Explain why a unified config has a given value
Trace one field of a config unified from base, team, and environment files back to the line that set it, and fail CI when a field still rests on a default.
How-to › Section 16
Model, configure and generate#
Spec languages for configuration, environment overlays, application models that generate artifacts, project generators, and templates that produce deterministic code.
7 guides in 4 topics. Every guide compares its approaches and shows the output its commands printed.
- Unify configuration with a spec language 2
- Model an application and generate from it 1
- Generate code and projects 2
- Engineer templates and AST transforms 2
Unify configuration with a spec language 2 guides
Configuration as a lattice: aontu (unification, types, defaults such as *8080 | integer, references, conjunction and disjunction, reading a contradiction error, the verbs vet, get, why, set, subsume, breaking, trim, relations, hash, mod, reaches, jsonschema; the LSP and the stdio MCP server) against CUE, Jsonnet, Dhall, Pkl, KCL and Nickel.
Let a coding agent edit a config spec without breaking it
Run counterexamples the spec must refuse beside vet, after every agent edit and at commit, so an agent that deletes a constraint to clear an error is stopped there.
Model an application and generate from it 1 guide
One model for entities, services, messages, fields and environments, then generating artifacts from it: @voxgig/model (unify .aon files into one model.json, actions that generate artifacts, --watch), model-react and model-vue bindings, decision tables with decide, and the early-stage apigen and udk projects.
Rebuild artifacts on model change with a watch loop
Regenerate TypeScript types and SQL within a second of a model edit, keep the last good output when a generator fails partway, and make the watch loop log why.
Generate code and projects 2 guides
Scaffolding and repeatable generation: jostraca (component tree of Project, Folder, File, Content, Fragment, Slot, Inject, Copy; define then build; in-memory generation for tests; byte-identical TypeScript and Go implementations; inks interpolation) against Yeoman, Plop, Hygen, Cookiecutter, Copier, Nx generators, Projen and Rails generators; plus pushing one template change to hundreds of repositories (repo-manager, the gh CLI, the Terraform GitHub provider, Renovate presets).
Push one CI template change to five hundred repositories
Fan one workflow change out over hundreds of repositories with a dry run, a checkpoint and three known end states, against four ways to stop copying the file.
Scaffold a Python API client project with Cookiecutter
Turn a Python client layout into a Cookiecutter template with derived names, a hook that survives a second run, and a test that bakes it into a temporary directory.
Engineer templates and AST transforms 2 guides
Deterministic generated code: EJS, Handlebars, Mustache, Jinja and Go templates; AST-based generation with ts-morph, jscodeshift and go/ast; codemods across generated files; formatting after generation; golden-file and snapshot tests of generated output; stable ordering and no timestamps.
Make a Handlebars template produce byte-identical output
Sort the model, keep helpers pure, normalise line endings and compile strict, so a Handlebars template renders the same bytes everywhere, checked with sha256sum.
Run a codemod across every generated file with jscodeshift
Rename a method across a directory of generated TypeScript with a jscodeshift transform, prove a second run changes nothing, then move the change into the template.
Generate the client instead of writing it#
Retries, timeouts, pagination and auth are the same problems in every client. Voxgig generates them from your OpenAPI description, in 23 languages, from one model.