package api

import "github.com/evanw/esbuild/pkg/api"

This API exposes esbuild's two main operations: building and transforming. It's intended for integrating esbuild into other tools as a library.

If you are just trying to run esbuild from Go without the overhead of creating a child process, there is also an API for the command-line interface itself: https://pkg.go.dev/github.com/evanw/esbuild/pkg/cli.

Build API

This function runs an end-to-end build operation. It takes an array of file paths as entry points, parses them and all of their dependencies, and returns the output files to write to the file system. The available options roughly correspond to esbuild's command-line flags.

Example usage: 

package main

import (
    "os"

    "github.com/evanw/esbuild/pkg/api"
)

func main() {
    result := api.Build(api.BuildOptions{
        EntryPoints: []string{"input.js"},
        Outfile:     "output.js",
        Bundle:      true,
        Write:       true,
        LogLevel:    api.LogLevelInfo,
    })

    if len(result.Errors) > 0 {
        os.Exit(1)
    }
}

Transform API

This function transforms a string of source code into JavaScript. It can be used to minify JavaScript, convert TypeScript/JSX to JavaScript, or convert newer JavaScript to older JavaScript. The available options roughly correspond to esbuild's command-line flags.

Example usage: 

package main

import (
    "fmt"
    "os"

    "github.com/evanw/esbuild/pkg/api"
)

func main() {
    jsx := `
        import * as React from 'react'
        import * as ReactDOM from 'react-dom'

        ReactDOM.render(
            <h1>Hello, world!</h1>,
            document.getElementById('root')
        );
    `

    result := api.Transform(jsx, api.TransformOptions{
        Loader: api.LoaderJSX,
    })

    fmt.Printf("%d errors and %d warnings\n",
        len(result.Errors), len(result.Warnings))

    os.Stdout.Write(result.Code)
}

Index

Functions

func AnalyzeMetafile 

func AnalyzeMetafile(metafile string, opts AnalyzeMetafileOptions) string

Documentation: https://esbuild.github.io/api/#analyze

func Context 

func Context(buildOptions BuildOptions) (BuildContext, *ContextError)

Documentation: https://esbuild.github.io/api/#build

func FormatMessages 

func FormatMessages(msgs []Message, opts FormatMessagesOptions) []string

Types

type AbsPaths 

type AbsPaths uint8
const (
	CodeAbsPath AbsPaths = 1 << iota
	LogAbsPath
	MetafileAbsPath
)

type AnalyzeMetafileOptions 

type AnalyzeMetafileOptions struct {
	Color   bool
	Verbose bool
}

type BuildContext 

type BuildContext interface {
	// Documentation: https://esbuild.github.io/api/#rebuild
	Rebuild() BuildResult

	// Documentation: https://esbuild.github.io/api/#watch
	Watch(options WatchOptions) error

	// Documentation: https://esbuild.github.io/api/#serve
	Serve(options ServeOptions) (ServeResult, error)

	Cancel()
	Dispose()
}

type BuildOptions 

type BuildOptions struct {
	Color       StderrColor         // Documentation: https://esbuild.github.io/api/#color
	LogLevel    LogLevel            // Documentation: https://esbuild.github.io/api/#log-level
	LogLimit    int                 // Documentation: https://esbuild.github.io/api/#log-limit
	LogOverride map[string]LogLevel // Documentation: https://esbuild.github.io/api/#log-override
	AbsPaths    AbsPaths            // Documentation: https://esbuild.github.io/api/#abs-path

	Sourcemap      SourceMap      // Documentation: https://esbuild.github.io/api/#sourcemap
	SourceRoot     string         // Documentation: https://esbuild.github.io/api/#source-root
	SourcesContent SourcesContent // Documentation: https://esbuild.github.io/api/#sources-content

	Target    Target          // Documentation: https://esbuild.github.io/api/#target
	Engines   []Engine        // Documentation: https://esbuild.github.io/api/#target
	Supported map[string]bool // Documentation: https://esbuild.github.io/api/#supported

	MangleProps       string                 // Documentation: https://esbuild.github.io/api/#mangle-props
	ReserveProps      string                 // Documentation: https://esbuild.github.io/api/#mangle-props
	MangleQuoted      MangleQuoted           // Documentation: https://esbuild.github.io/api/#mangle-props
	MangleCache       map[string]interface{} // Documentation: https://esbuild.github.io/api/#mangle-props
	Drop              Drop                   // Documentation: https://esbuild.github.io/api/#drop
	DropLabels        []string               // Documentation: https://esbuild.github.io/api/#drop-labels
	MinifyWhitespace  bool                   // Documentation: https://esbuild.github.io/api/#minify
	MinifyIdentifiers bool                   // Documentation: https://esbuild.github.io/api/#minify
	MinifySyntax      bool                   // Documentation: https://esbuild.github.io/api/#minify
	LineLimit         int                    // Documentation: https://esbuild.github.io/api/#line-limit
	Charset           Charset                // Documentation: https://esbuild.github.io/api/#charset
	TreeShaking       TreeShaking            // Documentation: https://esbuild.github.io/api/#tree-shaking
	IgnoreAnnotations bool                   // Documentation: https://esbuild.github.io/api/#ignore-annotations
	LegalComments     LegalComments          // Documentation: https://esbuild.github.io/api/#legal-comments

	JSX             JSX    // Documentation: https://esbuild.github.io/api/#jsx-mode
	JSXFactory      string // Documentation: https://esbuild.github.io/api/#jsx-factory
	JSXFragment     string // Documentation: https://esbuild.github.io/api/#jsx-fragment
	JSXImportSource string // Documentation: https://esbuild.github.io/api/#jsx-import-source
	JSXDev          bool   // Documentation: https://esbuild.github.io/api/#jsx-dev
	JSXSideEffects  bool   // Documentation: https://esbuild.github.io/api/#jsx-side-effects

	Define    map[string]string // Documentation: https://esbuild.github.io/api/#define
	Pure      []string          // Documentation: https://esbuild.github.io/api/#pure
	KeepNames bool              // Documentation: https://esbuild.github.io/api/#keep-names

	GlobalName        string            // Documentation: https://esbuild.github.io/api/#global-name
	Bundle            bool              // Documentation: https://esbuild.github.io/api/#bundle
	PreserveSymlinks  bool              // Documentation: https://esbuild.github.io/api/#preserve-symlinks
	Splitting         bool              // Documentation: https://esbuild.github.io/api/#splitting
	Outfile           string            // Documentation: https://esbuild.github.io/api/#outfile
	Metafile          bool              // Documentation: https://esbuild.github.io/api/#metafile
	Outdir            string            // Documentation: https://esbuild.github.io/api/#outdir
	Outbase           string            // Documentation: https://esbuild.github.io/api/#outbase
	AbsWorkingDir     string            // Documentation: https://esbuild.github.io/api/#working-directory
	Platform          Platform          // Documentation: https://esbuild.github.io/api/#platform
	Format            Format            // Documentation: https://esbuild.github.io/api/#format
	External          []string          // Documentation: https://esbuild.github.io/api/#external
	Packages          Packages          // Documentation: https://esbuild.github.io/api/#packages
	Alias             map[string]string // Documentation: https://esbuild.github.io/api/#alias
	MainFields        []string          // Documentation: https://esbuild.github.io/api/#main-fields
	Conditions        []string          // Documentation: https://esbuild.github.io/api/#conditions
	Loader            map[string]Loader // Documentation: https://esbuild.github.io/api/#loader
	ResolveExtensions []string          // Documentation: https://esbuild.github.io/api/#resolve-extensions
	Tsconfig          string            // Documentation: https://esbuild.github.io/api/#tsconfig
	TsconfigRaw       string            // Documentation: https://esbuild.github.io/api/#tsconfig-raw
	OutExtension      map[string]string // Documentation: https://esbuild.github.io/api/#out-extension
	PublicPath        string            // Documentation: https://esbuild.github.io/api/#public-path
	Inject            []string          // Documentation: https://esbuild.github.io/api/#inject
	Banner            map[string]string // Documentation: https://esbuild.github.io/api/#banner
	Footer            map[string]string // Documentation: https://esbuild.github.io/api/#footer
	NodePaths         []string          // Documentation: https://esbuild.github.io/api/#node-paths

	EntryNames string // Documentation: https://esbuild.github.io/api/#entry-names
	ChunkNames string // Documentation: https://esbuild.github.io/api/#chunk-names
	AssetNames string // Documentation: https://esbuild.github.io/api/#asset-names

	EntryPoints         []string     // Documentation: https://esbuild.github.io/api/#entry-points
	EntryPointsAdvanced []EntryPoint // Documentation: https://esbuild.github.io/api/#entry-points

	Stdin          *StdinOptions // Documentation: https://esbuild.github.io/api/#stdin
	Write          bool          // Documentation: https://esbuild.github.io/api/#write
	AllowOverwrite bool          // Documentation: https://esbuild.github.io/api/#allow-overwrite
	Plugins        []Plugin      // Documentation: https://esbuild.github.io/plugins/
}

type BuildResult 

type BuildResult struct {
	Errors   []Message
	Warnings []Message

	OutputFiles []OutputFile
	Metafile    string
	MangleCache map[string]interface{}
}

func Build 

func Build(options BuildOptions) BuildResult

Documentation: https://esbuild.github.io/api/#build

type CORSOptions 

type CORSOptions struct {
	Origin []string
}

Documentation: https://esbuild.github.io/api/#cors

type Charset 

type Charset uint8
const (
	CharsetDefault Charset = iota
	CharsetASCII
	CharsetUTF8
)

type ContextError 

type ContextError struct {
	Errors []Message // Option validation errors are returned here
}

func (*ContextError) Error 

func (err *ContextError) Error() string

type Drop 

type Drop uint8
const (
	DropConsole Drop = 1 << iota
	DropDebugger
)

type Engine 

type Engine struct {
	Name    EngineName
	Version string
}

type EngineName 

type EngineName uint8
const (
	EngineChrome EngineName = iota
	EngineDeno
	EngineEdge
	EngineFirefox
	EngineHermes
	EngineIE
	EngineIOS
	EngineNode
	EngineOpera
	EngineRhino
	EngineSafari
)

type EntryPoint 

type EntryPoint struct {
	InputPath  string
	OutputPath string
}

type Format 

type Format uint8
const (
	FormatDefault Format = iota
	FormatIIFE
	FormatCommonJS
	FormatESModule
)

type FormatMessagesOptions 

type FormatMessagesOptions struct {
	TerminalWidth int
	Kind          MessageKind
	Color         bool
}

type JSX 

type JSX uint8
const (
	JSXTransform JSX = iota
	JSXPreserve
	JSXAutomatic
)

type LegalComments 

type LegalComments uint8
const (
	LegalCommentsDefault LegalComments = iota
	LegalCommentsNone
	LegalCommentsInline
	LegalCommentsEndOfFile
	LegalCommentsLinked
	LegalCommentsExternal
)

type Loader 

type Loader uint16
const (
	LoaderNone Loader = iota
	LoaderBase64
	LoaderBinary
	LoaderCopy
	LoaderCSS
	LoaderDataURL
	LoaderDefault
	LoaderEmpty
	LoaderFile
	LoaderGlobalCSS
	LoaderJS
	LoaderJSON
	LoaderJSX
	LoaderLocalCSS
	LoaderText
	LoaderTS
	LoaderTSX
)

type Location 

type Location struct {
	File       string
	Namespace  string
	Line       int // 1-based
	Column     int // 0-based, in bytes
	Length     int // in bytes
	LineText   string
	Suggestion string
}

type LogLevel 

type LogLevel uint8
const (
	LogLevelSilent LogLevel = iota
	LogLevelVerbose
	LogLevelDebug
	LogLevelInfo
	LogLevelWarning
	LogLevelError
)

type MangleQuoted 

type MangleQuoted uint8
const (
	MangleQuotedFalse MangleQuoted = iota
	MangleQuotedTrue
)

type Message 

type Message struct {
	ID         string
	PluginName string
	Text       string
	Location   *Location
	Notes      []Note

	// Optional user-specified data that is passed through unmodified. You can
	// use this to stash the original error, for example.
	Detail interface{}
}

type MessageKind 

type MessageKind uint8
const (
	ErrorMessage MessageKind = iota
	WarningMessage
)

type Note 

type Note struct {
	Text     string
	Location *Location
}

type OnEndResult 

type OnEndResult struct {
	Errors   []Message
	Warnings []Message
}

type OnLoadArgs 

type OnLoadArgs struct {
	Path       string
	Namespace  string
	Suffix     string
	PluginData interface{}
	With       map[string]string
}

Documentation: https://esbuild.github.io/plugins/#on-load-arguments

type OnLoadOptions 

type OnLoadOptions struct {
	Filter    string
	Namespace string
}

Documentation: https://esbuild.github.io/plugins/#on-load-options

type OnLoadResult 

type OnLoadResult struct {
	PluginName string

	Errors   []Message
	Warnings []Message

	Contents   *string
	ResolveDir string
	Loader     Loader
	PluginData interface{}

	WatchFiles []string
	WatchDirs  []string
}

Documentation: https://esbuild.github.io/plugins/#on-load-results

type OnResolveArgs 

type OnResolveArgs struct {
	Path       string
	Importer   string
	Namespace  string
	ResolveDir string
	Kind       ResolveKind
	PluginData interface{}
	With       map[string]string
}

Documentation: https://esbuild.github.io/plugins/#on-resolve-arguments

type OnResolveOptions 

type OnResolveOptions struct {
	Filter    string
	Namespace string
}

Documentation: https://esbuild.github.io/plugins/#on-resolve-options

type OnResolveResult 

type OnResolveResult struct {
	PluginName string

	Errors   []Message
	Warnings []Message

	Path        string
	External    bool
	SideEffects SideEffects
	Namespace   string
	Suffix      string
	PluginData  interface{}

	WatchFiles []string
	WatchDirs  []string
}

Documentation: https://esbuild.github.io/plugins/#on-resolve-results

type OnStartResult 

type OnStartResult struct {
	Errors   []Message
	Warnings []Message
}

type OutputFile 

type OutputFile struct {
	Path     string
	Contents []byte
	Hash     string
}

type Packages 

type Packages uint8
const (
	PackagesDefault Packages = iota
	PackagesBundle
	PackagesExternal
)

type Platform 

type Platform uint8
const (
	PlatformDefault Platform = iota
	PlatformBrowser
	PlatformNode
	PlatformNeutral
)

type Plugin 

type Plugin struct {
	Name  string
	Setup func(PluginBuild)
}

type PluginBuild 

type PluginBuild struct {
	// Documentation: https://esbuild.github.io/plugins/#build-options
	InitialOptions *BuildOptions

	// Documentation: https://esbuild.github.io/plugins/#resolve
	Resolve func(path string, options ResolveOptions) ResolveResult

	// Documentation: https://esbuild.github.io/plugins/#on-start
	OnStart func(callback func() (OnStartResult, error))

	// Documentation: https://esbuild.github.io/plugins/#on-end
	OnEnd func(callback func(result *BuildResult) (OnEndResult, error))

	// Documentation: https://esbuild.github.io/plugins/#on-resolve
	OnResolve func(options OnResolveOptions, callback func(OnResolveArgs) (OnResolveResult, error))

	// Documentation: https://esbuild.github.io/plugins/#on-load
	OnLoad func(options OnLoadOptions, callback func(OnLoadArgs) (OnLoadResult, error))

	// Documentation: https://esbuild.github.io/plugins/#on-dispose
	OnDispose func(callback func())
}

type ResolveKind 

type ResolveKind uint8
const (
	ResolveNone ResolveKind = iota
	ResolveEntryPoint
	ResolveJSImportStatement
	ResolveJSRequireCall
	ResolveJSDynamicImport
	ResolveJSRequireResolve
	ResolveCSSImportRule
	ResolveCSSComposesFrom
	ResolveCSSURLToken
)

type ResolveOptions 

type ResolveOptions struct {
	PluginName string
	Importer   string
	Namespace  string
	ResolveDir string
	Kind       ResolveKind
	PluginData interface{}
	With       map[string]string
}

Documentation: https://esbuild.github.io/plugins/#resolve-options

type ResolveResult 

type ResolveResult struct {
	Errors   []Message
	Warnings []Message

	Path        string
	External    bool
	SideEffects bool
	Namespace   string
	Suffix      string
	PluginData  interface{}
}

Documentation: https://esbuild.github.io/plugins/#resolve-results

type ServeOnRequestArgs 

type ServeOnRequestArgs struct {
	RemoteAddress string
	Method        string
	Path          string
	Status        int
	TimeInMS      int // The time to generate the response, not to send it
}

type ServeOptions 

type ServeOptions struct {
	Port      int
	Host      string
	Servedir  string
	Keyfile   string
	Certfile  string
	Fallback  string
	CORS      CORSOptions
	OnRequest func(ServeOnRequestArgs)
}

Documentation: https://esbuild.github.io/api/#serve-arguments

type ServeResult 

type ServeResult struct {
	Port  uint16
	Hosts []string
}

Documentation: https://esbuild.github.io/api/#serve-return-values

type SideEffects 

type SideEffects uint8
const (
	SideEffectsTrue SideEffects = iota
	SideEffectsFalse
)

type SourceMap 

type SourceMap uint8
const (
	SourceMapNone SourceMap = iota
	SourceMapInline
	SourceMapLinked
	SourceMapExternal
	SourceMapInlineAndExternal
)

type SourcesContent 

type SourcesContent uint8
const (
	SourcesContentInclude SourcesContent = iota
	SourcesContentExclude
)

type StderrColor 

type StderrColor uint8
const (
	ColorIfTerminal StderrColor = iota
	ColorNever
	ColorAlways
)

type StdinOptions 

type StdinOptions struct {
	Contents   string
	ResolveDir string
	Sourcefile string
	Loader     Loader
}

type Target 

type Target uint8
const (
	DefaultTarget Target = iota
	ESNext
	ES5
	ES2015
	ES2016
	ES2017
	ES2018
	ES2019
	ES2020
	ES2021
	ES2022
	ES2023
	ES2024
)

type TransformOptions 

type TransformOptions struct {
	Color       StderrColor         // Documentation: https://esbuild.github.io/api/#color
	LogLevel    LogLevel            // Documentation: https://esbuild.github.io/api/#log-level
	LogLimit    int                 // Documentation: https://esbuild.github.io/api/#log-limit
	LogOverride map[string]LogLevel // Documentation: https://esbuild.github.io/api/#log-override
	AbsPaths    AbsPaths            // Documentation: https://esbuild.github.io/api/#abs-path

	Sourcemap      SourceMap      // Documentation: https://esbuild.github.io/api/#sourcemap
	SourceRoot     string         // Documentation: https://esbuild.github.io/api/#source-root
	SourcesContent SourcesContent // Documentation: https://esbuild.github.io/api/#sources-content

	Target    Target          // Documentation: https://esbuild.github.io/api/#target
	Engines   []Engine        // Documentation: https://esbuild.github.io/api/#target
	Supported map[string]bool // Documentation: https://esbuild.github.io/api/#supported

	Platform   Platform // Documentation: https://esbuild.github.io/api/#platform
	Format     Format   // Documentation: https://esbuild.github.io/api/#format
	GlobalName string   // Documentation: https://esbuild.github.io/api/#global-name

	MangleProps       string                 // Documentation: https://esbuild.github.io/api/#mangle-props
	ReserveProps      string                 // Documentation: https://esbuild.github.io/api/#mangle-props
	MangleQuoted      MangleQuoted           // Documentation: https://esbuild.github.io/api/#mangle-props
	MangleCache       map[string]interface{} // Documentation: https://esbuild.github.io/api/#mangle-props
	Drop              Drop                   // Documentation: https://esbuild.github.io/api/#drop
	DropLabels        []string               // Documentation: https://esbuild.github.io/api/#drop-labels
	MinifyWhitespace  bool                   // Documentation: https://esbuild.github.io/api/#minify
	MinifyIdentifiers bool                   // Documentation: https://esbuild.github.io/api/#minify
	MinifySyntax      bool                   // Documentation: https://esbuild.github.io/api/#minify
	LineLimit         int                    // Documentation: https://esbuild.github.io/api/#line-limit
	Charset           Charset                // Documentation: https://esbuild.github.io/api/#charset
	TreeShaking       TreeShaking            // Documentation: https://esbuild.github.io/api/#tree-shaking
	IgnoreAnnotations bool                   // Documentation: https://esbuild.github.io/api/#ignore-annotations
	LegalComments     LegalComments          // Documentation: https://esbuild.github.io/api/#legal-comments

	JSX             JSX    // Documentation: https://esbuild.github.io/api/#jsx
	JSXFactory      string // Documentation: https://esbuild.github.io/api/#jsx-factory
	JSXFragment     string // Documentation: https://esbuild.github.io/api/#jsx-fragment
	JSXImportSource string // Documentation: https://esbuild.github.io/api/#jsx-import-source
	JSXDev          bool   // Documentation: https://esbuild.github.io/api/#jsx-dev
	JSXSideEffects  bool   // Documentation: https://esbuild.github.io/api/#jsx-side-effects

	TsconfigRaw string // Documentation: https://esbuild.github.io/api/#tsconfig-raw
	Banner      string // Documentation: https://esbuild.github.io/api/#banner
	Footer      string // Documentation: https://esbuild.github.io/api/#footer

	Define    map[string]string // Documentation: https://esbuild.github.io/api/#define
	Pure      []string          // Documentation: https://esbuild.github.io/api/#pure
	KeepNames bool              // Documentation: https://esbuild.github.io/api/#keep-names

	Sourcefile string // Documentation: https://esbuild.github.io/api/#sourcefile
	Loader     Loader // Documentation: https://esbuild.github.io/api/#loader
}

type TransformResult 

type TransformResult struct {
	Errors   []Message
	Warnings []Message

	Code          []byte
	Map           []byte
	LegalComments []byte

	MangleCache map[string]interface{}
}

func Transform 

func Transform(input string, options TransformOptions) TransformResult

Documentation: https://esbuild.github.io/api/#transform

type TreeShaking 

type TreeShaking uint8
const (
	TreeShakingDefault TreeShaking = iota
	TreeShakingFalse
	TreeShakingTrue
)

type WatchOptions 

type WatchOptions struct {
	Delay int // In milliseconds
}

Documentation: https://esbuild.github.io/api/#watch-arguments

Source Files

api.go api_impl.go api_js_table.go favicon.go serve_other.go watcher.go

Version
v0.25.8 (latest)
Published
Jul 19, 2025
Platform
linux/amd64
Imports
37 packages
Last checked
8 months ago –

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