One Window for API, Database, and Browser Testing

Think about what testing a feature actually looks like. You send a request in an API client to hit the endpoint. Then you switch to a database GUI to confirm the row was written correctly. Then, if there's a UI, you flip to a browser to make sure the change actually rendered. Three tools, three windows, three sets of credentials, three places where state lives — and a constant tax of context-switching between them.

Each tool is fine on its own. The problem is the seams between them. The endpoint you just called, the table you're inspecting, and the page you're checking are all the same feature — but your tooling treats them as three unrelated worlds. You re-enter connection details. You copy IDs from a JSON response into a SQL WHERE clause by hand. You lose your train of thought every time you change windows.

The pitch for an all-in-one API testing tool is simple: keep the whole verification loop — request, data, UI — in one place, so the seams disappear.

Start with a great API client

An all-in-one tool is only worth it if the core is genuinely strong. So that's where Rostyman starts: it's a full API client first, and the rest is built around it.

It handles the protocols you actually work with — HTTP/REST, GraphQL, gRPC (all streaming modes), WebSocket, Socket.IO, MQTT, Server-Sent Events, and MCP for AI agents. There are 14 authentication types, including OAuth2, AWS SigV4, NTLM, Hawk, and JWT, so real-world auth flows aren't a fight. Pre- and post-request scripting runs locally with pm.* compatibility, you get environments and variables, and secrets live in an encrypted vault.

Crucially, your collections are stored as files on disk — Git-versionable, diffable, reviewable in a pull request. Your API workspace can live in the same repository as the service it tests. And when you need to run requests in CI, rosty-cli gives you a command-line runner with full parity to the app — same collections, same behavior, no separate scripting.

That's the foundation. Now look at what folding in the next two layers buys you.

Add the database, drop the second window

The most common follow-up to an API call is checking what it did to the data. Normally that means a separate database client and a second mental model. Rostyman brings the database into the same app.

It includes database clients for 8 engines — PostgreSQL, MySQL, MariaDB, MSSQL, MongoDB, Redis, CockroachDB, and SQLite — so you can confirm what an endpoint wrote without leaving the tool. And these aren't bare query consoles:

• ER diagrams let you see how tables relate, generated from the live schema.
• An EXPLAIN visualizer turns a query plan into something you can read at a glance — useful when “the API is slow” turns out to be “the query is slow.”
• AI-assisted queries help you draft and understand SQL when you're working against an unfamiliar schema.

The workflow that used to span two apps — call the endpoint, then go verify the row — now happens in one. The response is right there; the data is one panel away.

Close the loop with browser testing — honestly, in beta

The third layer is the user-facing one: did the change actually show up correctly in the UI? Rostyman includes browser automation — we call it Web Intelligence — that lets you record and replay UI interactions as tests.

We want to be straight with you about its maturity, because nothing erodes trust faster than overselling. Web Intelligence is in Beta. It works well on simpler sites and on localhost, which covers a lot of real development and internal-tool testing. It is not yet reliable on complex single-page applications with heavy client-side state and dynamic rendering. We label it Beta inside the app for exactly this reason, and we'd rather you adopt it knowing where the edges are than be surprised by them.

Used within those limits, it closes the loop: API request, database check, and a recorded UI flow — all in one place, all reproducible.

More of the pieces that surround the loop

Around that core API-to-DB-to-UI flow, Rostyman adds the connective tissue that turns testing into a workflow:

• A visual workflow editor to chain steps — call an endpoint, branch on the result, hit another — without writing glue scripts.
• A cron scheduler for running checks on a schedule.
• A mock server for standing up endpoints before the real ones exist.
• LAN file sharing (mDNS + TLS) for moving things between machines on your network.
• Imports from common formats, so you can bring an existing API workspace in rather than rebuilding it.

And the AI assistant runs through all of it — opt-in, able to use local models or cloud providers, and MCP-native — to help you build requests, understand responses, and draft queries.

Offline, free, and no account

The whole thing runs as a local-first desktop app. It works fully offline, the core is free forever, and it never requires an account or cloud sign-in for core features. Your collections, credentials, and database connections stay on your machine. An optional Pro tier (~$9/mo) is planned for opt-in cloud sync and team features — for the people who want them — but the everyday all-in-one workflow costs nothing and asks for nothing.

It runs on Windows, macOS, and Linux, including ARM64 builds.

Try the whole loop in one window

If your current setup is an API client in one window, a database GUI in another, and a browser in a third, it's worth seeing what happens when they're the same window. Send a request, check the row it wrote, and — within its beta limits — replay the UI flow it powers, without ever switching apps.

Download Rostyman →

A note on the current build: Rostyman is in its v1.0 release-candidate stage and isn't code-signed yet, so your OS may show a security prompt on first install. Signing is in progress. You can find every platform build on our download page and on GitHub.