postiz-app

Postiz does that as an open source app you can self-host. It supports Twitter/X, LinkedIn, Instagram, Facebook, TikTok, and more. The AI features generate post variations and suggest optimal posting times. You get a content calendar, team collaboration, and analytics.

Self-hosting is free under AGPL-3.0. The cloud version at postiz.com has a free tier and paid plans; details vary but expect typical SaaS pricing for social scheduling ($15-30/mo range for individuals, more for teams).

The catch: AGPL means if you modify the code and offer it as a service, you must open source your changes. The growth is impressive but the project is young, expect rough edges and breaking changes. Self-hosting requires Docker, PostgreSQL, Redis, and an LLM API key for the AI features (OpenAI, etc.) which adds cost. And honestly, if you're one person managing one account, Buffer's free tier is less work to set up.