Ready to supercharge your AI agents?

Install any skill in seconds. Free to start, no credit card required.

Using spf13/cobra for CLI command trees in Go · samber | DecimalAI

codingby samber

Using spf13/cobra for CLI command trees in Go

samber/golang-spf13-cobra

Source samber/cc-skills-golang ↗License MIT

Golang CLI command tree library using spf13/cobra — cobra.Command, RunE vs Run, PersistentPreRunE hook chain, Args validators (NoArgs, ExactArgs, MatchAll, custom), persistent vs local flags, command groups, ValidArgsFunction, RegisterFlagCompletionFunc, ShellCompDirective, usage/help template customization, man-page and markdown doc generation, and testing with SetArgs/SetOut/SetErr. Apply when using or adopting spf13/cobra, or when the codebase imports `github.com/spf13/cobra`. For configurati

SkillScore100Maintained

Automatic

Coding pack

Last verified 9/9/2026

What it changes

Passed 24 of 24 test cases with the skill, and 21 of 24 without it.

Without skill88%

With skill100%

Checks it passed that the model alone missed

Uses cmd.OutOrStdout() for writing command output instead of stdout calls.
Recommends using Viper alongside Cobra to handle configuration file layering.
Explains that command groups must be registered using AddGroup before adding subcommands.

3 fixed21 passed either way0 still failing0 broke

Pass-rate lift: +13 pp
Tokens: +115%
Agent turns: 0%
Response time: -7%

Model gemini-3.6-flashMeasured 9/9/2026v224 of 24 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/samber-golang-spf13-cobra/SKILL.md https://app.decimal.ai/s/samber-golang-spf13-cobra/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add samber-golang-spf13-cobra, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/samber-golang-spf13-cobra/ and pins it in .decimal/skills.lock

decimalai skills add samber-golang-spf13-cobra

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/samber-golang-spf13-cobra/SKILL.md https://app.decimal.ai/s/samber-golang-spf13-cobra/SKILL.md

Raw file: /s/samber-golang-spf13-cobra/SKILL.md ↗ · machine-readable summary at /s/samber-golang-spf13-cobra.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

One of 3 test cases the skill fixed. Same model, same prompt, with and without the skill.

1 of 3

Prompt

Can you write a Go CLI tool structure using Cobra for managing cloud instances? I need a root command and a deploy subcommand. The subcommand should enforce a required environment flag and exactly one target server parameter. Make sure runtime failures return errors cleanly without dumping usage instructions automatically, and configure global versus command-specific options appropriately. Provide the complete Go implementation with the command structure and execution hooks.

What was checked, without and with the skill
Checked	Without skill	With skill
Uses cmd.OutOrStdout() for writing command output instead of stdout calls.	Missed	Passed
Configures SilenceUsage: true on the root command struct.	Passed	Passed
Enforces positional argument count using Cobra's built-in ExactArgs validator instead of checking argument length manually.	Passed	Passed

case-01 · gemini-3.6-flash · 9/9/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md154 lines6 files

Persona: You are a Go CLI engineer building command trees that feel native to the Unix shell. You design the user-facing surface first, then wire behavior into the right hook.

Modes:

Build — creating a new CLI from scratch: follow command tree setup, hook wiring, and flag sections sequentially.
Extend — adding subcommands, flags, or completions to an existing CLI: read the current command tree first, then apply changes consistent with the existing structure.
Review — auditing an existing CLI: check the Common Mistakes table, verify RunE usage, OutOrStdout(), hook chain ordering, and args validation.

Using spf13/cobra for CLI command trees in Go

Cobra is the de facto standard for Go CLI applications. It provides the command/subcommand tree, flag parsing (via pflag), args validation, shell completion generation, and documentation generation. It does not handle configuration layering — that's viper's job.

Official Resources:

This skill is not exhaustive — 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), preferred 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 github.com/spf13/cobra@latest

Cobra vs. viper

These libraries do fundamentally different things and can be used independently.

Concern	cobra	viper
Owns	Command tree, flags, arg validation, completions	Configuration value resolution
User-facing?	Yes — subcommands, flags, help text	No — purely a key-value resolver
Without the other?	Yes — a CLI with flags only needs cobra	Yes — a daemon reading YAML + env needs only viper
Integration seam	Hands `pflag.Flag` to viper via `BindPFlag`	Treats the cobra flag as the highest-precedence layer

Use cobra alone when your binary takes flags and args but needs no config file or env resolution. Use viper alone when you have a long-running service reading config from YAML + env with no CLI subcommands. Use both when you need both — bind at PersistentPreRunE on the root command.

Track record

Benchmark

24 / 24

test cases passed, vs 21 / 24 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v5 — 9/8/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

samber / cc-skills-golang

skills/golang-spf13-cobra/SKILL.md

View on GitHub ↗

License MITImported 9/8/2026Version v2Bundled 5 files

Other skills for the same job

Published skills whose descriptions closely match this one, with their headline benchmark lift.

terminalskills/cobraYou are an expert in Cobra, the most popular Go library for building modern CLI applications. You help developers create command-line tools with subcommands, flags, argument validation, shell completions, and help generation — powering CLIs like kubectl, Hugo, GitHub CLI, and Docker.Close match+4 pp pass-rate lift

More skills from the same source and nearby in the registry, with their headline benchmark lift.

Ready to supercharge your AI agents?

See it in action

What's inside

Using spf13/cobra for CLI command trees in Go

Cobra vs. viper

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

Related skills