solvecraft/skills

Agent skills

Skills for contributing to SolidCraft and modelling through its MCP server. Each folder is one skill in the Agent Skills format: a SKILL.md with a name and a description that tell the agent when to load it, and an optional supporting reference file.

The modelling documents are built into SolidCraft: its MCP server's skill_reference tool returns them, so an agent without file access (such as the one in SolidCraft's own chat) can still read a skill's reference. The contributor skills (everything except modeling, editing, checking and mechanisms) are for repository work and are not embedded in that tool. AGENTS.md routes to them; cargo xtask skills fails when its table and this folder disagree or a file, cargo xtask command or skill they name is gone.

Skill	Loads when the agent
solidcraft-contributing	helps someone set up a fork, choose and claim an issue, and submit a contribution for review; the rules every PR follows
solidcraft-ground-rules	adds a dependency, asset or wording: independence, licences, attribution, the product name
solidcraft-crash-safety	writes non-test Rust, handles hostile input or investigates a crash report
solidcraft-commands	adds a command or decides which crate code belongs in
solidcraft-ui	adds a dialog, panel, camera input, icon or colour
solidcraft-ui-text	adds a label, message or translation
solidcraft-file-formats	changes what a design saves, or touches import and export
solidcraft-preferences	adds a setting or changes a default
solidcraft-tests	places or runs tests
solidcraft-performance	works on slow code, the window thread or the wasm build
solidcraft-packaging	prepares a release or changes packages
solidcraft-agent-tools	runs the app, drives the control channel or changes MCP tools
solidcraft-modeling	builds a new part (enclosure, bracket, plate, flange, …)
solidcraft-editing	changes, fixes or extends an existing design
solidcraft-checking	builds, changes or ports a design, next to the two above: parameter ranges, every allowed value, exact STEP comparison, regression tests, designs kept in git
solidcraft-mechanisms	builds, drives or animates an assembly: components, joints, motion links, closed loops such as actuators, contact sets, motion studies
solidcraft-reporting	hears that something went wrong (a crash, a failed command, a wrong shape or number, a hang): reproduces it in a fresh design, shrinks it to a minimal script and writes the bug report

The modelling skills teach the agent to:

• plan the part as numbers
• build it in a few batch calls with parametric positions
• verify every stage with measure against values it computed itself
• skip the large replies it doesn't need, such as the unfiltered command catalog and full topology dumps

They also list the traps that otherwise cost failed calls. Examples are the sketch axes of the XZ plane, edge picks that snap to the nearest edge, and cuts that miss but still report success.

The modelling skills are written for SolidCraft 0.8 and later; solidcraft-mechanisms for main after 0.11.1 (the next release), which counts the degrees of freedom of closed loops; solidcraft-reporting for 0.18 and later.

Install

The modelling skills, for Claude Code in all projects:

git clone --depth 1 https://github.com/tangency-labs/solidcraft
cp -r solidcraft/skills/solidcraft-{modeling,editing,checking,mechanisms} ~/.claude/skills/

Windows (PowerShell):

git clone --depth 1 https://github.com/tangency-labs/solidcraft
foreach ($s in 'modeling','editing','checking','mechanisms') { Copy-Item -Recurse solidcraft\skills\solidcraft-$s $HOME\.claude\skills\ }

• One project only: copy the folders into that project's .claude/skills/ instead.
• Other agents: for agents that read the Agent Skills format, copy the folders into the skills directory their documentation names.
• Updating: copy the folders again after you update SolidCraft.
• Contributing: the contributor skills need no install. Tell your assistant: "I want to contribute to SolidCraft. Read https://github.com/tangency-labs/solidcraft/blob/main/skills/solidcraft-contributing/SKILL.md and help me get started."

Maintaining

• The worked example in solidcraft-modeling/reference.md runs in CI. skill_reference_example_builds_as_documented in crates/mcp/src/tests.rs builds it, checks the documented volume, changes a parameter and checks it again.
• The sketch-plane table is covered by sketch_plane_axes_match_the_skill_reference in the same file.
• The worked example in solidcraft-mechanisms/reference.md runs in CI too: mechanisms_skill_example_moves_as_documented builds it, drives the hinge and checks the actuator stroke, the linked panel and the stop against their analytic values.
• skills_name_only_real_tools_and_commands checks that every tool and command the skills call exists.
• solidcraft-checking/scripts/tests checks that skill's helpers, its traps and conventions, and the facts behind the corrections in solidcraft-modeling: PYTHONDONTWRITEBYTECODE=1 uv run --no-project --with pytest --with build123d pytest -p no:cacheprovider skills/solidcraft-checking/scripts/tests. The tests run the solidcraft-cli on PATH, not the workspace build, and CI does not run them.
• When a command, a parameter name or a behaviour that these files describe changes, update them in the same PR.
• Facts that describe current limitations, such as edge picks without a distance limit, should go once the limitation is fixed.