> ## Documentation Index > Fetch the complete documentation index at: https://80x.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # How the engine works > Reference pages tell you what a block does; these pages explain why the Attio Workflows engine behaves the way it does. Reference pages tell you what a block does; these pages explain why the Attio Workflows engine behaves the way it does. Read them when a reference page raises a "but why?" question. They cover the mental models that stop you building workflows that silently misfire, double-charge, or loop forever. ## The engine The trigger-then-blocks-then-run model, and where workflows live in the workspace. Agents, code, multi-trigger workflows, and the repriced credit model. Picking a record, attribute, schedule, webhook, or command trigger, and the one distinction that trips everyone. How an earlier block's output becomes a later block's input. If, switch, and filter, and why a condition that stops a run costs nothing. The distinction that decides which trigger and which block you reach for. ## Running, scaling, and governing What a run is, and how to read one in the run viewer. Why loop contents dominate the cost of most expensive workflows. How a self-triggering workflow burns credits until someone notices, and how to prevent it. What a workflow can read and write, and the "Run as" model. Naming, ownership, and change control once you have more than a handful. The canonical credit table, plan allowances, and timeout numbers for every block. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.