Chapar - Native API Testing Tool

Chapar is a fast, native API client for REST, gRPC, GraphQL and WebSocket, with a built-in proxy for inspecting the traffic of other apps. It is written in Go and draws its UI with Yoga, a GPU-rendered (WebGPU) UI toolkit, so it starts quickly, stays light, and runs the same on macOS, Linux and Windows without a browser engine. Your requests, environments and cookies are plain files on your machine: no account, no cloud sync, nothing sent anywhere you did not ask for.

MQTT is next on the list.

What Chapar means?

Herodus described the Chapar as follows:

There is nothing in the world that travels faster than these Persian couriers. Neither snow, nor rain, nor heat, nor darkness of night prevents these couriers from completing their designated stages with utmost speed.

> Herodotus, about 440 BC

Screenshots

Features

Protocols

• REST / HTTP: every method, query and path params, JSON, XML, text, form-data, URL-encoded and binary bodies, with syntax highlighting and formatting.
• gRPC: server reflection or proto files, unary and server-streaming methods, metadata and trailers, TLS and client certificates, and a sample message for any method.
• GraphQL: queries and variables, with the response data and errors split out.
• WebSocket: connect, send text, JSON or binary messages and save them to resend, and watch everything that arrives in a filterable log. Subprotocols, pings, compression, headers and auth like HTTP requests.

Proxy

• Capture traffic from apps, browsers and phones through a built-in HTTP(S) proxy, and see each request and response side by side.
• Filter by app or domain, by protocol and content type, or search; pin what you care about and skip domains you don't want decrypted.
• Open in Chapar turns a captured request into a request you can edit and send. Copy as cURL and Export HAR take traffic elsewhere.
• Easy certificate setup: Chapar makes its own certificate authority, trusts it in one click on macOS, and checks every step. Phones get the certificate and instructions from http://chapar.mitm.
• Chapar never changes your system's proxy settings, and the proxy only runs while you have it started.

Workflow

• Workspaces keep separate collections, requests and environments; switch between them from the title bar.
• Collections share headers, auth and notes with every request inside them.
• Environments hold variables you use as {{name}} anywhere in a request. Values you mark secret are encrypted with a key kept in the OS keychain, and stored on your machine only: the environment file names a secret but leaves its value out, so a workspace can be shared (in git, say) without its secrets.
• Cookie jar per environment: cookies from responses are stored and sent back automatically, and you can view, edit, add or clear them.
• Auth: Basic, Bearer token and API key, set per request or inherited from the collection.
• Pre and post-request actions: run another request first, extract values from the response body, headers or cookies into the environment, or write Python scripts with tests and logs.
• Test cases send your requests in order, check their responses (status, headers, JSON paths, timing and more) and pass values from one step to the next, with setup, teardown and retries. Run them in the app, or in CI with chapar-cli.
• Timeline of every request: DNS, connect, TLS, time to first byte, scripts.
• Code generation for cURL, Python, Go, JavaScript (fetch, axios), Java and Kotlin (OkHttp), Ruby and .NET.
• Import Postman collections, OpenAPI specs and proto files.
• Command palette (⌘K / Ctrl+K) to open any request, collection or environment and run any command.

Editor and app

• Code editors with language-server completion and diagnostics (Python out of the box; JSON, XML, Go, JavaScript and more in Settings).
• Themes, including Tokyo Night, Catppuccin, Dracula, Nord, Gruvbox, One, Solarized and GitHub.
• Side-by-side or stacked request/response layout, a console panel and a notification history.
• Everything is stored as YAML files, so a workspace can live in git.

Roadmap

• MQTT support.
• Tunneling to servers and Kubernetes clusters as pre-request actions.

Getting Started

Install on macOS

Homebrew (recommended)

brew tap chapar-rest/chapar
brew install --cask chapar

To upgrade to the latest version:

brew upgrade --cask chapar

App Store

Note that the App Store version is running in a sandbox environment and if you are already using the downloaded or custom build version, you need to copy your data to the sandbox environment. you can do it by running the following command:

cp -r $HOME/.config/chapar $HOME/Library/Containers/rest.chapar.app/Data/.config

ln -s $HOME/.config/chapar $HOME/Library/Containers/rest.chapar.app/Data/.config

Install From AUR

yay -S chapar-bin

Command-line runner (chapar-cli)

# Linux and macOS
curl -fsSL https://github.com/chapar-rest/chapar/releases/latest/download/install-cli.sh | sh
or with Homebrew
brew install chapar-rest/chapar/chapar-cli

On Windows, download chapar-cli-windows-*.zip from the releases page. Pin a version with sh -s -- -v v0.8.0, or pick the install directory with -b DIR.

Run a workspace committed to your repo, or a test case exported from the app (Export, in the test case's title row):

chapar-cli test --workspace path/to/workspace --env staging --report junit=results.xml
chapar-cli test smoke.chapar-test.yaml --os-env API_ --var base=https://staging.example.com

In GitHub Actions:

- name: Install chapar-cli
  run: curl -fsSL https://github.com/chapar-rest/chapar/releases/latest/download/install-cli.sh | sh -s -- -b "$HOME/.local/bin"
name: Run API tests
  run: chapar-cli test --workspace api-tests --env ci --report junit=results.xml
  env:
    API_TOKEN: ${{ secrets.API_TOKEN }}

Install From Source

git clone https://github.com/chapar-rest/chapar.git
cd chapar
go build -o chapar .
go build -o chapar-cli ./cmd/chapar-cli   # the command-line runner

To build the same packages the releases ship (DMG, tar.xz, zip), install the Yoga CLI with make install_deps (the version go.mod uses); yoga.toml holds the packaging config:

yoga package -os darwin -arch arm64 -version v0.7.0   # dist/darwin/*.dmg
yoga package -os linux -version v0.7.0                # dist/linux/*.tar.xz
yoga package -os windows -version v0.7.0              # dist/windows/*.zip

Dependencies are vendored. Update them with make vendor, not go mod vendor: the script also copies the tree-sitter C sources that go mod vendor leaves out.

Dependencies

• macOS: Xcode Command Line Tools (xcode-select --install).
• Linux (Debian/Ubuntu): sudo apt install gcc libx11-dev libxrandr-dev libxinerama-dev libxcursor-dev libxi-dev libxxf86vm-dev libgl1-mesa-dev.
• Windows: a MinGW-w64 GCC on PATH (for example from MSYS2).

Contributing

Support the Project

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