CALLSTACK

Build requests for every HTTP method with a full-featured editor. URL params, headers, JSON/XML body, and file attachments — all in one place.

• GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS
• Query params editor with enable/disable toggles
• Header autocomplete + value presets (Authorization, Content-Type, Accept, Cache-Control, User-Agent…)
• Form URL-encoded body as a key/value editor (no more hand-encoding)
• JSON & XML body validation
• Multipart file attachments
• Per-request follow-redirects & cookie jar toggles, saved with the request
• Duplicate-name detection inline as you rename
• Cancel requests mid-flight

Any request can declare an ordered list of sibling requests that run silently before it — perfect for login-then-call flows without leaving the request builder.

• Configure in the new Setup tab inside each request
• Captured tokens propagate to subsequent steps and the main request
• Per-step continue on error toggle
• Recursive (nested chains supported) with built-in cycle detection
• Silent execution — only the main response renders; chain output streams to the script console + footer logs with copyable curl
• Skipped automatically when the request runs inside an Automation

Define variables per project and substitute them everywhere with {{variable}} syntax. Keep base URLs, tokens, and secrets organized by environment.

• Multiple environments per project
• Template syntax in URL, headers, body, params
• Recursive variable resolution (vars that reference other vars)
• 25+ dynamic tokens: {{$randomUUID}}, {{$isoTimestamp}}, and more
• Secrets (masked values with hold-to-reveal)
• Runtime variable manipulation in scripts
• Environment switching without editing requests

Run JavaScript before or after every request. Extract tokens, set variables, assert response values, and generate test data with the built-in Faker library.

• Full request & response objects
• Read/write env and secrets at runtime
• emitter for inter-step communication
• test() assertions with PASS/FAIL reporting
• Faker data: names, emails, addresses, UUIDs
• CodeMirror editor with JS autocomplete
• Copy-paste recipes for Base64, JWT decode, response-header capture, URL param parsing, and more

Build multi-step request workflows visually. Loop over datasets, branch on responses, run steps in parallel, and collect test results across every run.

• Sequential request chains
• CSV Iterator — loop over data files row by row
• Set Env — switch environments mid-run
• Branch on status code, emitted values, or test results
• Fanout — parallel execution lanes
• Repeat loops with iteration context
• Full run history with PASS/FAIL/PARTIAL status

Inspect responses with syntax highlighting, a header browser, and a live HTML/image preview tab. See timing, size, and test results at a glance.

• JSON syntax highlighting with line numbers
• XML and HTML pretty-printing
• Preview tab: renders HTML, images, video, audio
• Status code, response time (ms), size (bytes)
• Copy body or save to file
• Collapsible test results panel

Group requests into projects and folders. Drag to reorder. Collapse the sidebar for more space. Everything persists to SQLite automatically.

• Projects → Folders → Requests hierarchy
• Drag-and-drop reordering at every level
• Collapsible sidebar for full-screen editing
• Persistent expansion state across sessions
• Import from Postman collections
• Export with full response history