# Header Parameters { #header-parameters }

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header` { #import-header }

First import `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

func setEventStreamHeaders(w http.ResponseWriter) {
	w.Header().Set(xhttp.ContentType, "text/event-stream")
	w.Header().Set(xhttp.CacheControl, "no-cache") // nginx to turn off buffering
	w.Header().Set("X-Accel-Buffering", "no")      // nginx to turn off buffering
}

// Write http common headers
func setCommonHeaders(w http.ResponseWriter) {
	// Set the "Server" http header.
	w.Header().Set(xhttp.ServerInfo, MinioStoreName)

# Header Parameter Models { #header-parameter-models }

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

///

## Custom Headers { #custom-headers }

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

    peer.acceptFrame() // ACK
    peer.acceptFrame() // SYN_STREAM
    peer.sendFrame().headers(false, 3, headerEntries("a", "android"))
    val expectedRequestHeaders =
      listOf(
        Header(Header.TARGET_METHOD, "GET"),
        Header(Header.TARGET_SCHEME, "https"),
        Header(Header.TARGET_AUTHORITY, "squareup.com"),
        Header(Header.TARGET_PATH, "/cached"),
      )

      )

    fun http2HeadersList(request: Request): List<Header> {
      val headers = request.headers
      val result = ArrayList<Header>(headers.size + 4)
      result.add(Header(TARGET_METHOD, request.method))
      result.add(Header(TARGET_PATH, RequestLine.requestPath(request.url)))
      val host = request.header("Host")
      if (host != null) {
        result.add(Header(TARGET_AUTHORITY, host)) // Optional.
      }

      }

    /** Removes all headers on this builder and adds [headers]. */
    open fun headers(headers: Headers) =
      apply {
        this.headers = headers.newBuilder()
      }

    /**
     * Sets this request's `Cache-Control` header, replacing any cache control headers already
     * present. If [cacheControl] doesn't define any directives, this clears this request's
     * cache-control headers.

        return contentException;
    }

    /**
     * Sets the headers for the response.
     *
     * @param headers the headers to set.
     */
    public void setHeaders(final Map<String, List<String>> headers) {
        if (headers != null) {
            final Map<String, List<String>> map = new HashMap<>();
            headers.entrySet().stream().filter(e -> e.getKey() != null)

    /**
     * Retrieves a specific request header by its ID.
     *
     * @param id the unique identifier of the request header
     * @return an OptionalEntity containing the request header if found, empty otherwise
     */
    public OptionalEntity<RequestHeader> getRequestHeader(final String id) {
        return requestHeaderBhv.selectByPK(id);
    }

    /**
     * Stores a request header configuration to the database.

      for (pushPromise in promises) {
        val pushedHeaders = mutableListOf<Header>()
        pushedHeaders.add(Header(Header.TARGET_AUTHORITY, url(pushPromise.path).host))
        pushedHeaders.add(Header(Header.TARGET_METHOD, pushPromise.method))
        pushedHeaders.add(Header(Header.TARGET_PATH, pushPromise.path))
        val pushPromiseHeaders = pushPromise.headers
        for ((name, value) in pushPromiseHeaders) {