cobra-dev

Development

Use when developing or debugging spf13/cobra internals — Command struct internals, ExecuteC dispatch, Find vs Traverse, flag set hierarchy, completion engine (__complete, getCompletions, ShellCompDirective), shell script generation (bash V1/V2, zsh, fish, powershell), flag group validation, global state, Levenshtein suggestions, or understanding the internal execution model. Triggers on: "cobra internals", "cobra ExecuteC", "cobra Find", "cobra Traverse", "cobra findNext", "cobra mergePersistentFlags", "cobra ParseFlags", "cobra getCompletions", "cobra __complete", "cobra completion engine", "cobra bash V2", "cobra flag resolution", "cobra flag groups internals", "cobra global state", "cobra EnablePrefixMatching", "cobra EnableCaseInsensitive", "cobra Levenshtein", "cobra stripFlags", "cobra legacyArgs", "cobra execute", "cobra preRun", "cobra postRun", "cobra mousetrap", "cobra templateFuncs".

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Cobra Development Reference

Reference for developing and debugging cobra internals. Covers the Command struct, execution flow, flag resolution, completion engine, and shell script generation.

Data Flow

os.Args[1:]
  → ExecuteC()
    → Root().ExecuteC() (always starts at root)
    → InitDefaultHelpCmd, initCompleteCmd, InitDefaultCompletionCmd
    → Find(args) or Traverse(args) (based on TraverseChildren)
      → findNext() (exact match → alias → prefix match)
    → execute(flags)
      → ParseFlags
      → ValidateArgs
      → PersistentPreRun chain (parent → child)
      → PreRun
      → ValidateRequiredFlags, ValidateFlagGroups
      → Run / RunE
      → PostRun
      → PersistentPostRun chain (child → parent)

Sub-Resources

Load the reference that matches your task. When in doubt, load multiple references.

Keywords	Reference
Command struct, all fields, internal state, commands slice, parent, flags, pflags, lflags, iflags, parentsPflags, FParseErrWhitelist, CompletionOptions, commandCalledAs, ctx	references/command-struct.md
ExecuteC, execute, Find, Traverse, findNext, stripFlags, argsMinusFirstX, legacyArgs, command resolution, flag stripping, prefix matching, TraverseChildren	references/execute-flow.md
Flags, PersistentFlags, LocalFlags, InheritedFlags, LocalNonPersistentFlags, NonInheritedFlags, mergePersistentFlags, ParseFlags, flag set hierarchy, parentsPflags, globNormFunc, Flag lookup, persistentFlag lookup	references/flag-resolution.md
__complete, __completeNoDesc, getCompletions, checkIfFlagCompletion, ShellCompDirective, CompletionFunc, RegisterFlagCompletionFunc, flagCompletionFunctions, completion output format, directive handling, ValidArgsFunction, completion flow	references/completion-engine.md
bash V1, bash V2, zsh, fish, powershell, GenBashCompletion, GenBashCompletionV2, GenZshCompletion, GenFishCompletion, GenPowerShellCompletion, script architecture, V1 vs V2 comparison, completion script internals	references/shell-completions.md
flag groups, MarkFlagsRequiredTogether, MarkFlagsMutuallyExclusive, MarkFlagsOneRequired, ValidateFlagGroups, processFlagForGroupAnnotation, annotation storage, requiredAsGroupAnnotation, oneRequiredAnnotation, mutuallyExclusiveAnnotation, enforceFlagGroupsForCompletion	references/flag-groups-internals.md
global state, OnInitialize, OnFinalize, initializers, finalizers, EnablePrefixMatching, EnableCaseInsensitive, EnableCommandSorting, EnableTraverseRunHooks, templateFuncs, AddTemplateFunc, MousetrapHelpText, MousetrapDisplayDuration, CheckErr, Gt, Eq	references/global-state.md
suggestions, Levenshtein, findNext, prefix matching, case-insensitive, SuggestFor, SuggestionsMinimumDistance, DisableSuggestions, ld function, hasNameOrAliasPrefix, commandNameMatches	references/suggestions.md

Quick Guide

How does ExecuteC dispatch to the right command? → references/execute-flow.md
What is the difference between Find and Traverse? → references/execute-flow.md
How does the flag set hierarchy work? → references/flag-resolution.md
How does the __complete hidden command work? → references/completion-engine.md
How are shell completion scripts generated? → references/shell-completions.md
How do flag group annotations work internally? → references/flag-groups-internals.md
What global state does cobra maintain? → references/global-state.md
How does the suggestion/typo system work? → references/suggestions.md
What are all the Command struct fields? → references/command-struct.md

Cross-Project References

For user-facing cobra topics (creating commands, defining flags, argument validation, lifecycle hooks, help/usage, completions API, Viper integration), use the cobra skill.
For pflag internals (non-POSIX modes, carapace-pflag extensions), use the carapace-dev skill → references/pflag.md.