///

**FastAPI** está todo basado en Pydantic.

Vas a ver mucho más de esto en práctica en el [Tutorial - User Guide](tutorial/index.md){.internal-link target=_blank}.

## Type hints en **FastAPI**

**FastAPI** aprovecha estos type hints para hacer varias cosas.

Con **FastAPI** declaras los parámetros con type hints y obtienes:

    TF_EXCLUSIVE_LOCKS_REQUIRED(fn_body->mu) {
  input_tensors->reserve(ninputs);
  for (int i = 0; i < ninputs; ++i) {
    Node* node = inputs[i].oper ? &inputs[i].oper->node : nullptr;
    int idx = inputs[i].index;

    TF_RETURN_WITH_CONTEXT_IF_ERROR(
        fn_body->graph.IsValidOutputTensor(node, idx),
        "Encountered while processing input ", i, " into function '", fn_name,
        "'");

			if err != nil {
				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
				return
			}
			if dstOpts.IndexCB != nil {
				dstOpts.IndexCB = compressionIndexEncrypter(objEncKey, dstOpts.IndexCB)
			}
		}
	}

	srcInfo.PutObjReader = pReader

	srcInfo.UserDefined, err = getCpObjMetadataFromHeader(ctx, r, srcInfo.UserDefined)
	if err != nil {

/// info

In this example we use invented custom headers `X-Key` and `X-Token`.

But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

///

## Dependencies errors and return values

You can use the same dependency *functions* you use normally.

### Dependency requirements

    //                                                                       Login Execute
    //                                                                      ==============

    @Execute
    public HtmlResponse index() {
        getSession().ifPresent(session -> session.removeAttribute(INVALID_OLD_PASSWORD));
        return asIndexPage(null).useForm(LoginForm.class);
    }

    private HtmlResponse asIndexPage(final LoginForm form) {

import org.codelibs.fess.es.config.cbean.cq.bs.BsFileConfigCQ;
import org.dbflute.cbean.ConditionQuery;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.index.query.QueryBuilder;

/**
 * @author ESFlute (using FreeGen)
 */
public class BsFileConfigCB extends EsAbstractConditionBean {

    // ===================================================================================

import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.opensearch.action.admin.indices.analyze.AnalyzeAction.AnalyzeToken;
import org.opensearch.index.IndexNotFoundException;

public class AnalyzerSettingsTest {
    String id = "analyzerSettingsTest";

    static SuggestSettings settings;

    static OpenSearchRunner runner;

    @BeforeClass

## Explore Further

- [MinIO STS Quickstart Guide](https://min.io/docs/minio/linux/developers/security-token-service.html)

import org.codelibs.fess.es.user.cbean.cq.RoleCQ;
import org.codelibs.fess.es.user.cbean.cq.bs.BsRoleCQ;
import org.dbflute.cbean.ConditionQuery;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.index.query.QueryBuilder;

/**
 * @author ESFlute (using FreeGen)
 */
public class BsRoleCB extends EsAbstractConditionBean {

    // ===================================================================================

import org.codelibs.fess.es.config.cbean.cq.bs.BsElevateWordToLabelCQ;
import org.dbflute.cbean.ConditionQuery;
import org.opensearch.action.search.SearchRequestBuilder;
import org.opensearch.index.query.QueryBuilder;

/**
 * @author ESFlute (using FreeGen)
 */
public class BsElevateWordToLabelCB extends EsAbstractConditionBean {