1.floci-io / floci
Light, fluffy, and always free - The AWS Local Emulator alternative
+24,426 stars
from 4,322 · score 10.10
Trending repositories
Ranked by Attention Score: stars gained over the last 180 complete days
41 repositories by Attention Score · May 8, 2026 – Nov 3, 2026 (UTC)
2.keploy / keploy
Open-source platform for creating safe, isolated production sandboxes for API, integration, and E2E testing.
- testing
- test-automation
- api-testing
- testing-tools
- test-automation-framework
- test-generation
- +8 more
+2,666 stars
from 16,614 · score 7.89
3.axllent / mailpit
An email and SMTP testing tool with API for developers
- email-testing
- go
- golang
- smtp-server
- smtp-relay
- smtp-testing
- +2 more
+1,560 stars
from 9,264 · score 7.35
4.google / googletest
GoogleTest - Google Testing and Mocking Framework
+1,384 stars
from 38,316 · score 7.23
5.typicode / json-server
Get a full fake REST API with zero coding in less than 30 seconds (seriously)
+559 stars
from 75,175 · score 6.33
6.mswjs / msw
The industry standard for API mocking in JavaScript.
+527 stars
from 17,803 · score 6.27
7.stretchr / testify
A toolkit with common assertions and mocks that plays nicely with the standard library
+433 stars
from 25,809 · score 6.07
+321 stars
from 15,879 · score 5.77
9.getmoto / moto
A library that allows you to easily mock out tests based on AWS infrastructure.
+300 stars
from 8,433 · score 5.71
10.mockoon / mockoon
Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.
+268 stars
from 8,200 · score 5.59
+220 stars
from 7,198 · score 5.40
12.karatelabs / karate
Test Automation Made Simple
- test-automation
- assertions
- testing-tools
- mock-server
- automated-testing
- webdriver
- +10 more
+202 stars
from 8,802 · score 5.31
13.stoplightio / prism
Turn any OpenAPI2/3 and Postman Collection file into an API server with mocking, transformations and validations.
- oas
- prism
- mocking
- api-testing
- http-proxy
- swagger
- +9 more
+165 stars
from 4,900 · score 5.11
14.mock-server / mockserver-monorepo
MockServer is an HTTP(S) mock server and proxy for testing that lets you mock APIs, inspect and modify live traffic, and inject failures. It supports HTTP/1.1, HTTP/2, gRPC, WebSockets, TCP and more on a single port, with additional support for HTTP/3, message brokers, and AI/LLM APIs.
- mock-server
- proxy
- java-client
- javascript-client
- node-module
- node-client
- +9 more
+149 stars
from 4,854 · score 5.01
15.YMFE / yapi
TranslatedYApi is a visual API management platform that can be deployed locally and connects front-end, back-end, and QA
- api
- api-manager
- api-management
- api-test
+140 stars
from 27,559 · score 4.95
16.uber-go / mock
GoMock is a mocking framework for the Go programming language.
+120 stars
from 3,308 · score 4.80
17.vektra / mockery
A mock code autogenerator for Go
+115 stars
from 7,060 · score 4.75
18.pester / Pester
Pester is the ubiquitous test and mock framework for PowerShell.
- powershell
- pester-tests
- powershell-tests
- assertions
- mocking
- mock
- +5 more
+114 stars
from 3,261 · score 4.74
19.mockito / mockito
Most popular Mocking framework for unit tests written in Java
- mockito
- java
- mocking-framework
- testing-tools
- mocking
- mock
- +6 more
+108 stars
from 15,341 · score 4.69
20.nock / nock
HTTP server mocking and expectations library for Node.js
+74 stars
from 13,061 · score 4.32
21.ChangemakerStudios / Papercut-SMTP
Papercut SMTP -- The Simple Desktop Email Server
+70 stars
from 3,267 · score 4.26
+68 stars
from 6,346 · score 4.23
23.kevin1024 / vcrpy
Automatically mock your HTTP interactions to simplify and speed up testing
+68 stars
from 2,954 · score 4.23
24.DATA-DOG / go-sqlmock
Sql mock driver for golang to test database interactions
+60 stars
from 6,512 · score 4.11
25.vcr / vcr
Record your test suite's HTTP interactions and replay them during future test runs for fast, deterministic, accurate tests.
+53 stars
from 6,029 · score 3.99
26.sj26 / mailcatcher
Catches mail and serves it through a dream.
+52 stars
from 6,731 · score 3.97
+52 stars
from 4,481 · score 3.97
28.nsubstitute / NSubstitute
A friendly substitute for .NET mocking libraries.
- c-sharp
- dotnet
- dot-net
- testing
- testing-tools
- test
- +6 more
+46 stars
from 2,937 · score 3.85
29.Netflix / pollyjs
Record, Replay, and Stub HTTP Interactions.
+40 stars
from 10,211 · score 3.71
+30 stars
from 19,526 · score 3.43
+29 stars
from 4,417 · score 3.40
32.mockery / mockery
Mockery is a simple yet flexible PHP mock object framework for use in unit testing with PHPUnit, PHPSpec or any other testing framework. Its core goal is to offer a test double framework with a succinct API capable of clearly defining all possible object operations and interactions using a human readable Domain Specific Language (DSL).
+26 stars
from 10,698 · score 3.30
33.sinonjs / sinon
Test spies, stubs and mocks for JavaScript.
- stubs
- javascript
- tdd
- test-driven-development
- unit-testing
- sinon
- +2 more
+25 stars
from 9,727 · score 3.26
+22 stars
from 4,320 · score 3.14
35.travisjeffery / timecop
A gem providing "time travel", "time freezing", and "time acceleration" capabilities, making it simple to test time-dependent code. It provides a unified method to mock Time.now, Date.today, and DateTime.now in a single call.
+19 stars
from 3,406 · score 3.00
36.ardatan / graphql-tools
:wrench: Utility library for GraphQL to build, stitch and mock GraphQL schemas in the SDL-first approach
+18 stars
from 5,415 · score 2.94
37.AliSoftware / OHHTTPStubs
Stub your network requests easily! Test your apps with fake network data and custom response time, response code and headers!
+14 stars
from 5,052 · score 2.71
38.bblimke / webmock
Library for stubbing and setting expectations on HTTP requests in Ruby.
+10 stars
from 4,043 · score 2.40
39.powermock / powermock
PowerMock is a Java framework that allows you to unit test code normally regarded as untestable.
+7 stars
from 4,158 · score 2.08
+5 stars
from 8,457 · score 1.79
41.curtis0x / fake-s3Archived
A lightweight server clone of Amazon S3 that simulates most of the commands supported by S3 with minimal dependencies
+1 stars
from 2,921 · score 0.69