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Studio dataflow graph

caliper-graph is the Phase-8 dataflow graph executor — the engine behind Studio's Simulink-style node editor, and equally usable from the CLI and Python.

What it is

A deterministic, serde-serializable graph IR (GraphDoc, persisted as the .caliper-graph.json schema) that composes existing engine ops into a runnable pipeline. All three faces (the Studio Tauri backend, the CLI's graph subcommand, and the PyO3 run_graph) (de)serialize a GraphDoc, then call validate and run.

No new math lives here. Every COMPUTE node dispatches to an existing engine free function or type. The crate is pure Rust and lean — serde plus the engine crates plus nalgebra, with no rand and no tokio.

Shape of the IR

  • ir — the persisted schema: PortType, NodeKind, Node, Edge, GraphDoc, PortValue, ClipData, ReportData.
  • validate — returns Diagnostics (per-node / per-edge errors) plus a topological order, or a cycle report.
  • exec — run returns a GraphResult or a GraphError.

Node kinds

The NodeKind enum covers source, compute, and sink nodes, each mapping to engine functionality:

  • Sources / configs — StartConfig, GoalPose, NamedConfig.
  • Compute — Ik, MoveJ, MoveL, PlanRrt, Control (kp/kd), GravityDrop, CollisionCheck.
  • Sinks / views — View (3D scene), Scope (a named signal plotted over time), Report.

Determinism

The executor is deterministic: PlanRrt is seeded, and control/dynamics rollouts are tick-driven and clock-free (consistent with the rest of the engine). A wired graph like StartConfig → GoalPose → Ik → MoveL → View + Scope produces the same result on every face and every run.

How the graph is verified

The executor's dispatch is verified faithful — a MoveJ/MoveL node produces the same result as calling caliper_motion::move_j / the Cartesian path directly (a parity test), and the executor is deterministic. It has its own oracle coverage. Note the scope of this: it verifies that the graph wrapper faithfully calls the engine, on top of the engine's own verification — it does not add a new independent check of the underlying math.