diff --git a/src/routes/sources/crud.rs b/src/routes/sources/crud.rs
new file mode 100644
index 0000000..cb5421f
--- /dev/null
+++ b/src/routes/sources/crud.rs
@@ -0,0 +1,315 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::Json,
+};
+use std::sync::Arc;
+use uuid::Uuid;
+use tracing::{error, info};
+
+use crate::{
+    auth::AuthUser,
+    models::{CreateSource, SourceResponse, SourceWithStats, UpdateSource, SourceType},
+    AppState,
+};
+
+/// List all sources for the authenticated user
+#[utoipa::path(
+    get,
+    path = "/api/sources",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    responses(
+        (status = 200, description = "List of user sources", body = Vec<SourceResponse>),
+        (status = 401, description = "Unauthorized"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn list_sources(
+    auth_user: AuthUser,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<Vec<SourceResponse>>, StatusCode> {
+    let sources = state
+        .db
+        .get_sources(auth_user.user.id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    // Get source IDs for batch counting
+    let source_ids: Vec<Uuid> = sources.iter().map(|s| s.id).collect();
+    
+    // Get document counts for all sources in one query
+    let counts = state
+        .db
+        .count_documents_for_sources(&source_ids)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    
+    // Create a map for quick lookup
+    let count_map: std::collections::HashMap<Uuid, (i64, i64)> = counts
+        .into_iter()
+        .map(|(id, total, ocr)| (id, (total, ocr)))
+        .collect();
+
+    let responses: Vec<SourceResponse> = sources
+        .into_iter()
+        .map(|s| {
+            let (total_docs, total_ocr) = count_map.get(&s.id).copied().unwrap_or((0, 0));
+            let mut response: SourceResponse = s.into();
+            response.total_documents = total_docs;
+            response.total_documents_ocr = total_ocr;
+            response
+        })
+        .collect();
+    
+    Ok(Json(responses))
+}
+
+/// Create a new source
+#[utoipa::path(
+    post,
+    path = "/api/sources",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    request_body = CreateSource,
+    responses(
+        (status = 201, description = "Source created successfully", body = SourceResponse),
+        (status = 400, description = "Bad request - invalid source data"),
+        (status = 401, description = "Unauthorized"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn create_source(
+    auth_user: AuthUser,
+    State(state): State<Arc<AppState>>,
+    Json(source_data): Json<CreateSource>,
+) -> Result<Json<SourceResponse>, StatusCode> {
+    // Validate source configuration based on type
+    if let Err(validation_error) = validate_source_config(&source_data) {
+        error!("Source validation failed: {}", validation_error);
+        error!("Invalid source data received: {:?}", source_data);
+        return Err(StatusCode::BAD_REQUEST);
+    }
+
+    let source = state
+        .db
+        .create_source(auth_user.user.id, &source_data)
+        .await
+        .map_err(|e| {
+            error!("Failed to create source in database: {}", e);
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?;
+
+    let mut response: SourceResponse = source.into();
+    // New sources have no documents yet
+    response.total_documents = 0;
+    response.total_documents_ocr = 0;
+
+    Ok(Json(response))
+}
+
+/// Get a specific source by ID with detailed stats
+#[utoipa::path(
+    get,
+    path = "/api/sources/{id}",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Source details with stats", body = SourceWithStats),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn get_source(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<SourceWithStats>, StatusCode> {
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Get recent documents for this source
+    let recent_documents = state
+        .db
+        .get_recent_documents_for_source(source_id, 10)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    // Get document counts
+    let (total_documents, total_documents_ocr) = state
+        .db
+        .count_documents_for_source(source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    // Calculate sync progress
+    let sync_progress = if source.total_files_pending > 0 {
+        Some(
+            (source.total_files_synced as f32
+                / (source.total_files_synced + source.total_files_pending) as f32)
+                * 100.0,
+        )
+    } else {
+        None
+    };
+
+    let mut source_response: SourceResponse = source.into();
+    source_response.total_documents = total_documents;
+    source_response.total_documents_ocr = total_documents_ocr;
+
+    let response = SourceWithStats {
+        source: source_response,
+        recent_documents: recent_documents.into_iter().map(|d| d.into()).collect(),
+        sync_progress,
+    };
+
+    Ok(Json(response))
+}
+
+/// Update a source
+#[utoipa::path(
+    put,
+    path = "/api/sources/{id}",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    request_body = UpdateSource,
+    responses(
+        (status = 200, description = "Source updated successfully", body = SourceResponse),
+        (status = 400, description = "Bad request - invalid update data"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn update_source(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+    Json(update_data): Json<UpdateSource>,
+) -> Result<Json<SourceResponse>, StatusCode> {
+    info!("Updating source {} with data: {:?}", source_id, update_data);
+    
+    // Check if source exists
+    let existing = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Validate config if provided
+    if let Some(config) = &update_data.config {
+        if let Err(validation_error) = validate_config_for_type(&existing.source_type, config) {
+            error!("Config validation failed for source {}: {}", source_id, validation_error);
+            error!("Invalid config received: {:?}", config);
+            return Err(StatusCode::BAD_REQUEST);
+        }
+    }
+
+    let source = state
+        .db
+        .update_source(auth_user.user.id, source_id, &update_data)
+        .await
+        .map_err(|e| {
+            error!("Failed to update source {} in database: {}", source_id, e);
+            StatusCode::INTERNAL_SERVER_ERROR
+        })?;
+
+    // Get document counts
+    let (total_documents, total_documents_ocr) = state
+        .db
+        .count_documents_for_source(source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    let mut response: SourceResponse = source.into();
+    response.total_documents = total_documents;
+    response.total_documents_ocr = total_documents_ocr;
+
+    info!("Successfully updated source {}: {}", source_id, response.name);
+    Ok(Json(response))
+}
+
+/// Delete a source
+#[utoipa::path(
+    delete,
+    path = "/api/sources/{id}",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 204, description = "Source deleted successfully"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn delete_source(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<StatusCode, StatusCode> {
+    let deleted = state
+        .db
+        .delete_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    if deleted {
+        Ok(StatusCode::NO_CONTENT)
+    } else {
+        Err(StatusCode::NOT_FOUND)
+    }
+}
+
+/// Validate source configuration based on type
+fn validate_source_config(source: &CreateSource) -> Result<(), &'static str> {
+    validate_config_for_type(&source.source_type, &source.config)
+}
+
+/// Validate configuration for a specific source type
+pub fn validate_config_for_type(
+    source_type: &SourceType,
+    config: &serde_json::Value,
+) -> Result<(), &'static str> {
+    match source_type {
+        SourceType::WebDAV => {
+            let _: crate::models::WebDAVSourceConfig =
+                serde_json::from_value(config.clone()).map_err(|_| "Invalid WebDAV configuration")?;
+            Ok(())
+        }
+        SourceType::LocalFolder => {
+            let _: crate::models::LocalFolderSourceConfig =
+                serde_json::from_value(config.clone()).map_err(|_| "Invalid Local Folder configuration")?;
+            Ok(())
+        }
+        SourceType::S3 => {
+            let _: crate::models::S3SourceConfig =
+                serde_json::from_value(config.clone()).map_err(|_| "Invalid S3 configuration")?;
+            Ok(())
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/routes/sources/estimation.rs b/src/routes/sources/estimation.rs
new file mode 100644
index 0000000..ecb630d
--- /dev/null
+++ b/src/routes/sources/estimation.rs
@@ -0,0 +1,124 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::Json,
+};
+use std::sync::Arc;
+use uuid::Uuid;
+
+use crate::{
+    auth::AuthUser,
+    AppState,
+};
+
+/// Estimate crawl for an existing source
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/estimate",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Crawl estimate result", body = serde_json::Value),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn estimate_crawl(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    match source.source_type {
+        crate::models::SourceType::WebDAV => {
+            let config: crate::models::WebDAVSourceConfig = serde_json::from_value(source.config)
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+            estimate_webdav_crawl_internal(&config).await
+        }
+        _ => Ok(Json(serde_json::json!({
+            "error": "Source type not supported for estimation"
+        }))),
+    }
+}
+
+/// Estimate crawl with a configuration (before creating source)
+#[utoipa::path(
+    post,
+    path = "/api/sources/estimate",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    request_body = serde_json::Value,
+    responses(
+        (status = 200, description = "Crawl estimate result", body = serde_json::Value),
+        (status = 400, description = "Bad request - invalid configuration"),
+        (status = 401, description = "Unauthorized"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn estimate_crawl_with_config(
+    _auth_user: AuthUser,
+    State(_state): State<Arc<AppState>>,
+    Json(config_data): Json<serde_json::Value>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    // Parse the WebDAV config from the request
+    let config: crate::models::WebDAVSourceConfig = serde_json::from_value(config_data)
+        .map_err(|_| StatusCode::BAD_REQUEST)?;
+
+    estimate_webdav_crawl_internal(&config).await
+}
+
+/// Internal helper function to estimate WebDAV crawl
+async fn estimate_webdav_crawl_internal(
+    config: &crate::models::WebDAVSourceConfig,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    // Create WebDAV service config
+    let webdav_config = crate::services::webdav::WebDAVConfig {
+        server_url: config.server_url.clone(),
+        username: config.username.clone(),
+        password: config.password.clone(),
+        watch_folders: config.watch_folders.clone(),
+        file_extensions: config.file_extensions.clone(),
+        timeout_seconds: 300,
+        server_type: config.server_type.clone(),
+    };
+
+    // Create WebDAV service and estimate crawl
+    match crate::services::webdav::WebDAVService::new(webdav_config) {
+        Ok(webdav_service) => {
+            match webdav_service.estimate_crawl(&config.watch_folders).await {
+                Ok(estimate) => Ok(Json(serde_json::to_value(estimate).unwrap())),
+                Err(e) => Ok(Json(serde_json::json!({
+                    "error": format!("Crawl estimation failed: {}", e),
+                    "folders": [],
+                    "total_files": 0,
+                    "total_supported_files": 0,
+                    "total_estimated_time_hours": 0.0,
+                    "total_size_mb": 0.0,
+                }))),
+            }
+        }
+        Err(e) => Ok(Json(serde_json::json!({
+            "error": format!("Failed to create WebDAV service: {}", e),
+            "folders": [],
+            "total_files": 0,
+            "total_supported_files": 0,
+            "total_estimated_time_hours": 0.0,
+            "total_size_mb": 0.0,
+        }))),
+    }
+}
\ No newline at end of file
diff --git a/src/routes/sources/mod.rs b/src/routes/sources/mod.rs
new file mode 100644
index 0000000..c6f9d57
--- /dev/null
+++ b/src/routes/sources/mod.rs
@@ -0,0 +1,10 @@
+pub mod crud;
+pub mod sync;
+pub mod validation;
+pub mod estimation;
+
+// Re-export commonly used functions and types for backward compatibility
+pub use crud::*;
+pub use sync::*;
+pub use validation::*;
+pub use estimation::*;
\ No newline at end of file
diff --git a/src/routes/sources/sync.rs b/src/routes/sources/sync.rs
new file mode 100644
index 0000000..a99d367
--- /dev/null
+++ b/src/routes/sources/sync.rs
@@ -0,0 +1,434 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::Json,
+};
+use std::sync::Arc;
+use uuid::Uuid;
+use tracing::{error, info};
+
+use crate::{
+    auth::AuthUser,
+    models::SourceStatus,
+    AppState,
+};
+
+/// Trigger a sync for a source
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/sync",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Sync triggered successfully"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 409, description = "Source is already syncing"),
+        (status = 500, description = "Internal server error"),
+        (status = 501, description = "Not implemented - Source type not supported")
+    )
+)]
+pub async fn trigger_sync(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<StatusCode, StatusCode> {
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Check if already syncing
+    if matches!(source.status, SourceStatus::Syncing) {
+        return Err(StatusCode::CONFLICT);
+    }
+
+    // Update status to syncing
+    state
+        .db
+        .update_source_status(source_id, SourceStatus::Syncing, None)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+    // Trigger sync using the universal source scheduler
+    if let Some(scheduler) = &state.source_scheduler {
+        if let Err(e) = scheduler.trigger_sync(source_id).await {
+            error!("Failed to trigger sync for source {}: {}", source_id, e);
+            state
+                .db
+                .update_source_status(
+                    source_id,
+                    SourceStatus::Error,
+                    Some(format!("Failed to trigger sync: {}", e)),
+                )
+                .await
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+            return Err(StatusCode::INTERNAL_SERVER_ERROR);
+        }
+    } else {
+        // Fallback to WebDAV scheduler for backward compatibility
+        match source.source_type {
+            crate::models::SourceType::WebDAV => {
+                if let Some(webdav_scheduler) = &state.webdav_scheduler {
+                    webdav_scheduler.trigger_sync(source_id).await;
+                } else {
+                    state
+                        .db
+                        .update_source_status(
+                            source_id,
+                            SourceStatus::Error,
+                            Some("No scheduler available".to_string()),
+                        )
+                        .await
+                        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+                    return Err(StatusCode::INTERNAL_SERVER_ERROR);
+                }
+            }
+            _ => {
+                state
+                    .db
+                    .update_source_status(
+                        source_id,
+                        SourceStatus::Error,
+                        Some("Source type not supported".to_string()),
+                    )
+                    .await
+                    .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+                return Err(StatusCode::NOT_IMPLEMENTED);
+            }
+        }
+    }
+
+    Ok(StatusCode::OK)
+}
+
+/// Stop sync for a source
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/sync/stop",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Sync stopped successfully"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 409, description = "Source is not currently syncing"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn stop_sync(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<StatusCode, StatusCode> {
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Allow stopping sync regardless of current status to handle edge cases
+    // where the database status might be out of sync with actual running tasks
+
+    // Stop sync using the universal source scheduler
+    if let Some(scheduler) = &state.source_scheduler {
+        if let Err(e) = scheduler.stop_sync(source_id).await {
+            let error_msg = e.to_string();
+            // If no sync is running, treat it as success since the desired state is achieved
+            if error_msg.contains("No running sync found") {
+                info!("No sync was running for source {}, updating status to idle", source_id);
+                // Update status to idle since no sync is running
+                state
+                    .db
+                    .update_source_status(
+                        source_id,
+                        SourceStatus::Idle,
+                        None,
+                    )
+                    .await
+                    .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+            } else {
+                error!("Failed to stop sync for source {}: {}", source_id, e);
+                return Err(StatusCode::INTERNAL_SERVER_ERROR);
+            }
+        }
+    } else {
+        // Update status directly if no scheduler available (fallback)
+        state
+            .db
+            .update_source_status(
+                source_id,
+                SourceStatus::Idle,
+                Some("Sync cancelled by user".to_string()),
+            )
+            .await
+            .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    }
+
+    Ok(StatusCode::OK)
+}
+
+/// Trigger a deep scan for a source
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/deep-scan",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Deep scan started successfully"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 409, description = "Source is already syncing"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn trigger_deep_scan(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    info!("Starting deep scan for source {} by user {}", source_id, auth_user.user.username);
+    
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Check if source is already syncing
+    if matches!(source.status, SourceStatus::Syncing) {
+        return Ok(Json(serde_json::json!({
+            "success": false,
+            "error": "source_already_syncing",
+            "message": "Source is already syncing. Please wait for the current sync to complete before starting a deep scan."
+        })));
+    }
+
+    match source.source_type {
+        crate::models::SourceType::WebDAV => {
+            // Handle WebDAV deep scan
+            let config: crate::models::WebDAVSourceConfig = serde_json::from_value(source.config)
+                .map_err(|e| {
+                    error!("Failed to parse WebDAV config for source {}: {}", source_id, e);
+                    StatusCode::INTERNAL_SERVER_ERROR
+                })?;
+
+            // Create WebDAV service
+            let webdav_config = crate::services::webdav::WebDAVConfig {
+                server_url: config.server_url.clone(),
+                username: config.username.clone(),
+                password: config.password.clone(),
+                watch_folders: config.watch_folders.clone(),
+                file_extensions: config.file_extensions.clone(),
+                timeout_seconds: 600, // 10 minutes for deep scan
+                server_type: config.server_type.clone(),
+            };
+
+            let webdav_service = crate::services::webdav::WebDAVService::new(webdav_config.clone())
+                .map_err(|e| {
+                    error!("Failed to create WebDAV service for deep scan: {}", e);
+                    StatusCode::INTERNAL_SERVER_ERROR
+                })?;
+
+            // Update source status to syncing
+            state
+                .db
+                .update_source_status(
+                    source_id,
+                    SourceStatus::Syncing,
+                    Some("Deep scan in progress".to_string()),
+                )
+                .await
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+            // Start deep scan in background
+            let state_clone = state.clone();
+            let user_id = auth_user.user.id;
+            let source_name = source.name.clone();
+            let source_id_clone = source_id;
+            let config_clone = config.clone();
+            
+            tokio::spawn(async move {
+                let start_time = chrono::Utc::now();
+                
+                // Use guaranteed completeness deep scan method
+                match webdav_service.deep_scan_with_guaranteed_completeness(user_id, &state_clone).await {
+                    Ok(all_discovered_files) => {
+                        info!("Deep scan with guaranteed completeness discovered {} files", all_discovered_files.len());
+                        
+                        if !all_discovered_files.is_empty() {
+                            info!("Deep scan discovery completed for source {}: {} files found", source_id_clone, all_discovered_files.len());
+                            
+                            // Filter files by extensions and process them
+                            let files_to_process: Vec<_> = all_discovered_files.into_iter()
+                            .filter(|file_info| {
+                                if file_info.is_directory {
+                                    return false;
+                                }
+                                let file_extension = std::path::Path::new(&file_info.name)
+                                    .extension()
+                                    .and_then(|ext| ext.to_str())
+                                    .unwrap_or("")
+                                    .to_lowercase();
+                                config_clone.file_extensions.contains(&file_extension)
+                            })
+                            .collect();
+                        
+                            info!("Deep scan will process {} files for source {}", files_to_process.len(), source_id_clone);
+                        
+                            // Process files using the existing sync mechanism
+                            match crate::routes::webdav::webdav_sync::process_files_for_deep_scan(
+                                state_clone.clone(),
+                                user_id,
+                                &webdav_service,
+                                &files_to_process,
+                                true, // enable background OCR
+                                Some(source_id_clone)
+                            ).await {
+                                Ok(files_processed) => {
+                                    let duration = chrono::Utc::now() - start_time;
+                                    info!("Deep scan completed for source {}: {} files processed in {:?}", 
+                                        source_id_clone, files_processed, duration);
+                                    
+                                    // Update source status to idle
+                                    if let Err(e) = state_clone.db.update_source_status(
+                                        source_id_clone,
+                                        SourceStatus::Idle,
+                                        Some(format!("Deep scan completed: {} files processed", files_processed)),
+                                    ).await {
+                                        error!("Failed to update source status after deep scan: {}", e);
+                                    }
+                                    
+                                    // Send success notification
+                                    let notification = crate::models::CreateNotification {
+                                        notification_type: "success".to_string(),
+                                        title: "Deep Scan Completed".to_string(),
+                                        message: format!(
+                                            "Deep scan of {} completed successfully. {} files processed in {:.1} minutes.",
+                                            source_name,
+                                            files_processed,
+                                            duration.num_seconds() as f64 / 60.0
+                                        ),
+                                        action_url: Some("/documents".to_string()),
+                                        metadata: Some(serde_json::json!({
+                                            "source_id": source_id_clone,
+                                            "scan_type": "deep_scan",
+                                            "files_processed": files_processed,
+                                            "duration_seconds": duration.num_seconds()
+                                        })),
+                                    };
+                                    
+                                    if let Err(e) = state_clone.db.create_notification(user_id, &notification).await {
+                                        error!("Failed to create deep scan success notification: {}", e);
+                                    }
+                                }
+                                Err(e) => {
+                                    error!("Deep scan file processing failed for source {}: {}", source_id_clone, e);
+                                    
+                                    // Update source status to error
+                                    if let Err(e2) = state_clone.db.update_source_status(
+                                        source_id_clone,
+                                        SourceStatus::Error,
+                                        Some(format!("Deep scan failed: {}", e)),
+                                    ).await {
+                                        error!("Failed to update source status after deep scan error: {}", e2);
+                                    }
+                                    
+                                    // Send error notification
+                                    let notification = crate::models::CreateNotification {
+                                        notification_type: "error".to_string(),
+                                        title: "Deep Scan Failed".to_string(),
+                                        message: format!("Deep scan of {} failed: {}", source_name, e),
+                                        action_url: Some("/sources".to_string()),
+                                        metadata: Some(serde_json::json!({
+                                            "source_id": source_id_clone,
+                                            "scan_type": "deep_scan",
+                                            "error": e.to_string()
+                                        })),
+                                    };
+                                    
+                                    if let Err(e) = state_clone.db.create_notification(user_id, &notification).await {
+                                        error!("Failed to create deep scan error notification: {}", e);
+                                    }
+                                }
+                            }
+
+                        } else {
+                            info!("Deep scan found no files for source {}", source_id_clone);
+                            
+                            // Update source status to idle even if no files found
+                            if let Err(e) = state_clone.db.update_source_status(
+                                source_id_clone,
+                                SourceStatus::Idle,
+                                Some("Deep scan completed: no files found".to_string()),
+                            ).await {
+                                error!("Failed to update source status after empty deep scan: {}", e);
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        error!("Deep scan with guaranteed completeness failed for source {}: {}", source_id_clone, e);
+                        
+                        // Update source status to error
+                        if let Err(e2) = state_clone.db.update_source_status(
+                            source_id_clone,
+                            SourceStatus::Error,
+                            Some(format!("Deep scan failed: {}", e)),
+                        ).await {
+                            error!("Failed to update source status after deep scan error: {}", e2);
+                        }
+                        
+                        // Send error notification
+                        let notification = crate::models::CreateNotification {
+                            notification_type: "error".to_string(),
+                            title: "Deep Scan Failed".to_string(),
+                            message: format!("Deep scan of {} failed: {}", source_name, e),
+                            action_url: Some("/sources".to_string()),
+                            metadata: Some(serde_json::json!({
+                                "source_id": source_id_clone,
+                                "scan_type": "deep_scan",
+                                "error": e.to_string()
+                            })),
+                        };
+                        
+                        if let Err(e) = state_clone.db.create_notification(user_id, &notification).await {
+                            error!("Failed to create deep scan error notification: {}", e);
+                        }
+                    }
+                }
+            });
+
+            Ok(Json(serde_json::json!({
+                "success": true,
+                "message": format!("Deep scan started for source '{}'. This will perform a complete rescan of all configured folders.", source.name)
+            })))
+        }
+        _ => {
+            error!("Deep scan not supported for source type: {:?}", source.source_type);
+            Ok(Json(serde_json::json!({
+                "success": false,
+                "error": "unsupported_source_type",
+                "message": "Deep scan is currently only supported for WebDAV sources"
+            })))
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/routes/sources/validation.rs b/src/routes/sources/validation.rs
new file mode 100644
index 0000000..c047c2b
--- /dev/null
+++ b/src/routes/sources/validation.rs
@@ -0,0 +1,268 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::Json,
+};
+use std::sync::Arc;
+use uuid::Uuid;
+use tracing::{error, info};
+use serde::{Deserialize};
+use utoipa::ToSchema;
+
+use crate::{
+    auth::AuthUser,
+    models::SourceType,
+    AppState,
+};
+
+#[derive(Deserialize, ToSchema)]
+pub struct TestConnectionRequest {
+    pub source_type: SourceType,
+    pub config: serde_json::Value,
+}
+
+/// Test connection for an existing source
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/test",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Connection test result", body = serde_json::Value),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn test_connection(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    match source.source_type {
+        SourceType::WebDAV => {
+            // Test WebDAV connection
+            let config: crate::models::WebDAVSourceConfig = serde_json::from_value(source.config)
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+            match crate::services::webdav::test_webdav_connection(
+                &config.server_url,
+                &config.username,
+                &config.password,
+            )
+            .await
+            {
+                Ok(success) => Ok(Json(serde_json::json!({
+                    "success": success,
+                    "message": if success { "Connection successful" } else { "Connection failed" }
+                }))),
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("Connection failed: {}", e)
+                }))),
+            }
+        }
+        SourceType::LocalFolder => {
+            // Test Local Folder access
+            let config: crate::models::LocalFolderSourceConfig = serde_json::from_value(source.config)
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+            match crate::services::local_folder_service::LocalFolderService::new(config) {
+                Ok(service) => {
+                    match service.test_connection().await {
+                        Ok(message) => Ok(Json(serde_json::json!({
+                            "success": true,
+                            "message": message
+                        }))),
+                        Err(e) => Ok(Json(serde_json::json!({
+                            "success": false,
+                            "message": format!("Local folder test failed: {}", e)
+                        }))),
+                    }
+                }
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("Local folder configuration error: {}", e)
+                }))),
+            }
+        }
+        SourceType::S3 => {
+            // Test S3 connection
+            let config: crate::models::S3SourceConfig = serde_json::from_value(source.config)
+                .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+            match crate::services::s3_service::S3Service::new(config).await {
+                Ok(service) => {
+                    match service.test_connection().await {
+                        Ok(message) => Ok(Json(serde_json::json!({
+                            "success": true,
+                            "message": message
+                        }))),
+                        Err(e) => Ok(Json(serde_json::json!({
+                            "success": false,
+                            "message": format!("S3 test failed: {}", e)
+                        }))),
+                    }
+                }
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("S3 configuration error: {}", e)
+                }))),
+            }
+        }
+    }
+}
+
+/// Test connection with a configuration (before creating source)
+#[utoipa::path(
+    post,
+    path = "/api/sources/test-connection",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    request_body = TestConnectionRequest,
+    responses(
+        (status = 200, description = "Connection test result", body = serde_json::Value),
+        (status = 400, description = "Bad request - invalid configuration"),
+        (status = 401, description = "Unauthorized"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn test_connection_with_config(
+    _auth_user: AuthUser,
+    State(_state): State<Arc<AppState>>,
+    Json(request): Json<TestConnectionRequest>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    match request.source_type {
+        SourceType::WebDAV => {
+            // Test WebDAV connection
+            let config: crate::models::WebDAVSourceConfig = serde_json::from_value(request.config)
+                .map_err(|_| StatusCode::BAD_REQUEST)?;
+
+            match crate::services::webdav::test_webdav_connection(
+                &config.server_url,
+                &config.username,
+                &config.password,
+            )
+            .await
+            {
+                Ok(success) => Ok(Json(serde_json::json!({
+                    "success": success,
+                    "message": if success { "WebDAV connection successful" } else { "WebDAV connection failed" }
+                }))),
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("WebDAV connection failed: {}", e)
+                }))),
+            }
+        }
+        SourceType::LocalFolder => {
+            // Test Local Folder access
+            let config: crate::models::LocalFolderSourceConfig = serde_json::from_value(request.config)
+                .map_err(|_| StatusCode::BAD_REQUEST)?;
+
+            match crate::services::local_folder_service::LocalFolderService::new(config) {
+                Ok(service) => {
+                    match service.test_connection().await {
+                        Ok(message) => Ok(Json(serde_json::json!({
+                            "success": true,
+                            "message": message
+                        }))),
+                        Err(e) => Ok(Json(serde_json::json!({
+                            "success": false,
+                            "message": format!("Local folder test failed: {}", e)
+                        }))),
+                    }
+                }
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("Local folder configuration error: {}", e)
+                }))),
+            }
+        }
+        SourceType::S3 => {
+            // Test S3 connection
+            let config: crate::models::S3SourceConfig = serde_json::from_value(request.config)
+                .map_err(|_| StatusCode::BAD_REQUEST)?;
+
+            match crate::services::s3_service::S3Service::new(config).await {
+                Ok(service) => {
+                    match service.test_connection().await {
+                        Ok(message) => Ok(Json(serde_json::json!({
+                            "success": true,
+                            "message": message
+                        }))),
+                        Err(e) => Ok(Json(serde_json::json!({
+                            "success": false,
+                            "message": format!("S3 test failed: {}", e)
+                        }))),
+                    }
+                }
+                Err(e) => Ok(Json(serde_json::json!({
+                    "success": false,
+                    "message": format!("S3 configuration error: {}", e)
+                }))),
+            }
+        }
+    }
+}
+
+/// Validate source health and configuration
+#[utoipa::path(
+    post,
+    path = "/api/sources/{id}/validate",
+    tag = "sources",
+    security(
+        ("bearer_auth" = [])
+    ),
+    params(
+        ("id" = Uuid, Path, description = "Source ID")
+    ),
+    responses(
+        (status = 200, description = "Validation started successfully"),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Source not found"),
+        (status = 500, description = "Internal server error")
+    )
+)]
+pub async fn validate_source(
+    auth_user: AuthUser,
+    Path(source_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> Result<Json<serde_json::Value>, StatusCode> {
+    info!("Starting validation check for source {} by user {}", source_id, auth_user.user.username);
+    
+    let source = state
+        .db
+        .get_source(auth_user.user.id, source_id)
+        .await
+        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+        .ok_or(StatusCode::NOT_FOUND)?;
+
+    // Start validation in background
+    let state_clone = state.clone();
+    let source_clone = source.clone();
+    tokio::spawn(async move {
+        if let Err(e) = crate::scheduling::source_scheduler::SourceScheduler::validate_source_health(&source_clone, &state_clone).await {
+            error!("Manual validation check failed for source {}: {}", source_clone.name, e);
+        }
+    });
+
+    Ok(Json(serde_json::json!({
+        "success": true,
+        "message": format!("Validation check started for source '{}'", source.name)
+    })))
+}
\ No newline at end of file
diff --git a/src/routes/sources_main.rs.bak b/src/routes/sources_main.rs.bak
new file mode 100644
index 0000000..5f6850c
--- /dev/null
+++ b/src/routes/sources_main.rs.bak
@@ -0,0 +1,41 @@
+use axum::{
+    routing::{get, post, delete, put},
+    Router,
+};
+use std::sync::Arc;
+
+use crate::AppState;
+
+// Declare the modules
+mod crud;
+mod sync;
+mod validation;
+mod estimation;
+
+// Import all the modularized functions
+use crud::*;
+use sync::*;
+use validation::*;
+use estimation::*;
+
+/// Sources router with all source-related endpoints
+pub fn router() -> Router<Arc<AppState>> {
+    Router::new()
+        // Basic CRUD operations
+        .route("/", get(list_sources).post(create_source))
+        .route("/{id}", get(get_source).put(update_source).delete(delete_source))
+        
+        // Sync operations
+        .route("/{id}/sync", post(trigger_sync))
+        .route("/{id}/sync/stop", post(stop_sync))
+        .route("/{id}/deep-scan", post(trigger_deep_scan))
+        
+        // Validation and testing
+        .route("/{id}/validate", post(validate_source))
+        .route("/{id}/test", post(test_connection))
+        .route("/test-connection", post(test_connection_with_config))
+        
+        // Estimation
+        .route("/{id}/estimate", post(estimate_crawl))
+        .route("/estimate", post(estimate_crawl_with_config))
+}
\ No newline at end of file
diff --git a/src/routes/sources.rs b/src/routes/sources_old.rs.bak
similarity index 100%
rename from src/routes/sources.rs
rename to src/routes/sources_old.rs.bak
diff --git a/src/swagger.rs b/src/swagger.rs
index 51dd76b..8dbcd14 100644
--- a/src/swagger.rs
+++ b/src/swagger.rs
@@ -97,17 +97,19 @@ use crate::{
         crate::routes::notifications::mark_all_notifications_read,
         crate::routes::notifications::delete_notification,
         // Sources endpoints
-        crate::routes::sources::list_sources,
-        crate::routes::sources::create_source,
-        crate::routes::sources::get_source,
-        crate::routes::sources::update_source,
-        crate::routes::sources::delete_source,
-        crate::routes::sources::trigger_sync,
-        crate::routes::sources::stop_sync,
-        crate::routes::sources::test_connection,
-        crate::routes::sources::estimate_crawl,
-        crate::routes::sources::estimate_crawl_with_config,
-        crate::routes::sources::test_connection_with_config,
+        crate::routes::sources::crud::list_sources,
+        crate::routes::sources::crud::create_source,
+        crate::routes::sources::crud::get_source,
+        crate::routes::sources::crud::update_source,
+        crate::routes::sources::crud::delete_source,
+        crate::routes::sources::sync::trigger_sync,
+        crate::routes::sources::sync::stop_sync,
+        crate::routes::sources::sync::trigger_deep_scan,
+        crate::routes::sources::validation::test_connection,
+        crate::routes::sources::validation::validate_source,
+        crate::routes::sources::estimation::estimate_crawl,
+        crate::routes::sources::estimation::estimate_crawl_with_config,
+        crate::routes::sources::validation::test_connection_with_config,
         // WebDAV endpoints
         crate::routes::webdav::start_webdav_sync,
         crate::routes::webdav::cancel_webdav_sync,