Curated reference skills for writing Jac - the language and fullstack framework from Jaseci. Each skill is a focused, self-contained guide to one area of Jac: syntax, type system, Object-Spatial Programming (nodes/edges/walkers), the by llm() MTP pattern, and the fullstack .cl.jac / .sv.jac client–server model.
Each skill is a self-contained SKILL.md with YAML frontmatter, kept as the authoritative reference for Jac code generation.
Why this exists: training-time impressions of Jac are frequently wrong (the syntax has changed; Jac is easily confused with Python or JSX). These skills are the corrective spec.
Start with jac-core-cheatsheet (language baseline) and jac-types (the type system) - most other skills build on them.
| Skill | What it covers |
|---|---|
jac-core-cheatsheet |
Language baseline: imports, control flow, lambdas, ternary, strings, error handling. Read first. |
jac-types |
Type system: annotations, generics, unions, optionals, inference, common type errors. |
jac-has-fields |
Declaring typed fields on stateful archetypes - types, defaults, ordering, optionals. |
jac-impl-files |
Splitting declarations from method bodies into .jac / .impl.jac companion files. |
jac-node-edge-patterns |
Object-Spatial Programming: defining nodes/edges, connecting, querying by type/field. |
jac-walker-patterns |
Walkers that traverse the graph - entry points, visit, the OSP traversal model. |
jac-by-llm |
Delegating a function body to an LLM - structured outputs, tool use, prompt wiring. |
jac-scaffold |
Bootstrapping a project with jac create --use <template>. |
jac-fullstack-patterns |
Wiring main.jac for a fullstack app - endpoint registration, client mount. |
jac-sv-endpoints |
Server-side callable functions - visibility, typed responses, CRUD basics. |
jac-sv-auth |
Server auth model - public vs authenticated endpoints, per-user data isolation. |
jac-sv-persistence |
Modeling relationships and querying the graph from server endpoints. |
jac-cl-components |
Client UI components - shape, reactive has state, mount effects, events. |
jac-cl-organization |
Structuring a multi-component client app - layout, hooks, naming. |
jac-cl-routing |
Multi-page client navigation - routes, redirects, navigation from handlers. |
jac-cl-auth |
Client auth - signup/login/logout, guarding pages behind login. |
jac-cl-styling |
Tailwind patterns - conditional classes, cn(), semantic colors. |
jac-npm-packages |
Adding npm packages to jac.toml and importing them in .cl.jac. |
jac-shadcn-components |
Using pre-installed jac-shadcn primitives from components/ui/. |
These skills are actively curated and updated as the Jac language evolves. Open issues and pull requests in this repository.
