Open Source Projects using Cal.com
A curated collection of the 12 best open source software using Cal.com. Find the most popular and trending open source projects to learn from, contribute to, or use in your own projects.
Multi-channel notification infrastructure for apps
Stars
40,279Last commit
15 hours agoLicense
Unknown
Open-source platform for building in-app, email, push, SMS, and chat notifications with a unified API, workflow engine, and embeddable inbox component.
Open Source Alternative to:
Build a custom CRM without the proprietary lock-in
Stars
Stars growing over the last 30 days60,464Last commit
5 hours agoLicense
AGPL-3.0
Self-hostable CRM built for technical teams who need a fully customizable, extensible platform without vendor lock-in or proprietary tooling.
Open Source Alternative to:
Self-host your own scheduling page, no vendor required
Stars
49,700Last commit
2 days agoLicense
MIT
Cal.diy is the community edition of Cal.com for personal self-hosting, with calendar sync, video conferencing, payment support, and a REST API.
Open Source Alternative to:
AI workforce platform where agents, skills, and memory live in your repo
Stars
20,385Last commit
7 hours agoLicense
Elastic-2.0
Manages a team of AI agents across your company, with every agent, skill, memory, and connector stored as versioned files in a git repo you own and self-host.
Open Source Alternative to:
Privacy-first survey and experience management platform
Stars
13,217Last commit
5 hours agoLicense
AGPL-3.0
Collect feedback across websites, apps, and emails with targeted surveys, user segmentation, and GDPR-compliant data handling. Self-host or use the cloud.
Open Source Alternative to:
Self-hostable voice agent platform with full model control
Stars
Stars growing over the last 30 days6,028Last commit
19 hours agoLicense
BSD-2-Clause
Open-source voice agent platform that lets you plug in your own STT, LLM, and TTS models, deploy on-prem or in your VPC, and build agents via MCP or a visual workflow builder.
Open Source Alternative to:
Build reliable AI apps with comprehensive observability
Stars
6,266Last commit
8 days agoLicense
Apache-2.0
Open-source platform for logging, monitoring, and debugging LLM applications. Route, debug, and analyze AI apps with comprehensive observability tools.
Open Source Alternative to:
Get audit-ready for SOC 2, ISO 27001, HIPAA, and GDPR
Stars
Stars growing over the last 30 days2,078Last commit
22 hours agoLicense
AGPL-3.0
AI-driven compliance platform that automates evidence collection, policy generation, and continuous monitoring across 580+ integrations for SOC 2, ISO 27001, HIPAA, and GDPR.
Open Source Alternative to:
Transform team email into efficient collaborative workflows
Stars
1,761Last commit
9 months agoLicense
AGPL-3.0
Streamline team communication with shared inboxes, unlimited email addresses, and customizable workflows. Perfect for modern businesses seeking organized email management.
Open Source Alternative to:
Track your brand's visibility across AI answer engines
Stars
Stars growing over the last 30 days270Last commit
21 days agoLicense
AGPL-3.0
GEO tool that queries ChatGPT, Claude, Gemini, and Perplexity with your buyers' questions, then shows you who gets recommended and how to close the gap.
Open Source Alternative to:
Type-safe feature flags and remote config for developers
Stars
167Last commit
1 year agoLicense
AGPL-3.0
Abby offers open-source, fully typed feature flagging and remote configuration for React and Next.js, with multi-environment testing and debugging tools.
Open Source Alternative to:
Code-first email platform that deploys to your AWS
Stars
66Last commit
9 hours agoLicense
AGPL-3.0
Build email templates as React components and automations in TypeScript. Deploy to your AWS account with SES integration. Marketing teams edit content without code.
Open Source Alternative to:
Sent – Messaging Infrastructure for Developers. One API for SMS, WhatsApp, and RCS across 190+ countries.
Openlane