Vejas ships an integration platform with no builder UI at all, because agents write the flows.

Apache-2.0, flows are VejasScript code written by agents from a natural language prompt, reviewed in git, and run by a single Rust binary on NATS with no Python or subprocesses (GitHub). Domain experts adjust business rules, transcoding tables and thresholds through a panel without touching code, and the agent reads the language reference over MCP. The maker reports two production customers. The drag-and-drop canvas was the entire product in Zapier, n8n and Make, and this deletes it on the argument that the reviewable artifact should be a diff.