Replace the current circuit with the given circuit definition in Falstad CircuitJS1 text format (the same format produced by File > Export as Text, starting with a "$" line). Resets simulation time to 0. Returns the list of parsed elements so you can verify the circuit and note element indices for probing. The simulator keeps state between tool calls.

Export the current circuit as Falstad text format, or as an SVG drawing of the schematic.

Read the current simulation state: time, running flag, timestep, and every element with its voltage difference, current, post voltages and info string. Use the element index values with run_transient probes. Optionally pass node names (of labeled nodes, e.g. from "207 ..." labeled-node elements) to read their voltages.

Start/stop/reset the simulation, set the max timestep, or set the voltage of an external voltage source (an "Extern voltage" element, type ExtVoltageElm, addressed by its name). "reset" reloads the current circuit, zeroing time and all state.

Run the simulation for a given amount of SIMULATED time while sampling probes, then stop. Returns time-series data {t, }. Probes: {"node":"name"} reads a labeled node voltage; {"element":i,"quantity":"current"|"voltageDiff"|"power"} reads element i (indices from circuit_state/circuit_load). Simulation speed is bounded by the circuit's sim-speed setting and CPU, so wall-clock time may differ from simulated time; the call aborts with partial data if wallTimeoutMs elapses first.

Take a PNG screenshot of the circuit as currently drawn (including scope traces if the circuit defines scopes). Returns the image; optionally also saves it to save_path.

Return a URL that opens the circuit in the Falstad simulator in any normal browser (falstad.com, no install needed). Uses the current circuit unless text is given. Give this link to the user so they can view/edit the circuit interactively in Chrome.

Advanced escape hatch: run arbitrary JavaScript inside the CircuitJS1 page. The code is the body of an async function receiving sim (the CircuitJS1 object, see https://www.falstad.com/circuit/doc/js-interface.html). Return a JSON-serializable value. Example: "return sim.getElements().filter(e => e.getType()==='ResistorElm').map(e => e.getCurrent())".