What causes "unsupported plugin name: %q" in FiloSottile/age?

Ensure the recipient string's plugin name matches the plugin this process was invoked as (age-plugin- ).

unsupported plugin name: %q

Error message

unsupported plugin name: %q

What it means

In the recipient-v1 plugin protocol, each requested recipient string is parsed and its plugin name compared against the Plugin's own name. If a parsed recipient belongs to a different plugin, RecipientV1 fails that stanza with 'unsupported plugin name' — the plugin was invoked for name X but was asked to wrap a recipient for name Y.

Source

Thrown at plugin/plugin.go:249

			// Unsupported stanzas in uni-directional phases are ignored.
		}
	}

	if len(recipientStrings)+len(identityStrings) == 0 {
		return p.fatalf("no recipients or identities provided")
	}
	if len(fileKeys) == 0 {
		return p.fatalf("no file keys provided")
	}

	var recipients, identities []age.Recipient
	for i, s := range recipientStrings {
		name, data, err := ParseRecipient(s)
		if err != nil {
			return p.recipientError(i, err)
		}
		if name != p.name {
			return p.recipientError(i, fmt.Errorf("unsupported plugin name: %q", name))
		}
		if p.recipient == nil {
			return p.recipientError(i, fmt.Errorf("recipient encodings not supported"))
		}
		r, err := p.recipient(data)
		if err != nil {
			return p.recipientError(i, err)
		}
		recipients = append(recipients, r)
	}
	for i, s := range identityStrings {
		name, data, err := ParseIdentity(s)
		if err != nil {
			return p.identityError(i, err)
		}
		if name != p.name {
			return p.identityError(i, fmt.Errorf("unsupported plugin name: %q", name))
		}

View on GitHub (pinned to b74dce4cdb)

Solutions

Ensure the recipient string's plugin name matches the plugin this process was invoked as (age-plugin-<p.name>).
Filter recipient strings by prefix age1<p.name> before the plugin processes them, or better, let age dispatch each recipient to the matching plugin.
Fix the recipient's embedded name by re-encoding with plugin.EncodeRecipient under the correct name.
Check the installed binary's name matches the name passed to plugin.New.

Example fix

// before
// age-plugin-frood invoked with: age1wrongoth1qqq...
// after
if !strings.HasPrefix(recipientStr, "age1"+p.name) { skip / report to user }
name, data, err := plugin.ParseRecipient(recipientStr)

Defensive patterns

Strategy: validation

Validate before calling

for _, s := range recipientStrings {
	if n, _, err := plugin.ParseRecipient(s); err != nil || n != p.Name() {
		// skip or surface: this recipient belongs to another plugin
	}
}

Type guard

func belongsToPlugin(s, pluginName string) bool {
	n, _, err := plugin.ParseRecipient(s)
	return err == nil && n == pluginName
}

Try / catch

name, data, err := plugin.ParseRecipient(s)
if err != nil { return p.recipientError(i, err) }
if name != p.name { return p.recipientError(i, fmt.Errorf("unsupported plugin name: %q", name)) }

Prevention

Let age dispatch each recipient to its matching plugin instead of mixing in one invocation
Verify recipients carry the same plugin name as the invoked binary
Keep plugin binary names in sync with names embedded in recipients
Surface the offending recipient string in error output

When it happens

Trigger: age invoking age-plugin-<x> with a recipient file or -r argument containing an age1<other-plugin>... recipient; mixed recipient lists in one encryption; case where ParseRecipient extracts a different name than p.name.

Common situations: Users passing multiple -r flags across different plugins; stale config pointing at the wrong plugin binary; a typo in the recipient's plugin name section; symlinked/renamed plugin binaries under the wrong name.

Related errors

AI-assisted analysis of FiloSottile/age@b74dce4cdb (2026-08-31). Data as JSON: /api/errors/07d55ec3f08c4c62. Report an issue: GitHub.