micro-editor/micro · error

Invalid event %s

Error message

Invalid event %s

What it means

Thrown by findEvents() in internal/action/bindings.go while parsing a key *sequence* like "<Ctrl-x>k". The regex `<(.+?)>` splits the string into <token> groups and each token must resolve via findSingleEvent (a known key name in keyEvents/mouseEvents, modifiers + single rune, or an escape sequence). If any single token inside the angle brackets is unrecognized, parsing aborts with 'Invalid event <token>'. This surfaces through findEvent, i.e. every TryBindKey/UnbindKey/BindKey call including InitBindings at startup and the interactive >bind command.

Source

Thrown at internal/action/bindings.go:128

	// 	InfoMapKey(e, v)
	// }
}

var r = regexp.MustCompile("<(.+?)>")

func findEvents(k string) (b KeySequenceEvent, ok bool, err error) {
	var events []Event = nil
	for len(k) > 0 {
		groups := r.FindStringSubmatchIndex(k)

		if len(groups) > 3 {
			if events == nil {
				events = make([]Event, 0, 3)
			}

			e, ok := findSingleEvent(k[groups[2]:groups[3]])
			if !ok {
				return KeySequenceEvent{}, false, errors.New("Invalid event " + k[groups[2]:groups[3]])
			}

			events = append(events, e)

			k = k[groups[3]+1:]
		} else {
			return KeySequenceEvent{}, false, nil
		}
	}

	return KeySequenceEvent{events}, true, nil
}

// findSingleEvent will find binding Key 'b' using string 'k'
func findSingleEvent(k string) (b Event, ok bool) {
	modifiers := tcell.ModNone

	// First, we'll strip off all the modifiers in the name and add them to the

View on GitHub (pinned to 1c8b82b32e)

Solutions

  1. Fix the token inside <...> to a name micro knows: Ctrl<Letter>, Alt<Rune|Name>, Shift<Name>, F1-F12, PageUp/Down, Home, End, ArrowUp/Down/Left/Right, Delete, Insert, MouseLeft/Middle/Right (optionally with Drag/Release suffix)
  2. Open > help keybindings and copy the exact event-name grammar from the shipped documentation
  3. For single characters use the bare rune ('x') and for raw escapes use "\u001b..." RawEvent form instead of inventing names
  4. Re-run micro and watch the infobar; the message names exactly which token failed

Example fix

// before: ~/.config/micro/bindings.json
"<Cntrl-s>": "Save",
"<Ctrl-x>quux": "Quit"

// after
"CtrlS": "Save",
"<Ctrl-x>k": "Quit"
Defensive patterns

Strategy: validation

Validate before calling

// Validate a binding string before TryBindKey/BindKey
tokenRe := regexp.MustCompile(`<(.+?)>`)
func validBinding(k string) bool {
    for _, m := range tokenRe.FindAllStringSubmatch(k, -1) {
        if !validSingleEvent(m[1]) {
            return false // each <token> must itself be a valid event name
        }
    }
    return true
}
// validSingleEvent mirrors findSingleEvent: optional Ctrl/Alt/Shift prefixes +
// known key name (F1..F12, PageUp, Enter, ArrowLeft...), known mouse name
// (optionally +Drag/+Release), or exactly one rune.

Try / catch

if _, err := action.TryBindKey(seq, act, true, true); err != nil {
    if strings.HasPrefix(err.Error(), "Invalid event ") {
        // extract the token, suggest closest known event name, keep going
        log.Printf("skipping bad binding %q: %v", seq, err)
        continue
    }
    return err
}

Prevention

When it happens

Trigger: bindings.json (or a >bind argument) contains a sequence with a bad inner token, e.g. "<Ctrl-q><quux>": 'Ctrl-q' parses but 'quux' is not in keyEvents/mouseEvents and is longer than one character, so findSingleEvent returns !ok and findEvents errors. Also triggered by typos like "<Cntrl-s>" or "<Page Down>" inside brackets.

Common situations: Hand-editing bindings.json using Vim/Emacs-style notation that micro does not support; copying snippets from outdated blog posts or other editors' configs; renaming a binding in a Lua plugin that calls bindings.TryBindKeyplug.

Related errors

AI-assisted analysis of micro-editor/micro@1c8b82b32e (2026-08-15). Data as JSON: /api/errors/b64442c4b18778ec. Report an issue: GitHub.