Sinas is an open-source platform for building AI applications without handing over your data. It sits between your applications and the LLM models, bringing AI agents, Python functions, database queries, state, files and permissions together behind one API, in an instance that belongs to you. Sinas runs in two ways on the same AGPL v3 code. Sinas Cloud is a managed service with upgrades, monitoring and backups handled for you, and a free plan that needs no credit card. Self-hosted, it runs on any Linux server or Kubernetes cluster. AI agents work with OpenAI, Anthropic, Mistral or local models via Ollama, with tool calling, streaming and agent-to-agent orchestration. Python functions run in isolated containers, triggered by agents, APIs, webhooks or schedules. SQL templates connect to PostgreSQL, ClickHouse and Snowflake. Access control, OTP login, API keys and request logging are built in, and configuration can be exported to move between Cloud and self-hosting.