Chalkcast

Shade the area between a plotted function and the x-axis on [x_min, x_max] (the integral). [x_min, x_max] must lie within the plot's x_range, y = 0 must be on the axes, and the function must be defined and inside y_range there (otherwise an error says what to widen). It follows its plot (move the plot, not it).

Add a LaTeX equation (math mode, e.g. tex=r'e^{i\pi}+1=0'). Dirac notation (\ket{n}, \bra{n}, \braket{a}{b}, \expval{A}) and physics macros work.

Declare a continuous scene parameter (e.g. time t). Use it by name in plot expressions or shape anchors (expr='sin(x - t)'), then animate it smoothly with add_step(kind='tween', param=name, value=...). Curves, areas and anchored shapes that use it are redrawn every frame.

Add axes with functions of x. Each function: {'expr': 'sin(x)', 'color': 'YELLOW'}. Expressions use x, bare math functions (sin, exp, sqrt, sign, ...), np.<fn>, and declared scene parameters; they are validated now. Sampling is adaptive (dense, no spline overshoot on jumps, curves split at poles and clipped to the axes); optional overrides: 'smooth': bool, 'dx': step. x_label/y_label are LaTeX. Defaults: x_range [-5, 5, 1], y_range [-3, 3, 1]; a [min, max] range gets a readable tick step (4-8 ticks, starting at min, or at 0 if 0 is inside the range); the result echoes the ranges used. Curves without a color get distinct colors suited to the theme. The axes are centred at (x, y); labels hang off them. Without functions you get bare axes.

Riemann rectangles (left endpoints, fill opacity 0.6, one color) under a plotted function on [x_min, x_max] within the plot's x_range; (x_max - x_min)/dx must be a whole number, y = 0 must be on the axes and the function inside y_range there. Smaller dx = finer; transform coarse->fine to show convergence. They follow their plot.

Append a scene to the project; it becomes the default target of later calls without scene_id. The title is a label for you (it is not drawn: use add_text).

Add primitive geometry: circle|square|rectangle|triangle|arrow|dot|line, centred at (x, y) (default 0, 0). size (default 1): circle = diameter, square = side, triangle = circumradius, dot = 10 x radius (minimum radius 0.05), line/arrow = length (horizontal). rectangle: width x height (default 1 x 0.5) instead of size. line/arrow: give x1,y1,x2,y2 for an explicit segment (any direction) instead of size/x/y. Anchor in a plot's coordinates with plot_id + at_x + at_y expressions instead of x/y (they may use scene parameters, so a dot can track <x>(t) while a tween runs). Arguments that do not apply to the chosen shape are rejected.

Append a timed beat. kind: write|transform|highlight|fade|camera_move|wait|tween. write/highlight/fade: all targets animate together, over `duration` (a plot's axes and curves are drawn together; highlight is a brief 1.2x pulse in the theme's accent color). An object driven by a parameter cannot be written, highlighted or faded in the same beat as a tween of that parameter (Manim freezes it). transform: one target morphs into `to` (the target keeps its id afterwards). camera_move: zoom is absolute (1 = the full frame, 2 = twice as close); focus_x/ focus_y recentre the camera, omitted = keep the current centre. tween: animate scene parameter `param` to `value` continuously (linear in time). with_previous=true plays this step at the same time as the previous one (e.g. move a curve and a dot together); not after a wait. `note` is a label for you (not drawn). Arguments that do not apply to `kind` are rejected.

Add a title/label/callout (plain text, any language). The rendered size is font_size x scale.

Release a project session (default: the current one). If others are open, the most recently opened becomes current; the result names it.

Export the latest render of a scene as a shareable GIF, resampled to `width` pixels wide at `fps` (defaults keep GIFs small). Blocked by open error obligations of that render and by edits made since it.

Automatically repair measured problems that have a mechanical fix: objects pushed back inside the frame, labels moved to the nearest free spot, curve sampling corrected, too-small text enlarged. Repeats measure->fix up to max_rounds, reports every change, and lists what still needs the author.

Which providers are present (Manim, LaTeX, ffmpeg, vision) and what degrades without each.

Current project state: scenes, objects, steps, parameters and open obligations.

Verify a scene WITHOUT rendering video (~1-2 s): builds the real Manim objects and measures them -- LaTeX/expression compile errors, off-screen objects, label collisions, curve fidelity (drawn vs true function), legibility, timing. Call it after authoring and fix what it reports before render_scene.

Start a project session and make it the current one (later calls without project_id target it). quality: low (480p) | medium (720p) | high (1080p). fps: frame rate, default 15/30/60 for low/medium/high. theme: chalkboard|whiteboard|dark.

Delete an object. If steps or other objects (areas, anchored shapes) depend on it, nothing is removed unless cascade=true, which also removes the dependent objects and takes the removed ids out of steps (a step left with nothing to animate is deleted; other targets of a shared step stay). The reply lists exactly what was deleted or changed, and any object left without a step.

Delete one step of the timeline (later steps are renumbered). A with_previous step that was joined to the removed one starts its own beat; it is listed in regrouped_steps.

Fast single-still preview of a scene (last frame).

Render one scene to video + sampled frames, then run verification lanes. The scene is measured first; if it cannot compile, no render is attempted.

Change an existing object in place (only the fields you pass). Use it to reposition, rescale, recolor, retype text/LaTeX, replace plot functions or ranges, or adjust an area/Riemann interval -- no need to rebuild the scene. Explicit line/arrow segments move by their endpoints x1, y1, x2, y2. Everything is validated first: on error nothing changes. A plot's color is the default color of its curves without one (axes keep the theme ink). Areas, Riemann sums and anchored shapes follow their plot: move the plot instead.