*
     * ```
     * http://google.com/foo
     * GET
     * 2
     * Accept-Language: fr-CA
     * Accept-Charset: UTF-8
     * HTTP/1.1 200 OK
     * 3
     * Content-Type: image/png
     * Content-Length: 100
     * Cache-Control: max-age=600
     * ```
     *
     * A typical HTTPS file looks like this:
     *
     * ```

But let's save you the time of reading the full long specification just to find those little pieces of information you need.

Let's use the tools provided by **FastAPI** to handle security.

## How it looks

Let's first just use the code and see how it works, and then we'll come back to understand what's happening.

## Create `main.py`

Copy the example in a file `main.py`:

=== "Python 3.9+"

    ```Python

The latter runs on every PR and is a prerequisite for merging.

If you run the sanity check locally with the `./gradlew sanityCheck`, you can see the binary compatibility error in the output.
It looks like the following:

```
Execution failed for task ':architecture-test:checkBinaryCompatibility'.
> A failure occurred while executing me.champeau.gradle.japicmp.JApiCmpWorkAction
   > Detected binary changes.

setup_file() {
    bazel version  # Start the bazel server
}

# Do a bazel query specifically for the licenses checker. It searches for
# targets matching the provided query, which start with // or @ but not
# //tensorflow (so it looks for //third_party, //external, etc.), and then
# gathers the list of all packages (i.e. directories) which contain those
# targets.
license_query() {
 bazel cquery --experimental_cc_shared_library "$1" --keep_going \

  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  // `items` is a list of FlowSchemas.
  repeated FlowSchema items = 2;
}

// FlowSchemaSpec describes how the FlowSchema's specification looks like.
message FlowSchemaSpec {
  // `priorityLevelConfiguration` should reference a PriorityLevelConfiguration in the cluster. If the reference cannot

  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  // `items` is a list of FlowSchemas.
  repeated FlowSchema items = 2;
}

// FlowSchemaSpec describes how the FlowSchema's specification looks like.
message FlowSchemaSpec {
  // `priorityLevelConfiguration` should reference a PriorityLevelConfiguration in the cluster. If the reference cannot

* and from it, import the function `get_token_header`.

But that file doesn't exist, our dependencies are in a file at `app/dependencies.py`.

Remember how our app/file structure looks like:

<img src="/img/tutorial/bigger-applications/package.svg">

---

The two dots `..`, like in:

```Python
from ..dependencies import get_token_header
```

mean:

  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  // `items` is a list of FlowSchemas.
  repeated FlowSchema items = 2;
}

// FlowSchemaSpec describes how the FlowSchema's specification looks like.
message FlowSchemaSpec {
  // `priorityLevelConfiguration` should reference a PriorityLevelConfiguration in the cluster. If the reference cannot

  optional k8s.io.apimachinery.pkg.apis.meta.v1.ListMeta metadata = 1;

  // `items` is a list of FlowSchemas.
  repeated FlowSchema items = 2;
}

// FlowSchemaSpec describes how the FlowSchema's specification looks like.
message FlowSchemaSpec {
  // `priorityLevelConfiguration` should reference a PriorityLevelConfiguration in the cluster. If the reference cannot

---

"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._"