Dredd

Active

Founded: 2014
Developer: Apiary (LF Projects, LLC)
Pricing: Free (open-source)
Open source: Yes
Platforms: macOS, Windows, Linux, Web

Indexes

API Testing

Overview

Dredd is a language-agnostic command-line tool that validates API description documents against backend implementations. It reads API specifications in formats like OpenAPI and API Blueprint, automatically generates HTTP requests based on the documentation, and verifies that the actual API responses match the documented behavior. Dredd is designed for teams practicing documentation-driven development, ensuring that API documentation remains accurate and synchronized with implementation throughout the development lifecycle.

Key Features

API Description Validation - Validates API implementations against OpenAPI, Swagger, and API Blueprint specifications
Automated Request Generation - Automatically generates HTTP requests from API documentation to test endpoints
Response Verification - Checks that API responses match documented status codes, headers, and body formats
CI/CD Integration - Integrates into continuous integration workflows to detect documentation-implementation mismatches early
Hook Support - Supports customizable hooks for test setup, teardown, and advanced testing scenarios
Multi-language Support - Language-agnostic tool that works with any backend implementation regardless of programming language
Interactive Configuration - Provides interactive setup via dredd init command to generate configuration files
Transaction Inspection - Allows viewing and naming all transactions (requests) to be executed against the API

Pricing

Plan	Price	Includes
Open Source	Free	Full Dredd functionality, command-line tool, hook support, CI/CD integration

Platforms & Requirements

Dredd is a Node.js-based command-line tool that runs on macOS, Windows, and Linux systems with Node.js and npm installed. It operates as a CLI application and can be installed globally via npm. The tool integrates with various CI/CD platforms and can be configured to work with any HTTP API backend regardless of the server's platform or language.

Integrations & Ecosystem

API Blueprint specification format
OpenAPI 2.0 (Swagger) specification format
OpenAPI 3.0 specification format
npm package manager
CircleCI continuous integration
Apiary platform
Git version control
Custom hooks for Ruby, Python, and Node.js

Alternatives

App	Difference
Postman	Postman is a GUI-based API testing tool with broader testing capabilities beyond documentation validation, including manual testing and collection-based workflows
Swagger UI / SwaggerHub	Swagger UI focuses on API documentation visualization and exploration rather than automated testing against implementations
Karate Framework	Karate is a more comprehensive API testing framework with advanced scripting capabilities, better suited for complex test scenarios beyond documentation validation
REST Assured	REST Assured is a Java-based library for API testing with more granular control and assertion capabilities for unit and integration testing

Reputation

Dredd is recognized as a specialized tool for documentation-driven development with a focused purpose: ensuring API documentation stays synchronized with implementation. It is valued for its simplicity, language-agnostic approach, and seamless CI/CD integration. However, it is not intended as a replacement for comprehensive testing frameworks like PHPUnit or Cucumber, and its effectiveness depends on maintaining high-quality API documentation. The tool has a stable, active community and is particularly useful for teams prioritizing documentation accuracy and contract-based API development.

Sources (8)