Go API

The Go facade is the native surface for applications that want direct access to parsing, AST mutation, traversal, stringifying, and source maps.

Parse and transform

import "postcss-go/pkg/api"

root, err := api.Parse(".button { color: red; }")
if err != nil {
  return err
}

api.WalkDecls(root, func(decl *api.Declaration) error {
  if decl.Prop == "color" {
    decl.Value = "tomato"
  }
  return nil
})

output := api.Stringify(root)

Entry points

API	Purpose
`api.Parse`	Parse CSS into a position-aware Root AST.
`api.ParseWithOptions`	Parse with source and source-map options.
`api.New(...).Process`	Run plugins, then stringify (with maps).
`api.NoWork`	No-plugin map/annotation path; no parse.
`api.Stringify`	Serialize AST nodes into CSS.
`api.Walk*`	Walk all nodes or filtered node types.
`api.NewRoot`	Construct a root and mutate it directly.
`api.NewRule`, `NewAtRule`, `NewDeclaration`	Construct common AST nodes.

Source maps

Process and NoWork accept flat ProcessOptions (Map, MapInline, PreviousMap, MapAnnotation, …). Prefer setting output mode explicitly when you need an external .map payload:

bare Map: true → inline map (PostCSS-compatible default)
MapInline: &false (or annotation flags) → keep Result.Map as JSON

Annotation cleanup differs by path: Process removes # sourceMappingURL= comment nodes from the AST; NoWork clears raw /*# comments without parsing.

Best for

Native Go build tools and CSS pipelines
Synchronous, low-overhead processing
Go-native plugins using Plugin and Visitor (single-pass walk; no dirty rewalk)
Direct access to source locations, raw formatting, and source maps

The Go API does not require the Node.js runtime. Use the JavaScript API when you need PostCSS configuration files or JavaScript plugins. Go-native plugins share parse, stringify, and source maps with that path, but they do not rewalk a dirty tree the way the JavaScript plugin runtime does.

The public Go surface lives in pkg/api as package api; it is backed by the same internal parser, AST, processor, stringifier, and source-map packages used by the native Node and WASM bridges.