# Custom Response Classes - File, HTML, Redirect, Streaming, etc.

There are several custom response classes you can use to create an instance and return them directly from your *path operations*.

Read more about it in the [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/).

You can import them directly from `fastapi.responses`:

```python
from fastapi.responses import (
    FileResponse,

idated .form-check-input:valid~.valid-tooltip{display:block}.custom-control-input.is-valid~.custom-control-label,.was-validated .custom-control-input:valid~.custom-control-label{color:#28a745}.custom-control-input.is-valid~.custom-control-label::before,.was-validated .custom-control-input:valid~.custom-control-label::before{border-color:#28a745}.custom-control-input.is-valid:checked~.custom-control-label::before,.was-validated .custom-control-input:valid:checked~.custom-control-label::before{bor...

 + .custom-select,\n.input-group > .form-control-plaintext + .custom-file,\n.input-group > .custom-select + .form-control,\n.input-group > .custom-select + .custom-select,\n.input-group > .custom-select + .custom-file,\n.input-group > .custom-file + .form-control,\n.input-group > .custom-file + .custom-select,\n.input-group > .custom-file + .custom-file {\n  margin-left: -1px;\n}\n\n.input-group > .form-control:focus,\n.input-group > .custom-select:focus,\n.input-group > .custom-file .custom-file-input:focus...

        assertEquals("Custom minKey should match", "custom.min", customAnnotation.minKey());
        assertEquals("Custom maxKey should match", "custom.max", customAnnotation.maxKey());
        assertEquals("Annotation type should be CustomSize", CustomSize.class, customAnnotation.annotationType());
    }

    // Test annotation with empty keys

/**
 * Wrapper for HTTP servlet requests in web API context.
 * This class extends HttpServletRequestWrapper to provide custom servlet path handling
 * for web API requests.
 */
public class WebApiRequest extends HttpServletRequestWrapper {
    /**
     * The custom servlet path for this web API request.
     */
    protected String servletPath;

    /**

///

## 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>.

        "type": "prometheus",
        "uid": "${DS_PROMETHEUS}"
      },
      "fieldConfig": {
        "defaults": {
          "color": {
            "mode": "palette-classic"
          },
          "custom": {
            "axisBorderShow": false,
            "axisCenteredZero": false,
            "axisColorMode": "text",
            "axisLabel": "",
            "axisPlacement": "auto",
            "barAlignment": 0,

# setup.python.sh: Install a specific Python version and packages for it.
# Usage: setup.python.sh <pyversion> <requirements.txt>

# Sets up custom apt sources for our TF images.

# Prevent apt install tzinfo from asking our location (assumes UTC)
export DEBIAN_FRONTEND=noninteractive

# Set up shared custom sources
apt-get update
apt-get install -y gnupg ca-certificates

# Deadsnakes: https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa

## Install custom exception handlers { #install-custom-exception-handlers }

You can add custom exception handlers with <a href="https://www.starlette.io/exceptions/" class="external-link" target="_blank">the same exception utilities from Starlette</a>.

Let's say you have a custom exception `UnicornException` that you (or a library you use) might `raise`.

And you want to handle this exception globally with FastAPI.

        "uid": "${DS_PROMETHEUS}"
      },
      "description": "",
      "fieldConfig": {
        "defaults": {
          "color": {
            "mode": "palette-classic"
          },
          "custom": {
            "hideFrom": {
              "legend": false,
              "tooltip": false,
              "viz": false
            }
          },
          "mappings": [
            {