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+# GRASP-02: Proactive Sync v3 - Event-Driven Design
+
+## Overview
+
+This document presents v3 of the proactive sync design. Key principles:
+
+1. **Self-subscription as the only mechanism** - No database initialization at startup
+2. **Batch-based pending tracking** - Each batch confirms independently
+3. **Single action type** - AddFilters only, auto-spawn connections
+4. **Three-way state model** - RepoSyncIndex (want) → PendingSyncIndex (in-flight) → RelaySyncIndex (confirmed)
+
+---
+
+## Data Model
+
+### RepoSyncIndex (Source of Truth)
+
+```rust
+/// What we WANT to sync - derived from events received via self-subscription.
+/// Updated immediately when self-subscriber batch fires.
+/// Key: repo addressable ref ("30617:pubkey:identifier")
+pub type RepoSyncIndex = Arc<RwLock<HashMap<String, RepoSyncNeeds>>>;
+
+#[derive(Debug, Clone, Default)]
+pub struct RepoSyncNeeds {
+    /// Relay URLs listed in this repo's 30617 announcement
+    pub relays: HashSet<String>,
+    /// Root event IDs (1617/1618/1619/1621) that reference this repo
+    pub root_events: HashSet<EventId>,
+}
+```
+
+### RelaySyncIndex (Confirmed State + Connection)
+
+```rust
+/// What we've CONFIRMED syncing - includes connection state for integrated lifecycle.
+/// Key: relay URL
+pub type RelaySyncIndex = Arc<RwLock<HashMap<String, RelayState>>>;
+
+/// Connection status for a relay
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ConnectionStatus {
+    /// Not currently connected
+    Disconnected,
+    /// Connection attempt in progress
+    Connecting,
+    /// Successfully connected and subscribed
+    Connected,
+}
+
+/// Complete state for a single relay - combines sync needs with connection lifecycle
+#[derive(Debug)]
+pub struct RelayState {
+    /// Repos we've confirmed syncing from this relay
+    pub repos: HashSet<String>,
+    /// Root events we've confirmed tracking
+    pub root_events: HashSet<EventId>,
+    /// If true, never disconnect this relay
+    pub is_bootstrap: bool,
+    /// Current connection status
+    pub connection_status: ConnectionStatus,
+    /// When we last successfully connected (for since filter on reconnect)
+    pub last_connected: Option<Timestamp>,
+    /// When we disconnected (for 15-minute state retention rule)
+    pub disconnected_at: Option<Timestamp>,
+    /// The active connection (None if disconnected)
+    pub connection: Option<RelayConnection>,
+}
+
+impl RelayState {
+    /// Check if state should be cleared based on 15-minute rule
+    pub fn should_clear_state(&self) -> bool {
+        match self.disconnected_at {
+            Some(disconnected) => {
+                let now = Timestamp::now();
+                now.as_u64().saturating_sub(disconnected.as_u64()) > 900 // 15 minutes
+            }
+            None => false, // Still connected or never connected
+        }
+    }
+    
+    /// Clear repos and root_events (called when reconnect takes > 15 minutes)
+    pub fn clear_sync_state(&mut self) {
+        self.repos.clear();
+        self.root_events.clear();
+    }
+}
+```
+
+### PendingSyncIndex (In-Flight Batches)
+
+```rust
+/// Tracks batches of subscriptions that are in-flight, awaiting EOSE.
+/// Each batch has its own ID and can confirm independently.
+/// Key: relay URL
+pub type PendingSyncIndex = Arc<RwLock<HashMap<String, Vec<PendingBatch>>>>;
+
+#[derive(Debug, Clone)]
+pub struct PendingBatch {
+    /// Unique ID for this batch (for debugging/logging)
+    pub batch_id: u64,
+    /// The items this batch is syncing
+    pub items: PendingItems,
+    /// Subscription IDs that must ALL receive EOSE before confirming
+    pub outstanding_subs: HashSet<SubscriptionId>,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct PendingItems {
+    pub repos: HashSet<String>,
+    pub root_events: HashSet<EventId>,
+}
+```
+
+---
+
+## State Flow
+
+```mermaid
+flowchart TB
+    subgraph Input
+        SS[SelfSubscriber]
+        OWN[Own Relay]
+    end
+    
+    subgraph RepoSyncIndex - Want
+        RSI[HashMap of Repo to Relays+Events]
+    end
+    
+    subgraph Derived Target
+        DT[derive_relay_targets fn]
+        TGT[Per-relay: repos + events we should sync]
+    end
+    
+    subgraph PendingSyncIndex - In Flight
+        PSI[Vec of PendingBatch per relay]
+    end
+    
+    subgraph RelaySyncIndex - State + Connection
+        RLI[RelayState per relay]
+        CONN[connection: Option of RelayConnection]
+        STATUS[connection_status: Connected/Disconnected/Connecting]
+        REPOS[repos + root_events]
+    end
+    
+    SS -->|subscribe| OWN
+    OWN -->|events| SS
+    SS -->|batch fires| RSI
+    RSI --> DT
+    DT --> TGT
+    TGT -->|diff: target - pending - confirmed| DIFF[Compute new items]
+    PSI --> DIFF
+    RLI --> DIFF
+    DIFF -->|skip if disconnected| CHECK{Connected?}
+    CHECK -->|yes| AF[AddFilters]
+    CHECK -->|no| QUEUE[Queued in RelayState.repos]
+    AF -->|subscribe| CONN
+    AF -->|create batch| PSI
+    CONN -->|EOSE| PSI
+    PSI -->|batch complete| REPOS
+    CONN -->|disconnect event| DISC[Mark Disconnected + set disconnected_at]
+    DISC -->|reconnect| RECONN[On Reconnect]
+    RECONN -->|check 15min rule| RULE{disconnected > 15min?}
+    RULE -->|yes| CLEAR[Clear repos/root_events]
+    RULE -->|no| RETAIN[Keep retained state]
+    CLEAR --> REGEN[Regenerate AddFilters from RepoSyncIndex]
+    RETAIN --> RESUB[Resubscribe with since filter]
+```
+
+### Connection Lifecycle Integration
+
+The `RelayState` struct now owns both the connection and sync state:
+
+```rust
+// On disconnect (detected via RelayPoolNotification::Shutdown or handle_notifications returning)
+fn handle_disconnect(&mut self, relay_url: &str) {
+    if let Some(state) = self.relay_sync_index.write().await.get_mut(relay_url) {
+        state.connection_status = ConnectionStatus::Disconnected;
+        state.disconnected_at = Some(Timestamp::now());
+        state.connection = None;
+        
+        // Clear any pending batches for this relay
+        self.pending_sync_index.write().await.remove(relay_url);
+    }
+}
+
+// On reconnect
+async fn handle_reconnect(&mut self, relay_url: &str) -> Result<(), Error> {
+    let mut index = self.relay_sync_index.write().await;
+    let state = index.get_mut(relay_url).ok_or("Relay not in index")?;
+    
+    // Apply 15-minute state retention rule
+    if state.should_clear_state() {
+        tracing::info!("Reconnect after >15min for {}, clearing state", relay_url);
+        state.clear_sync_state();
+    }
+    
+    // Create new connection
+    state.connection_status = ConnectionStatus::Connecting;
+    let connection = RelayConnection::new(relay_url.to_string());
+    
+    // Connect with since filter if we have last_connected
+    let since = state.last_connected.map(|ts| {
+        Timestamp::from(ts.as_u64().saturating_sub(900)) // -15 min buffer
+    });
+    
+    connection.connect_and_subscribe_with_since(since).await?;
+    
+    state.connection = Some(connection);
+    state.connection_status = ConnectionStatus::Connected;
+    state.last_connected = Some(Timestamp::now());
+    state.disconnected_at = None;
+    
+    drop(index); // Release lock
+    
+    // Regenerate AddFilters from current state (either retained or fresh from RepoSyncIndex)
+    self.regenerate_filters_for_relay(relay_url).await;
+    
+    Ok(())
+}
+
+/// Regenerate AddFilters for a relay after reconnection
+async fn regenerate_filters_for_relay(&mut self, relay_url: &str) {
+    let repo_index = self.repo_sync_index.read().await;
+    let targets = derive_relay_targets(&repo_index);
+    
+    if let Some(target) = targets.get(relay_url) {
+        // Build filters for everything this relay should sync
+        let filters = build_filters(&target.repos, &target.root_events);
+        
+        // Create and process AddFilters action
+        let action = AddFilters {
+            relay_url: relay_url.to_string(),
+            repos: target.repos.clone(),
+            root_events: target.root_events.clone(),
+            filters,
+        };
+        
+        self.handle_add_filters(action).await;
+    }
+}
+```
+
+---
+
+## Action Type
+
+```rust
+/// Action sent from SelfSubscriber to SyncManager.
+/// SyncManager auto-spawns relay connections if they don't exist.
+pub struct AddFilters {
+    pub relay_url: String,
+    /// Items this action covers (for pending tracking)
+    pub repos: HashSet<String>,
+    pub root_events: HashSet<EventId>,
+    /// Pre-batched filters (each with <= 100 tags)
+    pub filters: Vec<Filter>,
+}
+```
+
+---
+
+## Core Algorithms
+
+### 1. derive_relay_targets
+
+Transform RepoSyncIndex into per-relay sync targets:
+
+```rust
+fn derive_relay_targets(
+    repo_index: &HashMap<String, RepoSyncNeeds>
+) -> HashMap<String, RelaySyncNeeds> {
+    let mut targets: HashMap<String, RelaySyncNeeds> = HashMap::new();
+    
+    for (repo_ref, needs) in repo_index {
+        for relay_url in &needs.relays {
+            let target = targets.entry(relay_url.clone()).or_default();
+            target.repos.insert(repo_ref.clone());
+            target.root_events.extend(needs.root_events.iter().cloned());
+        }
+    }
+    
+    targets
+}
+```
+
+### 2. compute_actions (Three-Way Diff)
+
+```rust
+fn compute_actions(
+    targets: &HashMap<String, RelaySyncNeeds>,
+    pending: &HashMap<String, Vec<PendingBatch>>,
+    confirmed: &HashMap<String, RelayState>,
+) -> Vec<AddFilters> {
+    let mut actions = Vec::new();
+    
+    for (relay_url, target) in targets {
+        // Skip disconnected relays - they'll get AddFilters on reconnect
+        if let Some(state) = confirmed.get(relay_url) {
+            if state.connection_status != ConnectionStatus::Connected {
+                continue;
+            }
+        }
+        
+        // Collect all pending items for this relay
+        let pending_repos: HashSet<_> = pending.get(relay_url)
+            .map(|batches| batches.iter()
+                .flat_map(|b| b.items.repos.iter().cloned())
+                .collect())
+            .unwrap_or_default();
+        let pending_events: HashSet<_> = pending.get(relay_url)
+            .map(|batches| batches.iter()
+                .flat_map(|b| b.items.root_events.iter().cloned())
+                .collect())
+            .unwrap_or_default();
+        
+        // Collect confirmed items for this relay
+        let confirmed_repos = confirmed.get(relay_url)
+            .map(|c| &c.repos)
+            .unwrap_or(&HashSet::new());
+        let confirmed_events = confirmed.get(relay_url)
+            .map(|c| &c.root_events)
+            .unwrap_or(&HashSet::new());
+        
+        // New = target - pending - confirmed
+        let new_repos: HashSet<_> = target.repos.iter()
+            .filter(|r| !pending_repos.contains(*r) && !confirmed_repos.contains(*r))
+            .cloned()
+            .collect();
+        let new_events: HashSet<_> = target.root_events.iter()
+            .filter(|e| !pending_events.contains(*e) && !confirmed_events.contains(*e))
+            .cloned()
+            .collect();
+        
+        if !new_repos.is_empty() || !new_events.is_empty() {
+            let filters = build_filters(&new_repos, &new_events);
+            actions.push(AddFilters {
+                relay_url: relay_url.clone(),
+                repos: new_repos,
+                root_events: new_events,
+                filters,
+            });
+        }
+    }
+    
+    actions
+}
+```
+
+### 3. handle_add_filters (SyncManager)
+
+```rust
+impl SyncManager {
+    async fn handle_add_filters(&mut self, action: AddFilters) {
+        let AddFilters { relay_url, repos, root_events, filters } = action;
+        
+        // Auto-spawn connection if needed
+        if !self.connections.contains_key(&relay_url) {
+            self.spawn_connection(&relay_url).await;
+        }
+        
+        let conn = self.connections.get(&relay_url).unwrap();
+        
+        // Subscribe and collect subscription IDs
+        // nostr-sdk 0.44: subscribe returns Output<Vec<SubscriptionId>>
+        // since we're only subscribed to one relay per connection
+        let mut sub_ids = HashSet::new();
+        for filter in filters {
+            // cloned filter for each subscription call
+            match conn.client.subscribe(filter, None).await {
+                Ok(output) => {
+                    // Output contains subscription IDs for each relay
+                    for sub_id in output.val {
+                        sub_ids.insert(sub_id);
+                    }
+                }
+                Err(e) => {
+                    tracing::warn!("Failed to subscribe: {}", e);
+                }
+            }
+        }
+        
+        // Create pending batch
+        let batch = PendingBatch {
+            batch_id: self.next_batch_id(),
+            items: PendingItems { repos, root_events },
+            outstanding_subs: sub_ids,
+        };
+        
+        // Add to pending index
+        self.pending_sync_index.write().await
+            .entry(relay_url)
+            .or_default()
+            .push(batch);
+    }
+}
+```
+
+### 4. handle_eose (Batch Completion)
+
+```rust
+impl SyncManager {
+    async fn handle_eose(&mut self, relay_url: &str, sub_id: SubscriptionId) {
+        let mut pending = self.pending_sync_index.write().await;
+        
+        if let Some(batches) = pending.get_mut(relay_url) {
+            // Find which batch this subscription belongs to
+            for batch in batches.iter_mut() {
+                if batch.outstanding_subs.remove(&sub_id) {
+                    // Check if batch is now complete
+                    if batch.outstanding_subs.is_empty() {
+                        // Move items to confirmed
+                        let items = batch.items.clone();
+                        drop(pending); // Release lock before acquiring another
+                        
+                        let mut confirmed = self.relay_sync_index.write().await;
+                        let relay_confirmed = confirmed
+                            .entry(relay_url.to_string())
+                            .or_default();
+                        relay_confirmed.repos.extend(items.repos);
+                        relay_confirmed.root_events.extend(items.root_events);
+                        
+                        tracing::info!(
+                            "Batch {} complete for {} - confirmed {} repos, {} events",
+                            batch.batch_id, relay_url,
+                            items.repos.len(), items.root_events.len()
+                        );
+                    }
+                    break;
+                }
+            }
+            
+            // Clean up completed batches
+            if let Some(batches) = pending.get_mut(relay_url) {
+                batches.retain(|b| !b.outstanding_subs.is_empty());
+            }
+        }
+    }
+}
+```
+
+---
+
+## Self-Subscriber Flow
+
+### State Tracking
+
+```rust
+pub struct SelfSubscriber {
+    own_relay_url: String,
+    relay_domain: String,
+    repo_sync_index: RepoSyncIndex,
+    pending_sync_index: PendingSyncIndex,
+    relay_sync_index: RelaySyncIndex,
+    action_tx: mpsc::Sender<AddFilters>,
+    /// Timestamp of last successful connection - used for since filter on reconnection
+    last_connected: Option<Timestamp>,
+    /// Is this the first connection attempt since startup?
+    is_initial_connect: bool,
+}
+```
+
+### On Startup
+
+```rust
+impl SelfSubscriber {
+    async fn run(mut self) {
+        // Connect to own relay
+        let client = Client::new(Keys::generate());
+        client.add_relay(&self.own_relay_url).await?;
+        client.connect().await;
+        
+        // Track connection time
+        self.last_connected = Some(Timestamp::now());
+        
+        // Subscribe WITHOUT since filter (get all historical) on first connect
+        let filter = Filter::new().kinds([
+            Kind::Custom(30617),  // Repository announcements
+            Kind::GitPatch,       // 1617
+            Kind::Custom(1618),   // PRs
+            Kind::Custom(1619),   // PR updates
+            Kind::GitIssue,       // 1621
+        ]);
+        
+        client.subscribe(filter, None).await?;
+        self.is_initial_connect = false;
+        
+        // Run event loop with batching
+        self.event_loop(&client).await;
+    }
+}
+```
+
+### On Reconnection
+
+```rust
+impl SelfSubscriber {
+    async fn reconnect(&mut self, client: &Client) -> Result<(), Error> {
+        // Reconnect to own relay
+        client.connect().await;
+        
+        // On reconnection ONLY, use since filter based on last_connected
+        let since = match self.last_connected {
+            Some(ts) => Timestamp::from(ts.as_u64().saturating_sub(900)), // -15 minutes buffer
+            None => Timestamp::from(0), // Shouldn't happen, but fall back to full sync
+        };
+        
+        // Update last_connected AFTER computing since
+        self.last_connected = Some(Timestamp::now());
+        
+        let filter = Filter::new()
+            .kinds([
+                Kind::Custom(30617),
+                Kind::GitPatch,
+                Kind::Custom(1618),
+                Kind::Custom(1619),
+                Kind::GitIssue,
+            ])
+            .since(since);
+        
+        client.subscribe(filter, None).await?;
+        Ok(())
+    }
+}
+```
+
+### Batching Logic
+
+```rust
+impl SelfSubscriber {
+    async fn event_loop(&self, client: &Client) {
+        let mut pending_events: Vec<Event> = Vec::new();
+        let mut batch_timer: Option<Instant> = None;
+        let batch_window = Duration::from_secs(5);
+        
+        loop {
+            let timeout = batch_timer
+                .map(|t| batch_window.saturating_sub(t.elapsed()))
+                .unwrap_or(Duration::from_secs(60));
+            
+            tokio::select! {
+                notification = client.notifications().recv() => {
+                    if let Ok(RelayPoolNotification::Event { event, .. }) = notification {
+                        pending_events.push(*event);
+                        
+                        // Start timer on first event (does NOT reset)
+                        if batch_timer.is_none() {
+                            batch_timer = Some(Instant::now());
+                        }
+                    }
+                }
+                _ = tokio::time::sleep(timeout), if batch_timer.is_some() => {
+                    // Batch window elapsed
+                    self.process_batch(pending_events.drain(..).collect()).await;
+                    batch_timer = None;
+                }
+            }
+        }
+    }
+    
+    async fn process_batch(&self, events: Vec<Event>) {
+        // 1. Update RepoSyncIndex
+        for event in events {
+            match event.kind.as_u16() {
+                30617 => self.handle_announcement(&event).await,
+                1617 | 1618 | 1619 | 1621 => self.handle_root_event(&event).await,
+                _ => {}
+            }
+        }
+        
+        // 2. Derive targets and compute actions
+        let repo_index = self.repo_sync_index.read().await;
+        let targets = derive_relay_targets(&repo_index);
+        
+        let pending = self.pending_sync_index.read().await;
+        let confirmed = self.relay_sync_index.read().await;
+        
+        let actions = compute_actions(&targets, &pending, &confirmed);
+        
+        drop(repo_index);
+        drop(pending);
+        drop(confirmed);
+        
+        // 3. Send actions to SyncManager
+        for action in actions {
+            let _ = self.action_tx.send(action).await;
+        }
+    }
+}
+```
+
+---
+
+## Bootstrap Relay
+
+```rust
+impl SyncManager {
+    async fn initialize_bootstrap(&mut self) {
+        if let Some(url) = &self.config.bootstrap_relay_url {
+            // Pre-mark as bootstrap (never removed)
+            self.relay_sync_index.write().await.insert(
+                url.clone(),
+                RelaySyncNeeds {
+                    repos: HashSet::new(),
+                    root_events: HashSet::new(),
+                    is_bootstrap: true,
+                }
+            );
+            
+            // Send Layer 1 filter
+            let filters = vec![
+                Filter::new().kinds([Kind::Custom(30617), Kind::Custom(30618)])
+            ];
+            
+            self.handle_add_filters(AddFilters {
+                relay_url: url.clone(),
+                repos: HashSet::new(),  // Layer 1 doesn't track specific repos
+                root_events: HashSet::new(),
+                filters,
+            }).await;
+        }
+    }
+}
+```
+
+---
+
+## Disconnect Handling
+
+Direct in SyncManager (not via action):
+
+```rust
+impl SyncManager {
+    async fn check_disconnects(&mut self) {
+        let confirmed = self.relay_sync_index.read().await;
+        
+        for (relay_url, state) in confirmed.iter() {
+            if state.is_bootstrap {
+                continue; // Never disconnect bootstrap
+            }
+            
+            if state.repos.is_empty() && state.root_events.is_empty() {
+                // No repos - disconnect
+                self.disconnect_relay(relay_url).await;
+            }
+        }
+    }
+    
+    async fn disconnect_relay(&mut self, relay_url: &str) {
+        self.relay_sync_index.write().await.remove(relay_url);
+        self.pending_sync_index.write().await.remove(relay_url);
+        
+        if let Some(conn) = self.connections.remove(relay_url) {
+            conn.disconnect().await;
+        }
+    }
+}
+```
+
+---
+
+## Relay Connection Lifecycle
+
+### State Machine for External Relays
+
+```mermaid
+stateDiagram-v2
+    [*] --> Connecting: spawn_connection
+    Connecting --> Connected: success
+    Connecting --> Backoff: failure
+    Connected --> Disconnected: connection lost
+    Connected --> [*]: intentional disconnect
+    Disconnected --> Backoff: record_failure
+    Backoff --> Connecting: backoff elapsed
+    Backoff --> Dead: 24h continuous failures
+    Dead --> Connecting: daily retry
+```
+
+### Health Integration
+
+Uses `RelayHealthTracker` from [`src/sync/health.rs`](../../src/sync/health.rs):
+
+```rust
+impl SyncManager {
+    /// Spawn a connection with health tracking
+    async fn spawn_connection(&mut self, relay_url: &str) {
+        // Check if we should attempt connection
+        if !self.health_tracker.should_attempt_connection(relay_url) {
+            let remaining = self.health_tracker.get_remaining_backoff(relay_url);
+            tracing::debug!(
+                "Skipping connection to {} - backoff {:?}",
+                relay_url,
+                remaining
+            );
+            return;
+        }
+        
+        match self.try_connect(relay_url).await {
+            Ok(conn) => {
+                self.health_tracker.record_success(relay_url);
+                self.connections.insert(relay_url.to_string(), conn);
+            }
+            Err(e) => {
+                self.health_tracker.record_failure(relay_url);
+                tracing::warn!("Connection to {} failed: {}", relay_url, e);
+            }
+        }
+    }
+}
+```
+
+### Reconnection Loop
+
+Each relay connection runs its own reconnection loop:
+
+```rust
+impl RelayConnection {
+    async fn run_with_reconnection(
+        mut self,
+        health_tracker: Arc<RelayHealthTracker>,
+        event_tx: mpsc::Sender<RelayEvent>,
+    ) {
+        loop {
+            // Check backoff before attempting
+            if !health_tracker.should_attempt_connection(&self.url) {
+                if let Some(remaining) = health_tracker.get_remaining_backoff(&self.url) {
+                    tokio::time::sleep(remaining).await;
+                    continue;
+                }
+            }
+            
+            // Attempt connection
+            match self.connect_and_subscribe().await {
+                Ok(()) => {
+                    health_tracker.record_success(&self.url);
+                    
+                    // Track when we connected for since filter on reconnect
+                    let connected_at = Timestamp::now();
+                    
+                    // Run event loop until disconnection
+                    self.run_event_loop(&event_tx).await;
+                    
+                    // Connection lost - will reconnect with since filter
+                    health_tracker.record_failure(&self.url);
+                    
+                    // On reconnect, use since = connected_at - 15 minutes
+                    self.set_reconnect_since(connected_at);
+                }
+                Err(e) => {
+                    health_tracker.record_failure(&self.url);
+                    tracing::warn!("Connection to {} failed: {}", self.url, e);
+                }
+            }
+            
+            // Get backoff duration and wait
+            let state = health_tracker.get_state(&self.url);
+            if state == HealthState::Dead {
+                // Dead relays retry once per 24 hours
+                tokio::time::sleep(Duration::from_secs(24 * 3600)).await;
+            }
+            // Otherwise, loop will check should_attempt_connection
+        }
+    }
+}
+```
+
+### Backoff Configuration
+
+From existing [`RelayHealthTracker`](../../src/sync/health.rs:91):
+
+| Parameter | Value | Notes |
+|-----------|-------|-------|
+| Base backoff | 5 seconds | First failure |
+| Backoff multiplier | 2x | Exponential increase |
+| Max backoff | 1 hour (configurable) | `sync_max_backoff_secs` |
+| Dead threshold | 24 hours | Continuous failures |
+| Dead retry interval | 24 hours | Once per day |
+
+---
+
+## Consolidation
+
+### Threshold-Based (70 filters)
+
+```rust
+impl SyncManager {
+    async fn maybe_consolidate(&mut self, relay_url: &str) {
+        let filter_count = self.get_filter_count(relay_url).await;
+        
+        if filter_count > 70 {
+            self.consolidate(relay_url).await;
+        }
+    }
+    
+    async fn consolidate(&mut self, relay_url: &str) {
+        // 1. Wait for all pending batches to complete
+        self.wait_pending_complete(relay_url).await;
+        
+        // 2. Close all subscriptions
+        self.close_all_subs(relay_url).await;
+        
+        // 3. Rebuild filters from confirmed state
+        let confirmed = self.relay_sync_index.read().await;
+        let state = confirmed.get(relay_url)?;
+        let filters = build_filters(&state.repos, &state.root_events);
+        
+        // 4. Resubscribe with since = now - 15 minutes
+        let since = Timestamp::now() - 900;
+        for filter in filters {
+            self.subscribe(relay_url, filter.since(since)).await;
+        }
+    }
+}
+```
+
+### Daily Timer (23-25h Random)
+
+```rust
+impl SyncManager {
+    async fn run_daily_consolidation(&self) {
+        loop {
+            let hours = 23 + rand::random::<f64>() * 2.0;
+            tokio::time::sleep(Duration::from_secs_f64(hours * 3600.0)).await;
+            
+            for relay_url in self.connections.keys() {
+                self.consolidate(relay_url).await;
+            }
+        }
+    }
+}
+```
+
+---
+
+## Key Design Decisions
+
+| Decision | Choice | Rationale |
+|----------|--------|-----------|
+| Startup mechanism | Self-subscription only | Single code path, fresh DB behaves same as reconnect |
+| Since filter | Only on reconnection | Initial subscribe gets full history |
+| Pending tracking | Per-batch with batch ID | Independent confirmation, no blocking |
+| EOSE requirement | All subs in batch must complete | Single repo may need multiple filter subs |
+| Action type | Struct not enum | Only one action type needed |
+| Relay spawning | Auto-spawn on AddFilters | Simplifies action logic |
+| Disconnect | Direct in SyncManager | Not worth an action type |
+| Consolidation | 70 filters + daily timer | Threshold for growth, timer for staleness |
+| Timestamps | In-memory only | Not critical for correctness |
+| Health tracking | Reuse existing RelayHealthTracker | Already implements exponential backoff, dead relay detection |
+| Reconnection backoff | Exponential to 1h max | Prevents hammering failed relays |
+| Dead relay policy | 24h threshold, daily retry | Balance between giving up and resource waste |
+| last_connected tracking | Per-connection in-memory | Enables 15-minute buffer on reconnect |
+| Connection ownership | Inside RelayState | Ties connection lifecycle to sync state, simpler than separate maps |
+| State retention rule | Clear if disconnected >15min | Matches since filter buffer, prevents stale subscriptions |
+| Skip disconnected | compute_actions skips disconnected | Prevents queuing AddFilters for offline relays |
+| Reconnect triggers | handle_notifications returns or Shutdown | nostr-sdk signals disconnect via event loop exit |
+| On-reconnect flow | Regenerate AddFilters from RepoSyncIndex | Fresh subscriptions for what we actually need |
+
+---
+
+## Module Structure
+
+```
+src/sync/
+├── mod.rs              # SyncManager, main loop
+├── state.rs            # RepoSyncIndex, RelaySyncIndex, PendingSyncIndex types
+├── actions.rs          # AddFilters struct, compute_actions
+├── self_subscriber.rs  # SelfSubscriber, batching logic
+├── relay_connection.rs # Per-relay WebSocket connection
+├── consolidation.rs    # Consolidation logic, daily timer
+├── health.rs           # Health tracking (reuse from v2)
+└── metrics.rs          # Prometheus metrics (reuse from v2)
\ No newline at end of file