/golang-google-wire

name: golang-google-wire
description: "Compile-time dependency injection in Golang using google/wire — wire.NewSet, wire.Build, wire.Bind (interface→concrete), wire.Struct, wire.Value, wire.InterfaceValue, wire.FieldsOf, cleanup functions, //go:build wireinject injector files, and generated wire_gen.go. Apply when using or adopting google/wire, when the codebase imports `github.com/google/wire`, or when wiring an application graph at compile time via `wire.Build`. For runtime DI with reflection, see `samber/cc-skills-golang@golang-uber-dig` skill."
user-invocable: true
license: MIT
compatibility: Designed for Claude Code or similar AI coding agents, and for projects using Golang.
metadata:
  author: samber
  version: "1.0.6"
  openclaw:
    emoji: "🪡"
    homepage: https://github.com/samber/cc-skills-golang
    requires:
      bins:
        - go
        - wire
    install:
      - kind: go
        package: github.com/google/wire/cmd/wire@latest
        bins: [wire]
    skill-library-version: "0.7.0"
allowed-tools: Read Edit Write Glob Grep Bash(go:*) Bash(golangci-lint:*) Bash(git:*) Agent WebFetch mcp__context7__resolve-library-id mcp__context7__query-docs Bash(wire:*) Bash(godig:*) Bash(gopls:*) LSP mcp__gopls__*

**Persona:** You are a Go architect using wire for compile-time DI. You let the compiler catch missing dependencies, treat `wire_gen.go` as committed source, and re-run `wire ./...` after every graph change.

**Dependencies:**

• wire: `go install github.com/google/wire/cmd/wire@latest`

Using google/wire for Compile-Time Dependency Injection in Go

Code-generation DI toolkit. Wire resolves the dependency graph at compile time and emits plain Go constructor calls — no runtime container, no reflection. Errors appear when you run `wire ./...`, not at first request.

Note: `google/wire` was archived in August 2025 (feature-complete; bug fixes still accepted).

**Official Resources:** [pkg.go.dev](https://pkg.go.dev/github.com/google/wire) · [github.com/google/wire](https://github.com/google/wire) · [User Guide](https://github.com/google/wire/blob/main/docs/guide.md) · [Best Practices](https://github.com/google/wire/blob/main/docs/best-practices.md)

This skill is not exhaustive. Please refer to library documentation and code examples for more information. For Go package docs, symbols, versions, importers, and known vulnerabilities, → See `samber/cc-skills-golang@golang-pkg-go-dev` skill (`godig`) — prefer it over Context7 for Go package facts. To navigate this library's usage in your own code (definitions, call sites, diagnostics), → See `samber/cc-skills-golang@golang-gopls` skill (`gopls`). Context7 remains a fallback for docs not indexed on pkg.go.dev.

go get -tool github.com/google/wire/cmd/wire@latest
go get github.com/google/wire

wire vs. Runtime DI

| Concern | wire | dig / fx / samber/do | | ----------------- | ------------------------- | ---------------------- | | Resolution | Compile time (codegen) | Runtime (reflection) | | Error detection | `wire ./...` fails | First `Invoke`/startup | | Runtime container | None — plain Go calls | Present | | Lifecycle hooks | Not built in | fx: OnStart/OnStop | | Generated files | `wire_gen.go` (committed) | None |

For lifecycle, lazy loading, and a full matrix see `samber/cc-skills-golang@golang-dependency-injection`.

Providers

A provider is any Go function — inputs are dependencies, outputs are provided types. Three return forms:

func NewConfig() *Config                          { return &Config{Addr: ":8080"} }
func NewDB(cfg *Config) (*sql.DB, error)          { return sql.Open("postgres", cfg.DSN) }
func NewRedis(cfg *Config) (*redis.Client, func(), error) { // cleanup chained in reverse order
    c := redis.NewClient(&redis.Options{Addr: cfg.RedisAddr})
    return c, func() { c.Close() }, nil
}

Provider Sets

`wire.NewSet` groups providers for reuse. Sets can reference other sets.

// infra/wire.go
var InfraSet = wire.NewSet(
    NewConfig,
    NewDB,
    NewRedis,
)

// service/wire.go
var ServiceSet = wire.NewSet(
    NewUserRepo,
    NewUserService,
    wire.Bind(new(UserStore), new(*UserRepo)), // interface binding
)

Keep sets small: library sets expose a stable surface (adding inputs or removing outputs breaks downstream injectors). One set per package is a useful default.

Injectors and `//go:build wireinject`

The injector file declares the initialization function. Wire generates its body into `wire_gen.go` and replaces the stub.

//go:build wireinject

package main

import "github.com/google/wire"

// Wire generates the body of this function.
func InitApp() (*App, func(), error) {
    wire.Build(InfraSet, ServiceSet, NewApp)
    return nil, nil, nil // replaced by codegen
}

The `//go:build wireinject` tag prevents the stub from being compiled into the binary — only `wire_gen.go` (which has no such tag) makes it through `go build`. Without this tag, both files define the same function, causing a compile error.

Alternative syntax when a dummy return is inconvenient:

func InitApp() (*App, func(), error) {
    panic(wire.Build(InfraSet, ServiceSet, NewApp))
}

Interface Bindings

Wire forbids implicit interface satisfaction — you must declare bindings explicitly so the graph is unambiguous when multiple types implement the same interface.

var Set = wire.NewSet(
    NewPostgresUserRepo,
    wire.Bind(new(UserStore), new(*PostgresUserRepo)), // tell wire: *PostgresUserRepo satisfies UserStore
)

Explicit bindings prevent graph breakage when a new type implementing the same interface is added elsewhere.

Struct Providers and Values

`wire.Struct` fills struct fields from the graph without a manual constructor. Tag fields `wire:"-"` to exclude them.

wire.Struct(new(Server), "Logger", "DB") // inject named fiel