0094 — Decorators are the only authoring style; workflows are declarative @Step graphs

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Context

The owner wants decorators everywhere (models, controllers, events, jobs, crons, resources) with no mixing. Two sources disagree. The AI Implementation Standard §7 prefers define*() functions over a decorator framework, and 0043 chose Medusa-style createStep and createWorkflow. Two authoring styles would mean two discovery paths in codegen (0090) and two ways to read every feature. For workflows, two class-based styles were weighed: a declarative step graph, and an imperative run() method with a journaled ctx.step(), which needs a determinism lint and a replay spike.

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Decision

1. Every framework concept is authored with decorators on classes: models, controllers, actions, events, jobs, crons, resources and workflows. There is no define*() API.
2. This overrides §7 of the AI Implementation Standard for Stackra and for products built on it.
3. Workflows are declarative. A @Workflow class declares its steps with @Step({ after, when, parallel, input, compensate }):
   • after names the steps that must finish first, so the step order is a graph read from metadata, not from code flow;
   • when is a predicate over earlier outputs that skips the step when it is false;
   • parallel groups steps that may run together;
   • input maps the workflow input and earlier outputs to this step’s input;
   • compensate names the method that undoes the step.
4. @Step({ workflow: Child }) is the escape hatch for loops and complex branching: the step runs a child workflow. There is no imperative run() method and no journaled ctx.step().
5. Decorators are legacy decorators with the container’s metadata store (0005). No reflect-metadata.

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Consequences

• One way to declare anything, and one discovery path for gen.
• Plain-data definitions (YAML, JSON) are gone. Anything an AI or a tool generates is generated as decorated TypeScript.
• A workflow’s shape is static metadata, so gen, the registry and the workflow studio (0122) can draw it without running it.
• Logic that does not fit a graph goes into a child workflow or into a step body, never into the workflow class.
• Where steps execute, the journal and compensation rules are in 0102.

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Enforcement

Planned: an oxlint rule banning exported define* factory functions in packages/**; the gen validation pass rejecting an undecorated handler, a @Step whose after names a missing step, and a step cycle. Nothing checks this today.

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Supersedes and sources

Supersedes: none. The authoring part of 0043 is replaced here; 0043 as a whole is superseded by 0102. Sources: owner direction in chat, 2026-10-19 (Round 9 G1; accepted in Round 10; W2 locked in Round 11). Informational: Figentra OS AI Implementation Standard §7 (Figentra_OS_AI_Implementation_Standard_TypeScript_Encore_AgentCore.md).