30 open-source projects similar to mulesoft/api-designer, ranked by shared indexed features. Tags may describe platforms or build tools rather than the same primary purpose. Check each project’s use case, license, and deployment requirements before treating it as a replacement.
api-blueprint is a markdown-based API design language and specification standard used to define the structure, behavior, and data schemas of HTTP web services. It provides a formal method for mapping HTTP methods to resources and defining payload validation rules through a machine-readable syntax. The project functions as a blueprint for creating interactive technical documentation and functional mock servers. These tools transform design specifications into human-readable guides and simulated backend environments to enable integration testing before implementation. The language covers API m
RAML is a declarative YAML-based specification language used for modeling RESTful interfaces and data structures. It functions as a contract-first API framework and modeling standard, establishing a formal agreement for service communication and a single source of truth before implementation begins. The specification enables the automation of functional mock servers and the generation of language-specific client SDKs directly from the definition files. It supports a modular approach to API design through the use of external libraries, overlays for extending contracts, and reusable traits and
Swagger Editor is a web-based authoring tool and development environment used to design, document, and validate API specifications. It specifically supports the OpenAPI Specification, providing a browser interface for writing API schemas and verifying their structure. The tool features real-time rendering that produces a visual preview of the API documentation as the specification is edited. It includes syntax highlighting based on standardized schemas to improve the readability of the API definitions. The editor supports importing specifications from files, external URLs, or example fixture
Postcat is an integrated platform for API design and documentation, serving as a REST API client and a mock server. It provides a workspace to define technical requirements and data schemas, allowing development teams to align on interface behavior. The platform features a plugin architecture that enables the integration of third-party tools and custom capabilities. It decouples frontend and backend development cycles by generating simulated server responses based on predefined data structures. The toolset includes an environment management system for switching between development, staging,
openapi-devtools is a browser extension and OpenAPI specification generator that captures network traffic to automatically document the API structures of websites and applications. It functions as an HTTP traffic capturer and browser-based documentation tool, mapping real-time network requests into standardized API specifications. The tool enables API reverse engineering by intercepting outbound HTTP traffic and using heuristic-based merging to combine headers, bodies, and parameters from multiple requests into unified endpoint definitions. These captured definitions can be visualized as huma
This project is a multi-protocol API simulation and mocking system designed to replace external dependencies during development and testing. It provides an API mocking server, a network traffic proxy, and specialized simulators for language model services and identity providers. The system distinguishes itself through deep AI simulation capabilities, including the emulation of language model providers and Model Context Protocol servers using JSON-RPC 2.0. It supports multi-turn conversational logic, state tracking for AI chat APIs, and the visualization of agent execution through call graphs
swagger-node is a toolkit for OpenAPI API development that ensures a project's implementation matches its documented design. It enables the generation of functional API servers and interactive documentation directly from YAML specification files. The project features a system for mapping API endpoints to specific controller functions and a mock mode that simulates API responses from the specification. This allows for API prototyping and frontend development before backend business logic is implemented. The platform provides a command-line interface for project bootstrapping, server managemen
The OpenAPI Specification is a formal, vendor-neutral standard for defining the structure, endpoints, and data models of HTTP-based web services. By providing a machine-readable interface definition language, it enables developers to establish clear API contracts that ensure consistency across diverse programming languages and backend systems. This specification promotes a design-first development approach, where interface behavior is defined through static, declarative configuration files rather than imperative code. This structure allows for the automated generation of type-safe client libr
moco is a multi-protocol mock server and programmable API stub used to simulate HTTP, REST, WebSocket, and Server-Sent Events endpoints. It enables the creation of fake backend services to facilitate development and integration testing without requiring a live server. The project distinguishes itself through its ability to act as a network traffic replay tool, capturing real request-response pairs via a proxy and playing them back locally. It also supports bidirectional communication simulations, including WebSocket server simulation and SSE stream simulation with configurable delivery delays
Hoppscotch is an open-source API development ecosystem designed for building, testing, and debugging REST, GraphQL, and real-time APIs. It provides a unified platform that functions across web browsers, desktop applications, and command-line interfaces, allowing developers to manage the entire API lifecycle from a single environment. The platform distinguishes itself through a highly interactive, command-driven interface that utilizes a global spotlight palette and keyboard shortcuts to streamline complex workflows. It supports advanced request manipulation and validation by executing JavaScr
Connexion is a spec-first Python web framework designed to derive server behavior and validation logic directly from a predefined API contract. It enables the development of web services by using an OpenAPI specification to automatically handle routing, request validation, and response serialization. The framework distinguishes itself by acting as an OpenAPI request validator and mock server. It can simulate API behavior by serving example responses based on specification schemas, allowing for frontend development and prototyping before a backend implementation is completed. Additionally, it
This platform serves as a centralized web interface for managing, executing, and reporting on automated API test suites and manual endpoint validation tasks. It provides a comprehensive environment for RESTful service testing, allowing users to organize projects, track team access, and maintain a clear history of execution results to monitor system stability. The platform distinguishes itself by integrating a mock server that generates synthetic responses for API endpoints, enabling client-side development and testing before backend services are fully implemented. It supports complex testing
Vue-typescript-admin-template is a TypeScript-based admin panel starter built with Vue CLI 3, providing a complete foundation for building enterprise back-office interfaces. It enforces type safety across Vue components using TypeScript, reducing runtime errors and improving code maintainability, while offering a dynamic route permission system that controls sidebar navigation and page access by mapping user roles to route permissions at runtime. The template includes a mock API service layer that simulates backend responses for frontend development without a live server, along with internati
Responses is a Python mocking library designed to intercept outgoing HTTP calls made with the Requests library to return predefined simulated responses. It functions as a request verification framework and a network simulation tool, allowing for the verification of application behavior against various API response patterns without making real network calls. The project distinguishes itself through a traffic recorder that captures real network interactions and saves them to files for deterministic replay. It further enables the simulation of complex network scenarios, including the triggering
Parses Swagger specs in JSON or YAML format - Validates against the Swagger 2.0 schema or OpenAPI 3.0 Schema - Resolves all $ref pointers, including external files and URLs - Can bundle all your Swagger files into a single file that only has internal $ref pointers - Can dereference all $ref…
Redoc is an API documentation generator that transforms standard API specification files into interactive, responsive, and highly customizable web-based documentation interfaces. It provides a three-panel layout that includes synchronized navigation, code samples, and search functionality, allowing developers to explore endpoints and schemas directly within a browser-based environment. Beyond rendering, the project functions as an API governance toolkit that enforces structural standards and quality rules across API definitions. It includes a suite of processing utilities for bundling, splitt
Swagger Search is an application that aggregates the Swagger/OpenAPI documentation of your microservice architecture in one place, where your can browse it or search endpoints based on their url, documentation, the parameters it accepts or their types.
This SwaggerProvider can be used to access RESTful API generated using Swagger.io
Spectral is a programmable linting engine and validation tool designed to enforce style guidelines and schema correctness within OpenAPI specifications and JSON configuration files. It functions as a rule-based validator that analyzes structured text files to ensure data consistency and adherence to predefined constraints. The engine utilizes a configuration-driven execution model, allowing users to manage pluggable rule sets and integrate JSON Schema definitions. It supports the creation of custom function-based rules to define complex validation logic beyond static declarations. The projec
A module to build validators for Swagger(OpenApi) Request parameters and Response objects.
Dredd is an HTTP API contract testing tool and specification validator. It functions as an automated test runner that verifies whether a live backend server's behavior adheres to a formal API specification document. The system performs language-agnostic API testing by transforming specification definitions into HTTP requests and matching the resulting responses against the defined JSON schemas. This process ensures that the server implementation remains compliant with the design contract regardless of the programming language used to build the backend. The tool manages the test lifecycle thr
A JSON schema validator for OpenAPI specifications, it currently supports:
This project is a comprehensive Node.js software development kit designed for integrating large language models into applications. It serves as a foundational client for interacting with REST and WebSocket services, enabling developers to implement chat functionality, multimodal content generation, and autonomous agent orchestration. The library provides a structured framework for defining executable tools and enforcing JSON schemas, ensuring that model outputs remain programmatically compatible with downstream systems. The SDK distinguishes itself through its robust request orchestration and
Dive into LLMs is a framework designed for fine-tuning large language models and constructing modular machine learning pipelines. It provides a structured environment for adjusting pre-trained models on custom datasets while optimizing computational efficiency and training time. The project distinguishes itself by offering an interactive web interface that allows for the deployment and publication of trained models directly to a browser. This enables users to test and interact with model results through a standardized web-based environment. The platform supports the creation of flexible work
This project is a self-hosted web interface and desktop application designed for interacting with language models. It provides a private platform for managing conversational sessions, allowing users to connect to external AI services while maintaining control over their interaction history and configuration settings. The application distinguishes itself by offering a unified interface that supports multimodal inputs and outputs, including voice interaction processing and generative image creation. It secures sensitive credentials by routing requests through a backend proxy and ensures data pr
Postman is an API platform that enables users to build, test, and interact with APIs by sending HTTP requests and viewing responses directly within the tool. It provides a graphical interface for designing and managing sequences of API interactions, allowing users to create and organize related API requests into named collections for reuse and sharing. The platform supports automating API workflows through test scripts and built-in sequences, and facilitates collaboration by enabling teams to share collections, specifications, and workflows. Users can document APIs by attaching descriptions a
This project is a web-based user interface for interacting with large language models via API keys. It functions as an OpenAI API client and a general LLM web chat interface, allowing users to send prompts and receive responses through a private web portal. The application features a security layer with password-based access control to restrict public usage. It supports custom request routing and proxy configurations to bypass network restrictions, and it is available as a progressive web app for native-like installation on mobile devices. The interface includes rich text rendering for Markd
Sloth is a plugin-extensible reliability engine that translates concise service level objective specifications into production-ready alerting rules and monitoring dashboards. It automates the generation of multi-window, multi-burn-rate alert rules alongside visual dashboards for metrics platforms like Prometheus and Grafana, establishing uniform monitoring outputs from simple definition formats. The tool provides static definition validation to inspect service configuration files for semantic and structural errors prior to rule generation, enforcing correctness early. It supports an abstract
Prism is a set of tools for generating mock servers and validation proxies based on OpenAPI specifications or Postman collection files. It serves as an API contract testing tool to verify that API implementations adhere to formal contracts. The project provides an OpenAPI mock server that simulates API responses and a validation proxy that checks live HTTP traffic against an OpenAPI specification to identify implementation discrepancies. It also includes a mock server capable of mimicking API behavior based on exported Postman Collection files. The tool covers API behavior simulation and tra
This project is a strongly-typed GraphQL client library and code generator designed for Android, JVM, and Kotlin Multiplatform. It provides a toolset for executing queries and mutations, generating immutable classes and parsers from GraphQL schemas to ensure compile-time type safety. The library features a normalized client-side caching system that flattens server responses into a lookup table to maintain a single source of truth. It includes a specialized subscription client for handling real-time server-side updates via WebSockets or Server-Sent Events, and a mocking framework for simulatin