Iskra

A safe, modern, Rust-native data transfer tool.

Iskra is a security-first, async-capable command-line and library tool for HTTP and data transfer. It aims to be a minimal, idiomatic, and robust alternative to cURL and HTTPie, with a user-friendly CLI and advanced features for modern workflows.

Benchmarks

Speed Test

New Micro-Benchmarks (2025-08)

[Lower is better]

Recent micro-optimizations to Iskra's in-memory cache and burst engine have resulted in a drastic speedup for hot-path requests:

Summary: With a hot cache, burst requests are now routinely served in under 10 µs for the fastest requests, and average sitting at 42 µs. This is a 10–1000x speedup over cold/sequential access.

Note: These results were measured using an actual website endpoint, specifically, Google. They reflect the latest (v5.1.0+) cache and burst engine.

Speed Test (Legacy)

The following test compares Iskra's burst mode (parallel) to sequential requests for 20 HTTP GETs to https://httpbin.org/delay/1 (each request has a 1s server delay):

Summary: Burst mode achieves near-linear speedup for parallelizable requests, making it ideal for load testing, batch data collection, and high-throughput scenarios.

Test setup:

• Local HTTP server (Rust, hyper)
• Local disk cache (default temp dir)
• Windows, Rust async, single-threaded test
• Each file is validated for integrity (first, middle, last byte)

Note: In some cases, "no cache" can be faster than "cold cache" or even "warm cache". This is because writing to both the output file and the cache file doubles disk I/O, and the OS may cache files in memory, making repeated reads or writes appear faster. For real-world remote transfers, or with a RAM disk, cache can provide a more significant speedup.

Usage

Installation

1. Install with Cargo (recommended):

   • Open a terminal (PowerShell, Command Prompt, or Bash).

   • To install the latest published version:

     cargo install iskra
     

   • To build and install from source (in the repo root):

     cargo install --path .
     

   • If you don't have Rust or Cargo, install them first from https://rustup.rs

2. Add to PATH:

   • Make sure the Cargo bin directory is in your system PATH so you can run iskra from anywhere:

     • Windows: %USERPROFILE%\.cargo\bin

     • Linux/macOS: $HOME/.cargo/bin

   • If you just installed Rust, you may need to restart your terminal or log out/in for the new PATH to take effect.

   • To update your PATH for the current session only:

     • PowerShell:

       $env:Path += ";$env:USERPROFILE\.cargo\bin"
       

     • Bash:

       export PATH="$HOME/.cargo/bin:$PATH"
       

3. Test your install:

   iskra --help
   

   If you see the help text, you're ready to go!

   The help command shows all available commands, options, and usage examples. For more details on a specific command, you can run:

   iskra <command> --help
   

   For example:

   iskra post --help
   

   This will display all options and usage for the post command. Use --help with any command to see its arguments and flags.

Troubleshooting:

• If iskra is not found, double-check your PATH and that the install completed successfully.
• On Windows, you may need to open a new terminal or restart your computer after changing PATH.
• If you see a permissions error, try running your terminal as administrator (Windows) or use sudo (Linux/macOS) for the install step.

Updating Iskra

To update Iskra to the latest published version from crates.io, run:

PowerShell/Windows:

cargo install iskra --force

Bash/Linux/macOS:

cargo install iskra --force

This will overwrite any previous version with the latest release. You can check your installed version with:

iskra --version

or

iskra --version

If you build from source (Git):

First, update your local repository:

git pull

Then rebuild and install:

cargo install --path . --force

This will install the latest code from your local repository. Again, check your version with:

iskra --version

Why Iskra?

Why choose Iskra?

• Security-first: Strict error handling, no unsafe code, validation for all edge cases.
• Performance: Async, streaming, and range-aware downloads for maximum speed and efficiency.
• Resumable & partial downloads: Advanced file-based cache with metadata, HTTP headers, and range support.
• Minimal dependencies: Small, modern Rust async stack.
• Cross-platform: Windows, Linux, macOS.
• User-friendly CLI: Intuitive, scriptable, and easy to use in any shell.
• Production-grade tests: All features are covered by stringent tests.
• Supports GET, POST, PUT, DELETE, and arbitrary HTTP methods (e.g. PATCH, OPTIONS), with custom headers, query parameters, output to file, status/exit code support, and configurable timeout.
• Advanced file-based cache, streaming writes, cache validation and reconstruction, overwrite/append/chunked/partial download support, automatic response decompression, progress bar, and more.

If you want a modern, safe, and fast HTTP tool that feels at home in your shell, Iskra is for you.

Command Overview

Iskra supports the following commands:

GET (default)

iskra get <url> [OPTIONS]
iskra <url> [OPTIONS]  # 'get' is the default command

POST

iskra post <url> [--body <data>] [OPTIONS]

PUT

iskra put <url> [--body <data>] [OPTIONS]

DELETE

iskra delete <url> [OPTIONS]

Custom HTTP Method

iskra custom --method <METHOD> <url> [--body <data>] [OPTIONS]

HEAD (show metadata, compare, export, diff)

iskra head <url> [OPTIONS]

Common Options

Examples

1. Install with Cargo (recommended):

   • Open a terminal (PowerShell, Command Prompt, or Bash).

   • To install the latest published version:

     cargo install iskra
     

   • To build and install from source (in the repo root):

     cargo install --path .
     

   • If you don't have Rust or Cargo, install them first from https://rustup.rs

2. Add to PATH:

   • Make sure the Cargo bin directory is in your system PATH so you can run iskra from anywhere:

     • Windows: %USERPROFILE%\.cargo\bin
     • Linux/macOS: $HOME/.cargo/bin

   • If you just installed Rust, you may need to restart your terminal or log out/in for the new PATH to take effect.

   • To update your PATH for the current session only:

     • PowerShell:

       $env:Path += ";$env:USERPROFILE\.cargo\bin"
       

     • Bash:

       export PATH="$HOME/.cargo/bin:$PATH"
       

3. Test your install:

   iskra --help
   

   If you see the help text, you're ready to go!

   The help command shows all available commands, options, and usage examples. For more details on a specific command, you can run:

   iskra <command> --help
   

   For example:

   iskra post --help
   

   This will display all options and usage for the post command. Use --help with any command to see its arguments and flags.

   Set-Alias iskra "$env:USERPROFILE\.cargo\bin\iskra.exe"
   

• Bash (Linux/macOS):

  • Add to your .bashrc or .zshrc:

     export PATH="$HOME/.cargo/bin:$PATH"
     alias iskra="$HOME/.cargo/bin/iskra"
    

• Command Prompt (cmd.exe):

  • Add %USERPROFILE%\.cargo\bin to your system PATH via System Properties.

For more details, see iskra --help or the source code in src/cli.rs.

Burst Mode: High-Performance Batch & Parallel HTTP

Iskra now supports a powerful burst subcommand for high-performance, parallel, and batch HTTP requests. Burst mode is ideal for:

• Load testing and benchmarking
• Batch data collection
• Parallel API calls
• Automated testing of endpoints

Burst Features

• Parallel execution (configurable concurrency)
• Throttling (requests per second)
• Retries with backoff (exponential, jitter)
• Batch/template input (file or stdin)
• Per-request headers, queries, body, and output
• Output to files, directories, or stdout
• Aggregated summary reporting (success/fail/timing)
• Robust error handling and validation

Usage

iskra burst -i <input_file> [OPTIONS]
iskra burst -i - [OPTIONS]  # Read from stdin

Common Burst Options

Input File Format

Each line describes a request:

METHOD URL [header:Key:Value ...] [query:key=value ...] [body:...] [output:filename]

Examples:

GET https://httpbin.org/get
POST https://httpbin.org/post body:hello
GET https://httpbin.org/get header:X-Test:Value query:foo=bar
GET https://httpbin.org/bytes/16 output:bytes16.bin

Real-World Examples

Basic burst from file:

iskra burst -i burst_input.txt --summary

Burst with concurrency, throttling, retries, and output dir:

iskra burst -i burst_input2.txt --output-dir out --concurrency 4 --throttle 2 --retries 2 --backoff 500 --summary

Burst from stdin:

cat burst_input.txt | iskra burst -i - --summary

Example input file:

GET https://httpbin.org/get
POST https://httpbin.org/post body:hello
GET https://httpbin.org/status/404
GET https://httpbin.org/status/500

Output and summary: All responses are written to files or stdout as specified. At the end, a summary is printed:

--- Burst Summary ---
Total: 4 | Success: 2 | Fail: 2
Avg Time: 456.14ms | Total Time: 1.37s
[0] GET https://httpbin.org/get -> OK [200]
[1] POST https://httpbin.org/post -> OK [200]
[2] GET https://httpbin.org/status/404 -> FAIL [404]
	Error: HTTP error: status 404
[3] GET https://httpbin.org/status/500 -> FAIL [500]
	Error: HTTP error: status 500
---------------------

See the CLI help (iskra burst --help) for all options and usage details.

Licence

MIT OR Apache-2.0