這些資訊都在應用的 **OpenAPI 結構**中，並顯示在 API 文件裡。

同樣包含在 OpenAPI 中的模型資訊，也可以用來**產生用戶端程式碼**。

### Hey API { #hey-api }

當我們有含模型的 FastAPI 應用後，就能用 Hey API 來產生 TypeScript 用戶端。最快的方法是透過 npx：

```sh
npx @hey-api/openapi-ts -i http://localhost:8000/openapi.json -o src/client
```

這會在 `./src/client` 產生一個 TypeScript SDK。

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

    /**
     * Converts a long value to hexadecimal characters and writes them to the specified character array.
     *
     * @param val the long value to convert to hexadecimal characters
     * @param dst the destination character array to write the hex digits into
     * @param dstIndex the starting index in the destination array
     * @param size the number of hex digits to write (will be left-padded with zeros)
     */

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * instantiated. Similar to <code>System</code> properties the namespace
 * is global therefore property names should be unique. Before use,
 * the <code>load</code> method should be called with the name of a
 * <code>Properties</code> file (or <code>null</code> indicating no
 * file) to initialize the <code>Config</code>. The <code>System</code>
 * properties will then populate the <code>Config</code> as well potentially

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

    }

    @Test
    void testDerive() {
        ndrBuffer.advance(50); // Advance the original buffer
        NdrBuffer derivedBuffer = ndrBuffer.derive(10);

        // Verify derived buffer properties
        assertSame(buffer, derivedBuffer.buf);
        assertEquals(0, derivedBuffer.start); // Derived buffer starts from the original buffer's start
        assertEquals(10, derivedBuffer.index);

/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *