xonsh

name	xonsh
description	Use when working with xonsh shell internals — completion system, RichCompletion, CommandContext, contextual_command_completer, completer pipeline, prompt-toolkit integration, key bindings, Python/shell hybrid model, subprocess execution, xontribs, event system, rc.xsh configuration, or environment variables. Triggers on: "xonsh", "xonsh completion", "xonsh RichCompletion", "xonsh CommandContext", "xonsh completer", "contextual_command_completer", "xonsh prompt-toolkit", "xonsh xontrib", "xonsh event", "xonsh rc.xsh", "add_one_completer", "sub_proc_get_output", "XONSH_COMPLETER_MODE", "xonsh subprocess", "xonsh quoting", "xonsh environment".
user-invocable	true

Xonsh Shell In-Depth Reference

Comprehensive reference for xonsh shell internals, with emphasis on the completion system and how external tools hook into it.

Sub-Resources

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

Keywords	Reference
RichCompletion, CommandContext, CommandArg, CompletionContext, contextual_command_completer, contextual_command_completer_for, non_exclusive_completer, add_one_completer, Completer class, completer pipeline, exclusive vs non-exclusive, deduplication, sorting tiers, filter function, prefix_len, append_closing_quote, append_space, display, description, style, provider, tag_provider, apply_lprefix, complete_from_sub_proc, comp_based_completer, on_completer_filter, XONSH_COMPLETER_MODE, XONSH_COMPLETER_TRACE, COMPLETION_QUERY_LIMIT, XONSH_COMPLETER_DIRS, CommandCompleter, xompletions, bash completion bridge, path completer, command completer, python completer, base completer	references/completion.md
PromptToolkitShell, PromptToolkitCompleter, PromptSession, Completion, CompleteStyle, key bindings, on_ptk_create, COMPLETIONS_DISPLAY, COMPLETION_MODE, COMPLETIONS_CONFIRM, COMPLETIONS_MENU_ROWS, UPDATE_COMPLETIONS_ON_KEYPRESS, COMPLETION_IN_THREAD, AUTO_SUGGEST_IN_COMPLETIONS, XONSH_PROMPT_AUTO_SUGGEST, auto-suggest, menu-complete, display_meta, _highlight_match, unquote, ptk shell, vi mode, emacs mode, XONSH_AUTOPAIR	references/prompt-toolkit.md
Python-powered shell, subprocess execution, SubprocSpec, CommandPipeline, capture modes, $() vs !() vs $[] vs ![], pipe redirect, a>p, e>p, subprocess syntax, Python expressions, shell expressions, @(), $(), ![], subprocess wrapping, quoting, string literals, raw strings, p-strings, f-strings, path strings, word splitting, glob expansion, tilde expansion, environment access, $VAR, ${VAR}, ${{VAR}}, alias system, callable alias, ExecAlias	references/language-execution.md
rc.xsh, .xonshrc, XONSHRC, XONSHRC_DIR, XONSH_CONFIG_DIR, xontrib, xontrib load, xontrib list, load_xontrib, unload_xontrib, entry points, event system, Event, LoadEvent, EventManager, on_chdir, on_precommand, on_postcommand, on_command_not_found, on_pre_prompt, on_post_prompt, on_envvar_change, on_transform_command, on_exit, on_ptk_create, on_completer_filter, XSH, XSH.env, XSH.completers, XSH.commands_cache, XSH.builtins, environment variables, Env class, Var, VarPattern, detype, LsColors, EnvPath, XONSH_* env vars, BASH_COMPLETIONS, COMPLETE_DOTS, SUBSEQUENCE_PATH_COMPLETION, FUZZY_PATH_COMPLETION, SUGGEST_THRESHOLD, CMD_COMPLETIONS_SHOW_DESC, ALIAS_COMPLETIONS_OPTIONS_BY_DEFAULT	references/startup-config.md

Quick Guide

• How do I write a contextual completer? → references/completion.md
• How does the completer pipeline work? → references/completion.md
• What is RichCompletion and its fields? → references/completion.md
• How do I register a completer with add_one_completer? → references/completion.md
• How does exclusive vs non-exclusive work? → references/completion.md
• How does the bash completion bridge work? → references/completion.md
• How does prompt-toolkit render completions? → references/prompt-toolkit.md
• How do I configure completion display? → references/prompt-toolkit.md
• How do I add custom key bindings? → references/prompt-toolkit.md
• How does xonsh execute subprocess commands? → references/language-execution.md
• What are the capture modes ($() vs !())? → references/language-execution.md
• How does quoting work in xonsh? → references/language-execution.md
• How do I set up rc.xsh? → references/startup-config.md
• How do I write a xontrib? → references/startup-config.md
• How does the event system work? → references/startup-config.md
• What are the XONSH_ environment variables?* → references/startup-config.md

Cross-Project References

• For carapace-specific xonsh integration (snippet, patch phase, value formatting, JSON output, style conversion), see the carapace-dev skill → references/shell-xonsh.md.