## OpenAPI { #openapi }

OpenAPI (previously known as Swagger) is the open specification for building APIs (now part of the Linux Foundation).

**FastAPI** is based on **OpenAPI**.

That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

You will see examples of this in the next chapters, about relational and NoSQL databases, security, etc.

## **FastAPI** compatibility { #fastapi-compatibility }

The simplicity of the dependency injection system makes **FastAPI** compatible with:

* all the relational databases
* NoSQL databases
* external packages
* external APIs
* authentication and authorization systems
* API usage monitoring systems

* There should be tests testing the source example.
* Before the PR is applied, the new tests should fail.
* After applying the PR, the new tests should pass.
* Coverage should stay at 100%.
* If you see the PR makes sense, or we discussed it and considered it should be accepted, you can add commits on top of the PR to tweak it, to add docs, tests, format, refactor, remove extra files, etc.

## Restarts { #restarts }

Similar to making sure your application is run on startup, you probably also want to make sure it is **restarted** after failures.

### We Make Mistakes { #we-make-mistakes }

We, as humans, make **mistakes**, all the time. Software almost *always* has **bugs** hidden in different places. 🐛

ALL.  Soup does very well without--Maybe it's always pepper that
makes people hot-tempered,' she went on, very much pleased at
having found out a new kind of rule, `and vinegar that makes them
sour--and camomile that makes them bitter--and--and barley-sugar
and such things that make children sweet-tempered.  I only wish
people knew that:  then they wouldn't be so stingy about it, you
know--'

  // Extending CharEscaper (instead of Escaper) makes Escapers.compose() easier.
  private static final Escaper NULL_ESCAPER =
      new CharEscaper() {
        @Override
        public String escape(String string) {
          return checkNotNull(string);
        }

        @Override
        protected char @Nullable [] escape(char c) {
          // TODO: Fix tests not to call this directly and make it throw an error.
          return null;

		c.Compiler = build.Default.Compiler
	}

	walkers := make([]*Walker, len(contexts))
	var wg sync.WaitGroup
	for i, context := range contexts {
		i, context := i, context
		wg.Add(1)
		go func() {
			defer wg.Done()
			walkers[i] = NewWalker(context, filepath.Join(testenv.GOROOT(t), "src"))
		}()
	}
	wg.Wait()

	var featureCtx = make(map[string]map[string]bool) // feature -> context name -> true

      }
    }
  }

  /**
   * To make an HTTPS connection over an HTTP proxy, send an unencrypted CONNECT request to create
   * the proxy connection. This may need to be retried if the proxy requires authorization.
   */
  @Throws(IOException::class)
  private fun createTunnel(): Request? {
    var nextRequest = tunnelRequest!!
    // Make an SSL Tunnel on the first message pair of each SSL + proxy connection.

    * Tell me how you use FastAPI (I love to hear that).
    * Hear when I make announcements or release new tools.
    * You can also <a href="https://x.com/fastapi" class="external-link" target="_blank">follow @fastapi on X (Twitter)</a> (a separate account).
* <a href="https://www.linkedin.com/in/tiangolo/" class="external-link" target="_blank">Follow me on **LinkedIn**</a>.

		}, idx, *client.host)
	}
	return ng.Wait()
}

var errPeerNotReachable = errors.New("peer is not reachable")

// GetLocks - makes GetLocks RPC call on all peers.
func (sys *NotificationSys) GetLocks(ctx context.Context, r *http.Request) []*PeerLocks {
	locksResp := make([]*PeerLocks, len(sys.peerClients))
	g := errgroup.WithNErrs(len(sys.peerClients))
	for index, client := range sys.peerClients {
		client := client