activepieces

A self-hosted alternative to Zapier and Make, with hundreds of integrations and around 400 MCP servers ready to plug an agent into. For an agency the argument is cost: it doesn't charge per task executed, so high-volume flows stop scaling in price. In exchange you pay in operations, because the server is yours, and so are the updates and the outages. Its license is not a clean MIT, so check it before reselling the service to a client.