# Phase 7: Workflow Graph

**Purpose:** DAG-based dynamic workflow execution.
**TS Module:** `src/tier2-primitives/workflows/workflow-graph.ts`

## What It Does

Executes workflows defined as JSON DAGs (nodes = steps, edges = dependencies).
Topological-sort execution with conditional branching and fallback steps.

## Step Types

| Type | Description |
|------|-------------|
| `action` | Execute a handler function |
| `decision` | Branch based on state |
| `subworkflow` | Run a nested workflow |
| `parallel` | Run multiple steps concurrently |
| `transform` | Transform data between steps |

## Usage

```bash
# Register a workflow
fable-agent workflow path/to/workflow.json

# Run with a workflow
fable-agent run "Goal" --workflow <workflow-id>
```

## Key Rules

- All edges and dependsOn must reference valid step IDs
- Topological sort ensures correct execution order
- Conditional branching: `if context.key == value` evaluates at runtime
- Fallback steps execute when primary step fails