JuliusBrussee/caveman · error

native session marker: invalid key or session id

Error message

native session marker: invalid key or session id

What it means

SessionMarker validated its inputs before building the signed correlation marker and found the session key unusable (nil/wrong length) or the session id invalid (empty/too long/bad characters). Markers are HMAC-protected, so malformed inputs are refused outright.

Source

Thrown at proxy/internal/nativeruntime/marker.go:73

	}
	key, err = os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("native session key read: %w", err)
	}
	if len(key) != sessionKeyBytes {
		return nil, fmt.Errorf("native session key length = %d, want %d", len(key), sessionKeyBytes)
	}
	if err := os.Chmod(path, 0o600); err != nil {
		return nil, fmt.Errorf("native session key chmod: %w", err)
	}
	return key, nil
}

// SessionMarker builds model-temporary correlation context. Local proxy removes
// valid markers byte-surgically before provider inspection or forwarding.
func SessionMarker(key []byte, sessionID string) (string, error) {
	if len(key) != sessionKeyBytes || sessionID == "" || len(sessionID) > 256 {
		return "", errors.New("native session marker: invalid key or session id")
	}
	encoded := base64.RawURLEncoding.EncodeToString([]byte(sessionID))
	sig := markerMAC(key, encoded)
	return fmt.Sprintf(`[[caveman-session-v1 sid="%s" sig="%s"]]`, encoded, sig), nil
}

// StripSessionMarkers removes only valid HMAC-signed markers. Invalid marker-
// shaped user text remains byte-identical. Conflicting valid session IDs are
// stripped but return no correlation identity.
func StripSessionMarkers(body, key []byte) (stripped []byte, sessionID string, changed bool) {
	if len(key) != sessionKeyBytes {
		return body, "", false
	}
	matches := markerPattern.FindAllSubmatchIndex(body, -1)
	if len(matches) == 0 {
		return body, "", false
	}
	out := make([]byte, 0, len(body))

View on GitHub (pinned to 766dce6b13)

Solutions

1. Load the session key via the runtime helper that enforces the 32-byte length
2. Pass a non-empty, identity-safe session id

When it happens

Trigger: Thrown at proxy/internal/nativeruntime/marker.go:73 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of JuliusBrussee/caveman@766dce6b13 (2026-08-18). Data as JSON: /api/errors/79c402e4fc56b1c8. Report an issue: GitHub.