Models — Layer 2 Graph API

core — Graph API Components

class Node:            # Symbolic intermediate result (see architecture.md §Graph API)
class Input(Node):     # Named graph entry point
    def __init__(self, name: str): ...
class Graph(Operator): # Compiled computation DAG (see architecture.md §Graph API)
    def __init__(self, inputs: dict[str, Input], outputs: dict[str, Node]): ...

The Graph API is the Layer 2 high-level user API for building arbitrary computation DAGs. See architecture.md for the full specification of Node, Input, and Graph classes, including use cases for multi-input metrics, branching, and merging workflows.