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Every team I have worked with has the same bottleneck, and it is never the code. It is waiting on APIs.

The third-party service with no sandbox. The internal service another team owns. The endpoint that exists in a spec but not in reality yet. So we build workarounds: hardcoded stubs that rot, shared dev environments that break when someone else deploys, integration tests that fail because a sandbox went down.

I got tired of it. So I built MockForge.

🔗What it does

MockForge is an open-source API mocking framework, built in Rust. Define realistic mocks for REST, gRPC, GraphQL, and WebSocket from a single config or UI. Run them locally or in CI. Share them with your team through MockForge Cloud: hosted mocks, a plugin registry, and team workspaces.

One tool, four protocols, one config. Install via cargo.

🔗Real systems are multi-protocol

Most mocking tools pick one protocol and stop. Real systems don't. A typical backend I work on talks REST to a payment provider, gRPC to internal services, GraphQL to a data layer, and WebSocket for realtime updates. Mock three of those and hand-roll the fourth, and the hand-rolled one is the one that goes stale.

MockForge treats all four as first-class. One place for mock definitions. Same behavior everywhere. Same run on a laptop and in CI.

🔗Built for CI

A mock that only works on one developer's machine is a liability. MockForge runs headless, so contract tests and integration tests run against deterministic mocks on every commit. No sandbox credentials. No flaky third-party dependencies. No "the tests pass except when they don't."

🔗Plugins instead of copy-paste

Common scenarios shouldn't need custom code every time. The plugin registry holds reusable mock behaviors: realistic data generation, stateful scenarios, failure injection. Teams share what works instead of rebuilding it per project.

🔗Cloud for teams that don't want the ops

MockForge Cloud is hosted mocks with the plugin registry and team workspaces. Same definitions, zero infrastructure to run.

🔗Why Rust

Mocking has performance characteristics that matter: low latency, small footprint, fast startup. Rust gives all three. And MockForge is open source under a permissive license, because the tool I wished for every time I waited on an API should exist for everyone.

🔗Next step