# Separate OpenAPI Schemas for Input and Output or Not

When using **Pydantic v2**, the generated OpenAPI is a bit more exact and **correct** than before. 😎

In fact, in some cases, it will even have **two JSON Schemas** in OpenAPI for the same Pydantic model, for input and output, depending on if they have **default values**.

Let's see how that works and how to change it if you need to do that.

## Pydantic Models for Input and Output

You can have sub-dependencies and "trees" of sub-dependencies of any size and shape, and any or all of them can use `yield`.

**FastAPI** will make sure that the "exit code" in each dependency with `yield` is run in the correct order.

For example, `dependency_c` can have a dependency on `dependency_b`, and `dependency_b` on `dependency_a`:

//// tab | Python 3.9+

```Python hl_lines="6  14  22"

        request.getProjectBuildingRequest().setRepositorySession(session.getRepositorySession());

        // 1. Collect project for invocation without a POM.
        if (request.getPom() == null) {
            return pomlessCollectionStrategy.collectProjects(request);
        }

        // 2. Collect projects for all modules in the multi-module project.

	resp, err := httpClient.Do(req)
	if err != nil {
		return err
	}
	xhttp.DrainBody(resp.Body)

	return nil
}

// connect to list of endpoints and load all Erasure disk formats, validate the formats are correct
// and are in quorum, if no formats are found attempt to initialize all of them for the first
// time. additionally make sure to close all the disks used in this attempt.

        "The data was too large to fit into the specified buffer.", "A device attached to the system is not functioning.", "Incorrect function.",
        "The parameter is incorrect.", "Invalid access to memory location.", "The handle is invalid.", "The parameter is incorrect.",
        "The system cannot find the file specified.", "The system cannot find the file specified.", "End of file", "More data is available.",

    }

    protected PromptBuilder confirmPrompt(PromptBuilder promptBuilder) {
        promptBuilder
                .createConfirmPromp()
                .name("confirm")
                .message("Are values above correct?")
                .defaultValue(ConfirmChoice.ConfirmationValue.YES)
                .addPrompt();
        return promptBuilder;
    }

    protected PromptBuilder dispatcherPrompt(PromptBuilder promptBuilder) {

</div>

The command line program called `fastapi` is **FastAPI CLI**.

FastAPI CLI takes the path to your Python program (e.g. `main.py`) and automatically detects the `FastAPI` instance (commonly named `app`), determines the correct import process, and then serves it.

For production you would use `fastapi run` instead. 🚀

     * 10^floor(log10(x)).
     */

    if (approxCmp > 0) {
      /*
       * The code is written so that even completely incorrect approximations will still yield the
       * correct answer eventually, but in practice this branch should almost never be entered, and
       * even then the loop should not run more than once.
       */
      do {
        approxLog10--;

 * </pre>
 * 
 * the access check would fail because the direct ACE has an access mask
 * of <tt>0x001200A9</tt> which doesn't have the
 * <tt>FILE_WRITE_DATA</tt> bit on (bit <tt>0x00000002</tt>). Actually, this isn't quite correct. If
 * <tt>WNET\alice</tt> is in the local <tt>Administrators</tt> group the access check
 * will succeed because the inherited ACE allows local <tt>Administrators</tt>

     * hashes (meaning negotiated via NTLM HTTP Authentication) and the other does not they will not be equal. This is
     * technically not correct however the server 8 byte challenge would be required to compute and compare the password
     * hashes but that it not available with this method.
     */
    @Override
    public boolean equals ( Object obj ) {