# Bigger Applications - Multiple Files { #bigger-applications-multiple-files }

If you are building an application or a web API, it's rarely the case that you can put everything in a single file.

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure { #an-example-file-structure }

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.

class ResponseLevel0(JSONResponse):
    media_type = "application/x-level-0"


class ResponseLevel1(JSONResponse):
    media_type = "application/x-level-1"


class ResponseLevel2(JSONResponse):
    media_type = "application/x-level-2"


class ResponseLevel3(JSONResponse):
    media_type = "application/x-level-3"


class ResponseLevel4(JSONResponse):
    media_type = "application/x-level-4"

                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

			<arg>"application/vnd.ms-excel.sheet.3"</arg>
		</postConstruct>
		<postConstruct name="addCondition">
			<arg>"mimetype"</arg>
			<arg>"application/vnd.ms-excel.sheet.4"</arg>
		</postConstruct>
		<postConstruct name="addCondition">
			<arg>"mimetype"</arg>
			<arg>"application/vnd.ms-excel.workspace.3"</arg>
		</postConstruct>
		<postConstruct name="addCondition">
			<arg>"mimetype"</arg>

        assertContentType("application/msword", "test/text1.txt", "hoge.doc");
        assertContentType("application/msword", "extractor/msoffice/test.doc", "hoge.doc");
        assertContentType("application/vnd.ms-excel", "test/text1.txt", "hoge.xls");
        assertContentType("application/vnd.ms-excel", "extractor/msoffice/test.xls", "hoge.xls");
        assertContentType("application/vnd.ms-powerpoint", "test/text1.txt", "hoge.ppt");

application/mac-binhex40       hqx              # Macintosh binhexed archives
application/mspowerpoint       ppt              # Microsoft Powerpoint
application/msword             doc              # Microsoft Word
application/octet-stream       bin exe ani      # Binary File
application/oda                oda
application/pagemaker          pm5 pt5 pm       # PageMaker
application/pdf                pdf              # Adobe Acrobat

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

                    "summary": "Post Root",
                    "operationId": "foo_post_root",
                    "requestBody": {
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/Body_foo_post_root"
                                }
                            }