Multi ISP Proxy

Multi ISP Proxy is a local HTTP and SOCKS5 proxy that distributes new outbound connections across selected network interfaces. It is intended for machines with multiple active internet connections, such as Wi-Fi, Ethernet, or mobile tethering.

Windows is the primary supported platform. Linux support is experimental and is validated by GitHub Actions on Ubuntu; Linux system-proxy configuration is still manual.

What it does

• Runs an HTTP proxy on 127.0.0.1:1080 by default.
• Runs a SOCKS5 proxy on the next port, 127.0.0.1:1081 by default, when that port is available.
• Selects an outbound interface using round-robin or failover mode.
• Can configure and restore the current-user Windows HTTP proxy.
• Displays interface health, traffic counters, and connection counts in a TUI.

Load balancing happens per connection, not per packet. A single TCP connection uses one interface and will not migrate seamlessly if that interface goes offline. Multi-connection applications can use more than one interface, but this is not equivalent to network-layer bonding.

Platform status

Platform	Status	System proxy
Windows 10/11	Primary	Optional automatic setup and restore
Ubuntu/Linux	Experimental	Manual application configuration

SOCKS5 TCP is supported. SOCKS5 UDP is experimental and should be verified with the target application before relying on it.

Installation

Download one of these assets from the latest release:

• multi-isp-proxy_windows_amd64.exe
• multi-isp-proxy_linux_amd64
• checksums.txt

Verify the downloaded binary against checksums.txt before running it.

Build from source

Go uses the version declared in go.mod.

git clone https://github.com/YudaKusumaID/multi-isp-proxy.git
cd multi-isp-proxy
go mod download

Windows PowerShell:

New-Item -ItemType Directory -Force dist | Out-Null
go build -o dist/multi-isp-proxy.exe ./cmd/multi-isp-proxy
.\dist\multi-isp-proxy.exe

Linux:

mkdir -p dist
go build -o dist/multi-isp-proxy ./cmd/multi-isp-proxy
./dist/multi-isp-proxy

Build output belongs in dist/, which is ignored by Git.

Usage

multi-isp-proxy [-addr 127.0.0.1:1080] [-allow-remote] [-auth-file PATH] [-version]

1. Select one or more interfaces.
2. Choose round-robin or failover mode.
3. On Windows, choose whether the application may configure the current-user HTTP proxy. On Linux, configure the browser or application manually.
4. Press r to reset displayed counters or q to stop and restore settings.

Use a complete loopback address when changing the port:

.\dist\multi-isp-proxy.exe -addr 127.0.0.1:8080

Loopback is enforced by default. A wildcard, LAN, or other non-loopback address is rejected unless -allow-remote is supplied. Remote mode also requires non-empty credentials, shared by HTTP Basic proxy authentication and SOCKS5 username/password authentication.

Prefer an environment variable so the secret is not exposed in command-line history or process arguments:

$env:MULTI_ISP_PROXY_AUTH = "proxy-user:use-a-long-random-password"
.\dist\multi-isp-proxy.exe -addr 0.0.0.0:1080 -allow-remote

Alternatively, put username:password in a user-readable credential file and pass -auth-file PATH. Do not use both methods. Remote mode should also be restricted with the operating-system firewall; it is not intended to be an internet-facing public proxy. See SECURITY.md.

Logs

New runs write multi-isp-proxy.log below the operating system's user cache directory instead of the repository root. At 5 MiB, it rotates to multi-isp-proxy.log.1:

• Windows: %LocalAppData%\multi-isp-proxy\multi-isp-proxy.log
• Linux: $XDG_CACHE_HOME/multi-isp-proxy/multi-isp-proxy.log, or ~/.cache/multi-isp-proxy/multi-isp-proxy.log

Existing venn.log and old binaries may be kept under dist/legacy/; they are not used by the new build workflow.

Crash recovery and single instance

Only one instance may run per user. Before changing Windows proxy settings, the application writes a recovery journal below the user configuration directory. After power loss or hard termination, the next launch restores the saved values before opening the TUI. If the current settings were changed externally after the crash, recovery refuses to overwrite them and preserves the journal for manual inspection.

Typical Windows files:

• %AppData%\multi-isp-proxy\instance.lock
• %AppData%\multi-isp-proxy\proxy-recovery.json

Do not delete the recovery journal while Multi ISP Proxy controls the Windows proxy. For conflict recovery guidance, see SECURITY.md.

Architecture

Runtime ownership, dependency direction, lifecycle invariants, and protocol boundaries are documented in docs/architecture.md.

Development

Run the local verification commands before opening a pull request:

gofmt -w .
go mod tidy
go vet ./...
go test -race ./...

CI runs formatting, module consistency, vet, tests, and the race detector on Linux, plus native tests on Windows. Tagging a commit with a semantic version such as v1.2.0 runs the same CI before producing release binaries.

Contributing

See CONTRIBUTING.md. Linux support was initially contributed by @anugrahiyyan.

License

Licensed under the MIT License.