⚡ Blitz — The Native, Local-First Postman Alternative

The fast, private, offline-first API workbench built in Rust.
Tired of Postman taking 1GB RAM and forcing cloud accounts? Blitz gives you instant startup, zero telemetry, Git-native team sync, and a built-in MCP server for AI coding agents.

What is Blitz? • Interface • Comparison • Install • Features • MCP Server • Docs

⚡ What is Blitz?

Blitz is a lightweight, open-source API development and testing client written in pure Rust (Dioxus). It replaces heavy Electron-based tools with a native desktop application that respects your hardware and privacy:

🚀 10x Faster, 90% Less RAM: Starts in <150ms and sits at ~40MB RAM (CLI runner uses only ~10MB). No bundled Chromium or multi-process Electron overhead.
🔒 100% Offline & Local-First: No accounts, no logins, no cloud tracking. Your collections, tokens, and environments stay on your machine.
🐙 Git-Native Collaboration: No $19/user/month cloud workspace paywalls. Save collections right inside your Git repo and sync via git pull / git push.
🤖 First-Class AI Agent Support (MCP): Comes with a built-in 37-tool Model Context Protocol server. Let Cursor, Claude, Antigravity, or Windsurf inspect, trigger, and debug your API endpoints automatically.
🌐 All Major Protocols: REST, GraphQL, WebSocket, gRPC (Protobuf), SSE, Socket.IO, and MQTT in a unified, modern interface.

📸 Interface Preview

⚖️ Blitz vs Alternatives

Feature	Postman	Bruno	Yaak	⚡ Blitz
Language & Engine	Electron + Node.js	Electron + Node.js	Tauri + React	Pure Rust + Dioxus
Startup Time	~3,500 ms	~1,200 ms	~450 ms	< 150 ms
Memory Footprint	800 MB – 1.5 GB	150 MB – 300 MB	~120 MB	~40 MB (GUI) / ~10 MB (CLI)
Account Required	Mandatory Cloud	No	No	Never (100% Offline)
Team Sync	Paid Cloud ($19+/mo)	Git (.bru files)	Git / Cloud	Git-Native (standard JSON)
AI Agent Bridge	Proprietary AI add-on	None	None	Built-in MCP Server (37 tools)
Protocols	REST / WS / gRPC	REST / GraphQL	REST / WS / gRPC	REST / WS / gRPC / MQTT / SSE
Secret Storage	Cloud or Plaintext	Plaintext `.env`	SQLite	OS Encrypted Keychain
Mock Server	Cloud-only	No	No	Localhost 127.0.0.1
License	Proprietary	MIT	Commercial / Fair-Core	MIT / Apache-2.0

📦 Downloads & Installation

⚡ 1-Line Quick Install

macOS

curl -fsSL https://raw.githubusercontent.com/h3ma209/Blitz/master/install.sh | bash

Downloads latest DMG, installs to /Applications/Blitz.app, and automatically clears Gatekeeper quarantine.

Linux

curl -fsSL https://raw.githubusercontent.com/h3ma209/Blitz/master/install.sh | bash

Downloads latest binary and installs executable to ~/.local/bin/blitz.

Windows

PowerShell:

irm https://raw.githubusercontent.com/h3ma209/Blitz/master/install.ps1 | iex

Command Prompt (curl):

curl.exe -fsSL https://raw.githubusercontent.com/h3ma209/Blitz/master/install.ps1 -o install.ps1 && powershell -ExecutionPolicy Bypass -File install.ps1

Git Bash / WSL:

curl -fsSL https://raw.githubusercontent.com/h3ma209/Blitz/master/install.sh | bash

Installs to %LOCALAPPDATA%\Blitz\blitz.exe, adds to User PATH, and creates Start Menu shortcut.

Homebrew Tap

brew tap h3ma209/blitz https://github.com/h3ma209/homebrew-blitz
brew install --cask blitz

Direct Downloads

Pre-built binaries for macOS, Linux, and Windows are available directly from the Releases Page.

Platform	Download	Package / Command
macOS (Apple Silicon)	Blitz-macos-arm64.dmg	Drag to Applications
macOS (Tarball)	blitz-macos-arm64.tar.gz	`tar -xzf blitz-macos-arm64.tar.gz`
Linux (x86_64)	blitz-linux-x86_64.tar.gz	`tar -xzf blitz-linux-x86_64.tar.gz`
Windows (x86_64)	blitz-windows-x86_64.zip	Unzip & run `blitz.exe`
Cargo (Any OS)	Source crate	`cargo install --git https://github.com/h3ma209/Blitz.git`

🛡️ First-Launch Security Notice (macOS & Windows)

Because Blitz is an open-source project distributed without paid Apple Developer ($99/yr) or Windows EV enterprise certificates, your operating system may display a security verification warning on first manual launch.

🍎 macOS Fix: "Apple cannot verify that this app is free of malware" or "Blitz is damaged"

Apple Gatekeeper attaches a quarantine attribute to files downloaded via web browsers.

Method 1 — 1-Line Terminal Command (Recommended):

xattr -cr /Applications/Blitz.app

(If installed to user folder ~/Applications/Blitz.app, run xattr -cr ~/Applications/Blitz.app)

Method 2 — GUI Right-Click:

Open Finder → navigate to Applications.
Right-click (or Control-click) on Blitz and select Open.
Click Open in the confirmation prompt (macOS will remember this permanently).

Method 3 — System Settings: Open System Settings → Privacy & Security, scroll down to the Security section, and click Open Anyway.

🪟 Windows Fix: "Windows protected your PC (SmartScreen)"

Microsoft Defender SmartScreen flags newly downloaded open-source executables.

Method 1 — GUI:

On the "Windows protected your PC" popup, click More info.
Click Run anyway.

Method 2 — PowerShell (Instant Unblock):

Unblock-File "$env:LOCALAPPDATA\Blitz\blitz.exe"

(Or if downloaded zip: Unblock-File .\blitz-windows-x86_64.zip before unzipping)

🐧 Linux: "Permission denied"

Ensure the binary has executable permissions:

chmod +x ~/.local/bin/blitz

🎯 Core Features & Capabilities

🔌 Multi-Protocol Support

Interact with any modern API standard in one place:

REST / HTTP: Query parameters, headers, GraphQL, form-data, multipart uploads.
WebSockets: Interactive bidirectional streaming, frame inspection, Socket Deck, and message presets.
gRPC: Unary calls and streaming with Protobuf schema reflection and decoding.
MQTT: Real-time publish and subscribe to IoT brokers.
SSE (Server-Sent Events): Live streaming event reader.
Socket.IO: Native engine handshake and event listener.
MCP (Model Context Protocol): Direct connection to AI agent tooling and context servers.

📑 Comprehensive Collection Workspace

Manage complex API suites with dedicated tabs:

Instant Search & Type Filtering: Real-time debounced sidebar search with zero UI lag. Type inline prefixes directly in the search bar to filter by node type:
- folder:<query> or f:<query> (e.g. folder:auth or folder: alone to browse all folders)
- req:<query> or r:<query> (e.g. req:login or req: alone to browse all requests)
- col:<query> or c:<query> (e.g. col:store)
- Alternative syntax: is:folder, is:req, type:folder, type:req
Overview: Collection documentation, structure preview, and real-time statistics.
Authorization: Inherited authentication (Bearer, Basic, API Key, OAuth2) applied across child requests.
Pre-request & Test Scripts: Collection-wide scripting for setup, teardown, and validation.
Variables: Environment and collection variable scope resolution.
Runner: Batch test execution with iteration controls, delays, and pass/fail diagnostics.

🧪 Postman-Compatible JavaScript Testing

Write familiar assertions and workflows locally without remote runtime limits:

blitz.test() and blitz.expect() assertion suites.
blitz.sendRequest() for chained requests and token pre-fetching.
Built-in CryptoJS library (SHA256, HmacSHA256, MD5, Base64, Hex).
Dynamic variables ({{$guid}}, {{$timestamp}}, {{var}}).

🔐 Secure Credential Storage

Protect sensitive environment secrets and tokens:

Native OS Keychain integration (macOS Keychain, Linux Secret Service, Windows Credential Manager).
Secrets stay encrypted locally and are automatically stripped before committing to Git remotes.

🔄 Seamless Migration & Local Mocks

Postman: Import and export Postman v2.1 collections with full script fidelity.
OpenAPI: Import and export OpenAPI 3.0 specifications.
cURL & HAR: Paste raw terminal cURL commands or drop browser HAR files directly into the workbench.
Local Mock Server: Instant zero-config HTTP mocks on 127.0.0.1 served from your saved examples.

Quick Start

Prerequisites

Rust Toolchain (1.83+)
macOS, Linux, or Windows

Build and Run from Source

# Clone repository
git clone https://github.com/h3ma209/Blitz.git
cd Blitz

# Run debug build
cargo run

# Or run optimized release build
cargo run --release

Install as Native Desktop App

make install

Operating System	Default Install Destination	Uninstall
macOS	`~/Applications/Blitz.app`	`make uninstall`
Linux	`~/.local/share/blitz/` + `~/.local/bin/blitz`	`make uninstall`
Windows	`%LOCALAPPDATA%\Blitz\`	`powershell -File scripts/install.ps1 -Uninstall`

CI/CD Automation & AI Agent Integration

Headless CLI Runner

Run test collections headless in your CI/CD pipelines without cloud subscriptions or proprietary API keys:

# Execute collection headless (returns exit code 0 on pass, 1 on failure)
blitz run collection.json --env staging.json

🤖 AI Agent Integration via MCP (Cursor, Claude, Antigravity, Windsurf, VS Code, Zed)

Blitz includes a built-in Model Context Protocol (MCP) server (blitz mcp), allowing AI coding assistants and autonomous agents to list collections, inspect request schemas, execute endpoints, and run API test suites directly through Blitz.

Automatic IDE & Agent Setup:

Blitz can automatically scan your machine for installed IDEs and AI coding agents, and configure the MCP server for you:

# Scan and interactively select which IDEs/agents to configure:
blitz mcp setup

# Or configure all detected IDEs automatically without prompting:
blitz mcp setup --all

# Or target a specific IDE:
blitz mcp setup --target cursor
blitz mcp setup --target claude_desktop
blitz mcp setup --target vscode
blitz mcp setup --target zed

# Scan only (preview detected tools without modifying configs):
blitz mcp setup --scan

Supported IDEs and coding agents detected out of the box:

Cursor (~/.cursor/mcp.json)
Claude Desktop (claude_desktop_config.json)
Antigravity / Gemini CLI (~/.gemini/antigravity/mcp_config.json)
Windsurf (~/.codeium/windsurf/mcp_config.json)
VS Code (~/Library/Application Support/Code/User/mcp.json)
Cline extension for VS Code (cline_mcp_settings.json)
Roo Code extension for VS Code (cline_mcp_settings.json)
Zed (settings.json context_servers)
Claude Code CLI (~/.claude.json)

Manual Configuration:

If you prefer manual setup, add Blitz to your IDE's mcpServers configuration:

{
  "mcpServers": {
    "blitz": {
      "command": "/Applications/Blitz.app/Contents/MacOS/Blitz",
      "args": ["mcp"]
    }
  }
}

Exposed MCP Tools:

blitz_list_collections: Discover all collections, folders, and requests with folder breadcrumb paths (path, folder).
blitz_get_request: Retrieve full request details (URL, headers, query params, body, auth).
blitz_send_request: Execute a saved request through Blitz pipeline (returns parsed json, supports save_to_env auto-extraction, records history).
blitz_execute_http: Run an ad-hoc HTTP request through Blitz engine (returns parsed json, supports save_to_env auto-extraction, records history).
blitz_list_environments: List available environments, active state, and variable keys/values.
blitz_set_env_var: Update or create an environment variable (e.g. auth token or baseUrl) directly from agent output.
blitz_set_active_environment: Switch or clear the active environment.
blitz_upsert_request: Create or edit request drafts in collections and folders.
blitz_import_curl: Import raw cURL commands directly into collections.
blitz_generate_code: Generate client code snippets (cURL, Python, TypeScript, Rust, Go, Java, C#) with variable interpolation.
blitz_list_history: Query past request executions with status, latency, and timestamps.
blitz_run_collection: Run a complete collection test suite (supports folder scoping) and return assertion results.
blitz_suggest_assertions: Automatically generate test scripts & assertions (status, JSON path, headers, latency ceiling) from an HTTP response or request, with optional auto-attachment.
blitz_perf_test: Run concurrent load/benchmark testing against any request or collection (concurrency VUs, duration) and get RPS throughput, error rate, and p50/min/max latencies.
blitz_sync_openapi: Sync or import an OpenAPI 3.0 specification (JSON/YAML or file path) non-destructively, preserving custom tests, scripts, and auth.
blitz_get_collection: Retrieve the full collection configuration tree (folders, requests, scripts, variables, auth) in a single call.
blitz_create_environment: Create a new named environment with initial key-value variables and optional instant activation.
blitz_delete_request: Delete an existing request from a collection by ID or name.
blitz_start_mock: Spin up a local HTTP mock server (127.0.0.1:<port>) serving saved request examples or routes.
blitz_stop_mock: Stop the active local mock HTTP server.
blitz_export_collection: Export any collection as Postman v2.1 JSON or OpenAPI 3.0 specification.
blitz_diff_responses: Compare two response payloads or compare live execution across two environments (staging vs local).
blitz_delete_collection: Delete a collection by ID or name.
blitz_generate_docs: Generate standalone HTML documentation (static single-file or Swagger UI) from collections.
blitz_create_folder: Create nested organizational folders inside collections.
blitz_delete_folder: Delete a folder and all contained requests recursively.
blitz_delete_environment: Delete a named environment.
blitz_clear_history: Clear execution history globally or filtered by request ID.
blitz_import_har: Import HTTP Archive (.har file path or raw JSON) into collections.
blitz_manage_cookies: Inspect or clear session cookies stored in Blitz's global cookie jar.
blitz_websocket_send: Connect to a WebSocket endpoint (ws:// or wss://), transmit text/JSON payload, capture streaming inbound frames, and gracefully disconnect.
blitz_grpc_unary: Execute a gRPC unary procedure call over HTTP/2 with JSON body encoding (google.protobuf.Struct) returning response data and status code.
blitz_sse_listen: Connect to Server-Sent Events (SSE) HTTP stream, capture streaming events (event, data, id), and return trace.
blitz_mqtt_publish: Publish a message to an MQTT broker topic with QoS 1 confirmation and disconnect.
blitz_mqtt_subscribe: Subscribe to an MQTT topic on a broker and wait for incoming message with timeout.
blitz_graphql_ws_subscribe: Execute GraphQL subscription over WebSocket (graphql-transport-ws) and collect streaming payloads.
blitz_socketio_emit: Connect to Socket.IO server, emit event with payload, and capture inbound events.

Exposed MCP Resources:

blitz://collections: Hierarchy of all collections, folders, and requests.
blitz://environments: Configured environments and variables.
blitz://active-env: Currently active environment with resolved key-value pairs.
blitz://history: Recent execution history.

Team Collaboration via Git

Sync team workspaces directly through Git without cloud intermediaries:

Link Git Remote: In the top toolbar, select Team → Link Git Remote…
Work Locally: Add endpoints, edit environments, and write tests.
Sync: Click Sync — Blitz pulls changes, handles merges, and pushes through standard Git (SSH or gh CLI).
Leak Prevention: Passwords, tokens, and local secret variables are kept local and excluded from commits.

License

Distributed under the MIT / Apache 2.0 open-source licenses. Not affiliated with or endorsed by Postman Inc.

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
assets		assets
docs		docs
packaging		packaging
scripts		scripts
src		src
.gitignore		.gitignore
Cargo.lock		Cargo.lock
Cargo.toml		Cargo.toml
Dioxus.toml		Dioxus.toml
FEATURES.md		FEATURES.md
Makefile		Makefile
README.md		README.md
install.ps1		install.ps1
install.sh		install.sh

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