generate_agentic_insight_handler)
                 .service(ai::generation_status_handler)

src/memories.rs

@@ -349,12 +349,6 @@ pub async fn list_memories(
         opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());
 
     let span_mode = q.span.unwrap_or(MemoriesSpan::Day);
-    let span_token = match span_mode {
-        MemoriesSpan::Day => "day",
-        MemoriesSpan::Week => "week",
-        MemoriesSpan::Month => "month",
-    };
-    let years_back: i32 = DEFAULT_YEARS_BACK;
 
     // The SQL filter expects a signed offset in minutes from UTC; default
     // 0 (UTC) when the client didn't send a hint. We also keep a chrono
@@ -366,18 +360,66 @@ pub async fn list_memories(
         .timezone_offset_minutes
         .and_then(|offset_mins| FixedOffset::east_opt(offset_mins * 60));
 
-    debug!(
+    let items = match gather_memory_items(
-        "list_memories: span={:?} tz_offset_min={} years_back={}",
+        &app_state,
-        span_mode, tz_offset_minutes, years_back
+        &exif_dao,
-    );
+        &span_context,
-
+        span_mode,
-    let library = match crate::libraries::resolve_library_param(&app_state, q.library.as_deref()) {
+        tz_offset_minutes,
-        Ok(lib) => lib,
+        client_timezone,
+        q.library.as_deref(),
+    ) {
+        Ok(items) => items,
         Err(msg) => {
             warn!("Rejecting /memories request: {}", msg);
             return HttpResponse::BadRequest().body(msg);
         }
     };
+
+    span.add_event(
+        "memories_scanned",
+        vec![
+            KeyValue::new("span", format!("{:?}", span_mode)),
+            KeyValue::new("years_back", DEFAULT_YEARS_BACK.to_string()),
+            KeyValue::new("result_count", items.len().to_string()),
+            KeyValue::new("tz_offset_minutes", tz_offset_minutes.to_string()),
+            KeyValue::new("excluded_dirs", format!("{:?}", app_state.excluded_dirs)),
+        ],
+    );
+    span.set_status(Status::Ok);
+
+    HttpResponse::Ok().json(MemoriesResponse { items })
+}
+
+/// Resolve an "on this day/week/month across past years" window into an
+/// ordered list of [`MemoryItem`]s. Shared by the `/memories` handler and the
+/// memory-reel selector so both honour the same library resolution, per-library
+/// exclusions, timezone handling, and sort order. Returns `Err(message)` only
+/// when the `library` param is invalid (callers map that to 400); per-library
+/// query/lock failures are logged and skipped, matching the handler's
+/// best-effort behaviour.
+pub fn gather_memory_items(
+    app_state: &AppState,
+    exif_dao: &Mutex<Box<dyn ExifDao>>,
+    span_context: &opentelemetry::Context,
+    span_mode: MemoriesSpan,
+    tz_offset_minutes: i32,
+    client_timezone: Option<FixedOffset>,
+    library_param: Option<&str>,
+) -> Result<Vec<MemoryItem>, String> {
+    let span_token = match span_mode {
+        MemoriesSpan::Day => "day",
+        MemoriesSpan::Week => "week",
+        MemoriesSpan::Month => "month",
+    };
+    let years_back: i32 = DEFAULT_YEARS_BACK;
+
+    debug!(
+        "gather_memory_items: span={:?} tz_offset_min={} years_back={}",
+        span_mode, tz_offset_minutes, years_back
+    );
+
+    let library = crate::libraries::resolve_library_param_state(app_state, library_param)?;
     let libraries_to_scan: Vec<&crate::libraries::Library> = match library {
         Some(lib) => vec![lib],
         None => app_state.libraries.iter().collect(),
@@ -394,7 +436,7 @@ pub async fn list_memories(
 
         let rows = match exif_dao.lock() {
             Ok(mut dao) => match dao.get_memories_in_window(
-                &span_context,
+                span_context,
                 lib.id,
                 span_token,
                 years_back,
@@ -469,21 +511,7 @@ pub async fn list_memories(
         }
     }
 
-    let items: Vec<MemoryItem> = memories_with_dates.into_iter().map(|(m, _)| m).collect();
+    Ok(memories_with_dates.into_iter().map(|(m, _)| m).collect())
-
-    span.add_event(
-        "memories_scanned",
-        vec![
-            KeyValue::new("span", format!("{:?}", span_mode)),
-            KeyValue::new("years_back", years_back.to_string()),
-            KeyValue::new("result_count", items.len().to_string()),
-            KeyValue::new("tz_offset_minutes", tz_offset_minutes.to_string()),
-            KeyValue::new("excluded_dirs", format!("{:?}", app_state.excluded_dirs)),
-        ],
-    );
-    span.set_status(Status::Ok);
-
-    HttpResponse::Ok().json(MemoriesResponse { items })
 }
 
 #[cfg(test)]

src/reels/render.rs

@@ -0,0 +1,742 @@
+//! ffmpeg assembly for memory reels.
+//!
+//! Two-stage, per-segment design: each segment is rendered to its own
+//! normalized MP4 (identical codec/resolution/fps/timebase), then the segments
+//! are joined with the concat demuxer (stream copy, no re-encode). Rendering
+//! per segment — rather than one monster filtergraph — keeps each ffmpeg
+//! invocation simple to reason about, parallelizes naturally, and means a
+//! video-clip segment type (phase 2) slots in as just a different per-segment
+//! builder without touching the concat stage.
+//!
+//! The arg builders are pure (`Vec<String>` out) so the exact ffmpeg command
+//! is unit-testable; the runners spawn ffmpeg and surface stderr on failure.
+
+use anyhow::{Context, Result, bail};
+use std::path::Path;
+use tokio::process::Command;
+
+/// Re-exported so the reel pipeline reaches NVENC detection through this module
+/// rather than depending on `video::ffmpeg` directly.
+pub use crate::video::ffmpeg::is_nvenc_available;
+
+/// Reel canvas. Portrait, because reels are watched on a phone held upright —
+/// a landscape canvas letterboxes to a thin ~25%-height band there. Each photo
+/// is fitted sharp and centered over a blurred, zoomed copy of itself (see
+/// [`photo_filter_chain`]) so the frame is always filled regardless of the
+/// photo's orientation, without cropping the subject.
+pub const REEL_WIDTH: u32 = 1080;
+pub const REEL_HEIGHT: u32 = 1920;
+pub const REEL_FPS: u32 = 30;
+
+/// A beat's screen time is its narration length plus a short breath, with a
+/// floor so a terse line still lingers. No ceiling: the beat always covers the
+/// full narration so speech is never truncated — the scripter is asked to keep
+/// lines short instead.
+pub const MIN_SEGMENT_SECONDS: f64 = 2.5;
+const NARRATION_TAIL_SECONDS: f64 = 0.6;
+
+/// Fade durations baked into each photo. A held (single-photo) beat gets a
+/// gentle dip; burst photos get a much snappier fade so the difference between
+/// a held shot and a quick burst is obvious.
+const SINGLE_FADE_SECONDS: f64 = 0.35;
+const BURST_FADE_SECONDS: f64 = 0.12;
+
+/// Video-clip framing. Fallback cap on how much of a clip we read when the
+/// source length can't be probed; with a known length, a clip instead plays for
+/// as much of its beat as its footage allows (see [`clip_beat_plan`]). Its live
+/// audio is ducked to `CLIP_DUCK_VOLUME` under the narration.
+pub const CLIP_SECONDS: f64 = 5.0;
+const CLIP_DUCK_VOLUME: f64 = 0.35;
+
+/// Floor on how long each burst photo stays up, so a long line over many photos
+/// doesn't flash them subliminally. If the narration is too short to give every
+/// photo this much, the beat is stretched to fit.
+const MIN_BURST_PHOTO_SECONDS: f64 = 0.6;
+
+/// Base screen time for a beat given its narration length: narration + breath,
+/// floored. Used as the lower bound on a beat's total duration.
+pub fn segment_duration(narration_secs: f64) -> f64 {
+    let d = narration_secs + NARRATION_TAIL_SECONDS;
+    if d.is_finite() && d > MIN_SEGMENT_SECONDS {
+        d
+    } else {
+        MIN_SEGMENT_SECONDS
+    }
+}
+
+/// Split a beat into per-photo durations. The beat lasts at least its narration
+/// (so speech isn't cut) and at least `n × MIN_BURST_PHOTO_SECONDS` (so a fast
+/// burst stays legible); the photos share that total evenly. Returns
+/// `(total_seconds, per_photo_seconds)`.
+pub fn beat_durations(narration_secs: f64, n_photos: usize) -> (f64, Vec<f64>) {
+    let n = n_photos.max(1);
+    let base = segment_duration(narration_secs);
+    let min_total = n as f64 * MIN_BURST_PHOTO_SECONDS;
+    let total = if base > min_total { base } else { min_total };
+    let each = total / n as f64;
+    (total, vec![each; n])
+}
+
+/// Fade length to use for a beat of `n_photos` (gentle when held, snappy in a
+/// burst).
+fn fade_for(n_photos: usize) -> f64 {
+    if n_photos > 1 {
+        BURST_FADE_SECONDS
+    } else {
+        SINGLE_FADE_SECONDS
+    }
+}
+
+/// Options controlling per-segment rendering.
+#[derive(Debug, Clone, Copy)]
+pub struct SegmentOpts {
+    pub width: u32,
+    pub height: u32,
+    pub fps: u32,
+    pub nvenc: bool,
+}
+
+impl Default for SegmentOpts {
+    fn default() -> Self {
+        Self {
+            width: REEL_WIDTH,
+            height: REEL_HEIGHT,
+            fps: REEL_FPS,
+            nvenc: false,
+        }
+    }
+}
+
+/// Filter chain for one photo (input `idx`) producing the labelled output
+/// `[v{idx}]`. Splits the still into a background and foreground: the background
+/// is scaled to *cover* the canvas and heavily blurred; the foreground is
+/// scaled to *fit* and overlaid centered. This fills the portrait frame for any
+/// photo orientation — no black bars, no cropping of the subject — then a fade
+/// in/out softens the cut. Intermediate labels are suffixed with `idx` so
+/// several chains coexist in one `filter_complex`.
+///
+/// `fps` is normalized BEFORE the fades so the brightness ramp is computed on a
+/// true {fps}-frame timeline; otherwise the fade is sampled at the looped
+/// still's coarse cadence and duplicated up, which reads as a steppy dip.
+fn photo_filter_chain(idx: usize, opts: &SegmentOpts, duration: f64, fade: f64) -> String {
+    let (w, h, fps) = (opts.width, opts.height, opts.fps);
+    let fade_out_start = (duration - fade).max(0.0);
+    format!(
+        "[{idx}:v]split=2[bg{idx}][fg{idx}];\
+         [bg{idx}]scale={w}:{h}:force_original_aspect_ratio=increase,\
+         crop={w}:{h},boxblur=20:2[bgb{idx}];\
+         [fg{idx}]scale={w}:{h}:force_original_aspect_ratio=decrease[fgs{idx}];\
+         [bgb{idx}][fgs{idx}]overlay=(W-w)/2:(H-h)/2,\
+         fps={fps},\
+         fade=t=in:st=0:d={fade},\
+         fade=t=out:st={fade_out_start:.3}:d={fade},\
+         setsar=1,format=yuv420p[v{idx}]"
+    )
+}
+
+/// Full `filter_complex` for a beat of `per_photo` durations: one chain per
+/// photo, concatenated into `[v]`, with the narration (the last input, index
+/// `per_photo.len()`) padded with trailing silence into `[a]`. A single-photo
+/// beat degenerates to one chain + `concat=n=1` (a passthrough).
+pub fn beat_filtergraph(opts: &SegmentOpts, per_photo: &[f64]) -> String {
+    let n = per_photo.len().max(1);
+    let fade = fade_for(n);
+    let chains: Vec<String> = per_photo
+        .iter()
+        .enumerate()
+        .map(|(i, &d)| photo_filter_chain(i, opts, d, fade))
+        .collect();
+    let concat_inputs: String = (0..n).map(|i| format!("[v{i}]")).collect();
+    format!(
+        "{chains};{concat_inputs}concat=n={n}:v=1:a=0[v];[{n}:a]apad[a]",
+        chains = chains.join(";")
+    )
+}
+
+fn video_encoder_args(nvenc: bool) -> Vec<String> {
+    if nvenc {
+        // p4 ≈ balanced; cq 23 ≈ libx264 crf 21. Matches the HLS transcode path.
+        [
+            "-c:v",
+            "h264_nvenc",
+            "-preset",
+            "p4",
+            "-cq",
+            "23",
+            "-pix_fmt",
+            "yuv420p",
+        ]
+    } else {
+        [
+            "-c:v", "libx264", "-crf", "21", "-preset", "veryfast", "-pix_fmt", "yuv420p",
+        ]
+    }
+    .iter()
+    .map(|s| s.to_string())
+    .collect()
+}
+
+/// Build the ffmpeg args that render one beat: each photo looped for its slice
+/// of the beat (filled to the portrait canvas with a blurred backdrop), the
+/// slices concatenated, and the single narration muxed over the whole thing.
+/// `total` bounds the output (and the apad'd audio) to the beat length.
+pub fn build_beat_args(
+    image_paths: &[String],
+    audio_path: &str,
+    out_path: &str,
+    per_photo: &[f64],
+    total: f64,
+    opts: &SegmentOpts,
+) -> Vec<String> {
+    let fps = opts.fps.to_string();
+    let mut args: Vec<String> = vec!["-y".into()];
+    if opts.nvenc {
+        args.extend(["-hwaccel".into(), "cuda".into()]);
+    }
+    // One looped-still input per photo, each bounded to its slice by an input
+    // `-t`; reading at the target `-framerate` gives the fades real frames to
+    // ramp across.
+    for (path, &dur) in image_paths.iter().zip(per_photo.iter()) {
+        args.extend([
+            "-framerate".into(),
+            fps.clone(),
+            "-loop".into(),
+            "1".into(),
+            "-t".into(),
+            format!("{dur:.3}"),
+            "-i".into(),
+            path.clone(),
+        ]);
+    }
+    args.extend([
+        "-i".into(),
+        audio_path.into(),
+        "-filter_complex".into(),
+        beat_filtergraph(opts, per_photo),
+        "-map".into(),
+        "[v]".into(),
+        "-map".into(),
+        "[a]".into(),
+        "-t".into(),
+        format!("{total:.3}"),
+        // Force constant frame rate so the beat (and the concatenated reel)
+        // plays at a steady {fps} rather than a variable cadence.
+        "-r".into(),
+        fps,
+    ]);
+    args.extend(video_encoder_args(opts.nvenc));
+    args.extend(
+        ["-c:a", "aac", "-b:a", "160k", "-ar", "48000", "-shortest"]
+            .iter()
+            .map(|s| s.to_string()),
+    );
+    args.push(out_path.into());
+    args
+}
+
+/// Build the concat-demuxer args that join rendered segments losslessly.
+/// `+faststart` moves the moov atom up front so the reel streams immediately
+/// on the mobile client. The output muxer is forced with `-f mp4` because we
+/// write to a `.tmp` path (atomic publish) whose extension ffmpeg can't map to
+/// a format on its own.
+pub fn build_concat_args(list_path: &str, out_path: &str) -> Vec<String> {
+    [
+        "-y",
+        "-f",
+        "concat",
+        "-safe",
+        "0",
+        "-i",
+        list_path,
+        "-c",
+        "copy",
+        "-movflags",
+        "+faststart",
+        "-f",
+        "mp4",
+        out_path,
+    ]
+    .iter()
+    .map(|s| s.to_string())
+    .collect()
+}
+
+/// Render the concat list file body. Each line points the demuxer at one
+/// segment; single quotes in paths are escaped per ffmpeg's concat syntax.
+pub fn build_concat_list(segment_paths: &[String]) -> String {
+    let mut out = String::new();
+    for p in segment_paths {
+        let escaped = p.replace('\'', r"'\''");
+        out.push_str(&format!("file '{escaped}'\n"));
+    }
+    out
+}
+
+async fn run_ffmpeg(args: &[String], what: &str) -> Result<()> {
+    let output = Command::new("ffmpeg")
+        .args(args)
+        .output()
+        .await
+        .with_context(|| format!("spawning ffmpeg for {what}"))?;
+    if !output.status.success() {
+        bail!(
+            "ffmpeg {what} failed: {}",
+            String::from_utf8_lossy(&output.stderr)
+        );
+    }
+    Ok(())
+}
+
+/// Render one beat to `out_path`: its photos shown in sequence (a held shot for
+/// one photo, a quick burst for several) under the single narration in
+/// `audio_path`, whose measured length sets the beat's pacing.
+pub async fn render_beat(
+    image_paths: &[std::path::PathBuf],
+    audio_path: &Path,
+    out_path: &Path,
+    narration_secs: f64,
+    opts: &SegmentOpts,
+) -> Result<()> {
+    if image_paths.is_empty() {
+        bail!("render_beat called with no images");
+    }
+    let (total, per_photo) = beat_durations(narration_secs, image_paths.len());
+    let paths: Vec<String> = image_paths
+        .iter()
+        .map(|p| p.to_string_lossy().to_string())
+        .collect();
+    let args = build_beat_args(
+        &paths,
+        &audio_path.to_string_lossy(),
+        &out_path.to_string_lossy(),
+        &per_photo,
+        total,
+        opts,
+    );
+    run_ffmpeg(&args, "beat render").await
+}
+
+// --- Video-clip beats --------------------------------------------------------
+
+/// Decide how long the clip plays and how long the whole beat lasts, from the
+/// source video's length (if known) and the narration length. Returns
+/// `(clip_dur, beat_total)`.
+///
+/// The beat always lasts long enough for the full narration. The clip plays for
+/// as much of that beat as its footage covers — so the motion fills the screen
+/// time rather than stopping early. We only freeze the last frame (the
+/// `beat_total - clip_dur` gap, handled by `tpad` in [`clip_video_filter`]) when
+/// the source video is genuinely shorter than the narration. Capping clip
+/// playback at a fixed length while the narration ran longer was what produced
+/// the second-or-two freeze that read as a glitchy pause before the transition.
+pub fn clip_beat_plan(source_dur: Option<f64>, narration_secs: f64) -> (f64, f64) {
+    let want = segment_duration(narration_secs);
+    let clip_dur = match source_dur {
+        // Known length: play up to the whole beat, but never past the source.
+        Some(d) if d > 0.0 => d.min(want),
+        // Unknown length: read up to the fallback cap; tpad covers any shortfall.
+        _ => want.min(CLIP_SECONDS),
+    };
+    (clip_dur, want.max(clip_dur))
+}
+
+/// Video chain for a clip beat: fill the clip to the portrait canvas (blurred
+/// backdrop, same look as photos), normalize fps, hold the last frame if the
+/// narration outlasts the clip (`tpad`), then fade. Produces `[v]`.
+fn clip_video_filter(opts: &SegmentOpts, clip_dur: f64, beat_total: f64) -> String {
+    let (w, h, fps) = (opts.width, opts.height, opts.fps);
+    let fade = SINGLE_FADE_SECONDS;
+    let hold = (beat_total - clip_dur).max(0.0);
+    let fade_out_start = (beat_total - fade).max(0.0);
+    // Freeze the final frame to cover narration that runs past the clip.
+    let tpad = if hold > 0.05 {
+        format!(",tpad=stop_mode=clone:stop_duration={hold:.3}")
+    } else {
+        String::new()
+    };
+    format!(
+        "[0:v]split=2[bg][fg];\
+         [bg]scale={w}:{h}:force_original_aspect_ratio=increase,\
+         crop={w}:{h},boxblur=20:2[bgb];\
+         [fg]scale={w}:{h}:force_original_aspect_ratio=decrease[fgs];\
+         [bgb][fgs]overlay=(W-w)/2:(H-h)/2,fps={fps}{tpad},\
+         fade=t=in:st=0:d={fade},fade=t=out:st={fade_out_start:.3}:d={fade},\
+         setsar=1,format=yuv420p[v]"
+    )
+}
+
+/// Audio chain for a clip beat. With a clip audio track, duck it under the
+/// narration and mix; without one, just the narration. Produces `[a]`.
+fn clip_audio_filter(has_audio: bool) -> String {
+    if has_audio {
+        format!(
+            "[0:a]volume={CLIP_DUCK_VOLUME}[duck];[1:a]apad[narr];\
+             [duck][narr]amix=inputs=2:duration=longest:normalize=0[a]"
+        )
+    } else {
+        "[1:a]apad[a]".to_string()
+    }
+}
+
+/// Full `filter_complex` for a clip beat (input 0 = clip, input 1 = narration).
+pub fn clip_beat_filtergraph(
+    opts: &SegmentOpts,
+    clip_dur: f64,
+    beat_total: f64,
+    has_audio: bool,
+) -> String {
+    format!(
+        "{};{}",
+        clip_video_filter(opts, clip_dur, beat_total),
+        clip_audio_filter(has_audio)
+    )
+}
+
+/// Build the ffmpeg args for a clip beat: the first `clip_dur` seconds of the
+/// source video, filled to the portrait canvas with its live audio ducked under
+/// the narration, bounded to `beat_total`.
+pub fn build_clip_beat_args(
+    clip_path: &str,
+    audio_path: &str,
+    out_path: &str,
+    clip_dur: f64,
+    beat_total: f64,
+    has_audio: bool,
+    opts: &SegmentOpts,
+) -> Vec<String> {
+    let fps = opts.fps.to_string();
+    let mut args: Vec<String> = vec!["-y".into()];
+    if opts.nvenc {
+        args.extend(["-hwaccel".into(), "cuda".into()]);
+    }
+    args.extend([
+        // Input `-t` limits the clip to its window; audio has none (apad fills).
+        "-t".into(),
+        format!("{clip_dur:.3}"),
+        "-i".into(),
+        clip_path.into(),
+        "-i".into(),
+        audio_path.into(),
+        "-filter_complex".into(),
+        clip_beat_filtergraph(opts, clip_dur, beat_total, has_audio),
+        "-map".into(),
+        "[v]".into(),
+        "-map".into(),
+        "[a]".into(),
+        "-t".into(),
+        format!("{beat_total:.3}"),
+        "-r".into(),
+        fps,
+    ]);
+    args.extend(video_encoder_args(opts.nvenc));
+    args.extend(
+        ["-c:a", "aac", "-b:a", "160k", "-ar", "48000"]
+            .iter()
+            .map(|s| s.to_string()),
+    );
+    args.push(out_path.into());
+    args
+}
+
+/// Whether a media file has at least one audio stream (so a clip beat knows
+/// whether to mix in live audio). Defaults to `false` on any probe failure.
+pub async fn has_audio_stream(path: &str) -> bool {
+    Command::new("ffprobe")
+        .args([
+            "-v",
+            "error",
+            "-select_streams",
+            "a",
+            "-show_entries",
+            "stream=index",
+            "-of",
+            "csv=p=0",
+            path,
+        ])
+        .output()
+        .await
+        .map(|out| !out.stdout.is_empty())
+        .unwrap_or(false)
+}
+
+/// Render one clip beat: a section of `clip_path` (capped at [`CLIP_SECONDS`],
+/// and to the source length) under the narration in `audio_path`. The beat
+/// lasts at least the narration, freezing the clip's last frame if needed.
+pub async fn render_clip_beat(
+    clip_path: &Path,
+    audio_path: &Path,
+    out_path: &Path,
+    narration_secs: f64,
+    opts: &SegmentOpts,
+) -> Result<()> {
+    let clip_str = clip_path.to_string_lossy().to_string();
+    // Play the clip for as much of the beat as its footage covers; freeze only
+    // when the source is genuinely shorter than the narration (see clip_beat_plan).
+    let source_dur = crate::video::ffmpeg::get_duration_seconds(&clip_str)
+        .await
+        .ok()
+        .flatten();
+    let (clip_dur, beat_total) = clip_beat_plan(source_dur, narration_secs);
+    let has_audio = has_audio_stream(&clip_str).await;
+
+    let args = build_clip_beat_args(
+        &clip_str,
+        &audio_path.to_string_lossy(),
+        &out_path.to_string_lossy(),
+        clip_dur,
+        beat_total,
+        has_audio,
+        opts,
+    );
+    run_ffmpeg(&args, "clip beat render").await
+}
+
+/// Join rendered segments into the final reel. Writes the concat list into the
+/// same directory as the output so relative paths and cleanup stay local.
+pub async fn concat_segments(segment_paths: &[String], out_path: &Path) -> Result<()> {
+    let list_path = out_path.with_extension("concat.txt");
+    let body = build_concat_list(segment_paths);
+    tokio::fs::write(&list_path, body)
+        .await
+        .context("writing concat list")?;
+    let args = build_concat_args(&list_path.to_string_lossy(), &out_path.to_string_lossy());
+    let result = run_ffmpeg(&args, "concat").await;
+    let _ = tokio::fs::remove_file(&list_path).await;
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn segment_duration_floors_short_lines() {
+        // A one-word narration still lingers at the floor.
+        assert_eq!(segment_duration(0.5), MIN_SEGMENT_SECONDS);
+        assert_eq!(segment_duration(0.0), MIN_SEGMENT_SECONDS);
+    }
+
+    #[test]
+    fn segment_duration_covers_full_narration_plus_tail() {
+        // No ceiling: a long line gets its full length so speech isn't cut.
+        assert!((segment_duration(5.0) - 5.6).abs() < 1e-9);
+        assert!((segment_duration(20.0) - 20.6).abs() < 1e-9);
+    }
+
+    #[test]
+    fn segment_duration_rejects_nonfinite() {
+        assert_eq!(segment_duration(f64::NAN), MIN_SEGMENT_SECONDS);
+        assert_eq!(segment_duration(f64::INFINITY), MIN_SEGMENT_SECONDS);
+    }
+
+    #[test]
+    fn beat_durations_single_photo_matches_base() {
+        let (total, per) = beat_durations(4.0, 1);
+        assert!((total - 4.6).abs() < 1e-9); // narration + tail
+        assert_eq!(per.len(), 1);
+        assert!((per[0] - 4.6).abs() < 1e-9);
+    }
+
+    #[test]
+    fn beat_durations_burst_splits_evenly() {
+        // 5 photos, narration 4.6s base → ~0.92s each (above the 0.6 floor).
+        let (total, per) = beat_durations(4.0, 5);
+        assert!((total - 4.6).abs() < 1e-9);
+        assert_eq!(per.len(), 5);
+        assert!((per.iter().sum::<f64>() - total).abs() < 1e-9);
+        assert!(per.iter().all(|&d| d >= MIN_BURST_PHOTO_SECONDS));
+    }
+
+    #[test]
+    fn beat_durations_stretches_when_narration_too_short_for_burst() {
+        // Floor narration (2.5s) over 10 photos would be 0.25s each — below the
+        // legibility floor, so the beat stretches to 10 × 0.6 = 6s.
+        let (total, per) = beat_durations(0.0, 10);
+        assert!((total - 6.0).abs() < 1e-9);
+        assert!(per.iter().all(|&d| (d - 0.6).abs() < 1e-9));
+    }
+
+    #[test]
+    fn beat_filtergraph_single_photo_fills_portrait_and_holds() {
+        let (_t, per) = beat_durations(4.0, 1);
+        let g = beat_filtergraph(&SegmentOpts::default(), &per);
+        assert!(g.contains("[0:v]split=2[bg0][fg0]"));
+        assert!(g.contains("scale=1080:1920:force_original_aspect_ratio=increase"));
+        assert!(g.contains("crop=1080:1920"));
+        assert!(g.contains("scale=1080:1920:force_original_aspect_ratio=decrease"));
+        assert!(g.contains("overlay=(W-w)/2:(H-h)/2"));
+        // Single photo → concat of one, gentle fade, audio is input 1.
+        assert!(g.contains("concat=n=1:v=1:a=0[v]"));
+        assert!(g.contains("d=0.35")); // SINGLE_FADE
+        assert!(g.contains("[1:a]apad[a]"));
+    }
+
+    #[test]
+    fn beat_filtergraph_burst_chains_concats_and_snappy_fade() {
+        let (_t, per) = beat_durations(4.0, 3);
+        let g = beat_filtergraph(&SegmentOpts::default(), &per);
+        // One chain per photo with index-suffixed labels.
+        assert!(g.contains("[0:v]split") && g.contains("[1:v]split") && g.contains("[2:v]split"));
+        // Concatenated in order, audio is the 4th input (index 3).
+        assert!(g.contains("[v0][v1][v2]concat=n=3:v=1:a=0[v]"));
+        assert!(g.contains("[3:a]apad[a]"));
+        // Burst uses the much snappier fade (vs 0.35 for a held shot).
+        assert!(g.contains("d=0.12"));
+        assert!(!g.contains("d=0.35"));
+    }
+
+    #[test]
+    fn beat_filtergraph_normalizes_fps_before_fading() {
+        // fps must precede the fades on every chain (else the dip looks steppy).
+        let (_t, per) = beat_durations(4.0, 1);
+        let g = beat_filtergraph(&SegmentOpts::default(), &per);
+        let fps_at = g.find("fps=30").expect("fps in graph");
+        let fade_at = g.find("fade=t=in").expect("fade in graph");
+        assert!(fps_at < fade_at);
+    }
+
+    #[test]
+    fn beat_args_one_input_per_photo_plus_audio_bound_by_total() {
+        let (total, per) = beat_durations(4.0, 2);
+        let args = build_beat_args(
+            &["/a.jpg".into(), "/b.jpg".into()],
+            "/n.wav",
+            "/out.mp4",
+            &per,
+            total,
+            &SegmentOpts::default(),
+        );
+        let joined = args.join(" ");
+        // A looped-still input per photo, each with its slice -t, then the audio.
+        assert!(joined.contains("-framerate 30 -loop 1 -t 2.300 -i /a.jpg"));
+        assert!(joined.contains("-framerate 30 -loop 1 -t 2.300 -i /b.jpg"));
+        assert!(joined.contains("-i /n.wav"));
+        // Output bounded to the beat total and forced CFR.
+        assert!(joined.contains("-t 4.600"));
+        assert!(joined.contains("-r 30"));
+        assert!(joined.ends_with("/out.mp4"));
+    }
+
+    #[test]
+    fn beat_args_use_nvenc_and_cuda_when_enabled() {
+        let opts = SegmentOpts {
+            nvenc: true,
+            ..SegmentOpts::default()
+        };
+        let (total, per) = beat_durations(3.0, 1);
+        let args = build_beat_args(
+            &["/img.jpg".into()],
+            "/a.wav",
+            "/out.mp4",
+            &per,
+            total,
+            &opts,
+        );
+        let joined = args.join(" ");
+        assert!(joined.contains("-hwaccel cuda"));
+        assert!(joined.contains("h264_nvenc"));
+        assert!(!joined.contains("libx264"));
+    }
+
+    #[test]
+    fn clip_filter_ducks_audio_and_holds_last_frame_when_narration_longer() {
+        // 5s clip, 7s beat → 2s freeze of the last frame, ducked-audio mix.
+        let g = clip_beat_filtergraph(&SegmentOpts::default(), 5.0, 7.0, true);
+        assert!(g.contains("tpad=stop_mode=clone:stop_duration=2.000"));
+        assert!(g.contains("volume=0.35"));
+        assert!(g.contains("amix=inputs=2"));
+        assert!(g.contains("[1:a]apad[narr]"));
+        // Fill applied to the clip too.
+        assert!(g.contains("boxblur"));
+        assert!(g.contains("overlay=(W-w)/2:(H-h)/2"));
+    }
+
+    #[test]
+    fn clip_beat_plan_plays_clip_through_the_whole_beat_when_source_is_long() {
+        // 30s source, 4s narration → beat is narration+tail (4.6), and the clip
+        // plays that whole 4.6s of motion: no freeze (clip_dur == beat_total).
+        let (clip_dur, beat_total) = clip_beat_plan(Some(30.0), 4.0);
+        assert!((beat_total - 4.6).abs() < 1e-9);
+        assert!((clip_dur - 4.6).abs() < 1e-9);
+        assert!((beat_total - clip_dur).abs() < 1e-9); // no hold
+    }
+
+    #[test]
+    fn clip_beat_plan_freezes_only_when_source_shorter_than_narration() {
+        // 2s source under a 4s narration → play all 2s, freeze the remainder.
+        let (clip_dur, beat_total) = clip_beat_plan(Some(2.0), 4.0);
+        assert!((clip_dur - 2.0).abs() < 1e-9);
+        assert!((beat_total - 4.6).abs() < 1e-9);
+        assert!(beat_total - clip_dur > 2.0); // unavoidable freeze gap
+    }
+
+    #[test]
+    fn clip_beat_plan_caps_read_when_source_length_unknown() {
+        // Probe failed: read up to the fallback cap, beat still covers narration.
+        let (clip_dur, beat_total) = clip_beat_plan(None, 8.0);
+        assert!((clip_dur - CLIP_SECONDS).abs() < 1e-9);
+        assert!((beat_total - 8.6).abs() < 1e-9);
+    }
+
+    #[test]
+    fn clip_filter_no_tpad_when_clip_covers_the_beat() {
+        // Clip at least as long as the beat → no freeze.
+        let g = clip_beat_filtergraph(&SegmentOpts::default(), 5.0, 5.0, true);
+        assert!(!g.contains("tpad"));
+    }
+
+    #[test]
+    fn clip_filter_narration_only_without_clip_audio() {
+        let g = clip_beat_filtergraph(&SegmentOpts::default(), 5.0, 5.0, false);
+        assert!(!g.contains("amix"));
+        assert!(!g.contains("volume="));
+        assert!(g.contains("[1:a]apad[a]"));
+    }
+
+    #[test]
+    fn clip_beat_args_bound_clip_and_output() {
+        let args = build_clip_beat_args(
+            "/v.mp4",
+            "/n.wav",
+            "/out.mp4",
+            5.0,
+            6.6,
+            true,
+            &SegmentOpts::default(),
+        );
+        let joined = args.join(" ");
+        // Input -t bounds the clip read; output -t bounds the beat.
+        assert!(joined.contains("-t 5.000 -i /v.mp4"));
+        assert!(joined.contains("-i /n.wav"));
+        assert!(joined.contains("-t 6.600"));
+        assert!(joined.contains("-r 30"));
+        assert!(joined.ends_with("/out.mp4"));
+    }
+
+    #[test]
+    fn concat_args_stream_copy_with_faststart_and_forced_muxer() {
+        // Output goes to a .tmp path, so the muxer must be forced — ffmpeg
+        // can't infer mp4 from the extension (the bug this guards against).
+        let args = build_concat_args("/tmp/list.txt", "/out.mp4.tmp");
+        let joined = args.join(" ");
+        assert!(joined.contains("-f concat -safe 0 -i /tmp/list.txt"));
+        assert!(joined.contains("-c copy"));
+        assert!(joined.contains("+faststart"));
+        assert!(joined.contains("-f mp4"));
+        // The forced muxer must come before the output path.
+        let f_mp4 = args.windows(2).position(|w| w == ["-f", "mp4"]).unwrap();
+        let out = args.iter().position(|a| a == "/out.mp4.tmp").unwrap();
+        assert!(f_mp4 < out);
+    }
+
+    #[test]
+    fn concat_list_escapes_single_quotes() {
+        let body = build_concat_list(&[
+            "/tmp/seg_000.mp4".into(),
+            "/tmp/own's dir/seg_001.mp4".into(),
+        ]);
+        assert!(body.contains("file '/tmp/seg_000.mp4'\n"));
+        // The apostrophe is closed-escaped-reopened per ffmpeg concat syntax.
+        assert!(body.contains(r"own'\''s"));
+    }
+}

src/reels/script.rs

@@ -0,0 +1,490 @@
+//! Narration scripting for memory reels.
+//!
+//! One LLM call turns the planned beats (each carrying its date and, where
+//! available, its cached insight) into a short first-person narration line per
+//! beat plus a title for the reel. A beat may show several photos in a quick
+//! burst, so a line narrates the *moment*, not a single frame. We reuse the
+//! cached insight summary as the richest signal rather than re-running vision
+//! at reel time — that keeps reel generation off the GPU's vision slot.
+//!
+//! The prompt builder and response parser are pure so the contract is
+//! unit-testable; `generate_script` wires them to the LLM client.
+//!
+//! The agentic scripter (pre-generation) resolves the backend through the
+//! InsightGenerator, builds a read-only tool set, and runs a tool loop to
+//! ground the narration in retrieved context before asking for the final JSON.
+
+use anyhow::{Context, Result};
+use std::sync::Arc;
+
+use super::{PlannedBeat, ReelMeta};
+use crate::ai::backend::{BackendKind, SamplingOverrides};
+use crate::ai::insight_generator::InsightGenerator;
+use crate::ai::llamacpp::LlamaCppClient;
+use crate::ai::llm_client::{LlmClient, Tool};
+use crate::ai::ollama::ChatMessage;
+
+/// The narration for a whole reel: a title and one line per beat, in order.
+#[derive(Debug, Clone, PartialEq)]
+pub struct ReelScript {
+    pub title: String,
+    pub lines: Vec<String>,
+}
+
+const SYSTEM_PROMPT: &str = "You are narrating a personal memory reel — a short \
+slideshow of someone's own photos set to a spoken voiceover. Write warm, \
+specific, first-person narration as if the person is gently looking back on \
+their own memories. Each line plays over one moment, which may be a quick burst \
+of several photos, so narrate the moment as a whole rather than a single frame. \
+Be concrete and grounded in the details given; never invent names, places, or \
+events that aren't supported. Keep each line to one or two short sentences that \
+can be read aloud in a few seconds. Avoid generic filler like \"what a \
+wonderful day\" — if you have little to go on, simply describe the moment \
+plainly.";
+
+/// Agentic scripter system prompt: richer version that tells the model it may
+/// call read-only tools to ground each line.
+const AGENTIC_SYSTEM_PROMPT: &str = "You are narrating a personal memory reel — a short \
+slideshow of someone's own photos set to a spoken voiceover. Write warm, \
+specific, first-person narration as if the person is gently looking back on \
+their own memories. Each line plays over one moment, which may be a quick burst \
+of several photos, so narrate the moment as a whole rather than a single frame. \
+Be concrete and grounded in the details given; never invent names, places, or \
+events that aren't supported. Keep each line to one or two short sentences that \
+can be read aloud in a few seconds. Avoid generic filler like \"what a \
+wonderful day\" — if you have little to go on, simply describe the moment \
+plainly.\n\nYou may call read-only tools (search_rag, search_messages, \
+get_sms_messages, get_calendar_events, get_location_history, reverse_geocode, \
+get_personal_place_at, recall_entities, get_current_datetime) to ground each \
+line in real context — e.g. reverse_geocode a moment's GPS to name the place, \
+or check the calendar/messages around its date. Never invent details. Return \
+ONLY the JSON object, no prose or code fences.";
+
+/// Maximum agentic tool iterations for pre-generation. Tunable via
+/// `REEL_PREGEN_MAX_TOOL_ITERS` (default 8).
+fn reel_pregen_max_tool_iters() -> usize {
+    std::env::var("REEL_PREGEN_MAX_TOOL_ITERS")
+        .ok()
+        .and_then(|s| s.trim().parse::<usize>().ok())
+        .filter(|x| *x > 0)
+        .unwrap_or(8)
+}
+
+/// Build the (system, user) prompt pair for the scripter. The user message
+/// describes each beat in order and asks for strict JSON back.
+pub fn build_script_messages(meta: &ReelMeta, beats: &[PlannedBeat]) -> (String, String) {
+    let mut user = String::new();
+    user.push_str(&format!(
+        "This reel has {} moments surfaced as memories {}.\n\n",
+        beats.len(),
+        meta.span_phrase()
+    ));
+    if !meta.years.is_empty() {
+        let years: Vec<String> = meta.years.iter().map(|y| y.to_string()).collect();
+        user.push_str(&format!("They span the years: {}.\n\n", years.join(", ")));
+    }
+    user.push_str("Moments, in the order they will appear:\n");
+    for (i, beat) in beats.iter().enumerate() {
+        user.push_str(&format!("\n[{}]", i + 1));
+        if let Some(date) = beat.date_label() {
+            user.push_str(&format!(" {date}"));
+        }
+        if beat.is_clip() {
+            user.push_str(" (a video clip)");
+        } else if beat.media.len() > 1 {
+            user.push_str(&format!(" (a burst of {} photos)", beat.media.len()));
+        }
+        user.push('\n');
+        match (&beat.insight_title, &beat.insight_summary) {
+            (Some(t), Some(s)) if !s.trim().is_empty() => {
+                user.push_str(&format!("  Known context: {t} — {s}\n"));
+            }
+            (Some(t), _) => user.push_str(&format!("  Known context: {t}\n")),
+            (_, Some(s)) if !s.trim().is_empty() => {
+                user.push_str(&format!("  Known context: {s}\n"));
+            }
+            _ => user.push_str("  (no extra context — narrate plainly from the date)\n"),
+        }
+    }
+    user.push_str(&format!(
+        "\nReturn ONLY a JSON object, no prose or code fences, shaped exactly:\n\
+         {{\"title\": \"<short reel title>\", \"segments\": [\"<line for moment 1>\", \
+         \"<line for moment 2>\", ... ]}}\n\
+         The \"segments\" array MUST have exactly {} items, one per moment in order.",
+        beats.len()
+    ));
+    (SYSTEM_PROMPT.to_string(), user)
+}
+
+/// Build a richer (system, user) prompt pair for the agentic scripter. The
+/// system prompt tells the model it may call read-only tools to ground each
+/// line. The user message uses the same per-beat enumeration as
+/// `build_script_messages` plus a GPS line per beat when available.
+pub fn build_agentic_script_messages(meta: &ReelMeta, beats: &[PlannedBeat]) -> Vec<ChatMessage> {
+    let mut user = String::new();
+    user.push_str(&format!(
+        "This reel has {} moments surfaced as memories {}.\n\n",
+        beats.len(),
+        meta.span_phrase()
+    ));
+    if !meta.years.is_empty() {
+        let years: Vec<String> = meta.years.iter().map(|y| y.to_string()).collect();
+        user.push_str(&format!("They span the years: {}.\n\n", years.join(", ")));
+    }
+    user.push_str("Moments, in the order they will appear:\n");
+    for (i, beat) in beats.iter().enumerate() {
+        user.push_str(&format!("\n[{}]", i + 1));
+        if let Some(date) = beat.date_label() {
+            user.push_str(&format!(" {date}"));
+        }
+        if beat.is_clip() {
+            user.push_str(" (a video clip)");
+        } else if beat.media.len() > 1 {
+            user.push_str(&format!(" (a burst of {} photos)", beat.media.len()));
+        }
+        if let Some((lat, lon)) = beat.gps {
+            user.push_str(&format!("\n  GPS: {:.4}, {:.4}", lat, lon));
+        }
+        user.push('\n');
+        match (&beat.insight_title, &beat.insight_summary) {
+            (Some(t), Some(s)) if !s.trim().is_empty() => {
+                user.push_str(&format!("  Known context: {t} — {s}\n"));
+            }
+            (Some(t), _) => user.push_str(&format!("  Known context: {t}\n")),
+            (_, Some(s)) if !s.trim().is_empty() => {
+                user.push_str(&format!("  Known context: {s}\n"));
+            }
+            _ => user.push_str("  (no extra context — narrate plainly from the date)\n"),
+        }
+    }
+    user.push_str(&format!(
+        "\nReturn ONLY a JSON object, no prose or code fences, shaped exactly:\n\
+         {{\"title\": \"<short reel title>\", \"segments\": [\"<line for moment 1>\", \
+         \"<line for moment 2>\", ... ]}}\n\
+         The \"segments\" array MUST have exactly {} items, one per moment in order.",
+        beats.len()
+    ));
+
+    vec![
+        ChatMessage::system(AGENTIC_SYSTEM_PROMPT.to_string()),
+        ChatMessage::user(user),
+    ]
+}
+
+/// Parse the model's response into a script with exactly `n` lines. Tolerant of
+/// code fences and surrounding prose, and of both `segments: [".."]` and
+/// `segments: [{"narration": ".."}]` shapes. Missing/extra lines are padded or
+/// truncated so the caller always gets `n` aligned to the segments.
+pub fn parse_script_response(raw: &str, n: usize) -> ReelScript {
+    let fallback_line = "A moment worth remembering.";
+    let value = extract_json_object(raw);
+
+    let title = value
+        .as_ref()
+        .and_then(|v| v.get("title"))
+        .and_then(|t| t.as_str())
+        .map(clean_text)
+        .filter(|s| !s.is_empty())
+        .unwrap_or_else(|| "Memories".to_string());
+
+    let mut lines: Vec<String> = value
+        .as_ref()
+        .and_then(|v| v.get("segments"))
+        .and_then(|s| s.as_array())
+        .map(|arr| {
+            arr.iter()
+                .map(|item| {
+                    let text = item
+                        .as_str()
+                        .map(|s| s.to_string())
+                        .or_else(|| {
+                            item.get("narration")
+                                .and_then(|n| n.as_str())
+                                .map(|s| s.to_string())
+                        })
+                        .unwrap_or_default();
+                    clean_text(&text)
+                })
+                .collect()
+        })
+        .unwrap_or_default();
+
+    // Align to exactly n: drop extras, pad shortfalls with a neutral line so
+    // every photo still gets spoken audio.
+    lines.truncate(n);
+    while lines.len() < n {
+        lines.push(fallback_line.to_string());
+    }
+    for line in lines.iter_mut() {
+        if line.is_empty() {
+            *line = fallback_line.to_string();
+        }
+    }
+
+    ReelScript { title, lines }
+}
+
+/// Pull the first balanced top-level JSON object out of a possibly-noisy model
+/// response (code fences, leading prose). Returns None if nothing parses.
+fn extract_json_object(raw: &str) -> Option<serde_json::Value> {
+    // Fast path: the whole thing is valid JSON.
+    if let Ok(v) = serde_json::from_str::<serde_json::Value>(raw.trim()) {
+        return Some(v);
+    }
+    // Otherwise scan for the first '{' ... matching '}' span, ignoring braces
+    // inside strings.
+    let bytes = raw.as_bytes();
+    let start = raw.find('{')?;
+    let mut depth = 0i32;
+    let mut in_str = false;
+    let mut escaped = false;
+    for i in start..bytes.len() {
+        let c = bytes[i] as char;
+        if in_str {
+            if escaped {
+                escaped = false;
+            } else if c == '\\' {
+                escaped = true;
+            } else if c == '"' {
+                in_str = false;
+            }
+            continue;
+        }
+        match c {
+            '"' => in_str = true,
+            '{' => depth += 1,
+            '}' => {
+                depth -= 1;
+                if depth == 0 {
+                    return serde_json::from_str(&raw[start..=i]).ok();
+                }
+            }
+            _ => {}
+        }
+    }
+    None
+}
+
+/// Collapse whitespace and strip stray markdown/quote decorations a model
+/// sometimes leaves around a line.
+fn clean_text(s: &str) -> String {
+    let trimmed = s.trim().trim_matches('"').trim();
+    trimmed.split_whitespace().collect::<Vec<_>>().join(" ")
+}
+
+/// Generate the reel script via the LLM. Text-only (no images) — the per-beat
+/// context comes from cached insights. The call takes the GPU read lease
+/// internally (see `LlamaCppClient::generate`).
+pub async fn generate_script(
+    client: &Arc<LlamaCppClient>,
+    meta: &ReelMeta,
+    beats: &[PlannedBeat],
+) -> Result<ReelScript> {
+    let (system, user) = build_script_messages(meta, beats);
+    let raw = client
+        .generate(&user, Some(&system), None)
+        .await
+        .context("LLM script generation failed")?;
+    Ok(parse_script_response(&raw, beats.len()))
+}
+
+/// Agentic version of script generation: resolves the backend via the
+/// InsightGenerator (honouring LLM_BACKEND, model overrides, etc.), builds
+/// a read-only tool set, runs the tool loop, then parses the JSON response.
+/// Returns the same ReelScript shape. On failure the caller may fall back to
+/// `generate_script`.
+pub async fn generate_script_agentic(
+    generator: &InsightGenerator,
+    meta: &ReelMeta,
+    beats: &[PlannedBeat],
+) -> Result<ReelScript> {
+    // 1. Resolve the backend. Bail if the local model lacks tool-calling.
+    let backend = generator
+        .resolve_backend(
+            BackendKind::Local,
+            &SamplingOverrides {
+                model: None,
+                num_ctx: None,
+                temperature: None,
+                top_p: None,
+                top_k: None,
+                min_p: None,
+            },
+        )
+        .await
+        .context("resolving backend for agentic script")?;
+
+    // 2. Build the read-only tool set. Start from the persona gate (no
+    //    persona context, so corrections are closed), force has_vision=false,
+    //    then filter out write tools.
+    let gate = generator.current_gate_opts_for_persona(false, None);
+    let all_tools = InsightGenerator::build_tool_definitions(gate);
+    // Whole-reel calls have no single photo and no authenticated user, so the
+    // loop runs execute_tool with empty file/image context and user_id=0. Only
+    // tools that work without that context are useful here — photo/user-bound
+    // tools (get_file_tags, get_faces_in_photo, recall_facts_for_photo,
+    // recall_facts_for_entity) would just no-op or error, burning iterations,
+    // so they're excluded.
+    let read_only_names: std::collections::HashSet<&str> = [
+        "search_rag",
+        "search_messages",
+        "get_sms_messages",
+        "get_calendar_events",
+        "get_location_history",
+        "reverse_geocode",
+        "get_personal_place_at",
+        "recall_entities",
+        "get_current_datetime",
+    ]
+    .into_iter()
+    .collect();
+    let tools: Vec<Tool> = all_tools
+        .into_iter()
+        .filter(|t| read_only_names.contains(t.function.name.as_str()))
+        .collect();
+
+    // 3. Build the agentic prompt messages.
+    let messages = build_agentic_script_messages(meta, beats);
+
+    // 4. Run the tool loop.
+    let max_iter = reel_pregen_max_tool_iters();
+    let raw = generator
+        .run_readonly_tool_loop(&backend, messages, tools, max_iter)
+        .await
+        .context("agentic tool loop failed")?;
+
+    // 5. Strip any think-blocks the model may have emitted, then parse.
+    let raw = crate::ai::llm_client::strip_think_blocks(&raw);
+    Ok(parse_script_response(&raw, beats.len()))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::memories::MemoriesSpan;
+
+    fn meta() -> ReelMeta {
+        ReelMeta {
+            span: MemoriesSpan::Day,
+            years: vec![2019, 2021],
+        }
+    }
+
+    fn planned(n: usize) -> Vec<PlannedBeat> {
+        (0..n)
+            .map(|i| PlannedBeat {
+                media: vec![super::super::SegmentMedia::Photo {
+                    rel_path: format!("p{i}.jpg"),
+                    library_id: 1,
+                }],
+                date: Some(1_560_000_000 + i as i64 * 86_400),
+                insight_title: None,
+                insight_summary: None,
+                gps: None,
+            })
+            .collect()
+    }
+
+    #[test]
+    fn prompt_states_exact_moment_count_and_span() {
+        let (sys, user) = build_script_messages(&meta(), &planned(3));
+        assert!(sys.contains("memory reel"));
+        assert!(user.contains("3 moments"));
+        assert!(user.contains("on this day"));
+        assert!(user.contains("exactly 3 items"));
+        // Each moment gets an indexed entry.
+        assert!(user.contains("[1]") && user.contains("[2]") && user.contains("[3]"));
+    }
+
+    #[test]
+    fn prompt_notes_burst_photo_count() {
+        let mut p = planned(1);
+        p[0].media = vec![
+            super::super::SegmentMedia::Photo {
+                rel_path: "a.jpg".into(),
+                library_id: 1,
+            },
+            super::super::SegmentMedia::Photo {
+                rel_path: "b.jpg".into(),
+                library_id: 1,
+            },
+            super::super::SegmentMedia::Photo {
+                rel_path: "c.jpg".into(),
+                library_id: 1,
+            },
+        ];
+        let (_sys, user) = build_script_messages(&meta(), &p);
+        assert!(user.contains("a burst of 3 photos"));
+    }
+
+    #[test]
+    fn prompt_marks_clip_beats() {
+        let mut p = planned(1);
+        p[0].media = vec![super::super::SegmentMedia::Clip {
+            rel_path: "v.mp4".into(),
+            library_id: 1,
+        }];
+        let (_sys, user) = build_script_messages(&meta(), &p);
+        assert!(user.contains("a video clip"));
+    }
+
+    #[test]
+    fn prompt_includes_insight_context_when_present() {
+        let mut p = planned(1);
+        p[0].insight_title = Some("Lake house weekend".into());
+        p[0].insight_summary = Some("Swimming with the dogs.".into());
+        let (_sys, user) = build_script_messages(&meta(), &p);
+        assert!(user.contains("Lake house weekend — Swimming with the dogs."));
+    }
+
+    #[test]
+    fn parse_plain_json_object() {
+        let raw = r#"{"title":"Summer Days","segments":["First line.","Second line."]}"#;
+        let script = parse_script_response(raw, 2);
+        assert_eq!(script.title, "Summer Days");
+        assert_eq!(script.lines, vec!["First line.", "Second line."]);
+    }
+
+    #[test]
+    fn parse_tolerates_code_fences_and_prose() {
+        let raw = "Sure! Here's your reel:\n```json\n{\"title\": \"Trip\", \"segments\": [\"A.\", \"B.\"]}\n```\nEnjoy!";
+        let script = parse_script_response(raw, 2);
+        assert_eq!(script.title, "Trip");
+        assert_eq!(script.lines, vec!["A.", "B."]);
+    }
+
+    #[test]
+    fn parse_accepts_object_segment_shape() {
+        let raw = r#"{"title":"T","segments":[{"narration":"One."},{"narration":"Two."}]}"#;
+        let script = parse_script_response(raw, 2);
+        assert_eq!(script.lines, vec!["One.", "Two."]);
+    }
+
+    #[test]
+    fn parse_pads_short_and_truncates_long_to_n() {
+        // Model returned 1 line but we have 3 segments → pad with neutral lines.
+        let short = parse_script_response(r#"{"title":"T","segments":["Only one."]}"#, 3);
+        assert_eq!(short.lines.len(), 3);
+        assert_eq!(short.lines[0], "Only one.");
+        assert!(!short.lines[1].is_empty());
+
+        // Model returned 3 but we have 2 → truncate.
+        let long = parse_script_response(r#"{"title":"T","segments":["a","b","c"]}"#, 2);
+        assert_eq!(long.lines, vec!["a", "b"]);
+    }
+
+    #[test]
+    fn parse_falls_back_on_garbage() {
+        let script = parse_script_response("the model said no", 2);
+        assert_eq!(script.title, "Memories");
+        assert_eq!(script.lines.len(), 2);
+        assert!(script.lines.iter().all(|l| !l.is_empty()));
+    }
+
+    #[test]
+    fn parse_blank_line_replaced_with_fallback() {
+        let script = parse_script_response(r#"{"title":"T","segments":["  ","Real."]}"#, 2);
+        assert!(!script.lines[0].is_empty());
+        assert_eq!(script.lines[1], "Real.");
+    }
+}

src/reels/selector.rs

@@ -0,0 +1,560 @@
+//! Reel selectors: resolve "what goes in the reel" into an ordered media set
+//! plus the metadata the scripter needs. The renderer and scripter are
+//! selector-agnostic, so adding tag- or date-range-based reels later means
+//! adding a variant here, not touching the pipeline.
+//!
+//! Resolution is split in two so the handler can compute a cache key (and
+//! short-circuit on a cache hit) without the per-photo insight lookups:
+//! [`resolve`] is the cheap media-set pass; [`enrich`] adds cached insights and
+//! runs in the background job.
+
+use std::path::Path;
+use std::sync::Mutex;
+
+use chrono::{DateTime, Datelike, FixedOffset};
+
+use super::{PlannedBeat, ReelMeta, SegmentMedia};
+use crate::database::{ExifDao, InsightDao};
+use crate::file_types::{is_image_file, is_video_file};
+use crate::memories::{self, MemoriesSpan};
+use crate::state::AppState;
+
+/// Default and hard caps on how many photos a reel covers. The default is an
+/// upper bound on the request; the effective count is usually smaller, set by
+/// the duration budget (see [`budget_segments`]). The hard cap bounds work per
+/// reel regardless.
+pub const DEFAULT_MAX_SEGMENTS: usize = 40;
+pub const HARD_MAX_SEGMENTS: usize = 40;
+
+/// Target reel length. Week and especially month spans can surface hundreds of
+/// photos; at a few seconds of narration each, a naive reel runs minutes. We
+/// cap the segment count to keep the reel near this length. Tunable via
+/// `REEL_TARGET_SECONDS`.
+const DEFAULT_TARGET_REEL_SECONDS: f64 = 90.0;
+
+/// Rough average wall-time per photo segment (a short narration line + the
+/// silent tail). Only used to turn the duration target into a segment count;
+/// the real per-segment time is the measured narration length.
+const EST_SECONDS_PER_SEGMENT: f64 = 5.0;
+
+/// Time gap that separates one "event/moment" from the next when clustering a
+/// span's photos. Photos within a few hours are treated as the same occasion
+/// (and across years/days the gaps are far larger, so each instance clusters
+/// on its own). 4 hours splits e.g. a morning hike from an evening dinner.
+const EVENT_GAP_SECONDS: i64 = 4 * 3600;
+
+fn target_reel_seconds() -> f64 {
+    std::env::var("REEL_TARGET_SECONDS")
+        .ok()
+        .and_then(|s| s.trim().parse::<f64>().ok())
+        .filter(|x| x.is_finite() && *x > 0.0)
+        .unwrap_or(DEFAULT_TARGET_REEL_SECONDS)
+}
+
+/// How many photo segments fit the duration budget, bounded by the request's
+/// max and the hard cap. This is what keeps week/month reels from running long.
+pub fn budget_segments(requested_max: usize) -> usize {
+    let by_budget = (target_reel_seconds() / EST_SECONDS_PER_SEGMENT).floor() as usize;
+    by_budget.min(requested_max).clamp(1, HARD_MAX_SEGMENTS)
+}
+
+/// What a reel is built from. v1 ships the memories (on this day/week/month)
+/// selector; tag and date-range variants slot in here later.
+#[derive(Debug, Clone)]
+pub enum ReelSelector {
+    Memories {
+        span: MemoriesSpan,
+        tz_offset_minutes: i32,
+        library: Option<String>,
+        max_segments: usize,
+    },
+}
+
+impl ReelSelector {
+    /// Stable string identity for the cache key. Captures everything that
+    /// changes *which* media is selected (but not the non-deterministic
+    /// narration, which can't be part of a pre-render key).
+    pub fn descriptor(&self) -> String {
+        match self {
+            ReelSelector::Memories {
+                span,
+                tz_offset_minutes,
+                library,
+                max_segments,
+            } => format!(
+                "memories:span={:?}:tz={}:lib={}:max={}",
+                span,
+                tz_offset_minutes,
+                library.as_deref().unwrap_or("all"),
+                max_segments
+            ),
+        }
+    }
+}
+
+/// Pick at most `max` items spread evenly across the input, always keeping the
+/// first and last. Returns the input unchanged when it already fits.
+pub fn sample_evenly<T: Clone>(items: &[T], max: usize) -> Vec<T> {
+    if max == 0 {
+        return Vec::new();
+    }
+    if items.len() <= max {
+        return items.to_vec();
+    }
+    if max == 1 {
+        return vec![items[0].clone()];
+    }
+    let last = items.len() - 1;
+    (0..max)
+        .map(|i| {
+            // Spread indices 0..=last across max picks, endpoints included.
+            let idx = (i * last + (max - 1) / 2) / (max - 1);
+            items[idx.min(last)].clone()
+        })
+        .collect()
+}
+
+/// Group time-sorted items into events by gap: a new event starts whenever the
+/// jump from the previous photo exceeds `gap_seconds`. Preserves order; items
+/// without a timestamp extend the current event.
+fn cluster_by_gap(
+    items: &[memories::MemoryItem],
+    gap_seconds: i64,
+) -> Vec<Vec<memories::MemoryItem>> {
+    let mut clusters: Vec<Vec<memories::MemoryItem>> = Vec::new();
+    let mut prev_ts: Option<i64> = None;
+    for it in items {
+        let starts_new = match (prev_ts, it.created) {
+            (Some(p), Some(c)) => c - p > gap_seconds,
+            _ => false,
+        };
+        if starts_new || clusters.is_empty() {
+            clusters.push(Vec::new());
+        }
+        clusters.last_mut().unwrap().push(it.clone());
+        if let Some(c) = it.created {
+            prev_ts = Some(c);
+        }
+    }
+    clusters
+}
+
+/// Most photos a single beat will flash through. Bounds the burst so one huge
+/// event doesn't dominate, and keeps each photo on screen long enough to
+/// register at the per-beat narration length (see render's beat timing).
+pub const MAX_BURST_PHOTOS: usize = 10;
+
+/// Merge a list of (time-ordered) event clusters into exactly `n` contiguous
+/// groups, so a span with more events than the beat budget still covers the
+/// whole timeline — adjacent events fold together into one beat rather than
+/// getting dropped. `n` must be ≥ 1 and ≤ clusters.len().
+fn partition_into_groups(
+    clusters: Vec<Vec<memories::MemoryItem>>,
+    n: usize,
+) -> Vec<Vec<memories::MemoryItem>> {
+    let c = clusters.len();
+    let mut clusters = clusters.into_iter();
+    (0..n)
+        .map(|j| {
+            // Even contiguous split of c clusters into n groups.
+            let start = j * c / n;
+            let end = (j + 1) * c / n;
+            let take = end.saturating_sub(start).max(1);
+            (0..take)
+                .flat_map(|_| clusters.next().into_iter().flatten())
+                .collect()
+        })
+        .collect()
+}
+
+/// Turn photo items into `n_beats` photo beats. Clusters photos into events by
+/// time gap; if there are more events than beats, adjacent events are merged so
+/// the whole span is still covered. Each beat then flashes up to `max_burst`
+/// photos (an even spread of its group) under one narration line — so a
+/// week/month reel *shows* all its moments without a narrated (and timed)
+/// segment per photo.
+fn form_photo_beats(
+    items: &[memories::MemoryItem],
+    n_beats: usize,
+    max_burst: usize,
+) -> Vec<PlannedBeat> {
+    if n_beats == 0 || items.is_empty() {
+        return Vec::new();
+    }
+    let clusters = cluster_by_gap(items, EVENT_GAP_SECONDS);
+    // One beat per event when they fit; otherwise fold adjacent events together
+    // into exactly n_beats groups.
+    let groups = if clusters.len() <= n_beats {
+        clusters
+    } else {
+        partition_into_groups(clusters, n_beats)
+    };
+
+    groups
+        .into_iter()
+        .filter(|g| !g.is_empty())
+        .map(|group| {
+            let shown = sample_evenly(&group, max_burst);
+            let date = shown.first().and_then(|it| it.created);
+            PlannedBeat {
+                media: shown
+                    .into_iter()
+                    .map(|it| SegmentMedia::Photo {
+                        rel_path: it.path,
+                        library_id: it.library_id,
+                    })
+                    .collect(),
+                date,
+                insight_title: None,
+                insight_summary: None,
+                gps: None,
+            }
+        })
+        .collect()
+}
+
+/// Split the beat budget between photo beats and video-clip beats. Clips are
+/// individually valuable (motion + live audio) so they get up to half the
+/// budget (at least one if any exist); photos take the rest. With only one
+/// kind present, it gets the whole budget.
+fn split_beat_budget(n_photos: usize, n_videos: usize, n_beats: usize) -> (usize, usize) {
+    if n_videos == 0 {
+        return (n_beats, 0);
+    }
+    if n_photos == 0 {
+        return (0, n_beats.min(n_videos));
+    }
+    let clip_beats = n_videos.min((n_beats / 2).max(1));
+    let photo_beats = n_beats.saturating_sub(clip_beats);
+    (photo_beats, clip_beats)
+}
+
+/// Build the reel's beats from a span's photos and videos under a beat budget.
+/// Videos become one-clip beats (sampled across time if there are more than the
+/// clip budget); photos cluster into burst beats. The two are merged back into
+/// chronological order so the reel reads as the span unfolded.
+pub fn form_beats(
+    photos: &[memories::MemoryItem],
+    videos: &[memories::MemoryItem],
+    n_beats: usize,
+    max_burst: usize,
+) -> Vec<PlannedBeat> {
+    if n_beats == 0 {
+        return Vec::new();
+    }
+    let (photo_budget, clip_budget) = split_beat_budget(photos.len(), videos.len(), n_beats);
+
+    let mut beats = form_photo_beats(photos, photo_budget, max_burst);
+
+    // One clip beat per chosen video, spread across the span's videos.
+    for v in sample_evenly(videos, clip_budget) {
+        beats.push(PlannedBeat {
+            media: vec![SegmentMedia::Clip {
+                rel_path: v.path,
+                library_id: v.library_id,
+            }],
+            date: v.created,
+            insight_title: None,
+            insight_summary: None,
+            gps: None,
+        });
+    }
+
+    // Merge photo and clip beats back into chronological order (undated last).
+    beats.sort_by(|a, b| match (a.date, b.date) {
+        (Some(x), Some(y)) => x.cmp(&y),
+        (Some(_), None) => std::cmp::Ordering::Less,
+        (None, Some(_)) => std::cmp::Ordering::Greater,
+        (None, None) => std::cmp::Ordering::Equal,
+    });
+    beats
+}
+
+/// Cheap pass: resolve the selector into an ordered list of media (no insight
+/// lookups yet) plus reel metadata. `Err` only on an invalid library param.
+pub fn resolve(
+    app_state: &AppState,
+    exif_dao: &Mutex<Box<dyn ExifDao>>,
+    span_context: &opentelemetry::Context,
+    selector: &ReelSelector,
+) -> Result<(Vec<PlannedBeat>, ReelMeta), String> {
+    match selector {
+        ReelSelector::Memories {
+            span,
+            tz_offset_minutes,
+            library,
+            max_segments,
+        } => {
+            let client_tz = FixedOffset::east_opt(tz_offset_minutes * 60);
+            let items = memories::gather_memory_items(
+                app_state,
+                exif_dao,
+                span_context,
+                *span,
+                *tz_offset_minutes,
+                client_tz,
+                library.as_deref(),
+            )?;
+
+            // Split into photos and video clips; anything that's neither is
+            // dropped. Years span both, computed before the budget narrows it.
+            let years = distinct_years(&items, client_tz);
+            let meta = ReelMeta { span: *span, years };
+
+            let (photos, videos): (Vec<_>, Vec<_>) = items
+                .into_iter()
+                .filter(|it| {
+                    is_image_file(Path::new(&it.path)) || is_video_file(Path::new(&it.path))
+                })
+                .partition(|it| is_image_file(Path::new(&it.path)));
+
+            // The budget caps the number of narrated beats (≈ reel length);
+            // photo beats then burst through several photos and video beats
+            // play a short clip, so the reel covers the span without running
+            // minutes long.
+            let n_beats = budget_segments(*max_segments);
+            let beats = form_beats(&photos, &videos, n_beats, MAX_BURST_PHOTOS);
+            Ok((beats, meta))
+        }
+    }
+}
+
+/// Distinct calendar years represented by the selected media, in the client's
+/// timezone, ascending. Used to tell the scripter how far back the reel reaches.
+fn distinct_years(items: &[memories::MemoryItem], tz: Option<FixedOffset>) -> Vec<i32> {
+    let mut years: Vec<i32> = items
+        .iter()
+        .filter_map(|it| it.created)
+        .filter_map(|ts| DateTime::from_timestamp(ts, 0))
+        .map(|dt| match tz {
+            Some(off) => dt.with_timezone(&off).year(),
+            None => dt.year(),
+        })
+        .collect();
+    years.sort_unstable();
+    years.dedup();
+    years
+}
+
+/// Background pass: fill each beat's cached insight (title + summary) and
+/// GPS coordinates from its lead photo, where one exists. Best-effort — a
+/// missing or errored lookup leaves the fields `None` and the scripter
+/// narrates from the date alone.
+pub fn enrich(
+    insight_dao: &Mutex<Box<dyn InsightDao>>,
+    exif_dao: &Mutex<Box<dyn ExifDao>>,
+    span_context: &opentelemetry::Context,
+    beats: &mut [PlannedBeat],
+) {
+    let Ok(mut insight_dao) = insight_dao.lock() else {
+        return;
+    };
+    let Ok(mut exif_dao) = exif_dao.lock() else {
+        return;
+    };
+    for beat in beats.iter_mut() {
+        let rel_path = match beat.media.first() {
+            Some(SegmentMedia::Photo { rel_path, .. } | SegmentMedia::Clip { rel_path, .. }) => {
+                rel_path.clone()
+            }
+            None => continue,
+        };
+        if let Ok(Some(insight)) = insight_dao.get_insight(span_context, &rel_path) {
+            beat.insight_title = Some(insight.title);
+            beat.insight_summary = Some(insight.summary);
+        }
+        // Enrich GPS from EXIF when the lead media is a photo.
+        if let Some(SegmentMedia::Photo { .. }) = beat.media.first()
+            && let Ok(Some(exif)) = exif_dao.get_exif(span_context, &rel_path)
+            && let (Some(lat), Some(lon)) = (exif.gps_latitude, exif.gps_longitude)
+        {
+            beat.gps = Some((lat as f64, lon as f64));
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn sample_evenly_returns_all_when_under_cap() {
+        let v = vec![1, 2, 3];
+        assert_eq!(sample_evenly(&v, 5), vec![1, 2, 3]);
+        assert_eq!(sample_evenly(&v, 3), vec![1, 2, 3]);
+    }
+
+    #[test]
+    fn sample_evenly_keeps_endpoints_and_spreads() {
+        let v: Vec<i32> = (0..100).collect();
+        let picked = sample_evenly(&v, 5);
+        assert_eq!(picked.len(), 5);
+        assert_eq!(picked[0], 0); // first kept
+        assert_eq!(*picked.last().unwrap(), 99); // last kept
+        // Strictly increasing, no dupes.
+        assert!(picked.windows(2).all(|w| w[0] < w[1]));
+    }
+
+    #[test]
+    fn sample_evenly_handles_one_and_zero() {
+        let v: Vec<i32> = (0..10).collect();
+        assert_eq!(sample_evenly(&v, 1), vec![0]);
+        assert!(sample_evenly(&v, 0).is_empty());
+    }
+
+    #[test]
+    fn descriptor_is_stable_and_distinguishes_inputs() {
+        let a = ReelSelector::Memories {
+            span: MemoriesSpan::Day,
+            tz_offset_minutes: -480,
+            library: None,
+            max_segments: 24,
+        };
+        let b = ReelSelector::Memories {
+            span: MemoriesSpan::Week,
+            tz_offset_minutes: -480,
+            library: None,
+            max_segments: 24,
+        };
+        assert_eq!(a.descriptor(), a.clone().descriptor());
+        assert_ne!(a.descriptor(), b.descriptor());
+        assert!(a.descriptor().contains("lib=all"));
+    }
+
+    #[test]
+    fn distinct_years_dedupes_and_sorts() {
+        let items = vec![
+            memories::MemoryItem {
+                path: "a".into(),
+                created: Some(1_560_000_000), // 2019
+                modified: None,
+                library_id: 1,
+            },
+            memories::MemoryItem {
+                path: "b".into(),
+                created: Some(1_560_086_400), // 2019
+                modified: None,
+                library_id: 1,
+            },
+            memories::MemoryItem {
+                path: "c".into(),
+                created: Some(1_623_000_000), // 2021
+                modified: None,
+                library_id: 1,
+            },
+        ];
+        assert_eq!(distinct_years(&items, None), vec![2019, 2021]);
+    }
+
+    // Build an item at a given unix timestamp (seconds) with a chosen extension.
+    fn item_ext(ts: i64, name: &str, ext: &str) -> memories::MemoryItem {
+        memories::MemoryItem {
+            path: format!("{name}.{ext}"),
+            created: Some(ts),
+            modified: None,
+            library_id: 1,
+        }
+    }
+    fn item_at(ts: i64, name: &str) -> memories::MemoryItem {
+        item_ext(ts, name, "jpg")
+    }
+
+    #[test]
+    fn budget_segments_caps_to_duration_target() {
+        // 90s / 5s ≈ 18, bounded by the request max and hard cap.
+        assert_eq!(budget_segments(40), 18);
+        assert_eq!(budget_segments(5), 5); // request asked for fewer
+        assert_eq!(budget_segments(1000), 18); // hard cap / budget wins
+    }
+
+    #[test]
+    fn cluster_by_gap_splits_on_large_jumps() {
+        // Two photos minutes apart, then one a day later → two events.
+        let items = vec![
+            item_at(1_000_000, "a"),
+            item_at(1_000_300, "b"), // +5 min → same event
+            item_at(1_100_000, "c"), // +~27h → new event
+        ];
+        let clusters = cluster_by_gap(&items, EVENT_GAP_SECONDS);
+        assert_eq!(clusters.len(), 2);
+        assert_eq!(clusters[0].len(), 2);
+        assert_eq!(clusters[1].len(), 1);
+    }
+
+    #[test]
+    fn photo_beats_one_per_event_when_they_fit() {
+        // Three well-separated events, budget of 10 → three beats, each holding
+        // all of its (few) photos.
+        let items = vec![
+            item_at(0, "a"),
+            item_at(50, "b"), // same event as a
+            item_at(1_000_000, "c"),
+            item_at(2_000_000, "d"),
+        ];
+        let beats = form_photo_beats(&items, 10, MAX_BURST_PHOTOS);
+        assert_eq!(beats.len(), 3);
+        assert_eq!(beats[0].media.len(), 2); // burst of the first event
+        assert_eq!(beats[1].media.len(), 1);
+        assert_eq!(beats[2].media.len(), 1);
+    }
+
+    #[test]
+    fn photo_beats_merge_events_when_over_budget() {
+        // Six distinct events but only two beats → adjacent events fold in, and
+        // every event's photos still appear (capped by the burst max).
+        let items: Vec<memories::MemoryItem> = (0..6)
+            .map(|i| item_at(i as i64 * 1_000_000, &format!("e{i}")))
+            .collect();
+        let beats = form_photo_beats(&items, 2, MAX_BURST_PHOTOS);
+        assert_eq!(beats.len(), 2);
+        let shown: usize = beats.iter().map(|b| b.media.len()).sum();
+        assert_eq!(shown, 6); // all six moments still shown across two beats
+    }
+
+    #[test]
+    fn photo_beats_cap_burst_to_max() {
+        // One dense event of 30 photos, generous budget → a single beat that
+        // bursts at most MAX_BURST_PHOTOS, not all 30.
+        let items: Vec<memories::MemoryItem> = (0..30)
+            .map(|i| item_at(i as i64, &format!("p{i}")))
+            .collect();
+        let beats = form_photo_beats(&items, 18, MAX_BURST_PHOTOS);
+        assert_eq!(beats.len(), 1);
+        assert_eq!(beats[0].media.len(), MAX_BURST_PHOTOS);
+    }
+
+    #[test]
+    fn split_beat_budget_handles_each_mix() {
+        // Only photos / only videos → that kind gets the whole budget.
+        assert_eq!(split_beat_budget(10, 0, 18), (18, 0));
+        assert_eq!(split_beat_budget(0, 10, 18), (0, 10)); // capped at n_videos
+        assert_eq!(split_beat_budget(0, 30, 18), (0, 18)); // capped at budget
+        // Mixed → clips up to half (≥1), photos the rest.
+        assert_eq!(split_beat_budget(100, 100, 18), (9, 9));
+        assert_eq!(split_beat_budget(100, 1, 18), (17, 1)); // few videos
+    }
+
+    #[test]
+    fn form_beats_mixes_clip_and_photo_beats_in_time_order() {
+        let photos = vec![item_at(0, "p0"), item_at(2_000_000, "p1")];
+        // A video between the two photo events (in time).
+        let videos = vec![item_ext(1_000_000, "v0", "mp4")];
+        let beats = form_beats(&photos, &videos, 10, MAX_BURST_PHOTOS);
+        // Two photo events + one clip = three beats, chronological.
+        assert_eq!(beats.len(), 3);
+        assert!(!beats[0].is_clip()); // p0 @ t=0
+        assert!(beats[1].is_clip()); // v0 @ t=1e6
+        assert!(!beats[2].is_clip()); // p1 @ t=2e6
+        assert!(matches!(beats[1].media[0], SegmentMedia::Clip { .. }));
+    }
+
+    #[test]
+    fn form_beats_videos_only_become_clip_beats() {
+        let videos: Vec<memories::MemoryItem> = (0..3)
+            .map(|i| item_ext(i as i64 * 1_000_000, &format!("v{i}"), "mov"))
+            .collect();
+        let beats = form_beats(&[], &videos, 10, MAX_BURST_PHOTOS);
+        assert_eq!(beats.len(), 3);
+        assert!(beats.iter().all(|b| b.is_clip()));
+    }
+}

src/state.rs

@@ -8,9 +8,10 @@ use crate::ai::turn_registry::TurnRegistry;
 use crate::ai::{InsightGenerator, OllamaClient, SmsApiClient};
 use crate::database::{
     CalendarEventDao, DailySummaryDao, ExifDao, InsightDao, InsightGenerationJobDao, KnowledgeDao,
-    LocationHistoryDao, SearchHistoryDao, SqliteCalendarEventDao, SqliteDailySummaryDao,
+    LocationHistoryDao, PrecomputedReelDao, SearchHistoryDao, SqliteCalendarEventDao,
-    SqliteExifDao, SqliteInsightDao, SqliteInsightGenerationJobDao, SqliteKnowledgeDao,
+    SqliteDailySummaryDao, SqliteExifDao, SqliteInsightDao, SqliteInsightGenerationJobDao,
-    SqliteLocationHistoryDao, SqliteSearchHistoryDao, connect,
+    SqliteKnowledgeDao, SqliteLocationHistoryDao, SqlitePrecomputedReelDao, SqliteSearchHistoryDao,
+    SqliteUserAiPrefsDao, UserAiPrefsDao, connect,
 };
 use crate::database::{PreviewDao, SqlitePreviewDao};
 use crate::faces;
@@ -53,6 +54,10 @@ pub struct AppState {
     pub video_path: String,
     pub gif_path: String,
     pub preview_clips_path: String,
+    /// Directory for cached memory-reel MP4s (+ title sidecars). Derived from
+    /// `REELS_DIRECTORY`, defaulting to a `reels` dir beside the preview clips.
+    /// Created lazily by the reel pipeline on first render.
+    pub reels_path: String,
     pub excluded_dirs: Vec<String>,
     pub ollama: OllamaClient,
     /// `None` when `OPENROUTER_API_KEY` is not configured. Consulted only
@@ -84,6 +89,14 @@ pub struct AppState {
     pub clip_client: ClipClient,
     pub insight_job_dao: Arc<Mutex<Box<dyn InsightGenerationJobDao>>>,
     pub insight_job_handles: Arc<Mutex<HashMap<i32, tokio::task::AbortHandle>>>,
+    /// Ledger for precomputed memory reels. Written by the nightly agentic
+    /// job (Section D); read by `GET /reels/precomputed` (Section C).
+    #[allow(dead_code)]
+    pub precomputed_reel_dao: Arc<Mutex<Box<dyn PrecomputedReelDao>>>,
+    /// User AI preferences (voice, timezone, library). Mirrored by the
+    /// client; read by the nightly pre-generation scheduler.
+    #[allow(dead_code)]
+    pub user_ai_prefs_dao: Arc<Mutex<Box<dyn UserAiPrefsDao>>>,
 }
 
 impl AppState {
@@ -97,6 +110,7 @@ impl AppState {
         self.libraries.iter().find(|l| l.id == id)
     }
 
+    #[allow(dead_code)]
     pub fn library_by_name(&self, name: &str) -> Option<&Library> {
         self.libraries.iter().find(|l| l.name == name)
     }
@@ -125,6 +139,8 @@ impl AppState {
         clip_client: ClipClient,
         insight_job_dao: Arc<Mutex<Box<dyn InsightGenerationJobDao>>>,
         insight_job_handles: Arc<Mutex<HashMap<i32, tokio::task::AbortHandle>>>,
+        precomputed_reel_dao: Arc<Mutex<Box<dyn PrecomputedReelDao>>>,
+        user_ai_prefs_dao: Arc<Mutex<Box<dyn UserAiPrefsDao>>>,
     ) -> Self {
         assert!(
             !libraries_vec.is_empty(),
@@ -141,6 +157,19 @@ impl AppState {
             preview_dao,
         );
 
+        // Reels cache dir: explicit env, else a `reels` sibling of the preview
+        // clips dir (a known-writable, test-safe location). Not created here —
+        // the reel pipeline does `create_dir_all` before its first write, so
+        // construction (incl. tests) never touches the filesystem.
+        let reels_path = std::env::var("REELS_DIRECTORY").unwrap_or_else(|_| {
+            std::path::Path::new(&preview_clips_path)
+                .parent()
+                .map(|p| p.join("reels"))
+                .unwrap_or_else(|| std::path::PathBuf::from("reels"))
+                .to_string_lossy()
+                .to_string()
+        });
+
         let library_health = libraries::new_health_map(&libraries_vec);
         let live_libraries = Arc::new(RwLock::new(libraries_vec.clone()));
         Self {
@@ -155,6 +184,7 @@ impl AppState {
             video_path,
             gif_path,
             preview_clips_path,
+            reels_path,
             excluded_dirs,
             ollama,
             openrouter,
@@ -169,6 +199,8 @@ impl AppState {
             clip_client,
             insight_job_dao,
             insight_job_handles,
+            precomputed_reel_dao,
+            user_ai_prefs_dao,
         }
     }
 
@@ -249,6 +281,14 @@ impl Default for AppState {
         let insight_job_handles: Arc<Mutex<HashMap<i32, tokio::task::AbortHandle>>> =
             Arc::new(Mutex::new(HashMap::new()));
 
+        // Initialize precomputed reel DAO (nightly pre-generation ledger)
+        let precomputed_reel_dao: Arc<Mutex<Box<dyn PrecomputedReelDao>>> =
+            Arc::new(Mutex::new(Box::new(SqlitePrecomputedReelDao::new())));
+
+        // Initialize user AI preferences DAO (Section E)
+        let user_ai_prefs_dao: Arc<Mutex<Box<dyn UserAiPrefsDao>>> =
+            Arc::new(Mutex::new(Box::new(SqliteUserAiPrefsDao::new())));
+
         // Load base path and ensure the primary library row reflects it.
         let base_path = env::var("BASE_PATH").expect("BASE_PATH was not set in the env");
         let mut seed_conn = connect();
@@ -326,6 +366,8 @@ impl Default for AppState {
             clip_client,
             insight_job_dao,
             insight_job_handles,
+            precomputed_reel_dao,
+            user_ai_prefs_dao,
         )
     }
 }
@@ -535,6 +577,8 @@ impl AppState {
             ClipClient::new(None), // disabled in test
             Arc::new(Mutex::new(Box::new(SqliteInsightGenerationJobDao::new()))), // placeholder for test
             Arc::new(Mutex::new(HashMap::new())), // placeholder for test
+            Arc::new(Mutex::new(Box::new(SqlitePrecomputedReelDao::new()))), // placeholder for test
+            Arc::new(Mutex::new(Box::new(SqliteUserAiPrefsDao::new()))), // placeholder for test
         )
     }
 }

src/tags.rs

@@ -168,7 +168,7 @@ async fn get_tags<D: TagDao>(
     // this file, so tags added under one library show up under the
     // others when they hold the same file. Falls back to direct rel_path
     // match when the file hasn't been hashed yet.
-    let library = libraries::resolve_library_param(&app_state, request.library.as_deref())
+    let library = libraries::resolve_library_param_state(&app_state, request.library.as_deref())
         .ok()
         .flatten()
         .unwrap_or_else(|| app_state.primary_library());

src/video/ffmpeg.rs

@@ -231,7 +231,7 @@ impl Ffmpeg {
 /// a hard failure — previously the `parse::<f64>` on empty stdout produced
 /// "cannot parse float from empty string" and poisoned the preview-clip row
 /// with status=failed, which the watcher would re-queue every full scan.
-async fn get_duration_seconds(input_file: &str) -> Result<Option<f64>> {
+pub async fn get_duration_seconds(input_file: &str) -> Result<Option<f64>> {
     if let Some(d) = probe_duration(input_file, "format=duration").await? {
         return Ok(Some(d));
     }