### Generate a TypeScript Client with Tags { #generate-a-typescript-client-with-tags }

If you generate a client for a FastAPI app using tags, it will normally also separate the client code based on the tags.

This way, you will be able to have things ordered and grouped correctly for the client code:

<img src="/img/tutorial/generate-clients/image06.png">

In this case, you have:

        super();
    }

    /**
     * Generates a thumbnail for the specified ID and output file.
     * This implementation always returns false, indicating no thumbnail was generated.
     *
     * @param thumbnailId the ID of the thumbnail to generate
     * @param outputFile the output file where the thumbnail should be saved
     * @return false always, as this generator does not create thumbnails
     */
    @Override

First, write all your **FastAPI** application as normally:

{* ../../docs_src/extending_openapi/tutorial001.py hl[1,4,7:9] *}

### Generate the OpenAPI schema { #generate-the-openapi-schema }

Then, use the same utility function to generate the OpenAPI schema, inside a `custom_openapi()` function:

{* ../../docs_src/extending_openapi/tutorial001.py hl[2,15:21] *}

```

### 3.2 Use OpenSSL to Generate a Certificate

Use one of the following methods to generate a certificate using `openssl`:

* 3.2.1 [Generate a private key with ECDSA](#generate-private-key-with-ecdsa)
* 3.2.2 [Generate a private key with RSA](#generate-private-key-with-rsa)
* 3.2.3 [Generate a self-signed certificate](#generate-a-self-signed-certificate)

#### 3.2.1 Generate a private key with ECDSA

        // Test generation with null thumbnail ID
        assertFalse(thumbnailGenerator.generate(null, tempOutputFile));
    }

    public void test_generate_withEmptyThumbnailId() {
        // Test generation with empty thumbnail ID
        assertFalse(thumbnailGenerator.generate("", tempOutputFile));
    }

    public void test_generate_withNullOutputFile() {

        }
    }

    /**
     * Destroys the command generator and cleanup resources.
     */
    @Override
    public void destroy() {
        destoryTimer.cancel();
        destoryTimer = null;
    }

    /**
     * Generates a thumbnail for the given ID and saves it to the output file.
     * @param thumbnailId The ID of the thumbnail to generate.
     * @param outputFile The file where the thumbnail will be saved.

        try {
            assertTrue(outputFile.exists());
            generator.setCommandList(Collections.singletonList("invalid_command_for_test"));
            assertTrue(generator.generate("test_id", outputFile));
        } finally {
            outputFile.delete();
        }
    }

    public void test_generate_outputFile_null() throws Exception {
        generator.setCommandList(Collections.singletonList("echo test"));
        try {

        // State 2: Process Type 2 and generate Type 3
        byte[] type3Token = context.initSecContext(type2Token, 0, type2Token.length);

        assertNotNull(type3Token);
        assertTrue(type3Token.length > 0);
        assertTrue(context.isEstablished());
        assertArrayEquals(serverChallenge, context.getServerChallenge());
        // Signing key may or may not be generated depending on flags negotiation

     * @param outputFile the file where the generated thumbnail will be saved
     * @return true if the thumbnail was successfully generated, false otherwise
     */
    @Override
    public boolean generate(final String thumbnailId, final File outputFile) {
        if (logger.isDebugEnabled()) {
            logger.debug("Generate Thumbnail: {}", thumbnailId);
        }

        if (outputFile.exists()) {

        generator = new TestThumbnailGenerator();

        // Default name should be null
        assertNull(generator.getName());

        // Set and get name
        generator.setName("test-generator");
        assertEquals("test-generator", generator.getName());

        // Change name
        generator.setName("new-name");
        assertEquals("new-name", generator.getName());
    }