Feature	Description	Priority
GUI Config Editing	Structured editing of the config in the GUI, currently only via YAML	High
Linux GUI packaging	Native .deb/.rpm packages and a repository for streamlined installation	High
Windows GUI packaging	MSI installer and/or winget package for first-class Windows support	High
Snapshot filtering	By host, tag, path, date ranges	Medium
Async I/O	Non-blocking storage operations	Medium
JSON output mode	Structured JSON output for all CLI commands to enable scripting and integration with monitoring tools	Medium
Per-token permissions	Expand permissions from full/append-only to also limit reading and maintenance	Medium

Feature	Description
Pack files	Chunks grouped into ~32 MiB packs with dynamic sizing, separate data/tree packs
Retention policies	keep_daily, keep_weekly, keep_monthly, keep_yearly, keep_last, keep_within
snapshot delete command	Remove individual snapshots, decrement refcounts
prune command	Apply retention policies, remove expired snapshots
check command	Structural integrity + optional --verify-data for full content verification
Type-safe PackId	Newtype for pack file identifiers with storage_key()
compact command	Rewrite packs to reclaim space from orphaned blobs after delete/prune
REST server	axum-based backup server with auth, append-only, quotas, freshness tracking, lock TTL, server-side compaction
REST backend	StorageBackend over HTTP with range-read support
Tiered dedup index	Backup dedup via session map + xor filter + mmap dedup cache, with safe fallback to HashMap dedup mode
Restore mmap cache	Index-light restore planning via local restore cache; fallback to filtered full-index loading when needed
Incremental index update	save_state() fast path merges IndexDelta into local full-index cache and serializes index from cache
Bounded parallel pipeline	Byte-budgeted pipeline (pipeline_buffer_mib) with bounded worker/upload concurrency
mmap-backed pack assembly	Data-pack assembly uses mmap-backed temp files (with fallback chain) to reduce heap residency under memory pressure
cache_dir override	Configurable root for file cache, dedup/restore/full-index caches, and preferred mmap temp-file location
Parallel transforms	rayon-backed compression/encryption within the bounded pipeline
break-lock command	Forced stale-lock cleanup for backend/object lock recovery
Compact pack health accounting	Compact analysis reports/tracks corrupt and orphan packs in addition to reclaimable dead bytes
File-level cache	inode/mtime/ctime skip for unchanged files — avoids read, chunk, compress, encrypt. Keys are 16-byte BLAKE2b path hashes (with transparent legacy migration). Stored locally under the per-repo cache root (default platform cache dir + vykar, or cache_dir override).
Daemon mode	vykar daemon runs scheduled backup→prune→compact→check cycles with two-stage signal handling
Server-side pack verification	vykar check delegates pack integrity checks to vykar-server when available; --distrust-server opts out
Upload integrity	REST PUT includes X-Content-BLAKE2b header; server verifies during streaming write
vykar-protocol crate	Shared wire-format types and pack/protocol version constants between client and server
Type-safe SnapshotId	Newtype for snapshot identifiers with storage_key() (ManifestId dropped — manifest is a singleton)