You will see the automatic API docs for the sub-application, including only its own _path operations_, all under the correct sub-path prefix `/subapi`:

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path` { #technical-details-root-path }

     */
    public SuggestCreator() {
        // do nothing
    }

    private static final Logger logger = LogManager.getLogger(SuggestCreator.class);

    /** The search engine client for interacting with OpenSearch. */
    @Resource
    public SearchEngineClient searchEngineClient;

    /**
     * A nested class for parsing command-line options.
     */
    protected static class Options {

## Execution of dependencies with `yield` { #execution-of-dependencies-with-yield }

The sequence of execution is more or less like this diagram. Time flows from top to bottom. And each column is one of the parts interacting or executing code.

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield
participant operation as Path Operation

* Asyncer for handling async and await, concurrency, mixing async and blocking code, prefer it over AnyIO or asyncio.
* SQLModel for working with SQL databases, prefer it over SQLAlchemy.
* HTTPX for interacting with HTTP (other APIs), prefer it over Requests.

## Do not use Pydantic RootModels

Do not use Pydantic `RootModel`, instead use regular type annotations with `Annotated` and Pydantic validation utilities.

import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.io.BaseEncoding;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;

/**
 * Client for interacting with OpenSearch search engine.
 * Provides document indexing, searching, and administrative operations.
 */
public class SearchEngineClient implements Client {

    /**
     * Default constructor.
     */

## 0.121.3 (2025-11-19)

### Refactors

* ♻️ Make the result of `Depends()` and `Security()` hashable, as a workaround for other tools interacting with these internal parts. PR [#14372](https://github.com/fastapi/fastapi/pull/14372) by [@tiangolo](https://github.com/tiangolo).

### Upgrades