中文：README_CN.md
Version Notice: aria2-rust is currently in a period of rapid iteration. Older versions may retain various issues and basic functionality is not guaranteed. Please use the latest version as soon as possible.
Start with the documentation index. The main user paths are:
The ultra-fast download utility — rewritten in Rust
Features • Quick Start • Usage • Architecture • Performance • Building • License
aria2_rust is an independent Rust download engine. It provides practical compatibility with the aria2 ecosystem so existing users and tools can migrate easily, while its architecture, safety, performance, and product direction are its own. The default build supports HTTP/HTTPS, FTP, BitTorrent, and JSON-RPC/XML-RPC/WebSocket paths; Metalink and SFTP require their Cargo features; compatibility status and verification evidence are tracked in docs/compatibility-status.md.
Phosona Manager is a
cross-platform GUI download tool highly based on aria2_rust. Its desktop
application, installers, and GUI releases will be published in the
Phosona_Manager repository,
while this repository remains the home for the Rust engine, protocol crates,
and RPC services.
Phosona Manager will also ship a new P2P network model focused on sharing and incentive mechanisms, inspired by BitTorrent, eMule, and similar systems.
Binary releases are available in four feature tiers; see the
release artifact guide to choose between
minimal, standard, tui, and full.
The capability inventory below describes code paths, not a claim that every feature has passed the complete cross-platform E2E matrix. See the compatibility status for the current gate.
- Multi-Protocol Download: HTTP/HTTPS, FTP, and BitTorrent by default; SFTP and Metalink are feature-gated
- Multi-Source Mirrors: Automatic segmented parallel downloads from multiple URIs for maximum bandwidth utilization
- Resume Support: Checkpoint-based resume for the main download paths; protocol-specific compatibility is tracked in the matrix
- BitTorrent:
- ✅ DHT network (KRPC + routing table + bootstrap)
- ✅ Tracker communication (UDP/HTTP)
- ✅ Peer Exchange (PEX, per-peer BEP 10 extension-ID negotiation)
- ✅ MSE/PE encryption (BEP14 handshake)
- ✅ Choking algorithms + seed-time/ratio support
- ✅ RarestFirst piece selection
- ✅ uTP protocol (BEP 29) - Not in original aria2 C++
- ✅ Web Seeds (BEP 19)
- ✅ LPD (Local Peer Discovery)
- ✅ Complete seeding mode with upload support
- Rate Limiting: Token bucket algorithm with per-task/global limits
- Cookie Management: Netscape format persistence + auto-loading from files
- Session Management: Auto-save + manual save/load with .aria2 control files
- RPC Remote Control: JSON-RPC 2.0, XML-RPC, and WebSocket; the method and notification sets depend on enabled features (up to 40 methods and 6 notifications)
- Configuration System: Typed option registry with four-source merging (CLI/file/environment/defaults)
- NetRC Authentication: Automatic FTP/HTTP credential loading from
.netrcfiles - URI List Files: Batch import download tasks via
-iparameter - Public Tracker List: Auto-update from trackerslist.com for BT peer discovery
Prebuilt artifacts are published on the GitHub Releases page. Each platform has minimal, standard, tui, and full variants with matching SHA-256 files. See the release artifact guide before choosing a variant.
Linux / macOS:
curl -fsSL https://raw.githubusercontent.com/balovess/aria2_rust/main/install.sh | bashWindows (PowerShell):
irm https://raw.githubusercontent.com/balovess/aria2_rust/main/install.ps1 | iexDocker (Linux amd64 image):
docker run -d --name aria2 -p 6800:6800 -v ~/downloads:/downloads ghcr.io/balovess/aria2-rust:latestPackage Managers:
| Platform | Command |
|---|---|
| Homebrew (macOS/Linux) | brew tap balovess/aria2_rust https://github.com/balovess/aria2_rust.git && brew install balovess/aria2_rust/aria2-rust |
| Scoop (Windows x64) | scoop bucket add aria2 https://github.com/balovess/aria2_rust.git && scoop install aria2/aria2-rust |
| Cargo (from source) | cargo install --path aria2 |
The Homebrew formula builds the full feature set from the tagged source archive
and works on supported macOS and Linux Intel/ARM hosts. The Scoop manifest
installs the verified Windows x64 full release package and exposes it as
aria2c. After the one-time tap/bucket setup, standard update commands work:
brew update && brew upgrade aria2-rustscoop update
scoop update aria2-rustChocolatey is not a supported installation channel. Use the GitHub Release ZIP, the PowerShell installer, or Scoop on Windows.
After installation, start downloading immediately:
# Download a file
aria2c http://example.com/file.zip
# Download with multiple connections
aria2c -x 16 -s 16 http://example.com/large.iso
# Download a torrent
aria2c file.torrent
# Download with custom directory
aria2c -d ~/downloads http://example.com/file.zipRun aria2c --init to choose system, current-directory, executable-directory,
portable, or custom storage. Existing configuration is backed up before reset.
Use --non-interactive with an explicit profile in automation:
aria2c --init
aria2c --init --profile=system --non-interactive
aria2c --init --profile=custom --state-dir="$HOME/.aria2" --download-dir="$HOME/Downloads" --non-interactive
aria2c --show-paths --profile=systemThe generated configuration is intentionally minimal. Session, logging, PID, cookies, DHT state, and server statistics are enabled only by explicit options.
Click to expand build instructions
Prerequisites:
- Rust 1.70+ (stable)
- Windows / macOS / Linux
Build Commands:
# Clone the repository
git clone https://github.com/balovess/aria2_rust.git
cd aria2_rust
# Build all crates
cargo build --release
# Download a file (HTTP)
cargo run --release -- http://example.com/file.zip
# Download with custom options
cargo run --release -- -d ./downloads -s 4 http://example.com/large.iso
# Show help
cargo run --release -- --help
# Show version
cargo run --release -- --versionWe provide ready-to-use configuration templates in examples/configs/:
| Template | Description |
|---|---|
| minimal.conf | Minimal configuration for quick setup |
| basic.conf | Basic configuration with common options |
| advanced.conf | Advanced configuration with RPC, proxy, etc. |
| bittorrent.conf | Optimized for BitTorrent downloads |
| windows.conf | Windows manual configuration template |
Usage:
# Copy template to config directory
mkdir -p ~/.aria2
cp examples/configs/basic.conf ~/.aria2/aria2.conf
# Edit as needed
nano ~/.aria2/aria2.conf
# Run with configuration
aria2c --conf-path=~/.aria2/aria2.conf http://example.com/file.zipFor common commands, configuration syntax, RPC/daemon setup, sessions, and configuration check/repair/reset workflows, see the user guide.
aria2c http://example.com/file.ziparia2c -o output.dat -d /downloads -s 4 -x 8 http://example.com/large.bin| Option | Description | Default |
|---|---|---|
-d, --dir |
Save directory | . |
-o, --out |
Output filename | auto |
-s, --split |
Concurrent segment requests per download | 16 |
-x, --max-connection-per-server |
Per-authority HTTP segment request cap; adaptive download may lower it | 16 |
--max-download-limit |
Max download speed | unlimited |
--timeout |
Timeout in seconds | 60 |
-q, --quiet |
Quiet mode | false |
For segmented HTTP downloads, split is the total concurrent request budget
for one file. max-connection-per-server is the independent cap for each
scheme://host:port authority. With multiple mirrors, different authorities
may run concurrently within the split budget; mirrors sharing one authority
share that authority's cap. HTTP adaptive concurrency starts at the configured
cap and lowers only the authority that returns 429 or 503.
aria2c file.torrentCreate a text file with URIs (one entry per block, Tab-separated mirrors):
dir=/downloads
split=16
http://mirror1.example.com/file.iso http://mirror2.example.com/file.iso
http://mirror3.example.com/file.iso
Then:
aria2c -i uris.txtThe workspace contains four Rust crates plus Python and Node.js bindings. Test status is reported from reproducible commands in docs/compatibility-status.md, rather than as a fixed historical test count.
Migration status (2026-09-14): the Rust implementation migration is
substantially complete and is now in the final compatibility and acceptance
phase. The latest reproducible verification covers the CLI, RPC, protocol,
BitTorrent, Metalink, FTP/SFTP, Node.js, and Python paths; see the
compatibility status for commands and evidence.
The latest focused snapshot includes 3,733 passing aria2-core library tests
(1 ignored), 866 passing aria2-protocol tests (1 ignored), 319 passing
aria2-rpc tests, and 379 passing aria2 tests (3 ignored), plus 123 Node.js
and 137 Python binding tests.
Remaining work is primarily compatibility evidence and release hardening: complete original-client and browser-extension interoperability, public C ABI parity, live cross-platform protocol/binding coverage, a few Metalink and pause/remove lifecycle edges, and a comparable aria2 C++ performance baseline. These do not represent a missing core protocol implementation; they remain explicit acceptance boundaries in the compatibility matrix.
The project is organized as a Cargo workspace with 4 crates:
aria2-rust/
├── aria2/ # Binary crate (CLI entry point, ~550 lines)
│ ├── src/main.rs # Entry point
│ ├── src/app.rs # App runtime (ConfigManager + Engine)
│ └── examples/ # Usage examples
├── aria2-core/ # Core library (~7,000 lines)
│ ├── src/engine/ # Download engine (12 command implementations)
│ │ ├── process_wait.rs # Native process-exit events with fallback watcher
│ │ ├── download_engine.rs # Event loop with command queue
│ │ ├── download_command.rs # HTTP/HTTPS downloader
│ │ ├── ftp_download_command.rs # FTP/SFTP downloader
│ │ ├── bt_download_command.rs # BitTorrent downloader
│ │ ├── magnet_download_command.rs # Magnet link downloader
│ │ ├── metalink_download_command.rs # Metalink downloader
│ │ └── concurrent_download_command.rs # Multi-segment downloader
│ ├── src/config/ # Typed configuration registry and parser
│ │ ├── option.rs # OptionType/Value/Def/Registry
│ │ ├── parser.rs # Multi-source parser (CLI/file/env/defaults)
│ │ ├── netrc.rs # NetRC authentication parser
│ │ ├── uri_list.rs # URI list file (-i option) parser
│ │ └── mod.rs # ConfigManager unified runtime manager
│ ├── src/request/ # Request management
│ │ ├── request_group_man.rs # Global task manager
│ │ └── request_group/ # Per-task state machine and activity signals
│ │ └── activity.rs # Notify + generation wake-up signal
│ ├── src/filesystem/ # Disk I/O
│ │ ├── disk_writer.rs # Disk writer trait
│ │ ├── disk_cache.rs # Cached writer (256KB direct write)
│ │ ├── control_file.rs # .aria2 control file format
│ │ ├── file_allocation.rs # Pre-allocation strategies
│ │ └── checksum.rs # Checksum verification
│ ├── src/http/ # Cookie management
│ │ ├── cookie.rs # Cookie structure
│ │ ├── cookie_storage.rs # Persistent storage
│ │ └── ns_cookie_parser.rs # Netscape format parser
│ ├── src/session/ # Session persistence
│ │ ├── session_serializer.rs # Serialization
│ │ ├── auto_save_coordinator.rs # Unified persistence deadlines
│ │ ├── auto_save_session.rs # Auto-save
│ │ └── save_session_command.rs # Save on exit
│ ├── src/rate_limiter.rs # Token bucket rate limiting
│ └── src/ui.rs # Progress bar & status panel
├── aria2-protocol/ # Protocol stack (~5,000 lines)
│ ├── src/http/ # HTTP/HTTPS client (auth/proxy/cookies/compression)
│ ├── src/ftp/ # FTP/SFTP client (anonymous+auth, passive mode)
│ ├── src/bittorrent/ # Full BT stack
│ │ ├── bencode/ # BEP3 bencode codec
│ │ ├── torrent/ # .torrent parsing
│ │ ├── magnet.rs # Magnet link parsing
│ │ ├── dht/ # KRPC + routing table + bootstrap
│ │ ├── tracker/ # UDP/HTTP tracker
│ │ ├── peer/ # Peer connection + handshake
│ │ ├── extension/ # MSE/PEX/ut_metadata
│ │ └── piece/ # Piece manager + picker
│ └── src/metalink/ # Metalink V3/V4 parser
├── aria2-rpc/ # RPC server (~1,000 lines)
│ ├── src/json_rpc.rs # JSON-RPC 2.0 codec
│ ├── src/xml_rpc.rs # XML-RPC codec
│ ├── src/websocket.rs # WebSocket event publisher
│ ├── src/server.rs # HTTP server (auth/CORS/status)
│ └── src/engine.rs # RpcEngine bridge (feature-gated RPC methods)
└── bindings/ # Language bindings (~1,200 lines)
├── python/ # Python SDK (~600 lines)
└── nodejs/ # Node.js SDK (~627 lines TS)
└── Cargo.toml # Workspace configuration
The implementation-oriented comparison with aria2_original is maintained in
Performance Differentiators. The current
Rust-specific differences are:
| Area | Current implementation |
|---|---|
| Disk I/O | Positioned offset writes, write-back range cache, threshold batching, and coalesced multi-file writes. Blocking syscalls run on Tokio's blocking pool; Linux io_uring is an opt-in backend. |
| Data path | bytes::Bytes is transferred through the cache, Piece writer, and multi-file slices to reduce copies and temporary allocations. This is a reduced-copy path, not an end-to-end zero-copy guarantee. |
| Hash verification | Bounded background hash workers, chunked integrity dispatch, cooperative yields, and RequestGroup-aware cancellation. |
| BitTorrent/DHT | Hash-based peer lifecycle, incremental piece-frequency tracking, shared HAVE frame encoding with bounded concurrent sends, bucket-tree/top-K routing, and bounded UDP workers. |
| File allocation | Platform-aware Linux fallocate, Windows SetFileValidData, macOS F_PREALLOCATE, and cooperative fallbacks that keep long allocation work off the reactor. |
| RPC control plane | Owned wire parsing, up to 64 concurrent read-only calls in HTTP/WebSocket batches, mutation barriers, and blocking workers for heavy payload conversion. system.multicall keeps original sequential semantics. |
The following data comes from a Release build and idle-RPC process measurement on the same Windows 11 x64 machine:
| Metric | Original aria2 1.37.0 | Current aria2-rust reference |
|---|---|---|
aria2c.exe file size |
about 5.39 MiB | about 13.6 MiB |
| Idle RPC Working Set | about 12.5 MiB | about 16.1 MiB |
| Idle RPC Private Bytes | about 3.25 MiB | about 3.6 MiB |
These values vary with compiler features, Windows version, allocator, and measurement timing. They are not a substitute for a same-load download benchmark. Private Bytes are already close to the original, while the current binary size and Working Set remain higher.
The same document records compatibility impact, source entry points, focused test
evidence, and known boundaries. DHT network maintenance and active peer
lookups now use the unified task queue, with duplicate periodic network ticks
coalesced while a lane is busy. Token rotation and local cleanup remain in the
deadline coordinator, while routing-table saves use a blocking worker. Linux
and macOS runtime evidence and a comparable full-download workload benchmark
against aria2_original are still pending.
Existing event-driven hot paths include:
- uTP receive waits on Tokio UDP readiness and retains fragmented frames in a
persistent buffer instead of retrying
recvafter a fixed sleep. - BitTorrent piece downloads use a bounded event-driven block pipeline; endgame peers are consumed concurrently and TCP/MSE readers preserve partial frames across cancellation.
- Dynamic rate-limit changes wake blocked token acquisitions immediately.
- Piece-stat and missing-piece queries scan bitfields bytewise; unrestricted rarest-first selection advances a sorted cursor instead of rescanning pieces.
- The engine idle path waits on commands, task completions, the earliest maintenance deadline, and shutdown instead of scanning on a fixed idle tick.
Implementation seams: engine idle wait, activity signal, save deadlines, and platform process wait.
Rust-only Criterion measurements on Windows release builds (50,000 pieces,
same-worktree before/after medians) show the following algorithm-level changes:
| Benchmark | Before | After |
|---|---|---|
| Bitfield all-missing query | 63.4 us | 4.3 us |
| Bitfield sparse selection | 194.9 us | 75.0 us |
| Rarest selection | 54.96 us | 2.13 us |
These are microbenchmark results, not a whole-download throughput claim or a
comparison with aria2_original. Details and validation commands are recorded
in docs/MIGRATION.md and
docs/engine-loop-performance.md.
To reproduce the focused benchmarks:
cargo bench -p aria2-core --features bittorrent --bench segment_scan_bench -- --noplot
cargo bench -p aria2-core --features bittorrent --bench sequential_picker_bench -- rarest_selection --noplotAdd to your Cargo.toml:
[dependencies]
aria2-core = { path = "../aria2-core" }
aria2-rpc = { path = "../aria2-rpc" }use aria2_core::config::ConfigManager;
use aria2_core::request::request_group_man::RequestGroupMan;
use aria2_core::request::request_group::DownloadOptions;
use aria2_core::config::OptionValue;
#[tokio::main]
async fn main() {
let mut config = ConfigManager::new();
config.set_global_option("dir", OptionValue::Str("./downloads".into())).await.unwrap();
config.set_global_option("split", OptionValue::Int(4)).await.unwrap();
let man = RequestGroupMan::new();
let opts = DownloadOptions {
split: Some(4),
..Default::default()
};
match man.add_group(vec!["http://example.com/file.zip".into()], opts).await {
Ok(gid) => println!("Download started: #{}", gid.value()),
Err(e) => eprintln!("Error: {}", e),
}
}use aria2_rpc::engine::RpcEngine;
use aria2_rpc::json_rpc::JsonRpcRequest;
#[tokio::main]
async fn main() {
let engine = RpcEngine::new();
let req = JsonRpcRequest {
version: Some("2.0".into()),
method: "aria2.addUri".into(),
params: serde_json::json!([["http://example.com/file.zip"]]),
id: Some(serde_json::Value::String("req-1".into())),
};
let resp = engine.handle_request(&req).await;
println!("{}", serde_json::to_string_pretty(&resp).unwrap());
}- Rust: 1.70 or later (install)
- OS: Windows 10+, macOS 10.15+, Linux (glibc 2.17+)
# Debug build (fast compilation)
cargo build
# Release build (optimized)
cargo build --release
# Run tests
cargo test --workspace
# Generate documentation
cargo doc --workspace --no-deps
# Run a specific example
cargo run -p aria2 --example simple_download -- http://example.com/test.bin# Run all tests in workspace
cargo test --workspace
# Run tests for specific crate
cargo test -p aria2-core
# Run tests with verbose output
cargo test --workspace -- --nocapture
# Run specific test category
cargo test "test_e2e" # E2E tests
cargo test "test_stress" # Stress tests
cargo test "test_edge" # Edge case tests
cargo test "test_error" # Error path tests| Category | Prefix | Description |
|---|---|---|
| Unit Tests | test_ |
Inline tests for individual functions |
| Integration Tests | test_ |
Module interaction tests |
| E2E Tests | test_e2e_ |
Complete workflow tests |
| Stress Tests | test_stress_ |
High-load stability tests |
| Edge Case Tests | test_edge_ |
Boundary condition tests |
| Error Path Tests | test_error_ |
Error handling tests |
# Install cargo-tarpaulin (Linux/macOS)
cargo install cargo-tarpaulin
# Generate HTML coverage report
cargo tarpaulin --workspace --out Html --output-dir coverage/
# Generate LCOV format for CI
cargo tarpaulin --workspace --out Lcov --output-dir coverage/# Run all benchmarks
cargo bench --workspace
# Run specific benchmark
cargo bench -p aria2-core --bench config_benchFor comprehensive testing guidance, see docs/testing-guide.md.
The table below records implemented code paths and their remaining acceptance
boundaries. The authoritative status is the module matrix in
docs/compatibility-status.md; an implemented
path can still be PARTIAL or UNVERIFIED when external interoperability or
cross-platform evidence is incomplete.
| Feature | Path state | Notes |
|---|---|---|
| CLI arguments | Implemented path | ~50 most-used options; full option parity is still open |
Configuration file (aria2.conf) |
Implemented path | Same syntax path; defaults and changeability still need comparison |
| Environment variables | Implemented path | ARIA2_* prefix mapping; full parity is still open |
| JSON-RPC API | Implemented path | Feature-dependent method set (up to 40 methods) returned by system.listMethods; BT metadata, tracker runtime state, and DHT runtime counters are available |
| XML-RPC API | Implemented path | MethodCall/response/fault paths exist; original-client matrix remains open |
| WebSocket events | Implemented path | 6 notifications returned by system.listNotifications |
URI list file (-i) |
Implemented path | Mirror + inline options |
| NetRC auth | Implemented path | machine/default/macdef parsing |
| Session save/load | Implemented path | Round-trip tests exist; complete control-file parity remains open |
| Metalink V3/V4 | Implemented path | Parsing and downloads exist; torrent metaurl lifecycle is partial |
| BitTorrent DHT | Implemented path | KRPC + routing table + bootstrap; live interoperability remains open |
| FTP/SFTP | Implemented path | Passive mode + auth; live-server evidence remains open |
| Rate limiting | Implemented path | Shared token bucket and runtime updates are tested |
| Cookie management | Implemented path | Netscape and SQLite parsing paths exist |
| MSE/PE encryption | Implemented path | BEP14 handshake |
| Magnet link support | Implemented path | ut_metadata fetching |
| RarestFirst piece | Implemented path | Piece selection implementation and tests |
| Endgame mode | Implemented path | Last-piece optimization |
| DHT persistence | Implemented path | dht.dat serialization |
| uTP Protocol | Extension path | Not in original aria2 C++ |
| Web Seeds | Implemented path | BEP 19 |
| LPD | Implemented path | Local Peer Discovery |
| Seeding Mode | Implemented path | Upload support |
Known gaps and verification status:
- This table is a capability inventory, not a release compatibility claim.
- The implementation migration is substantially complete; optional-feature evidence, ignored network tests, platform-specific binding runs, original-client interoperability, and public C ABI parity remain tracked.
aria2.forceShutdown,system.listMethods, andsystem.listNotificationsare implemented and covered by handler/integration tests.- HTTPS RPC has TLS configuration, server implementation, and dedicated test coverage; broader client/server interoperability testing remains tracked.
- IPv6 DHT has CLI and protocol support; full network interoperability coverage remains tracked.
- BitTorrent RPC exposes torrent metadata, live tracker tiers/runtime state, files, URIs, servers, peers, piece progress, and aggregated DHT counters. Tracker and DHT values are published from the active BT command and are removed when that command exits; peer discovery attribution is retained internally and is not added to the upstream
getPeerswire response. - Additional CLI/runtime option behavior still requires systematic comparison against
aria2_original.
This project is licensed under GPL-3.0-or-later.
Copyright (C) 2024 aria2-rust contributors.