diff --git a/crates/api-types/Cargo.toml b/crates/api-types/Cargo.toml
index 6942318..0b44152 100644
--- a/crates/api-types/Cargo.toml
+++ b/crates/api-types/Cargo.toml
@@ -4,9 +4,10 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-domain     = { workspace = true }
-serde      = { workspace = true }
-serde_json = { workspace = true }
-uuid       = { workspace = true }
-chrono     = { workspace = true }
-utoipa     = { workspace = true }
+domain      = { workspace = true }
+application = { workspace = true }
+serde       = { workspace = true }
+serde_json  = { workspace = true }
+uuid        = { workspace = true }
+chrono      = { workspace = true }
+utoipa      = { workspace = true }
diff --git a/crates/api-types/src/requests.rs b/crates/api-types/src/requests.rs
index 157a047..76bc3e2 100644
--- a/crates/api-types/src/requests.rs
+++ b/crates/api-types/src/requests.rs
@@ -58,3 +58,79 @@ pub struct GenerateShareLinkRequest {
     pub expires_in_hours: Option<u64>,
     pub max_uses: Option<u32>,
 }
+
+// --- Organization ---
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct TagAssetRequest {
+    pub tag_name: String,
+}
+
+// --- Storage ---
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct CheckQuotaParams {
+    pub usage_type: Option<String>,
+    pub amount: Option<u64>,
+}
+
+// --- Catalog ---
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct RegisterAssetRequest {
+    pub volume_id: uuid::Uuid,
+    pub relative_path: String,
+    pub checksum: String,
+    pub asset_type: String,
+    pub mime_type: String,
+    pub file_size: u64,
+}
+
+// --- Sidecar ---
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct ResolveConflictRequest {
+    pub policy: String,
+}
+
+// --- Processing ---
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct EnqueueJobRequest {
+    pub job_type: String,
+    pub priority: Option<u32>,
+    pub payload: Option<std::collections::HashMap<String, serde_json::Value>>,
+    pub target_asset_id: Option<uuid::Uuid>,
+    pub batch_id: Option<uuid::Uuid>,
+}
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct CompleteJobRequest {
+    pub result: std::collections::HashMap<String, serde_json::Value>,
+}
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct FailJobRequest {
+    pub error: String,
+}
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct ManagePluginRequest {
+    pub plugin_id: Option<uuid::Uuid>,
+    pub action: String,
+    pub name: Option<String>,
+    pub plugin_type: Option<String>,
+    pub config: Option<std::collections::HashMap<String, serde_json::Value>>,
+}
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct ConfigurePipelineRequest {
+    pub trigger_event: String,
+    pub steps: Vec<PipelineStepRequest>,
+}
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct PipelineStepRequest {
+    pub plugin_id: uuid::Uuid,
+    pub config: std::collections::HashMap<String, serde_json::Value>,
+}
diff --git a/crates/api-types/src/responses.rs b/crates/api-types/src/responses.rs
index 4833bbc..b5eb4ae 100644
--- a/crates/api-types/src/responses.rs
+++ b/crates/api-types/src/responses.rs
@@ -196,3 +196,157 @@ impl SharedResourceResponse {
         }
     }
 }
+
+// --- Tag ---
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct TagResponse {
+    pub tag_id: Uuid,
+    pub name: String,
+    pub tag_source: String,
+}
+
+impl TagResponse {
+    pub fn from_domain(tag: &domain::entities::Tag) -> Self {
+        Self {
+            tag_id: *tag.tag_id.as_uuid(),
+            name: tag.name.clone(),
+            tag_source: format!("{:?}", tag.tag_source),
+        }
+    }
+}
+
+// --- Quota ---
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct QuotaCheckResponse {
+    pub allowed: bool,
+    pub current_usage: u64,
+    pub limit: u64,
+    pub is_unlimited: bool,
+}
+
+impl QuotaCheckResponse {
+    pub fn from_domain(result: &domain::storage::services::QuotaCheckResult) -> Self {
+        Self {
+            allowed: result.allowed,
+            current_usage: result.current_usage,
+            limit: result.limit,
+            is_unlimited: result.is_unlimited,
+        }
+    }
+}
+
+// --- Sidecar ---
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct SidecarExportResponse {
+    pub asset_id: Uuid,
+    pub status: String,
+    pub path: String,
+}
+
+impl SidecarExportResponse {
+    pub fn from_domain(record: &domain::entities::SidecarRecord) -> Self {
+        Self {
+            asset_id: *record.asset_id.as_uuid(),
+            status: format!("{:?}", record.sync_status),
+            path: record.sidecar_storage_path.clone(),
+        }
+    }
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct DetectChangesResponse {
+    pub changed_count: u32,
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct SidecarImportResponse {
+    pub asset_id: Uuid,
+    pub status: String,
+}
+
+// --- Processing ---
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct JobResponse {
+    pub job_id: Uuid,
+    pub job_type: String,
+    pub status: String,
+    pub priority: u32,
+    pub created_at: DateTime<Utc>,
+}
+
+impl JobResponse {
+    pub fn from_domain(job: &domain::entities::Job) -> Self {
+        Self {
+            job_id: *job.job_id.as_uuid(),
+            job_type: format!("{:?}", job.job_type),
+            status: format!("{:?}", job.status),
+            priority: job.priority,
+            created_at: *job.created_at.as_datetime(),
+        }
+    }
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct BatchProgressResponse {
+    pub batch_id: Uuid,
+    pub batch_type: String,
+    pub total: u32,
+    pub completed: u32,
+    pub failed: u32,
+    pub status: String,
+    pub jobs: Vec<JobResponse>,
+}
+
+impl BatchProgressResponse {
+    pub fn from_domain(progress: &application::processing::BatchProgress) -> Self {
+        Self {
+            batch_id: *progress.batch.batch_id.as_uuid(),
+            batch_type: progress.batch.batch_type.clone(),
+            total: progress.batch.total_jobs,
+            completed: progress.batch.completed_count,
+            failed: progress.batch.failed_count,
+            status: format!("{:?}", progress.batch.status),
+            jobs: progress.jobs.iter().map(JobResponse::from_domain).collect(),
+        }
+    }
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct PluginResponse {
+    pub plugin_id: Uuid,
+    pub name: String,
+    pub plugin_type: String,
+    pub is_enabled: bool,
+}
+
+impl PluginResponse {
+    pub fn from_domain(plugin: &domain::entities::Plugin) -> Self {
+        Self {
+            plugin_id: *plugin.plugin_id.as_uuid(),
+            name: plugin.name.clone(),
+            plugin_type: format!("{:?}", plugin.plugin_type),
+            is_enabled: plugin.is_enabled,
+        }
+    }
+}
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct PipelineResponse {
+    pub pipeline_id: Uuid,
+    pub trigger_event: String,
+    pub steps_count: usize,
+}
+
+impl PipelineResponse {
+    pub fn from_domain(pipeline: &domain::entities::ProcessingPipeline) -> Self {
+        Self {
+            pipeline_id: *pipeline.pipeline_id.as_uuid(),
+            trigger_event: pipeline.trigger_event.clone(),
+            steps_count: pipeline.steps.len(),
+        }
+    }
+}
diff --git a/crates/bootstrap/src/factory.rs b/crates/bootstrap/src/factory.rs
index 94e670d..443d34f 100644
--- a/crates/bootstrap/src/factory.rs
+++ b/crates/bootstrap/src/factory.rs
@@ -11,33 +11,52 @@ use adapters_auth::{BcryptPasswordHasher, JwtTokenIssuer};
 
 use adapters_postgres::{
     PostgresAlbumRepository, PostgresAssetMetadataRepository, PostgresAssetRepository,
-    PostgresIngestSessionRepository, PostgresLibraryPathRepository, PostgresQuotaRepository,
-    PostgresShareRepository, PostgresStorageVolumeRepository, PostgresUsageLedgerRepository,
-    PostgresUserRepository, PostgresVisibilityFilterRepository, connect, run_migrations,
+    PostgresDuplicateRepository, PostgresIngestSessionRepository, PostgresJobBatchRepository,
+    PostgresJobRepository, PostgresLibraryPathRepository, PostgresPipelineRepository,
+    PostgresPluginRepository, PostgresQuotaRepository, PostgresShareRepository,
+    PostgresSidecarRepository, PostgresStorageVolumeRepository, PostgresTagRepository,
+    PostgresUsageLedgerRepository, PostgresUserRepository, PostgresVisibilityFilterRepository,
+    connect, run_migrations,
 };
 
 use adapters_storage::LocalFileStorage;
 
 use application::{
-    catalog::{GetAssetHandler, GetTimelineHandler, ReadAssetFileHandler, UpdateMetadataHandler},
+    catalog::{
+        GetAssetHandler, GetTimelineHandler, ReadAssetFileHandler, RegisterAssetHandler,
+        UpdateMetadataHandler,
+    },
     identity::{GetProfileHandler, LoginUserHandler, RegisterUserHandler},
-    organization::{CreateAlbumHandler, GetAlbumHandler, ManageAlbumEntriesHandler},
+    organization::{
+        CreateAlbumHandler, GetAlbumHandler, ManageAlbumEntriesHandler, TagAssetHandler,
+    },
+    processing::{
+        CompleteJobHandler, ConfigurePipelineHandler, EnqueueJobHandler, FailJobHandler,
+        ManagePluginHandler, ReportBatchProgressHandler, StartJobHandler,
+    },
     sharing::{
         AccessSharedResourceHandler, GenerateShareLinkHandler, RevokeShareHandler,
         ShareResourceHandler,
     },
-    storage::{IngestAssetHandler, RegisterLibraryPathHandler, RegisterVolumeHandler},
+    sidecar::{
+        DetectExternalChangesHandler, ExportSidecarHandler, FullExportHandler, FullImportHandler,
+        ImportSidecarHandler, ResolveConflictHandler,
+    },
+    storage::{
+        CheckQuotaHandler, IngestAssetHandler, RegisterLibraryPathHandler, RegisterVolumeHandler,
+    },
 };
 use presentation::{
     routes::app_router,
     state::{
-        AppState, CatalogHandlers, IdentityHandlers, OrganizationHandlers, SharingHandlers,
-        StorageHandlers,
+        AppState, CatalogHandlers, IdentityHandlers, OrganizationHandlers, ProcessingHandlers,
+        SharingHandlers, SidecarHandlers, StorageHandlers,
     },
 };
 
 use crate::config::Config;
 use crate::log_event_publisher::LogEventPublisher;
+use crate::log_sidecar_writer::LogSidecarWriter;
 
 pub async fn build_app(config: &Config) -> Result<Router> {
     let pool = connect(&config.database_url).await?;
@@ -65,7 +84,15 @@ pub async fn build_app(config: &Config) -> Result<Router> {
     let session_repo = Arc::new(PostgresIngestSessionRepository::new(pool.clone()));
     let quota_repo = Arc::new(PostgresQuotaRepository::new(pool.clone()));
     let ledger_repo = Arc::new(PostgresUsageLedgerRepository::new(pool.clone()));
+    let tag_repo = Arc::new(PostgresTagRepository::new(pool.clone()));
+    let duplicate_repo = Arc::new(PostgresDuplicateRepository::new(pool.clone()));
+    let sidecar_repo = Arc::new(PostgresSidecarRepository::new(pool.clone()));
+    let job_repo = Arc::new(PostgresJobRepository::new(pool.clone()));
+    let batch_repo = Arc::new(PostgresJobBatchRepository::new(pool.clone()));
+    let plugin_repo = Arc::new(PostgresPluginRepository::new(pool.clone()));
+    let pipeline_repo = Arc::new(PostgresPipelineRepository::new(pool.clone()));
     let event_publisher: Arc<LogEventPublisher> = Arc::new(LogEventPublisher);
+    let sidecar_writer: Arc<LogSidecarWriter> = Arc::new(LogSidecarWriter);
 
     // File storage
     let storage_path = std::env::var("STORAGE_PATH").unwrap_or_else(|_| "./data/media".to_string());
@@ -80,8 +107,8 @@ pub async fn build_app(config: &Config) -> Result<Router> {
     let ingest_asset_handler = Arc::new(IngestAssetHandler::new(
         session_repo,
         path_repo.clone(),
-        quota_repo,
-        ledger_repo,
+        quota_repo.clone(),
+        ledger_repo.clone(),
         asset_repo.clone(),
         file_storage.clone(),
         event_publisher.clone(),
@@ -96,10 +123,78 @@ pub async fn build_app(config: &Config) -> Result<Router> {
     ));
     let update_metadata_handler = Arc::new(UpdateMetadataHandler::new(
         asset_repo.clone(),
-        metadata_repo,
+        metadata_repo.clone(),
         event_publisher.clone(),
     ));
-    let read_asset_file_handler = Arc::new(ReadAssetFileHandler::new(asset_repo, file_storage));
+    let read_asset_file_handler =
+        Arc::new(ReadAssetFileHandler::new(asset_repo.clone(), file_storage));
+
+    // Register asset handler
+    let register_asset_handler = Arc::new(RegisterAssetHandler::new(
+        asset_repo.clone(),
+        duplicate_repo,
+        event_publisher.clone(),
+    ));
+
+    // Tag handler
+    let tag_asset_handler = Arc::new(TagAssetHandler::new(asset_repo.clone(), tag_repo));
+
+    // Check quota handler
+    let check_quota_handler = Arc::new(CheckQuotaHandler::new(quota_repo, ledger_repo));
+
+    // Sidecar handlers
+    let export_sidecar_handler = Arc::new(ExportSidecarHandler::new(
+        metadata_repo.clone(),
+        sidecar_repo.clone(),
+        sidecar_writer.clone(),
+    ));
+    let detect_changes_handler = Arc::new(DetectExternalChangesHandler::new(
+        sidecar_repo.clone(),
+        sidecar_writer.clone(),
+    ));
+    let import_sidecar_handler = Arc::new(ImportSidecarHandler::new(
+        sidecar_repo.clone(),
+        sidecar_writer.clone(),
+        metadata_repo.clone(),
+    ));
+    let resolve_conflict_handler = Arc::new(ResolveConflictHandler::new(
+        sidecar_repo.clone(),
+        sidecar_writer.clone(),
+        metadata_repo.clone(),
+    ));
+    let full_export_handler = Arc::new(FullExportHandler::new(
+        asset_repo.clone(),
+        metadata_repo.clone(),
+        sidecar_repo.clone(),
+        sidecar_writer.clone(),
+    ));
+    let full_import_handler = Arc::new(FullImportHandler::new(
+        asset_repo,
+        metadata_repo,
+        sidecar_repo,
+        sidecar_writer,
+    ));
+
+    // Processing handlers
+    let enqueue_job_handler = Arc::new(EnqueueJobHandler::new(
+        job_repo.clone(),
+        event_publisher.clone(),
+    ));
+    let start_job_handler = Arc::new(StartJobHandler::new(job_repo.clone()));
+    let complete_job_handler = Arc::new(CompleteJobHandler::new(
+        job_repo.clone(),
+        batch_repo.clone(),
+        event_publisher.clone(),
+    ));
+    let fail_job_handler = Arc::new(FailJobHandler::new(
+        job_repo.clone(),
+        batch_repo.clone(),
+        event_publisher.clone(),
+    ));
+    let batch_progress_handler = Arc::new(ReportBatchProgressHandler::new(batch_repo, job_repo));
+    let manage_plugin_handler = Arc::new(ManagePluginHandler::new(plugin_repo.clone()));
+    let configure_pipeline_handler =
+        Arc::new(ConfigurePipelineHandler::new(pipeline_repo, plugin_repo));
 
     // Sharing repos & handlers
     let share_repo = Arc::new(PostgresShareRepository::new(pool.clone()));
@@ -130,17 +225,39 @@ pub async fn build_app(config: &Config) -> Result<Router> {
         get_timeline: get_timeline_handler,
         update_metadata: update_metadata_handler,
         read_asset_file: read_asset_file_handler,
+        register_asset: register_asset_handler,
     };
 
     let organization = OrganizationHandlers {
         create_album: create_album_handler,
         get_album: get_album_handler,
         manage_album_entries: manage_album_entries_handler,
+        tag_asset: tag_asset_handler,
     };
 
     let storage_handlers = StorageHandlers {
         register_volume: register_volume_handler,
         register_library_path: register_library_path_handler,
+        check_quota: check_quota_handler,
+    };
+
+    let sidecar = SidecarHandlers {
+        export: export_sidecar_handler,
+        detect_changes: detect_changes_handler,
+        import: import_sidecar_handler,
+        resolve: resolve_conflict_handler,
+        full_export: full_export_handler,
+        full_import: full_import_handler,
+    };
+
+    let processing = ProcessingHandlers {
+        enqueue_job: enqueue_job_handler,
+        start_job: start_job_handler,
+        complete_job: complete_job_handler,
+        fail_job: fail_job_handler,
+        batch_progress: batch_progress_handler,
+        manage_plugin: manage_plugin_handler,
+        configure_pipeline: configure_pipeline_handler,
     };
 
     let sharing = SharingHandlers {
@@ -156,6 +273,8 @@ pub async fn build_app(config: &Config) -> Result<Router> {
         organization,
         storage: storage_handlers,
         sharing,
+        sidecar,
+        processing,
         token_issuer: issuer,
     };
 
diff --git a/crates/bootstrap/src/lib.rs b/crates/bootstrap/src/lib.rs
index b8ba85b..b3a8391 100644
--- a/crates/bootstrap/src/lib.rs
+++ b/crates/bootstrap/src/lib.rs
@@ -1,3 +1,4 @@
 pub mod config;
 pub mod factory;
 pub mod log_event_publisher;
+pub mod log_sidecar_writer;
diff --git a/crates/bootstrap/src/log_sidecar_writer.rs b/crates/bootstrap/src/log_sidecar_writer.rs
new file mode 100644
index 0000000..2e6f0ba
--- /dev/null
+++ b/crates/bootstrap/src/log_sidecar_writer.rs
@@ -0,0 +1,21 @@
+use async_trait::async_trait;
+use domain::{errors::DomainError, ports::SidecarWriterPort, value_objects::StructuredData};
+
+pub struct LogSidecarWriter;
+
+#[async_trait]
+impl SidecarWriterPort for LogSidecarWriter {
+    fn format_name(&self) -> &str {
+        "log_noop"
+    }
+
+    async fn write_sidecar(&self, _data: &StructuredData, path: &str) -> Result<(), DomainError> {
+        tracing::info!(path, "sidecar write (no-op)");
+        Ok(())
+    }
+
+    async fn read_sidecar(&self, path: &str) -> Result<StructuredData, DomainError> {
+        tracing::info!(path, "sidecar read (no-op)");
+        Ok(StructuredData::new())
+    }
+}
diff --git a/crates/bootstrap/src/main.rs b/crates/bootstrap/src/main.rs
index a65ff78..61ac860 100644
--- a/crates/bootstrap/src/main.rs
+++ b/crates/bootstrap/src/main.rs
@@ -4,6 +4,7 @@ use tracing::info;
 mod config;
 mod factory;
 mod log_event_publisher;
+mod log_sidecar_writer;
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
diff --git a/crates/presentation/src/handlers/assets.rs b/crates/presentation/src/handlers/assets.rs
index 761f1ea..dbe5c1c 100644
--- a/crates/presentation/src/handlers/assets.rs
+++ b/crates/presentation/src/handlers/assets.rs
@@ -4,9 +4,16 @@ use crate::{
     extractors::{JwtClaims, UploadedAsset},
     state::AppState,
 };
-use api_types::responses::{AssetResponse, IngestResponse, TimelineResponse};
+use api_types::{
+    requests::{RegisterAssetRequest, TagAssetRequest},
+    responses::{AssetResponse, IngestResponse, TagResponse, TimelineResponse},
+};
 use application::{
-    catalog::{GetAssetQuery, GetTimelineQuery, ReadAssetFileQuery, UpdateMetadataCommand},
+    catalog::{
+        GetAssetQuery, GetTimelineQuery, ReadAssetFileQuery, RegisterAssetCommand,
+        UpdateMetadataCommand,
+    },
+    organization::TagAssetCommand,
     storage::IngestAssetCommand,
 };
 use axum::{
@@ -16,7 +23,11 @@ use axum::{
     http::{StatusCode, header},
     response::Response,
 };
-use domain::value_objects::{MetadataValue, StructuredData, SystemId};
+use domain::{
+    catalog::entities::AssetType,
+    errors::DomainError,
+    value_objects::{MetadataValue, StructuredData, SystemId},
+};
 
 #[derive(Debug, serde::Deserialize)]
 pub struct TimelineParams {
@@ -124,3 +135,51 @@ pub async fn serve_file(
         .body(Body::from(result.data))
         .map_err(|e| AppError::from(domain::errors::DomainError::Internal(e.to_string())))
 }
+
+pub async fn tag_asset(
+    State(state): State<AppState>,
+    claims: JwtClaims,
+    Path((asset_id,)): Path<(uuid::Uuid,)>,
+    Json(req): Json<TagAssetRequest>,
+) -> Result<(StatusCode, Json<TagResponse>), AppError> {
+    let cmd = TagAssetCommand {
+        asset_id: SystemId::from_uuid(asset_id),
+        tag_name: req.tag_name,
+        user_id: claims.user_id,
+    };
+    let (tag, _asset_tag) = state.organization.tag_asset.execute(cmd).await?;
+    Ok((StatusCode::CREATED, Json(TagResponse::from_domain(&tag))))
+}
+
+fn parse_asset_type(s: &str) -> Result<AssetType, AppError> {
+    match s {
+        "image" => Ok(AssetType::Image),
+        "video" => Ok(AssetType::Video),
+        "live_photo" => Ok(AssetType::LivePhoto),
+        _ => Err(AppError::from(DomainError::Validation(format!(
+            "Invalid asset type: {s}"
+        )))),
+    }
+}
+
+pub async fn register_asset(
+    State(state): State<AppState>,
+    claims: JwtClaims,
+    Json(req): Json<RegisterAssetRequest>,
+) -> Result<(StatusCode, Json<AssetResponse>), AppError> {
+    let asset_type = parse_asset_type(&req.asset_type)?;
+    let cmd = RegisterAssetCommand {
+        volume_id: SystemId::from_uuid(req.volume_id),
+        relative_path: req.relative_path,
+        checksum: req.checksum,
+        asset_type,
+        mime_type: req.mime_type,
+        file_size: req.file_size,
+        owner_id: claims.user_id,
+    };
+    let (asset, _dup_group) = state.catalog.register_asset.execute(cmd).await?;
+    Ok((
+        StatusCode::CREATED,
+        Json(AssetResponse::from_domain(&asset, &StructuredData::new())),
+    ))
+}
diff --git a/crates/presentation/src/handlers/mod.rs b/crates/presentation/src/handlers/mod.rs
index c04f858..5d2c2cf 100644
--- a/crates/presentation/src/handlers/mod.rs
+++ b/crates/presentation/src/handlers/mod.rs
@@ -2,5 +2,7 @@ pub mod albums;
 pub mod assets;
 pub mod auth;
 pub mod health;
+pub mod processing;
 pub mod sharing;
+pub mod sidecar;
 pub mod storage;
diff --git a/crates/presentation/src/handlers/processing.rs b/crates/presentation/src/handlers/processing.rs
new file mode 100644
index 0000000..0af6e1a
--- /dev/null
+++ b/crates/presentation/src/handlers/processing.rs
@@ -0,0 +1,197 @@
+use crate::{errors::AppError, extractors::JwtClaims, state::AppState};
+use api_types::{
+    requests::{
+        CompleteJobRequest, ConfigurePipelineRequest, EnqueueJobRequest, FailJobRequest,
+        ManagePluginRequest,
+    },
+    responses::{BatchProgressResponse, JobResponse, PipelineResponse, PluginResponse},
+};
+use application::processing::{
+    CompleteJobCommand, ConfigurePipelineCommand, EnqueueJobCommand, FailJobCommand,
+    ManagePluginCommand, PipelineStepConfig, PluginAction, ReportBatchProgressQuery,
+    StartJobCommand,
+};
+use axum::{
+    Json,
+    extract::{Path, State},
+    http::StatusCode,
+};
+use domain::{
+    entities::{JobType, PluginType},
+    errors::DomainError,
+    value_objects::{MetadataValue, StructuredData, SystemId},
+};
+
+fn parse_job_type(s: &str) -> JobType {
+    match s {
+        "scan_directory" => JobType::ScanDirectory,
+        "extract_metadata" => JobType::ExtractMetadata,
+        "generate_derivative" => JobType::GenerateDerivative,
+        "sync_sidecar" => JobType::SyncSidecar,
+        "detect_duplicates" => JobType::DetectDuplicates,
+        other => JobType::Custom(other.to_string()),
+    }
+}
+
+fn parse_plugin_type(s: &str) -> Result<PluginType, AppError> {
+    match s {
+        "media_processor" => Ok(PluginType::MediaProcessor),
+        "scheduled_task" => Ok(PluginType::ScheduledTask),
+        "sidecar_writer" => Ok(PluginType::SidecarWriter),
+        _ => Err(AppError::from(DomainError::Validation(format!(
+            "Invalid plugin type: {s}"
+        )))),
+    }
+}
+
+fn hashmap_to_structured(
+    map: &std::collections::HashMap<String, serde_json::Value>,
+) -> StructuredData {
+    let mut sd = StructuredData::new();
+    for (k, v) in map {
+        sd.insert(k.clone(), MetadataValue::from(v.clone()));
+    }
+    sd
+}
+
+pub async fn enqueue_job(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Json(req): Json<EnqueueJobRequest>,
+) -> Result<(StatusCode, Json<JobResponse>), AppError> {
+    let payload = req
+        .payload
+        .as_ref()
+        .map(hashmap_to_structured)
+        .unwrap_or_default();
+
+    let cmd = EnqueueJobCommand {
+        job_type: parse_job_type(&req.job_type),
+        priority: req.priority.unwrap_or(0),
+        payload,
+        target_asset_id: req.target_asset_id.map(SystemId::from_uuid),
+        batch_id: req.batch_id.map(SystemId::from_uuid),
+    };
+    let job = state.processing.enqueue_job.execute(cmd).await?;
+    Ok((StatusCode::CREATED, Json(JobResponse::from_domain(&job))))
+}
+
+pub async fn start_job(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((job_id,)): Path<(uuid::Uuid,)>,
+) -> Result<Json<JobResponse>, AppError> {
+    let cmd = StartJobCommand {
+        job_id: SystemId::from_uuid(job_id),
+    };
+    let job = state.processing.start_job.execute(cmd).await?;
+    Ok(Json(JobResponse::from_domain(&job)))
+}
+
+pub async fn complete_job(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((job_id,)): Path<(uuid::Uuid,)>,
+    Json(req): Json<CompleteJobRequest>,
+) -> Result<Json<JobResponse>, AppError> {
+    let cmd = CompleteJobCommand {
+        job_id: SystemId::from_uuid(job_id),
+        result: hashmap_to_structured(&req.result),
+    };
+    let job = state.processing.complete_job.execute(cmd).await?;
+    Ok(Json(JobResponse::from_domain(&job)))
+}
+
+pub async fn fail_job(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((job_id,)): Path<(uuid::Uuid,)>,
+    Json(req): Json<FailJobRequest>,
+) -> Result<Json<JobResponse>, AppError> {
+    let cmd = FailJobCommand {
+        job_id: SystemId::from_uuid(job_id),
+        error: req.error,
+    };
+    let job = state.processing.fail_job.execute(cmd).await?;
+    Ok(Json(JobResponse::from_domain(&job)))
+}
+
+pub async fn batch_progress(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((batch_id,)): Path<(uuid::Uuid,)>,
+) -> Result<Json<BatchProgressResponse>, AppError> {
+    let query = ReportBatchProgressQuery {
+        batch_id: SystemId::from_uuid(batch_id),
+    };
+    let progress = state.processing.batch_progress.execute(query).await?;
+    Ok(Json(BatchProgressResponse::from_domain(&progress)))
+}
+
+pub async fn manage_plugin(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Json(req): Json<ManagePluginRequest>,
+) -> Result<(StatusCode, Json<PluginResponse>), AppError> {
+    let action = match req.action.as_str() {
+        "create" => {
+            let name = req.name.ok_or_else(|| {
+                AppError::from(DomainError::Validation("name required for create".into()))
+            })?;
+            let pt = req.plugin_type.as_deref().unwrap_or("media_processor");
+            let plugin_type = parse_plugin_type(pt)?;
+            let config = req
+                .config
+                .as_ref()
+                .map(hashmap_to_structured)
+                .unwrap_or_default();
+            PluginAction::Create {
+                name,
+                plugin_type,
+                config,
+            }
+        }
+        "enable" => PluginAction::Enable,
+        "disable" => PluginAction::Disable,
+        other => {
+            return Err(AppError::from(DomainError::Validation(format!(
+                "Invalid plugin action: {other}. Use create, enable, or disable"
+            ))));
+        }
+    };
+
+    let cmd = ManagePluginCommand {
+        plugin_id: req.plugin_id.map(SystemId::from_uuid),
+        action,
+    };
+    let plugin = state.processing.manage_plugin.execute(cmd).await?;
+    Ok((
+        StatusCode::CREATED,
+        Json(PluginResponse::from_domain(&plugin)),
+    ))
+}
+
+pub async fn configure_pipeline(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Json(req): Json<ConfigurePipelineRequest>,
+) -> Result<(StatusCode, Json<PipelineResponse>), AppError> {
+    let steps = req
+        .steps
+        .iter()
+        .map(|s| PipelineStepConfig {
+            plugin_id: SystemId::from_uuid(s.plugin_id),
+            config: hashmap_to_structured(&s.config),
+        })
+        .collect();
+
+    let cmd = ConfigurePipelineCommand {
+        trigger_event: req.trigger_event,
+        steps,
+    };
+    let pipeline = state.processing.configure_pipeline.execute(cmd).await?;
+    Ok((
+        StatusCode::CREATED,
+        Json(PipelineResponse::from_domain(&pipeline)),
+    ))
+}
diff --git a/crates/presentation/src/handlers/sidecar.rs b/crates/presentation/src/handlers/sidecar.rs
new file mode 100644
index 0000000..c6e717b
--- /dev/null
+++ b/crates/presentation/src/handlers/sidecar.rs
@@ -0,0 +1,103 @@
+use crate::{errors::AppError, extractors::JwtClaims, state::AppState};
+use api_types::responses::{DetectChangesResponse, SidecarExportResponse, SidecarImportResponse};
+use application::sidecar::{
+    DetectExternalChangesCommand, ExportSidecarCommand, FullExportCommand, FullImportCommand,
+    ImportSidecarCommand, ResolveConflictCommand,
+};
+use axum::{
+    Json,
+    extract::{Path, State},
+};
+use domain::{entities::ConflictPolicy, errors::DomainError, value_objects::SystemId};
+
+fn parse_conflict_policy(s: &str) -> Result<ConflictPolicy, AppError> {
+    match s {
+        "db_wins" => Ok(ConflictPolicy::DbWins),
+        "file_wins" => Ok(ConflictPolicy::FileWins),
+        _ => Err(AppError::from(DomainError::Validation(format!(
+            "Invalid conflict policy: {s}. Use db_wins or file_wins"
+        )))),
+    }
+}
+
+pub async fn export_sidecar(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((asset_id,)): Path<(uuid::Uuid,)>,
+) -> Result<Json<SidecarExportResponse>, AppError> {
+    let cmd = ExportSidecarCommand {
+        asset_id: SystemId::from_uuid(asset_id),
+    };
+    let record = state.sidecar.export.execute(cmd).await?;
+    Ok(Json(SidecarExportResponse::from_domain(&record)))
+}
+
+pub async fn detect_changes(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+) -> Result<Json<DetectChangesResponse>, AppError> {
+    let count = state
+        .sidecar
+        .detect_changes
+        .execute(DetectExternalChangesCommand)
+        .await?;
+    Ok(Json(DetectChangesResponse {
+        changed_count: count,
+    }))
+}
+
+pub async fn import_sidecar(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((asset_id,)): Path<(uuid::Uuid,)>,
+) -> Result<Json<SidecarImportResponse>, AppError> {
+    let cmd = ImportSidecarCommand {
+        asset_id: SystemId::from_uuid(asset_id),
+    };
+    let metadata = state.sidecar.import.execute(cmd).await?;
+    Ok(Json(SidecarImportResponse {
+        asset_id: *metadata.asset_id.as_uuid(),
+        status: "imported".to_string(),
+    }))
+}
+
+pub async fn resolve_conflict(
+    State(state): State<AppState>,
+    _claims: JwtClaims,
+    Path((asset_id,)): Path<(uuid::Uuid,)>,
+    Json(req): Json<api_types::requests::ResolveConflictRequest>,
+) -> Result<Json<SidecarExportResponse>, AppError> {
+    let policy = parse_conflict_policy(&req.policy)?;
+    let cmd = ResolveConflictCommand {
+        asset_id: SystemId::from_uuid(asset_id),
+        policy,
+    };
+    let record = state.sidecar.resolve.execute(cmd).await?;
+    Ok(Json(SidecarExportResponse::from_domain(&record)))
+}
+
+pub async fn full_export(
+    State(state): State<AppState>,
+    claims: JwtClaims,
+) -> Result<Json<DetectChangesResponse>, AppError> {
+    let cmd = FullExportCommand {
+        owner_id: claims.user_id,
+    };
+    let count = state.sidecar.full_export.execute(cmd).await?;
+    Ok(Json(DetectChangesResponse {
+        changed_count: count,
+    }))
+}
+
+pub async fn full_import(
+    State(state): State<AppState>,
+    claims: JwtClaims,
+) -> Result<Json<DetectChangesResponse>, AppError> {
+    let cmd = FullImportCommand {
+        owner_id: claims.user_id,
+    };
+    let count = state.sidecar.full_import.execute(cmd).await?;
+    Ok(Json(DetectChangesResponse {
+        changed_count: count,
+    }))
+}
diff --git a/crates/presentation/src/handlers/storage.rs b/crates/presentation/src/handlers/storage.rs
index 37aa5e6..de87fda 100644
--- a/crates/presentation/src/handlers/storage.rs
+++ b/crates/presentation/src/handlers/storage.rs
@@ -1,11 +1,15 @@
 use crate::{errors::AppError, extractors::JwtClaims, state::AppState};
 use api_types::{
-    requests::{RegisterLibraryPathRequest, RegisterVolumeRequest},
-    responses::{LibraryPathResponse, VolumeResponse},
+    requests::{CheckQuotaParams, RegisterLibraryPathRequest, RegisterVolumeRequest},
+    responses::{LibraryPathResponse, QuotaCheckResponse, VolumeResponse},
 };
-use application::storage::{RegisterLibraryPathCommand, RegisterVolumeCommand};
-use axum::{Json, extract::State, http::StatusCode};
-use domain::value_objects::SystemId;
+use application::storage::{CheckQuotaQuery, RegisterLibraryPathCommand, RegisterVolumeCommand};
+use axum::{
+    Json,
+    extract::{Query, State},
+    http::StatusCode,
+};
+use domain::{entities::UsageType, errors::DomainError, value_objects::SystemId};
 
 pub async fn register_volume(
     State(state): State<AppState>,
@@ -41,3 +45,38 @@ pub async fn register_library_path(
         Json(LibraryPathResponse::from_domain(&path)),
     ))
 }
+
+const DEFAULT_QUOTA_USAGE_TYPE: &str = "storage_bytes";
+const DEFAULT_QUOTA_AMOUNT: u64 = 0;
+
+fn parse_usage_type(s: &str) -> Result<UsageType, AppError> {
+    match s {
+        "storage_bytes" => Ok(UsageType::StorageBytes),
+        "process_jobs" => Ok(UsageType::ProcessJobs),
+        "api_calls" => Ok(UsageType::ApiCalls),
+        "indexing_size" => Ok(UsageType::IndexingSize),
+        _ => Err(AppError::from(DomainError::Validation(format!(
+            "Invalid usage type: {s}"
+        )))),
+    }
+}
+
+pub async fn check_quota(
+    State(state): State<AppState>,
+    claims: JwtClaims,
+    Query(params): Query<CheckQuotaParams>,
+) -> Result<Json<QuotaCheckResponse>, AppError> {
+    let usage_type = parse_usage_type(
+        params
+            .usage_type
+            .as_deref()
+            .unwrap_or(DEFAULT_QUOTA_USAGE_TYPE),
+    )?;
+    let query = CheckQuotaQuery {
+        user_id: claims.user_id,
+        usage_type,
+        requested_amount: params.amount.unwrap_or(DEFAULT_QUOTA_AMOUNT),
+    };
+    let result = state.storage.check_quota.execute(query).await?;
+    Ok(Json(QuotaCheckResponse::from_domain(&result)))
+}
diff --git a/crates/presentation/src/routes.rs b/crates/presentation/src/routes.rs
index 0e42da9..51eb975 100644
--- a/crates/presentation/src/routes.rs
+++ b/crates/presentation/src/routes.rs
@@ -1,5 +1,5 @@
 use crate::{
-    handlers::{albums, assets, auth, health, sharing, storage},
+    handlers::{albums, assets, auth, health, processing, sharing, sidecar, storage},
     openapi::openapi_router,
     state::AppState,
 };
@@ -24,10 +24,12 @@ pub fn api_v1_router() -> Router<AppState> {
         )
         // assets
         .route("/assets/ingest", post(assets::ingest))
+        .route("/assets/register", post(assets::register_asset))
         .route("/assets/timeline", get(assets::timeline))
         .route("/assets/{id}", get(assets::get_asset))
         .route("/assets/{id}/metadata", put(assets::update_metadata))
         .route("/assets/{id}/file", get(assets::serve_file))
+        .route("/assets/{id}/tags", post(assets::tag_asset))
         // sharing
         .route("/sharing", post(sharing::share_resource))
         .route("/sharing/links", post(sharing::generate_link))
@@ -39,6 +41,25 @@ pub fn api_v1_router() -> Router<AppState> {
             "/storage/library-paths",
             post(storage::register_library_path),
         )
+        .route("/storage/quota", get(storage::check_quota))
+        // sidecar
+        .route("/sidecar/export/{asset_id}", post(sidecar::export_sidecar))
+        .route("/sidecar/detect-changes", post(sidecar::detect_changes))
+        .route("/sidecar/import/{asset_id}", post(sidecar::import_sidecar))
+        .route(
+            "/sidecar/resolve/{asset_id}",
+            post(sidecar::resolve_conflict),
+        )
+        .route("/sidecar/full-export", post(sidecar::full_export))
+        .route("/sidecar/full-import", post(sidecar::full_import))
+        // processing
+        .route("/jobs", post(processing::enqueue_job))
+        .route("/jobs/{id}/start", post(processing::start_job))
+        .route("/jobs/{id}/complete", post(processing::complete_job))
+        .route("/jobs/{id}/fail", post(processing::fail_job))
+        .route("/jobs/batches/{id}", get(processing::batch_progress))
+        .route("/plugins", post(processing::manage_plugin))
+        .route("/pipelines", post(processing::configure_pipeline))
 }
 
 pub fn app_router() -> Router<AppState> {
diff --git a/crates/presentation/src/state.rs b/crates/presentation/src/state.rs
index ebaed94..6490395 100644
--- a/crates/presentation/src/state.rs
+++ b/crates/presentation/src/state.rs
@@ -1,14 +1,29 @@
 use std::sync::Arc;
 
 use application::{
-    catalog::{GetAssetHandler, GetTimelineHandler, ReadAssetFileHandler, UpdateMetadataHandler},
+    catalog::{
+        GetAssetHandler, GetTimelineHandler, ReadAssetFileHandler, RegisterAssetHandler,
+        UpdateMetadataHandler,
+    },
     identity::{GetProfileHandler, LoginUserHandler, RegisterUserHandler},
-    organization::{CreateAlbumHandler, GetAlbumHandler, ManageAlbumEntriesHandler},
+    organization::{
+        CreateAlbumHandler, GetAlbumHandler, ManageAlbumEntriesHandler, TagAssetHandler,
+    },
+    processing::{
+        CompleteJobHandler, ConfigurePipelineHandler, EnqueueJobHandler, FailJobHandler,
+        ManagePluginHandler, ReportBatchProgressHandler, StartJobHandler,
+    },
     sharing::{
         AccessSharedResourceHandler, GenerateShareLinkHandler, RevokeShareHandler,
         ShareResourceHandler,
     },
-    storage::{IngestAssetHandler, RegisterLibraryPathHandler, RegisterVolumeHandler},
+    sidecar::{
+        DetectExternalChangesHandler, ExportSidecarHandler, FullExportHandler, FullImportHandler,
+        ImportSidecarHandler, ResolveConflictHandler,
+    },
+    storage::{
+        CheckQuotaHandler, IngestAssetHandler, RegisterLibraryPathHandler, RegisterVolumeHandler,
+    },
 };
 use domain::ports::TokenIssuer;
 
@@ -26,6 +41,7 @@ pub struct CatalogHandlers {
     pub get_timeline: Arc<GetTimelineHandler>,
     pub update_metadata: Arc<UpdateMetadataHandler>,
     pub read_asset_file: Arc<ReadAssetFileHandler>,
+    pub register_asset: Arc<RegisterAssetHandler>,
 }
 
 #[derive(Clone)]
@@ -33,12 +49,14 @@ pub struct OrganizationHandlers {
     pub create_album: Arc<CreateAlbumHandler>,
     pub get_album: Arc<GetAlbumHandler>,
     pub manage_album_entries: Arc<ManageAlbumEntriesHandler>,
+    pub tag_asset: Arc<TagAssetHandler>,
 }
 
 #[derive(Clone)]
 pub struct StorageHandlers {
     pub register_volume: Arc<RegisterVolumeHandler>,
     pub register_library_path: Arc<RegisterLibraryPathHandler>,
+    pub check_quota: Arc<CheckQuotaHandler>,
 }
 
 #[derive(Clone)]
@@ -49,6 +67,27 @@ pub struct SharingHandlers {
     pub access: Arc<AccessSharedResourceHandler>,
 }
 
+#[derive(Clone)]
+pub struct SidecarHandlers {
+    pub export: Arc<ExportSidecarHandler>,
+    pub detect_changes: Arc<DetectExternalChangesHandler>,
+    pub import: Arc<ImportSidecarHandler>,
+    pub resolve: Arc<ResolveConflictHandler>,
+    pub full_export: Arc<FullExportHandler>,
+    pub full_import: Arc<FullImportHandler>,
+}
+
+#[derive(Clone)]
+pub struct ProcessingHandlers {
+    pub enqueue_job: Arc<EnqueueJobHandler>,
+    pub start_job: Arc<StartJobHandler>,
+    pub complete_job: Arc<CompleteJobHandler>,
+    pub fail_job: Arc<FailJobHandler>,
+    pub batch_progress: Arc<ReportBatchProgressHandler>,
+    pub manage_plugin: Arc<ManagePluginHandler>,
+    pub configure_pipeline: Arc<ConfigurePipelineHandler>,
+}
+
 #[derive(Clone)]
 pub struct AppState {
     pub identity: IdentityHandlers,
@@ -56,5 +95,7 @@ pub struct AppState {
     pub organization: OrganizationHandlers,
     pub storage: StorageHandlers,
     pub sharing: SharingHandlers,
+    pub sidecar: SidecarHandlers,
+    pub processing: ProcessingHandlers,
     pub token_issuer: Arc<dyn TokenIssuer>,
 }