Golang Uber Fx

What it does

When your agent uses it

• Development work in your project

Example prompts

• “/golang-uber-fx”

Requirements

• Compatibility (from SKILL.md): Designed for Claude Code, Codex or similar harness, and for projects using Golang.
• Pre-approved tools (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(godig:*), Bash(gopls:*), LSP, mcp__gopls__*

Workflow steps

8 steps, taken from the first numbered list in SKILL.md.

1. 1Keep main() thin — providers, modules, and a single Run(). Push real work into modules so each can be tested in isolation.
2. 2Use lifecycle hooks instead of init() or goroutines launched from constructors — Start/Stop ordering depends on graph topology, but init()…
3. 3OnStart must return promptly — long work goes in a goroutine inside the hook. A blocking OnStart hangs the rest of the boot.
4. 4Respect ctx.Done() in hooks — a hook that ignores cancellation is reported as a timeout failure but its goroutine continues, leaking…
5. 5Group by module, not by layer — a module owns the providers, lifecycle, and decorators for one concern (HTTP, DB, metrics).
6. 6Use fx.Annotate for tags rather than wrapping a constructor in an fx.Out struct — keeps the constructor reusable outside fx.
7. 7Replace fx.Provide with fx.Supply for pre-built values (config, command-line flags). Shorter, signals intent.
8. 8Validate the graph in CI by booting under fx.New(...).Err() — catches missing providers and cycles before deploy.

What it can do on your machine

Read from SKILL.md and the folder at commit 8876467. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Edit
  • Write
  • Glob
  • Grep
  • Bash(go:*)
  • Bash(golangci-lint:*)
  • Bash(git:*)
  • Agent
  • WebFetch

  …and 6 more on the same allowed-tools line.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • go

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • github.com
  • pkg.go.dev
  • uber-go.github.io

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Designed for Claude Code, Codex or similar harness, and for projects using Golang.

  From compatibility in the SKILL.md frontmatter.

Context cost

Golang Uber Fx loads about 2.8k tokens when it runs, and up to ~7.1k if it reads all its reference files. Until then it costs about 74 tokens; SKILL.md has 994 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~74

When it runs · the whole SKILL.md, loaded when a task matches

~2.8k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~7.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from context-labs/whip at commit 8876467, republished under its MIT licence (© context-labs). 994 words, ~2,789 tokens.

name

golang-uber-fx

description

Golang application framework using uber-go/fx — fx.New, fx.Provide, fx.Invoke, fx.Module, fx.Lifecycle hooks, fx.Annotate, fx.Decorate, fx.Supply, signal-aware Run(). Apply when using/adopting fx or the codebase imports go.uber.org/fx. Raw DI without lifecycle → golang-uber-dig.

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(godig:*), Bash(gopls:*), LSP, mcp__gopls__*

compatibility

Designed for Claude Code, Codex or similar harness, and for projects using Golang.

user-invocable

true

license

MIT

metadata.author

samber

metadata.version

1.2.0

paths

**/*.go

go get go.uber.org/fx

import "go.uber.org/fx"

app := fx.New(
    fx.Provide(NewLogger, NewDatabase, NewServer),
    fx.Invoke(RegisterRoutes),
)
app.Run() // blocks until SIGINT/SIGTERM, then runs OnStop hooks

fx.New(
    fx.Provide(NewLogger, NewDatabase, NewServer),  // lazy
    fx.Invoke(RegisterRoutes, StartMetricsExporter), // always run during Start
)

func NewHTTPServer(lc fx.Lifecycle, log *zap.Logger, cfg *Config) *http.Server {
    srv := &http.Server{Addr: cfg.Addr}

    lc.Append(fx.Hook{
        OnStart: func(ctx context.Context) error {
            ln, err := net.Listen("tcp", srv.Addr)
            if err != nil { return err }
            go srv.Serve(ln)         // blocking work in a goroutine
            return nil
        },
        OnStop: func(ctx context.Context) error {
            return srv.Shutdown(ctx)
        },
    })
    return srv
}

lc.Append(fx.StartStopHook(srv.Start, srv.Stop))   // matched pair

type ServerParams struct {
    fx.In

    Logger *zap.Logger
    DB     *sql.DB
    Cache  *redis.Client     `optional:"true"`
    Routes []http.Handler    `group:"routes"`
}

func NewServer(p ServerParams) *Server { /* ... */ }

fx.Provide(
    fx.Annotate(NewPrimaryDB, fx.ResultTags(`name:"primary"`)),
    fx.Annotate(NewPostgresDB, fx.As(new(Database))),    // expose interface
    fx.Annotate(NewUserHandler,
        fx.As(new(http.Handler)),
        fx.ResultTags(`group:"routes"`),
    ),
)

type RouteResult struct {
    fx.Out
    Handler http.Handler `group:"routes"`
}

type ServerParams struct {
    fx.In
    Routes []http.Handler `group:"routes"`
}

var DatabaseModule = fx.Module("database",
    fx.Provide(NewConnection, NewUserRepository),
    fx.Decorate(func(log *zap.Logger) *zap.Logger {
        return log.Named("db")
    }),
)

func main() {
    fx.New(
        fx.Provide(NewConfig, NewLogger),
        DatabaseModule,
        HTTPModule,
    ).Run()
}

© context-labs, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 4 other files (references) in .agents/skills/golang-uber-fx of context-labs/whip.

• SKILL.md
• evals/evals.json
• references/advanced.md
• references/recipes.md
• references/testing.md

Open the folder on GitHubat commit 8876467

Used in 2 other repositories

We found 2 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 2 other GitHub owners. This page covers the copy in context-labs/whip, which our catalogue first saw on October 7, 2026.

• aiskillstore/marketplaceskills/samber/golang-uber-fx
• samber/cc-skills-golangskills/golang-uber-fx