Firelink/TORRENT_FEATURES.md

Firelink Torrent feature matrix

This is the current product-facing comparison for BitTorrent features exposed by Firelink's bundled Aria2 engine. It intentionally excludes Aria2's generic HTTP/FTP/Metalink options, shell hooks, and daemon-admin RPC methods that do not belong in the download UI. The Aria2 reference is the 1.37.0 manual.

Implemented

• Local .torrent files, magnet links, and remote HTTP(S) .torrent metadata. Remote metadata is bounded, SSRF-checked, redirect-checked, parsed, and cached before it enters the normal addTorrent path.
• Bencode validation, canonical info-hash checks, safe output paths, managed metadata retention, selected-file preview, select-file, and index-out.
• Firelink queue admission, per-queue/global permits, pause/resume, cancel, retry/GID replacement, restart recovery, terminal reconciliation, and output ownership for Torrent lifecycles.
• Optional seeding by time and/or ratio, upload progress, upload limits, seeders telemetry, per-Torrent maximum peers, and the Aria2 bt-request-peer-speed-limit threshold.
• Bounded, read-only Torrent peer diagnostics through aria2.getPeers. Firelink discards peer IPs, ports, IDs, and bitfields at the native boundary; the selected-Torrent detail view exposes only operational speeds, seeder, and choking flags, with a bounded display count.
• Global DHT, IPv6 DHT, PEX, and Local Peer Discovery toggles.
• Optional piece-integrity verification, including the explicit policy that disables unverified seeding when verification is requested.
• Optional stall timeout through bt-stop-timeout, persisted with each Torrent and re-applied when it starts or retries. A value of zero disables the policy; Aria2 stops the Torrent after the configured consecutive zero-download-speed interval.
• Additional per-Torrent tracker URLs through bt-tracker, with bounded and credential-free HTTP/HTTPS/UDP validation.
• Per-Torrent tracker exclusion through bt-exclude-tracker, including Aria2's explicit * value for excluding all announce URLs. Exclusions are persisted, normalized, reapplied on retries, and do not change DHT or PEX settings.
• Deterministic local Aria2 smoke coverage for metadata resolution, selected output, pause/resume, ownership, cancellation/removal, unavailable trackers, daemon failure, and bt-stop-timeout terminal behavior; RPC-boundary coverage is separate.

Priority tiers for remaining work

Tier 0 — reliability and user-visible control

No remaining Tier 0 items.

Tier 1 — transfer policy and storage behavior

1. Piece/file priority — expose bt-prioritize-piece for head/tail previewing and a deliberate file-priority model beyond the current binary selected/unselected state.
2. Safe removal of unselected files — expose bt-remove-unselected-file only as an explicit destructive choice, with ownership-aware confirmation and tests for cancellation, retry, and reconfiguration.
3. Encryption policy — expose bt-force-encryption, bt-require-crypto, and bt-min-crypto-level as one validated policy so users cannot accidentally select contradictory combinations.
4. Tracker timing controls — expose tracker connect timeout, request timeout, and interval only when their effect on battery/network behavior is explained and persisted.

Tier 2 — advanced networking and daemon tuning

1. Configurable TCP/UDP listen ports, external IP, DHT entry points, IPv6 DHT listen address, and LPD interface, with platform/firewall warnings.
2. Global BitTorrent open-file limits and peer identity/agent controls.
3. Aria2 follow-torrent/in-memory follow behavior for generic downloads only if the resulting child-GID ownership model can be represented safely; the current explicit metadata path intentionally avoids unmapped child jobs.

The first implementation in this task was remote .torrent metadata intake; follow-up implementations add stall-timeout control, bounded peer diagnostics, and persisted tracker exclusion.