But if we use the same model for another *path operation*, we could be sending our user's passwords to every client.

/// danger

Never store the plain password of a user or send it in a response like this, unless you know all the caveats and you know what you are doing.

///

## Add an output model { #add-an-output-model }

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

* Kullandığın geliştirme araçları ile iyi çalışır **<abbr title="Integrated Development Environment, kod editörüne benzer">IDE</abbr>/<abbr title="Code errorlarınızı inceleyen program">linter</abbr>/brain**:
    * Pydantic'in veri yapıları aslında sadece senin tanımladığın classlar; Bu yüzden doğrulanmış dataların ile otomatik tamamlama, linting ve mypy'ı kullanarak sorunsuz bir şekilde çalışabilirsin

### Override the `HTTPException` error handler { #override-the-httpexception-error-handler }

The same way, you can override the `HTTPException` handler.

For example, you could want to return a plain text response instead of JSON for these errors:

{* ../../docs_src/handling_errors/tutorial004.py hl[3:4,9:11,22] *}

/// note | Technical Details

    * If you know Python types you know how to use Pydantic.
* Plays nicely with your **<abbr title="Integrated Development Environment, similar to a code editor">IDE</abbr>/<abbr title="A program that checks for code errors">linter</abbr>/brain**:
    * Because pydantic data structures are just instances of classes you define; auto-completion, linting, mypy and your intuition should all work properly with your validated data.
* Validate **complex structures**:

### `HTMLResponse` { #htmlresponse }

Takes some text or bytes and returns an HTML response, as you read above.

### `PlainTextResponse` { #plaintextresponse }

Takes some text or bytes and returns a plain text response.

{* ../../docs_src/custom_response/tutorial005.py hl[2,7,9] *}

### `JSONResponse` { #jsonresponse }

Takes some data and returns an `application/json` encoded response.

       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain
       * ImmutableSet.Builder but y is an ImmutableSortedSet.Builder (or vice versa). Certainly
       * ImmutableSortedSet.Builder.combine() is written as if its argument will never be a plain
       * ImmutableSet.Builder: It casts immediately to ImmutableSortedSet.Builder.)
       */
      copyIfNecessary();

                bufferIndex += ((AndXServerMessageBlock) this.andx).readAndXWireFormat(buffer, bufferIndex);
            } else {

                /*
                 * Just a plain smb. Read it as normal.
                 */

                buffer[bufferIndex++] = (byte) (this.andx.wordCount & 0xFF);

                if ((this.andx.wordCount != 0) && (this.andx.wordCount > 2)) {

    val call =
      client.newCall(
        Request(
          url = server.url("/foo"),
          body =
            object : RequestBody() {
              override fun contentType(): MediaType = "text/plain; charset=utf-8".toMediaType()

              override fun writeTo(sink: BufferedSink) {
                sink.write(postBytes)
              }
            },
        ),
      )

        .addHeader("Content-Type: text/plain")
        .addHeader("Last-Modified: " + formatDate(-2, TimeUnit.HOURS))
        .addHeader("Expires: " + formatDate(-1, TimeUnit.HOURS))
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .code(HttpURLConnection.HTTP_NOT_MODIFIED)
        .addHeader("Content-Type: text/plain")
        .addHeader("Content-Encoding: gzip")