Best API Design Software for Linux

KrakenD is a high-performance API Gateway optimized for resource efficiency, capable of managing 70,000 requests per second on a single instance. The stateless architecture allows for straightforward, linear scalability, eliminating the need for complex coordination or database maintenance. It supports various protocols and API specifications, with features like fine-grained access controls, data transformation, and caching. Unique to KrakenD is its ability to aggregate multiple API responses into one, streamlining client-side operations. Security-wise, KrakenD aligns with OWASP standards and doesn't store data, making compliance simpler. It offers a declarative configuration and integrates with third-party logging and metrics tools. With transparent pricing and an open-source option, KrakenD is a comprehensive API Gateway solution for organizations prioritizing performance and scalability.

Gravitee is an AI agent management and API management platform designed to secure, observe, and govern interactions between AI agents, models, APIs, event streams, and enterprise services. Its AI Gateway provides centralized control for LLM traffic, MCP tool access, and agent-to-agent communication through LLM Proxy, MCP Proxy, and A2A Proxy capabilities. The platform can enforce authentication, authorization, least-privilege access, PII redaction, rate limits, spending controls, and audit logging across AI traffic. Gravitee also provides visibility into agent behavior, token consumption, dependencies, costs, and usage patterns so organizations can identify shadow AI and unmonitored workloads. Beyond AI governance, the platform manages APIs and event streams, including REST, GraphQL, gRPC, Kafka, and related enterprise integration patterns. Gravitee is designed for organizations that want a unified control layer for AI agents, APIs, events, and model access.

DreamFactory Software is the fastest way to build secure, internal REST APIs. Instantly generate APIs from any database with built-in enterprise security controls that operates on-premises, air-gapped, or in the cloud. Develop 4x faster, save 70% on new projects, remove project management uncertainty, focus talent on truly critical issues, win more clients, and integrate with newer & legacy technologies instantly as needed. DreamFactory is the easiest and fastest way to automatically generate, publish, manage, and secure REST APIs, convert SOAP to REST, and aggregate disparate data sources through a single API platform. See why companies like Disney, Bosch, Netgear, T-Mobile, Intel, and many more are embracing DreamFactory's innovative platform to get a competitive edge. Start a hosted trial or talk to our engineers to get access to an on-prem environment!

Build APIs that click with client apps. RepreZen API Studio is an integrated workbench that brings API-first design into focus for your whole team, harmonizes your API designs, and generates APIs that click into client apps. Effortlessly. Full-featured OpenAPI editor with content assist, customizable templates, outline navigation & more for fast, focused API design. Live documentation view gives you immediate clarity & insight from the API user's perspective. Interactive diagram lets you visualize the API as you design. Generate & view in any browser to give API users a fast, intuitive overview. Split a large Swagger API spec into multiple files, even share & reuse API components across projects & teams! Edit, navigate, document & generate, all fully compliant with OpenAPI standards. Consolidate & simplify complex multi-file projects to a single file, for easy downstream code generation & docs presentation.

The Platform to Build, Test & Secure APIs. Transform how you design, test, and manage APIs. Collaborate easily, run tests locally, and protect sensitive data every step of the way. No Signup or Login Get started instantly—no need for lengthy sign-ups or logins. VS Code Extension & Desktop Apps Work where you're comfortable! Our VS Code extension and desktop apps integrate seamlessly with your existing workflow. Local Storage & Execution Keep data secure with local storage and execution, ensuring sensitive information stays on your device. Run Unlimited Collections Test and manage unlimited API collections, enabling effortless scaling for all your projects. Mock Servers Streamline development by creating mock servers for fast testing and API response simulation. Scriptless Testing & Playground Simplify testing with our user-friendly interface—experiment with APIs without writing any code. Our enterprise features take it even further. Contact us!