# Extending OpenAPI

There are some cases where you might need to modify the generated OpenAPI schema.

In this section you will see how.

## The normal process

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

                        <id>compile</id>
                        <phase>process-sources</phase>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>test-compile</id>
                        <phase>process-test-sources</phase>
                        <goals>

	// We will iterate over all processes. Our goal is to find a process whose namespace has a veth with an IP matching the pod.
	// There should be 1 or 2 processes that match: the pause container should always be there, and the istio-validation *might*.
	// We want the pause container, as the istio-validation one may exit before we are done.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

The process normally is that **you define** in your code what is the message that you will send, the **body of the request**.

import org.codelibs.fess.crawler.processor.ResponseProcessor;

/**
 * @author kuma
 *
 */
public class NullResponseProcessor implements ResponseProcessor {

    @Override
    public void process(final ResponseData responseData) {
        // do nothing
    }

import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;

/**
 * Handles normalization of a model. In this context, normalization is the process of producing a canonical
 * representation for models that physically look different but are semantically equivalent.
 *
 * @deprecated use {@link org.apache.maven.api.services.ModelBuilder} instead
 */

@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.perf_counter()
    response = await call_next(request)
    process_time = time.perf_counter() - start_time
    response.headers["X-Process-Time"] = str(process_time)

### TODO

In subsequent releases we are planning to extend this to provide things like

- Reload() of MinIO server arguments without fully restarting the process.

- Expanding 1 node at a time by automating the process of creating a new pool
  and decommissioning to provide a functionality that smaller deployments
  care about.

 <font color="#4E9A06">│                                                     │</font>
 <font color="#4E9A06">╰─────────────────────────────────────────────────────╯</font>

<font color="#4E9A06">INFO</font>:     Started server process [<font color="#06989A">2306215</font>]
<font color="#4E9A06">INFO</font>:     Waiting for application startup.
<font color="#4E9A06">INFO</font>:     Application startup complete.

import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

public interface WebApiManager {

    boolean matches(HttpServletRequest request);

    void process(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException;