Support
Stampdrill support
Answers to common questions, and how to reach us.
About Stampdrill
What is Stampdrill?
Stampdrill is an API client and API testing tool for macOS, with a free command-line tool for Linux and CI. Requests, assertions, test plans, load tests and environment variables are written in plain text .stamp files that live in your own folder, so API work is reviewed and version-controlled like source code instead of sitting in a vendor's cloud.
What does it cost?
The Mac app is a one-off purchase on the Mac App Store. The stampdrill command-line tool is free, including for commercial use and in CI, and reads exactly the same files.
How is Stampdrill different from Postman, Insomnia or Bruno?
The files are the product. A workspace is a folder of plain text that diffs in a pull request, merges like code and runs unchanged in a terminal or a build pipeline. There is no account, no sync service and no cloud workspace: nothing leaves your Mac except the requests you send. It also covers work those tools leave to separate products — load tests, race-condition tests and Model Context Protocol servers — from the same files.
Can it run load tests and find race conditions?
Yes. A load block runs a scenario with a set number of users, a ramp and thresholds on p95 and error rate, with a live chart in the app. A concurrently block in a test plan fires requests at the same instant and asserts on the results together, which is how you catch a race condition such as a coupon redeemed twice.
Does it work in CI?
Yes. stampdrill test . runs the same plans on Linux and writes JUnit, HTML or JSON reports, exiting non-zero when a check fails. The Linux builds are fully static and need nothing else installed.
Getting started
How do I send my first request?
Choose Open Example Workspace on the welcome screen, select a request in the sidebar and press Send (⌘↩). The examples call public test APIs, so answers come back right away.
How do I start my own workspace?
A workspace is any folder of .stamp or .http files. Choose Open Workspace… and pick a folder, or create an empty one there. File › New Request (⌘N) adds requests; everything you change is saved into the files straight away.
Where is the language described?
The language reference covers requests, variables, scripts, test plans, load tests and environments.
Files and workspaces
Why does Stampdrill ask for a folder when I open a .stamp file from Finder?
Mac App Store apps can only read what you give them. Opening a file grants that file, but a request usually needs the rest of its workspace: environment.stamp, other requests and data files. Choose the workspace folder once and Stampdrill remembers it.
Can I edit the files in another editor?
Yes. Stampdrill watches the workspace and picks up changes made anywhere, including a text editor or a git pull.
A body or data file isn't found
Paths in < ./file bodies, readJson and readText are relative to the .stamp file and must stay inside the workspace folder.
Environments and secrets
What are dimensions?
Axes your API varies along, such as environment, region or user. Pick a value for each in the toolbar, or * for any, and every variable set that matches applies. Edit them with Environment › Edit Dimensions….
Why are some values blurred?
Tokens, passwords, cookies, JWTs and anything passed through secret() are blurred so they don't end up in a screenshot or a screen share. Click one to show it, or choose Request › Show Secrets (⇧⌘H) to show them all. You can turn blurring off in Settings.
Where do my personal tokens go?
Into environment.local.stamp, next to environment.stamp. When the workspace is a git repository, Stampdrill adds that file to .gitignore, so it stays on your Mac.
Teams and the command line
How do I share a workspace with my team?
Put the workspace folder in a git repository, next to your code if you like, and commit and pull with the tools you already use. Stampdrill reloads whatever changes.
Is there a command-line tool?
stampdrill runs the same workspaces in a terminal and in CI, for free. Install it with brew install samalstudios/tap/stampdrill, or download a macOS or Linux build from GitHub.
Can I bring my Postman, Insomnia or Bruno collections?
Yes. Choose File › Import… and pick a Postman collection together with its environment files, an Insomnia export, a Bruno collection folder, a HAR file from your browser, or a file of curl commands. Requests go into a new folder, environments become values of an environment dimension, and tokens and passwords go to environment.local.stamp. File › Paste curl as Request adds a copied curl command straight away. On the command line, use stampdrill import.
Can I test an MCP server?
Yes. A request like MCP http://localhost:3001/mcp connects to a Model Context Protocol server, and its script calls tools, reads resources and gets prompts; see MCP servers in the language reference. The app connects to servers over HTTP. Servers started with stdio: run from the stampdrill command-line tool, because Mac App Store apps can't start other programs.
Can an AI assistant write .stamp files?
Yes. The open stamp-files skill teaches agents the format and to check their work with stampdrill check. In Claude Code, run /plugin marketplace add samalstudios/stampdrill, then /plugin install stampdrill@stampdrill.
Troubleshooting
A request to a server with a self-signed certificate fails
Add @insecure to the request to skip certificate checks for it.
A request to localhost fails
Check that the server is running and listening on that port. Stampdrill can reach localhost and other machines on your network.
Contact
Something not working, or an idea for Stampdrill? Write to [email protected] with your macOS version and, if you can, the request that misbehaves (with its secrets removed).