Differences from NZBGet

At a glance

Area	NZBGet	RustyGet
Language	C++	C++ moving to Rust module by module; Rust port status lists the modules ported so far
An article missing on every server	Lost; par2 repair or failure	Fetched from a matching file in another copy of the release, then checked by its place in the file (for yEnc articles), and, where they're available, by its checksum (with the default `CrcCheck=yes`) and par2
Duplicates	Spare downloads, tried one after another	One fleet: copies lend each other articles, bytes, and par2 volumes
Proving two copies hold the same files	Not done	Par2 checksums prove twins; alts are told apart
Not enough par2 blocks	Repair fails	Repairs with a twin's recovery volumes
Holes after the download	Left to par2	Patched with verified bytes from duplicates, across RAR, ZIP, 7-Zip, splits, and encryption
A download that can't complete	Runs to the end, then fails over	`HealthCheck=dupe` fails over within seconds, and a probe catches dead copies before they start
Finding more copies	Only what feeds and clients send	`DupeSearch` queries NZBHydra2, checks each copy on your servers, and queues the live ones
Clients sending many copies	One `append` per copy	One `appendfleet` call; RustyGet checks every copy and picks the best
Health of a backup	Unknown until it downloads	Measured, shown with its score, and used to skip dead copies
Configuration	155 options	17 more options and a new `HealthCheck` value, all off by default
API	NZBGet API	NZBGet API plus `appendfleet` and new fields; unsafe methods need POST; may diverge later
Queue files	NZBGet formats	NZBGet formats, with RustyGet's data in a trailer that NZBGet ignores
Bug fixes		About 100 fixes to inherited bugs, 96 of them reported upstream
Build and test workflows	Builds for every platform on each push	Turned off while the tests are rebuilt; only the documentation deploys

Duplicate fleets

Feature	Setting	Summary
Article fallback	`DupeArticleFallback=article`	Missing articles come from matching files in other copies, matched by par2 content, name, or structure, and checked against the download's par2 block checksums when the download's par2 set describes the file.
Cutover and lead rotation	Part of article fallback	After three recoveries in a file, RustyGet asks the lead duplicate first; after three misses in a row, the next duplicate leads.
Twins and alts	Automatic with Rust	par2 file lists prove which copies are byte-identical (twins) and which are other encodes (alts).
par2 from a twin	Automatic	When recovery blocks run short, RustyGet fetches and uses the fewest twin recovery volumes that cover the damage.
Stream repair	`DupeArticleFallback=stream`	Byte-level repair from duplicates after the download, with same-byte, whole-file, cross-packaging, and cross-encryption methods.
Live repair	`DupeArticleFallback=live`	Stream repair during the download.
Compressed donors	`DupeStreamDecompress=yes`	Extracts a compressed duplicate to repair from its contents.
Repair time limit	`DupeStreamTimeout`	Stops a stream repair that stalls, or that would take longer than downloading again.
Early failover	`HealthCheck=dupe`	Fails over as soon as a download can't complete, by failure counts, projected health, or par2 block damage.
Dead-copy probe	`HealthCheck=dupe`	Ten articles checked on every server before a download starts, when a backup waits.
Failed-article recheck	Article fallback or `HealthCheck=dupe`	After a failure, RustyGet asks for a sample of the failed articles again and retries them once if most now exist.
Donor search	`DupeSearch=yes`	Finds, checks, and queues more copies through NZBHydra2.
Fleet submission	`appendfleet`	A client sends up to 50 copies in one call.

See Duplicate fleets and Donor search.

Changes to inherited duplicate handling

Failover skips a backup whose NZB file is gone, a backup found dead, and a copy of a posting that already failed.
Among backups with equal scores, the most complete one goes first.
A title already on disk isn't downloaded again, and once one copy is on disk, the other copies stop.
With HealthCheck=dupe, a forced download fails over to its backups like a scored one.
When no backup qualifies, the log gives the reason for each one.
The duplicate mode of a download survives a restart.

Options

Sixteen new options are in INCOMING NZBS, after DupeCheck, and default to NZBGet's behavior: DupeArticleFallback, DupeStreamDecompress, DupeStreamTimeout, DupeSearch, DupeSearchUrl, DupeSearchApiKey, DupeSearchDelay, DupeSearchDryRun, DupeSearchMaxDonors, DupeHealthPercent, DupeHealthMin, DupeHealthMax, DupeBodyChecks, DupeHealthBudget, DupeMinAlive, and DupeFastDonors. HealthCheck gains the value dupe. One new option is in SECURITY: JsonP, off by default, turns on answers to JSON-P requests, which NZBGet always answered. No existing default changed.

Option parsing also changed: a ScriptDir with several folders creates each folder correctly, and a scheduler task with an unknown command is reported and skipped instead of running as PauseDownload.

New startup warnings point out risky combinations, such as donor search without DupeCheck or with fewer than three article retries.

See Configuration options for every option.

API

New method appendfleet, and new fields DupeRecoveredArticles, DupeRecoveredBytesLo, DupeRecoveredBytesHi, DupeRecoveredHoles, and LiveRepairing.
New stage STREAM_REPAIRING.
New NZB parameters, including DupeKind, DupeFiles, DupeAlive, and DupeFleet.
Methods that change the system or reach out to the network need POST. Plain GET runs only the methods that read.
JSON-P is off unless option JsonP turns it on. Then it runs only the methods that read, with the restricted user's access, so user names, passwords, and API keys come back as ***. In NZBGet, JSON-P ran every method with full access, and any web page could read the answers.
system.multicall respects the caller's access level.
Out-of-range numbers are rejected, saveconfig refuses malformed input, and several decoding and output bugs are fixed.

See API and compatibility.

Web interface

Fleet tags such as PRIMARY-3fa9c2, TWIN-3fa9c2, and ALT-81d0e4 on downloads and history items. Copies with the same fingerprint hold the same files.
A score badge with each backup's measured health.
A Repair badge during live repair, and a dupe repair post-processing status.
Recovered from duplicates in the statistics dialog.
History shows twin or alt instead of dupe where known.
Escaping of names, categories, messages, and extension text that NZBGet printed as HTML, and http or https links only.
Fixes to keyboard shortcuts, the filter box, upload errors, and size totals.

Security and robustness

DupeSearchApiKey, and any option with an API key in its name, is protected like a password: the restricted user and JSON-P see ***.
Extension downloads use generated filenames, closing a path traversal, and a failed update keeps the old version.
File cleanup never follows symbolic links.
NZB parsing refuses XML entity declarations.
The control port limits concurrent connections and keeps running when a thread or a connection fails.
State files accept lines of any length. In NZBGet, a line over 1,024 characters can crash the program.
The lock file is deleted only by the process that owns it.
Scripts get close-on-exec pipes, full-length output lines, and a correct exit code when a signal kills them.

Bug fixes

RustyGet fixes about 100 inherited bugs. 96 of them are reported to the NZBGet project, as its issues 940 to 1046. Highlights:

Downloads: 451 errors count as missing, 502 login refusals move on, malformed headers move to the next server, a connection that times out in the middle of an article is closed instead of reused, yEnc data can't overrun its range, and uuencoded parts no longer pass through the article cache.
Post-processing: ParScan=extended and ParScan=dupe find extra blocks again, split files join correctly, a failed direct unpack no longer deletes the download folder, ParTimeLimit counts from the right moment, RAR-rename works per folder, and archives with encrypted headers parse.
Queue and history: concurrent appends, names with newlines or slashes, long names, merges, splits, and edits of missing items all behave.
Files: moves across file systems and copies that fail leave no partial file behind.
Feeds and URLs: fixes to dates in RFC 822 format, redirects, protocol-relative URLs, and the retry loop.
Clock changes: the scheduler, quotas, and maintenance handle a clock that moves backward.

Build

rust/rust-toolchain.toml pins Rust 1.99.0. CMake finds Cargo and builds the crate into the binary; without Rust, the C++ fallbacks build instead.
The par2 parsing for twins uses the rust-par2 crate.
The inherited GitHub workflows for builds, packages, and tests are turned off in the Actions tab while the tests are rebuilt. Only the documentation workflow runs.