Chalkcast
Describe a concept. Get a verified animated explainer.
Chalkcast is an MCP server that lets an agent author, render, and visually verify Manim animations — so the output is a video that's actually correct on screen, not a plausible script that renders wrong.
Authored, rendered, and verified entirely through the MCP server — Riemann rectangles refine and converge into the shaded area under y = x², synced with the typeset integral, on the chalkboard theme.
Who it's for
- Educators & students — turn "explain the Fourier series" into a clean animated explainer, without learning Manim or writing LaTeX by hand.
- STEM content creators — produce 3Blue1Brown-style animations in minutes instead of hours of coding and debugging renders.
- Agents & tooling — a typed, verifiable MCP surface an AI can drive end to end, with a verdict it can act on instead of a video it can't inspect.
Why another Manim MCP?
Existing Manim MCP servers give the agent one tool: run this code, return the video. The agent writes Manim blind and hopes — but Manim is unforgiving (a LaTeX typo, an off-screen label, two terms overlapping, a transition firing before its target exists). The video "renders" and is still wrong, and the agent has no way to know.
Chalkcast gives the agent eyes and a correction loop:
author scene ──► render ──► inspect (verification lanes) ──► verdict
▲ │
└──────────────── fix obligations ◄──── needs_fix ─────────┘
Every render returns evidence (the artifact + sampled frames) and a structured
verdict. Problems become obligations that block export until resolved. See
docs/SPEC.md for the full design.
Install
From source (not yet on PyPI):
git clone https://github.com/FredMichel/chalkcast.git
cd chalkcast
python -m venv .venv && source .venv/bin/activate
pip install -e ".[render]" # server + Manim
You also need ffmpeg (GIF/stitching) and, for equations, a LaTeX distribution (e.g. BasicTeX/TeX Live). Check what's present:
chalkcast doctor # reports Manim / LaTeX / ffmpeg / vision providers
chalkcast demo # builds + verifies + renders the demo scene
Register with an MCP client (e.g. Claude Code), then just ask in natural language:
claude mcp add chalkcast -- chalkcast serve
On a platform where Manim's native deps are awkward to install (e.g. an older macOS without Homebrew bottles), see
scripts/dev-env.shandscripts/serve.sh, which wire up a local libcairo + ffmpeg + LaTeX so the server renders anywhere.
What the agent gets (v0.1 tools)
| Group | Tools |
|---|---|
| Session | open_project · inspect_project · close_project |
| Authoring | add_scene · add_equation · add_plot · add_area · add_riemann · add_text · add_shape · add_step |
| Rendering | render_scene · render_frame |
| Verification | inspect_render (framing · collision · legibility · timing · compile lanes) |
| Export | export_gif |
| Discovery | inspect_environment |
Example (what the agent does)
open_project(theme="chalkboard")
add_scene(title="Area under a parabola")
add_text("Area under y = x^2", y=3)
add_plot(functions=[{"expr":"x**2","color":"YELLOW"}], x_range=[0,2,1], y=-0.8)
add_equation(r"\int_0^1 x^2 \, dx = \tfrac{1}{3}", y=2)
add_step("write", targets=["text_1"])
add_step("write", targets=["plot_1"])
add_step("write", targets=["equation_1"])
add_step("highlight", targets=["equation_1"])
render_scene() # -> video + frames + verdict + obligations
export_gif() # -> shareable GIF (blocked if error obligations remain)
Status
v0.1 baseline. Vision-based intent verification and auto-fix_scene land in v0.2
(see the roadmap in docs/SPEC.md).
License
MIT.