Top Open Source API Integration Tools in 2026
A curated collection of the 29 best free and open-source API Integration tools in 2026. Compare features, GitHub stars, tech stacks, and self-hosted software.
Skyvern
AI-powered browser automation for any website
Stars22,857Last commit12d agoLicenseAGPL-3.0
NocoBase
Open-source AI + no-code business system builder
Stars23,888Last commit11d agoLicenseOpen Source
Krakend
High-performance open source API gateway
Stars2,668Last commit17d agoLicenseApache-2.0
Flowglad
Unified workspace for cross-system automations
Stars1,718Last commit3mo agoLicenseOpen SourceACI.dev
Outcome Automation as a Service for professional and financial services firms
Stars4,885Last commit3mo agoLicenseApache-2.0WunderGraph
Open-source GraphQL Federation platform with governance
Stars1,256Last commit11d agoLicenseApache-2.0Windmill
Code-first platform for internal software
Stars17,693Last commit10d agoLicenseOpen Source
UserTourKit
Open-source React onboarding toolkit
Stars61Last commit2mo agoLicenseMIT
TryPost
Agentic social media scheduling with AI
Stars555Last commit11d agoLicenseAGPL-3.0ToolJet
Build enterprise apps with AI-powered low-code
Stars40,777Last commit11d agoLicenseAGPL-3.0
Structr
Open-source low-code platform with built-in graph database
Stars828Last commit27d agoLicenseOpen Source
Relaticle
Open-source AI-powered CRM with MCP tools
Stars1,554Last commit11d agoLicenseAGPL-3.0
Refine
Build internal tools 10x faster with AI agents
Stars35,586Last commit3mo agoLicenseMIT
Rallly
Free group meeting scheduling without logins
Stars5,225Last commit10d agoLicenseAGPL-3.0
Pixelfed
Decentralized photo sharing platform
Stars7,072Last commit11d agoLicenseAGPL-3.0
