Verified starter shortlist · 22 Sep 2026
Choose the layer before you install an agent.
A decision-first field guide to four open-source marketing projects: a platform, an orchestrator, a harness library and a narrow agent app. Start with the smallest layer that can safely do the job.
Make a safe first choice
Want the compiled research behind the choices? Start in the research library, read the four-layer comparison, or inspect the sources and uncertainty notes.
Four layers, four very different promises
The starter shortlist
Mautic
For self-hosted contacts, forms, campaigns and lifecycle email when you can run the database, mail transport and scheduled jobs.
Not for: a quick drafting experiment or a simple SaaS-to-SaaS link.
Activepieces CE
For human-reviewed flows across systems you already own. Its deployment and secrets still need an operator.
Not for: a CRM, consent ledger or mail service.
Marketing Agent OS
For reusable marketing instructions inside an approved coding-agent harness.
Not for: a hosted app, scheduler, credentials vault or campaign delivery system.
Loopmark Agent
For a technical solo founder’s small, local drafting pilot with social credentials left absent.
Not for: unattended publishing, team approvals or production operations.