You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

If a client tries to send some **extra** data in the **query parameters**, they will receive an **error** response.

For example, if the client tries to send a `tool` query parameter with a value of `plumbus`, like:

```http
https://example.com/items/?limit=10&tool=plumbus
```

        if (repository == null || repository.getBasedir() == null) {
            return session;
        }

        if (session != null) {
            LocalRepositoryManager lrm = session.getLocalRepositoryManager();
            if (lrm != null && lrm.getRepository().getBasedir().equals(new File(repository.getBasedir()))) {

     * @param scriptEngine The script engine.
     */
    public void add(final String name, final ScriptEngine scriptEngine) {
        if (name == null || scriptEngine == null) {
            throw new IllegalArgumentException("name or scriptEngine is null.");
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Loaded {}", name);
        }
        scriptEngineMap.put(name.toLowerCase(Locale.ROOT), scriptEngine);

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are
[many libraries][works_with_okhttp] that sit on top or hook in via existing APIs. If you build

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are
[many libraries][works_with_okhttp] that sit on top or hook in via existing APIs. If you build

    contains com.google.common.util.concurrent.ListenableFuture class, without
    any other Guava classes. The idea is:

    - If users want only ListenableFuture, they depend on listenablefuture-1.0.

    - If users want all of Guava, they depend on guava, which, as of Guava
    27.0, depends on
    listenablefuture-9999.0-empty-to-avoid-conflict-with-guava. The 9999.0-...

   * This is useful if the function instance already exists, or so that you can supply a lambda
   * expressions. If those circumstances don't apply, you probably don't need to use this; subclass
   * {@code TreeTraverser} and implement its {@link #children} method directly.
   *
   * @since 20.0
   * @deprecated Use {@link com.google.common.graph.Traverser#forTree} instead. If you are using a

        if (total == 0) {
            return 0.0;
        }
        return (double) operationErrors.get() / total;
    }

    /**
     * Calculate average read latency in microseconds
     *
     * @return average read latency
     */
    public double getAverageReadLatencyMicros() {
        long reads = rdmaReads.get();
        if (reads == 0) {
            return 0.0;

   * Returns a new bimap with the same mappings as the specified map. If the specified map is an
   * {@code EnumBiMap}, the new bimap has the same types as the provided map. Otherwise, the
   * specified map must contain at least one mapping, in order to determine the key and value types.
   *
   * @param map the map whose mappings are to be placed in this map
   * @throws IllegalArgumentException if map is not an {@code EnumBiMap} instance and contains no

In particular, this may be a good alternative to logic in a middleware.

For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases { #use-cases }

Some use cases include: