Inspect dependencies

Each displayed view reports the dependencies for its selected cells and the cells they need. Read them from view.state.graph.

import observablejs as obs

notebook = obs.Notebook(
    obs.js(
        """
        const cylinders = view(Inputs.select(
          ["All", ...new Set(cars.map((d) => d.cylinders))],
          {label: "Cylinders", value: "All"}
        ));
        """,
        key="cylinder_control",
    ),
    obs.js(
        """
        const filteredCars = cylinders === "All"
          ? cars
          : cars.filter((d) => d.cylinders === cylinders);
        """,
        key="filtered_cars",
        display=False,
    ),
    obs.js(
        """
        Plot.dot(filteredCars, {
          x: "weight (lb)",
          y: "economy (mpg)",
          fill: "cylinders",
          tip: {
            // This example references a theme variable used by mdx-marimo.
            // Replace it with a CSS color or remove `fill` in another host.
            fill: "var(--marimo-island-background)"
          }
        }).plot({height: 300, x: {grid: true}, y: {grid: true}})
        """,
        key="chart",
    ),
)

view = notebook.view()
view

After the graph arrives:

graph = view.state.graph

if graph is not None:
    chart = graph.cell("chart")
    print(chart.references)
    for edge in graph.edges:
        print(edge.source.key, "->", edge.target.key, "via", edge.variable)

graph.cell(key) uses public cell identity. Anonymous cells remain in graph.cells. cell_for_variable(name) finds one unique defining cell. external_references lists names supplied outside evaluated cells, including referenced builtins and Python variables.

Export the same snapshot as Mermaid or D2:

if graph is not None:
    mermaid_source = graph.to_mermaid()
    d2_source = graph.to_d2()

Diagram labels prefer cell keys and fall back to notebook position. See View state and graph for record fields.