Gapfy Echo overview

Gapfy Echo is an API client for Windows, with companion apps for Android and iOS. The Windows desktop is built with Avalonia and installs from the Microsoft Store. Echo is part of the Gapfy platform and comes in Free, Pro and Pro AI tiers. This guide starts with the desktop workflow and connects it to the hosted tools in Maestro.

One editor, five protocols

Echo speaks HTTP, gRPC, GraphQL, WebSocket and SSE in a single editor. gRPC uses reflection-based transport with service discovery and every streaming mode, GraphQL brings introspection, variables and subscriptions, WebSocket adds interactive send with a binary hex view, and SSE reconnects automatically. See requests and protocols for the details.

Built for real work

Collections live in spaces with nested folders, drag and drop, and bulk operations. You can share them with teammates at Read, Contribute or Full Access. Space-scoped environments with secret variables keep configuration out of your requests, and compare mode fires one request against up to 4 environments side by side with a structural JSON diff.

Automation covers a collection runner, declarative request chains, local request interception with mocks, cron-scheduled runs and pm.* scripting. Start with collections and sharing and automation and testing.

Take mocks beyond the desktop

Keep mocks on the desktop for free, or use a paid Echo plan to publish a synced mock from the public hosting panel in Maestro. The public URL at mock.gapfy.io answers your team without the desktop running. You can also create and edit mocks in Maestro. Public mock hosting explains the steps, including the permission needed for a team mock, and how it differs from rules loaded into a .NET application on a paid plan.

Contracts describe response shapes and compatibility between versions. Applications and keys connects each application's provided or consumed contracts with scoped access. The four .NET packages cover contract publication, validation, outbound request interception and mock responses in an ASP.NET Core application.

Private and local first

Echo works offline in guest mode without an account. On Windows, the local database is encrypted at rest and its key is protected by Windows DPAPI. When you need connected features, sign in with Microsoft Entra External ID through your system browser. Collections, requests, environments, schedules, mock servers and deletions sync across devices, with conflict capture and a repair action.

Everyday comforts

Request history has filters, the cookie jar has an editor, and network timing includes a slower than usual badge. Split view supports up to 4 panes. A command palette, rebindable shortcuts, a 7-language interface, and light and dark themes help you settle into your own workflow. The Android and iOS companion apps share the sync engine so your signed-in collections can follow you between devices.