v1.5.0 — Agentic Workflow Designer

Agentic Workflow Designer

Build multi-model agentic pipelines on a drag-and-drop canvas (sidebar button above Profile, or Cmd+D). Each cell picks a model, a subset of your connected tools, and a prompt; wire cells with flow edges to pipe output downstream, or feedback edges to create bounded revision loops where a reviewer routes work back until it passes. Mix providers freely — a Fable cell can feed an Opus cell whose work a Sonnet cell validates — all through the same governed gateway.

• Hand-rolled canvas (pan/zoom, drag-to-connect ports, labeled multi-input joins, fan-out/fan-in)
• Gate cells route via a forced route_output verdict — works across every tool-capable model
• Bounded feedback loops: per-cell revision cap (editable on the card), live running 3/5 status, and a hard 25-cell-run global budget so loops can't run away
• Per-cell tool selection; live transcript drawer; workflows saved to ~/.mason/workflows/
• Built-in Spec → Implement → Test → Review template

Cross-model compatibility

• Gate stream_options per model family — fixes 400 unknown field "stream_options" on Qwen 3.5 / Llama 4
• Collapse multiple system messages into one — fixes Gemini models only support one system prompt
• Per-family max_tokens caps
• Flatten array-shaped delta.content in the SSE stream — fixes [object Object] output on Qwen 3.5 / Gemini / gpt-oss
• New npm run test:models cross-model regression sweep (81 scenarios)