Blog
Thoughts on API testing, local-first development, and building better developer tools.
One Window for API, Database, and Browser Testing
Send a request, check the row it wrote, confirm the UI rendered — one feature, three tools, three windows. An all-in-one client folds API, database, and browser testing into one offline desktop app so the seams disappear.
Why Your API Client Should Work Offline (and Keep Your Data Local)
Testing an API is one of the most local things a developer does — the service is often on your own machine, the request is yours, the secrets are yours. So why does your API client want you to sign in first? The case for an offline, local-first client.
Run your API tests in CI with rosty-cli
Rostyman ships with a CLI runner called rosty-cli. Drop it into your GitHub Actions or GitLab CI pipeline, point it at a collection, and get JUnit XML results back without a GUI. No cloud account, no API key, no special CI plugin — just a binary and a collection file.
Why we built a browser test runner inside an API client
Every time we finished testing an API and needed to verify the UI reflected the change, we opened a second tool. Playwright, Cypress, Selenium — great tools, but separate. The moment you split your testing across two apps you lose context. Environment variables don't share. Database connections don't share. You copy-paste. We decided to fix that.
Database assertions in API tests — close the loop between HTTP and your data
A POST request that returns 201 doesn't prove data was written. Your test suite probably has a gap between "the API said OK" and "the database actually changed." Rostyman's DB Verify tab closes that gap — a SQL assertion that runs the moment the response arrives, right next to your existing test scripts.
Why we built Rostyman
Most API clients today assume you want your data in the cloud. Every new protocol behind a paywall. Every account prompt. Every "your data is synced to our servers" disclaimer. We started asking: why is the tool that's supposed to help us test our APIs so dependent on the cloud? So we built something different.
Test your API, your UI, and your database in one tool
When you're debugging a bug, you usually need three windows open: your API client, your browser, and a database GUI. You send the request, watch the response, check if the database updated correctly, then reload your UI to see if the UI reflects the change. It's a workflow loop that every developer knows. Rostyman is the first tool designed to close that loop.
How we think about building an API client
Mature API clients have years of polish, large ecosystems, and good team features. We're newer, rougher, and ambitious in a way that might feel overreaching. Here is where we think existing tools win, where we think we bring something new, and where we still have ground to cover — an honest self-assessment.
Local-first API testing — why your data should never leave your machine
Your API test collection is a map of your entire system. It contains endpoint URLs, authentication tokens, environment variables, and sometimes example payloads with real data. When you store that in the cloud — even with a reputable provider — you're trusting that provider with a detailed blueprint of your infrastructure. Local-first is not just a technical choice. It's a security posture.
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