vcad - Moses Yebei

The Problem

CAD software is a closed, proprietary market. Existing kernels (Parasolid, ACIS, OpenCASCADE) are either expensive, complex, or not designed for integration with modern AI tooling. vcad addresses this by building an open-source, parametric BRep kernel in Rust that compiles to WebAssembly, making it embeddable in web apps, desktop apps, and AI agent workflows.

What This Does

vcad is a portfolio of five self-contained projects: a Rust kernel (crates/), a TypeScript web app (packages/), an AI evaluation harness (mecheval/), a Supabase backend (supabase/), and a small services folder. The kernel covers solid modeling, sketching, assemblies, simulation, and STEP import/export. The TypeScript side includes a React/Three.js app, an MCP server for AI agents, and a wasm bridge.

The README.md documents a complete feature set: primitives, booleans, fillets, sweeps, lofts, assemblies with joints, physics via Rapier3D, and ray tracing. The changelog/ directory shows active development through early 2026, including AI text-to-CAD and CAM toolpaths.

How It Is Wired

Execution starts at crates/vcad-cli/src/main.rs:217 in main, which reaches 399 functions. The CLI entry point (vcad export input.vcad output.stl) drives the kernel through crates/vcad-cli/src/repl.rs:81 (execute, 303 functions). The kernel's core is crates/vcad-kernel-geom/src/lib.rs with 177 functions (16 types), defining evaluate, normal, d_du, d_dv, domain. The unified API in crates/vcad/src/lib.rs is called from 84 files and provides alloc_node_id, vertices, indices, and to_mesh.

The most critical functions are insert (called from 192 places), is_empty (185), and abs (145). The to_crdt_params -> insert edge (85 calls) shows the CRDT sync path. One traced network path: main -> run_login -> poll_for_token -> poll_for_token_async reaches client.get(&url).send. The packages/app/src/data/examples/index.ts participates in a circular import cycle.

How To Use It

# Clone the sibling dependency first (required)
git clone git@github.com:ecto/tang.git ../tang

# Rust kernel
cargo test --workspace
cargo clippy --workspace -- -D warnings

# Web app
npm ci
npm run dev -w @vcad/app

# Desktop (Tauri v2)
npm run tauri:dev

The CLI is cargo install vcad-cli then vcad export input.vcad output.stl. The MCP server is npm install -g @vcad/mcp. Configuration lives in .github/PROJECT_SETUP.md and .claude/ for agent workflows.

Real-World Use

A parametric part library for a manufacturing company: engineers design parts in the web app, the kernel generates STEP files for CNC, and an AI agent uses the MCP server to create variants. The Rust library API is direct:

use vcad_kernel::Solid;
let solid = Solid::cube(100.0, 60.0, 20.0);
let hole = Solid::cylinder(10.0, 25.0, 32);
let result = solid - hole;
let mesh = result.to_mesh(32);

Code Health & Issues

Static analysis found 288 issues (81 high, 207 medium). The critical one: ANTHROPIC_API_KEY is committed in .github/workflows/fix-ci.yml, exposing a credential to PR-triggered workflows. Three other high findings: unpinned GitHub Actions (tag-based, vulnerable to supply-chain attacks), discarded exit codes in ci.yml, and 42 deeply nested blocks in crates/stepperoni/src/parser.rs. The 1,634 duplicated 6-line blocks across 280 files suggest significant copy-paste in kernel STEP entities.

Repository hygiene is solid: tests present, CI, Dockerfile, license, lockfile. The packages/kernel-wasm/vcad_kernel_wasm_bg.wasm (9.5MB) and similar blobs should move to Git LFS.

The Bottom Line

A serious, well-structured attempt at an open-source CAD kernel with real depth across modeling, AI integration, and deployment. The security issues in CI workflows are actionable and should be fixed before public contribution. Worth evaluating if you need embeddable, AI-friendly CAD that runs in the browser.

What the analyser found

Deployment readiness

7/7

Container image
CI pipeline
Lockfile committed
Test suite
README
License
No committed secrets

Composition

4,119 files

JSON1136
Rust359
TypeScript317
TSX240
Markdown110
TOML56

ReactNext.jsFlaskExpressSpringDocker

Module dependencies

The 10 most depended-upon modules of 582, from static import analysis. Red outline marks a module in an import cycle.

graph LR n0_raining_src_generators_types["types"] n1_raining_src_generators_utils["utils"] n2_packages_auth_src_client["client"] n3_s_auth_src_stores_auth_store["auth-store"] n4__app_src_data_examples_index["index"] n5_packages_core_src_types["types"] n6_mecheval_harness_src_task["task"] n7_ectronics_pcb3d_pcb_geometry["pcb-geometry"] n8_packages_wasmosis_src_types["types"] n9_mecheval_harness_src_solver["solver"] n9_mecheval_harness_src_solver --> n6_mecheval_harness_src_task n1_raining_src_generators_utils --> n0_raining_src_generators_types classDef cyc stroke:#ef4444,stroke-width:2px; class n4__app_src_data_examples_index,n9_mecheval_harness_src_solver cyc;

What would stop me shipping this

Ranked by severity × confidence × production reach. Reach is the honest discriminator across a collection that is mostly other people's code: the same finding matters more in something that ships.

critical1

high2

medium3

low2

Keep secrets out of workflows a fork can triggercritical

.github/workflows/fix-ci.yml

ANTHROPIC_API_KEY

Contributor-controlled input reaches a job holding a publish token or cloud credential, so a pull request becomes credential exfiltration.

Fix: Move secret-using steps into a workflow_run job that never checks out pull request code, or gate on an environment with required reviewers.

Pin third-party GitHub Actions to a commit SHAhigh4 occurrences

.github/workflows

dtolnay/rust-toolchain@master, Swatinem/rust-cache@v2, anthropics/claude-code-action@v1, tauri-apps/tauri-action@v0

A tag can be moved, so the action running with your token and secrets is whatever its owner last pushed; this is how tj-actions/changed-files leaked secrets from thousands of repos.

Fix: Replace each @vN with the 40-character commit SHA, keep # vN as a comment, and let Dependabot bump the SHAs.

Stop discarding the exit code of steps whose failure mattershigh2 occurrences

.github/workflows/ci.yml

lines 225, 239 discard failure

The job reports green while the artifact it was supposed to produce was never produced, so a crash becomes a successful run built on stale data.

Fix: Let the step fail, or test the specific expected condition instead of discarding all exit codes.

Pin the container base image by digestmedium

packages/hf-space/render-api/Dockerfile

node:20-slim

An untagged or mutable base means today's build and last month's contain different libc and a different CVE set, with no record of which shipped.

Fix: Use image:tag@sha256:<digest> and enable Dependabot's docker ecosystem.

Move large binaries to Git LFS or out of the repositorymedium

packages/kernel-wasm/vcad_kernel_wasm_bg.wasm

1 blobs over 5MB: vcad_kernel_wasm_bg.wasm 9.5MB

One repository here carries twenty blobs over 5MB including a 10.9MB spreadsheet, so every clone and every CI checkout pays for data nobody diffs.

Fix: Track those extensions with LFS, or move datasets to object storage and fetch them in a setup step.

Set persist-credentials: false on checkoutmedium

.github/workflows/agent.yml

checkout keeps the token, then dependencies are installed

The token stays in .git/config for every later step, so a malicious postinstall script reads a pushable credential without one ever being passed to it.

Fix: Add with: persist-credentials: false, and pass an explicit token only to the step that pushes.

Set timeout-minutes on the workflow jobslow4 occurrences

.github/workflows/agent.yml

4 workflow(s) declare no job timeout

A wedged step runs to the six-hour platform default, which on a two-hourly schedule means three runs overlap behind it.

Fix: Add timeout-minutes with a realistic bound to each job.

Add the repository convention files this project lackslow3 occurrences

missing .editorconfig, .gitattributes, a formatter config

Without them one contributor's editor writes tabs into a Python file, a shell script commits with CRLF and fails in the container, and a notebook diff is unreviewable.

Fix: Add .editorconfig, .gitattributes with text=auto eol=lf, and a formatter config.

Checked deterministically against the repository tree and a bounded set of its files: committed credentials, unpinned actions and base images, missing lockfiles and update bots, workflows that discard failures, published advisories against the declared dependencies, runtime configuration, licensing and notebook reproducibility. No language model is involved in this section.