@Get("/api/v2/autocompleteKeys")
    @Blocking
    public AggregatedHttpResponse getAutocompleteKeys() throws IOException {
        Duration duration = new Duration();
        duration.setStep(Step.SECOND);
        DateTime endTime = DateTime.now();
        DateTime startTime = endTime.minus(org.joda.time.Duration.millis(defaultLookback));
        duration.setStart(startTime.toString("yyyy-MM-dd HHmmss"));
        duration.setEnd(endTime.toString("yyyy-MM-dd HHmmss"));
        Set<String> autocompleteKeys = getTagQueryService().queryTagAutocompleteKeys(TagType.ZIPKIN, duration);
        return cachedResponse(true, new ArrayList<>(autocompleteKeys));
    }
Reference from zipkin2.server.internal.ZipkinQueryApiV2 for the API consistent.
oap-server/server-query-plugin/zipkin-query-plugin/src/main/java/org/apache/skywalking/oap/query/zipkin/handler/ZipkinQueryHandler.java