# Query Parameters and String Validations { #query-parameters-and-string-validations }

**FastAPI** allows you to declare additional information and validation for your parameters.

Let's take this application as example:

{* ../../docs_src/query_params_str_validations/tutorial001_py310.py hl[7] *}

{* ../../docs_src/response_model/tutorial003_05_py310.py hl[7] *}

This will make FastAPI skip the response model generation and that way you can have any return type annotations you need without it affecting your FastAPI application. 🤓

## Response Model encoding parameters { #response-model-encoding-parameters }

Your response model could have default values, like:

{* ../../docs_src/response_model/tutorial004_py310.py hl[9,11:12] *}

	// arbitrary file sizes, filenames of arbitrary encoding and length,
	// sparse files, and other features.
	//
	// It is recommended that PAX be chosen over GNU unless the target
	// application can only parse GNU formatted archives.
	//
	// Reference:
	//	https://www.gnu.org/software/tar/manual/html_node/Standard.html
	FormatGNU

	// Schily's tar format, which is incompatible with USTAR.

     *
     * Using DoubleUtils.bigToDouble, getting a double approximation of x is extremely fast, and
     * then we can get a double approximation of the square root. Then, we iteratively improve this
     * guess with an application of Newton's method, which sets guess := (guess + (x / guess)) / 2.
     * This iteration has the following two properties:
     *
     * a) every iteration (except potentially the first) has guess >= floor(sqrt(x)). This is

		return
	}

	// Ensure body content type is opaque to ensure that request body has not
	// been interpreted as form data.
	contentType := r.Header.Get("Content-Type")
	if contentType != "application/octet-stream" {
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrBadRequest), r.URL)
		return
	}

	// Validate operation
	operation := mux.Vars(r)["operation"]

constraints.UriType.message = {item}에 인식할 수 없는 URI가 있습니다.
constraints.CronExpression.message = {item}는 올바른 CRON 표현식이 아닙니다.

# ----------------------------------------------------------
# Application Exception
# ---------------------
# /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# five framework-embedded messages (don't change key names)
# - - - - - - - - - -/
errors.login.failure = 로그인에 실패했습니다.

		Metadata: map[string]string{
			xhttp.AmzRestore:                 "FAILED",
			xhttp.ContentMD5:                 mustGetUUID(),
			xhttp.AmzBucketReplicationStatus: "PENDING",
			xhttp.ContentType:                "application/json",
		},
		Parts: []ObjectPartInfo{
			{
				Number:     1,
				Size:       1234345,
				ActualSize: 1234345,
			},
			{
				Number:     2,
				Size:       1234345,

"+f}}}return{state:"success",data:b}}n.extend({active:0,lastModified:{},etag:{},ajaxSettings:{url:fc,type:"GET",isLocal:jc.test(ec[1]),global:!0,processData:!0,async:!0,contentType:"application/x-www-form-urlencoded; charset=UTF-8",accepts:{"*":pc,text:"text/plain",html:"text/html",xml:"application/xml, text/xml",json:"application/json, text/javascript"},contents:{xml:/xml/,html:/html/,json:/json/},responseFields:{xml:"responseXML",text:"responseText",json:"responseJSON"},converters:{"* text":String,"text...

      .readTimeout(Duration.ofMillis(500))
      .addInterceptor(
        Interceptor { chain: Interceptor.Chain ->
          val response = chain.proceed(chain.request())
          // Ensure application interceptors never see a null body.
          assertThat(response.body).isNotNull()
          response
        },
      ).build()

  private fun configureClientTestRule(): OkHttpClientTestRule {

	// Uploading a new object with Content-Type  "application/json".
	objectName = "test-object.json"
	buffer2 := bytes.NewReader([]byte("hello world"))
	request, err = newTestSignedRequest(http.MethodPut, getPutObjectURL(s.endPoint, bucketName, objectName),
		int64(buffer2.Len()), buffer2, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)
	// setting the request header to be application/json.