How To Generate an OpenAPI Spec With FastAPI

Many developers start their API development with FastAPI, and with good reason. FastAPI has rapidly gained traction in the Python community for its excellent performance, intuitive design, and flexibility. It enables developers to craft API solutions that not only run fast but also meet their users' unique needs.

FastAPI is great for building your core API, but you'll want to layer on SDKs and docs to provide your users with easy integration. For that, you'll want an OpenAPI file.

The good news is that FastAPI provides you with an OpenAPI file out of the box. The less good news is that you'll need some tweaking to get the OpenAPI spec to a level where it becomes usable with other tooling.

This article will show you how to improve the default OpenAPI spec generation to make the most of the generated schema.

Generating an OpenAPI Spec With FastAPI

Understanding how FastAPI generates OpenAPI schemas can help you make more informed decisions when you customize your FastAPI setup.

The process is fairly straightforward: FastAPI builds the OpenAPI schema based on the routes and models you've defined in your application. For every route in your FastAPI application, FastAPI adds an operation to the OpenAPI schema. For every model used in these routes, FastAPI adds a schema definition. The request and response bodies, parameters, and headers all draw from these schema definitions.

While this process works well out of the box, FastAPI also offers several customization options that can change the generated OpenAPI schema. We'll cover some of these options in the following sections.

Our FastAPI Example App: APItizing Burgers

Let's get this out of the way: the name came in a daydream shortly before lunchtime.

To guide us through this journey, we'll use a simple example FastAPI application: the "APItizing Burgers" burger shop API. This API includes two models, Burger and Order, and provides basic CRUD operations for managing burgers and orders at our hypothetical burger shop. Additionally, we have a webhook defined for order status events.

We'll look at how we optimized this FastAPI application and refined our models and routes so that the generated OpenAPI specification is intuitive and easy to use. We will also explore how we can use this schema to generate SDKs using Speakeasy. The source code for our example API is available in the apitizing-burgers (opens in a new tab) repository.

The repository consists of two directories: app and sdk.

The app directory contains only our FastAPI server definition: app/main.py. This is where we'll look at what we customized.

The sdk directory and the two specifications, openapi.yaml and openapi.json, are generated by running gen.sh in the root of the project.

Join us as we dive into FastAPI customization and discover how these tweaks can streamline your SDK generation process.

WARN

When using Pydantic to define models, a known issue is that the serialization of datetime objects is not timezone-aware. This will cause a mismatch with the OpenAPI format date-time, which requires RFC 3339 date-time strings with timezones included. Consider using AwareDatetime fields in Pydantic models to enable the appropriate validation and ensure your SDK behavior matches the response definition from your server.

Basic FastAPI Setup

Let's get started with the basics – some things you probably do already.

These straightforward examples are trivial but will help you better understand the three steps in the automation pipeline: How FastAPI setup influences OpenAPI specifications, which, in turn, influences SDK code.

Add a List of Servers to Your FastAPI App

This may seem obvious, but while first working with FastAPI in development, the generated docs, development server, and API operations all work out of the box without the need to manually specify your server address.

However, when generating SDKs, your OpenAPI spec needs to list servers.

In our app/main.py, we added our local server as shown.

main.py


from fastapi import FastAPI
app = FastAPI(
    servers=[
        {"url": "http://127.0.0.1:8000", "description": "Local server"},
    ],
)

This leads to the following generated output in openapi.yaml.

main.py

openapi.yaml


servers:
- description: Local server
  url: http://127.0.0.1:8000/

Add a Title, Summary, Description, and Version to Your FastAPI App

In our app/main.py, if we have the following.

main.py

openapi.yaml


from fastapi import FastAPI
app = FastAPI(
    summary="A simple API to manage burgers and orders",
    description="This API is used to manage burgers and orders in a restaurant",
    version="0.1.0",
    title="Apitizing Burger API",
)

FastAPI generates the following yaml in our openapi.yaml file.

main.py

openapi.yaml


info:
  description: This API is used to manage burgers and orders in a restaurant
  summary: A simple API to manage burgers and orders
  title: Apitizing Burger API
  version: 0.1.0

Route-Level Customizations: Enhancing Usability

With the basics out of the way, let's look at a few more substantial recommendations.

Add Typed Additional Responses to FastAPI Routes

When developers use your generated SDK, they may wish to see what all the possible responses for an API call could be.

With FastAPI, you can add additional responses to each route by specifying a response type.

In our app/main.py, we added this abbreviated code.

main.py

openapi.yaml


from fastapi import FastAPI
from fastapi.responses import JSONResponse
from pydantic import BaseModel, Field
class ResponseMessage(BaseModel):
    """A response message"""
    message: str = Field(description="The response message")
OPENAPI_RESPONSE_BURGER_NOT_FOUND = {
    "model": ResponseMessage,
    "description": "Burger not found",
}
def response_burger_not_found(burger_id: int):
    """Response for burger not found"""
    return JSONResponse(
        status_code=404,
        content=f"Burger with id {burger_id} does not exist",
    )
class Burger(BaseModel):
    id: int
    name: str
    description: str = None
app = FastAPI()
@app.get(
    "/burger/{burger_id}",
    response_model=BurgerOutput,
    responses={404: OPENAPI_RESPONSE_BURGER_NOT_FOUND},
    tags=["burger"],
)
def read_burger(burger_id: Annotated[int, Path(title="Burger ID")]):
    """Read a burger"""
    for burger in burgers_db:
        if burger.id == burger_id:
            return burger
    return response_burger_not_found(burger_id)

FastAPI adds a schema for our specific error message to openapi.yaml.

main.py

openapi.yaml


components:
  schemas:
    ResponseMessage:
      description: A response message
      properties:
        message:
          description: The response message
          title: Message
          type: string
      required:
        - message
      title: ResponseMessage
      type: object

Group FastAPI Operations With OpenAPI Tags and Tag Metadata

As your API develops and grows bigger, you're likely to split it into separate files. FastAPI provides conveniences (opens in a new tab) to help reduce boilerplate and repetition when splitting an API into multiple modules.

While this separation may reduce cognitive overhead while you're working in particular sections of the API code, it doesn't mean similar groups are automatically created in your documentation and SDK code.

We recommend you add tags to all operations in FastAPI, whether you're building a big application or only have a handful of operations, so that operations can be grouped by tag in generated SDK code and documentation.

Add Tags to Operations

The most straightforward way to add tags is to edit each operation and add a list of tags. This example highlights the tags list.

main.py

openapi.yaml


from fastapi import FastAPI
app = FastAPI()
@app.get(
    "/burger/{burger_id}",
    tags=["burger"],
)
def read_burger(burger_id: int):
    return {
        "burger_id": burger_id,
    }

Add Metadata to Tags

You can add metadata to your tags to further improve the developer experience.

FastAPI accepts a parameter called openapi_tags, which we can use to add metadata, such as a description and a list of external documentation links.

Here's how to add metadata to tags.

main.py

openapi.yaml


from fastapi import FastAPI
tags_metadata = [
    {
        "name": "burger",
        "description": "Operations related to burgers",
        "externalDocs": {
            "description": "Burger external docs",
            "url": "https://en.wikipedia.org/wiki/Hamburger",
        },
    },
    {
        "name": "order",
        "description": "Operations related to orders",
    },
]
app = FastAPI(
    openapi_tags=tags_metadata,
)
@app.get(
    "/burger/{burger_id}",
    tags=["burger"],
)
def read_burger(burger_id: int):
    return {
        "burger_id": burger_id,
    }

How Tags Are Added to the OpenAPI Spec

When we add metadata to tags, FastAPI adds a top-level tags section to our OpenAPI spec.

main.py

openapi.yaml


tags:
- description: Operations related to burgers
  externalDocs:
    description: Burger external docs
    url: https://en.wikipedia.org/wiki/Hamburger
  name: burger
- description: Operations related to orders
  name: order

Each tagged path in our OpenAPI spec also gets a list of tags.

main.py

openapi.yaml


paths:
  /burger/{burger_id}:
    get:
      description: Read a burger
      operationId: readBurger
      summary: Read Burger
      tags:
      - burger
      # ...

Customize the OpenAPI `operationId` Generated by FastAPI

When FastAPI outputs an OpenAPI spec, it generates a unique OpenAPI operationId for each path. By default, this unique ID is generated by the FastAPI generate_unique_id function.

main.py

openapi.yaml


def generate_unique_id(route: "APIRoute") -> str:
    operation_id = route.name + route.path_format
    operation_id = re.sub(r"\W", "_", operation_id)
    assert route.methods
    operation_id = operation_id + "_" + list(route.methods)[0].lower()
    return operation_id

This can often lead to cumbersome and unintuitive names. To improve usability, we have two methods of customizing these generated strings.

Option 1: Customize the FastAPI `generate_unique_id_function` Function

The preferred method is to use a custom function when you generate unique IDs for paths.

The example below is an illustrative function that doesn't generate guaranteed-unique IDs and doesn't handle method names without an underscore. However, it demonstrates how you can add a function that generates IDs based on an operation's method name.

main.py

openapi.yaml


from fastapi import FastAPI
def convert_snake_case_to_camel_case(string: str) -> str:
    """Convert snake case to camel case"""
    words = string.split("_")
    return words[0] + "".join(word.title() for word in words[1:])
def custom_generate_unique_id_function(route: APIRoute) -> str:
    """Custom function to generate unique id for each endpoint"""
    return convert_snake_case_to_camel_case(route.name)
app = FastAPI(
    generate_unique_id_function=custom_generate_unique_id_function,
)

Option 2: Add an Operation ID per Operation

With FastAPI, you can specify the operationId per operation. For our example, we'll add a new parameter called operation_id to the operation decorator.

main.py

openapi.yaml


from fastapi import FastAPI
app = FastAPI()
@app.get(
    "/burger/{burger_id}",
    operation_id="readBurger",
)
def read_burger(burger_id: int):
    pass

Add Webhooks for Real-Time Notifications

Starting with OpenAPI version 3.1.0, it is possible to specify webhooks for your application in OpenAPI.

Here's how to add a webhook to FastAPI:

main.py

openapi.yaml


from fastapi import FastAPI
app = FastAPI()
class Order(BaseModel):
    id: int
    note: str
@app.webhooks.post(
    "order-status-changed",
    operation_id="webhookOrderStatusChanged",
)
def webhook_order_status_changed(body: Order):
    """
    When an order status is changed, this webhook will be triggered.
    The server will send a `POST` request with the order details to the webhook URL.
    """
    pass

FastAPI generates the following top-level webhooks section in openapi.yaml.

main.py

openapi.yaml


webhooks:
  order-status-changed:
    post:
      description: 'When an order status is changed, this webhook will be triggered.
        The server will send a `POST` request with the order details to the webhook
        URL.'
      operationId: webhookOrderStatusChanged
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Order'
        required: true
      responses:
        '200':
          content:
            application/json:
              schema: {}
          description: Successful Response
        '422':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
          description: Validation Error
      summary: Webhook Order Status Changed

Integrating Speakeasy

Now that we have a customized OpenAPI spec, we can use Speakeasy to generate SDKs based on it. Let's take a look at how the information we detailed in the OpenAPI specification affects how Speakeasy generates SDKs.

Server Information

After we added our local server information, this is how it generates in the openapi.yaml file.

main.py

openapi.yaml


servers:
- description: Local server
  url: http://127.0.0.1:8000/

After Speakeasy generates the SDK, this leads to the following abbreviated code in sdk/src/sdk/sdkconfiguration.py.

main.py

openapi.yaml

sdkconfiguration.py


from dataclasses import dataclass
SERVERS = [
    'http://127.0.0.1:8000/',
    # Local server
]
"""Contains the list of servers available to the SDK"""
@dataclass
class SDKConfiguration:
    server_url: str = ''
    server_idx: int = 0
    def get_server_details(self) -> tuple[str, dict[str, str]]:
        if self.server_url:
            return self.server_url.removesuffix('/'), {}
        if self.server_idx is None:
            self.server_idx = 0
        return SERVERS[self.server_idx], {}

You'll find calls to SDKConfiguration.get_server_details() when the SDK builds API URLs.

main.py

openapi.yaml

sdkconfiguration.py


from dataclasses import dataclass
SERVERS = [
    'http://127.0.0.1:8000/',
    # Local server
]
"""Contains the list of servers available to the SDK"""
@dataclass
class SDKConfiguration:
    server_url: str = ''
    server_idx: int = 0
    def get_server_details(self) -> tuple[str, dict[str, str]]:
        if self.server_url:
            return self.server_url.removesuffix('/'), {}
        if self.server_idx is None:
            self.server_idx = 0
        return SERVERS[self.server_idx], {}

Title, Summary, and Description

Speakeasy uses the title, summary, and descriptions we provided earlier to add helpful text to the generated SDK documentation, including comments in the SDK code. For example, in sdk/src/sdk/sdk.py.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py


class SDK:
    r"""Apitizing Burger API: A simple API to manage burgers and orders
    This API is used to manage burgers and orders in a restaurant
    """

Speakeasy adds the version to the SDKConfiguration in sdk/src/sdk/sdkconfiguration.py.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py


from dataclasses import dataclass
@dataclass
class SDKConfiguration:
    openapi_doc_version: str = '0.1.0'

Eventually, when your users call your API using the generated SDK, this version makes its way into the headers passed with requests. For example, in sdk/src/sdk/burger.py, we see that headers['user-agent'] includes a reference to SDKConfiguration.openapi_doc_version.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


def create_burger(self, request: shared.BurgerCreate, retries: Optional[utils.RetryConfig] = None) -> operations.CreateBurgerResponse:
    r"""Create Burger
    Create a burger
    """
    base_url = utils.template_url(*self.sdk_configuration.get_server_details())
    url = base_url + '/burger/'
    headers = {}
    req_content_type, data, form = utils.serialize_request_body(request, "request", 'json')
    if req_content_type not in ('multipart/form-data', 'multipart/mixed'):
        headers['content-type'] = req_content_type
    if data is None and form is None:
        raise Exception('request body is required')
    headers['Accept'] = 'application/json'
    headers['user-agent'] = f'speakeasy-sdk/{self.sdk_configuration.language} {self.sdk_configuration.sdk_version} {self.sdk_configuration.gen_version} {self.sdk_configuration.openapi_doc_version}'
    client = self.sdk_configuration.client

This way, your server logs will include the FastAPI App version along with other helpful details about the SDK.

Customizing FastAPI `operation_id`

The unique operation_id generated by FastAPI does not translate well into an SDK. We need to customize the unique operation_id that FastAPI generates for better readability.

For instance, in the operation that returns a burger by burger_id, the default unique ID would be read_burger_burger__burger_id__get. This makes its way into SDK code, leading to class names such as ReadBurgerBurgerBurgerIDGetRequest or function names like read_burger_burger_burger_id_get.

Here's a usage example after generating an SDK without customizing the operationId.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


import sdk
from sdk.models import operations
s = sdk.SDK()
req = operations.ReadBurgerBurgerBurgerIDGetRequest(
    burger_id=847252,
)
res = s.burger.read_burger_burger_burger_id_get(req)

However, after using the custom function we defined previously, the read_burger operation gets a much friendlier operation ID: readBurger. And the usage example becomes much easier to read.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


import sdk
from sdk.models import operations
s = sdk.SDK()
req = operations.ReadBurgerRequest(
    burger_id=847252,
)
res = s.burger.read_burger(req)

In addition to the two methods described earlier for customizing the operation_id, there is a third way. We can add the top-level x-speakeasy-name-override extension to our OpenAPI spec, allowing Speakeasy to override these generated names when it generates SDK code.

To add this extension, follow the Speakeasy guide on changing method names.

Add Retries to Your SDK With `x-speakeasy-retries`

Speakeasy can generate SDKs that follow custom rules for retrying failed requests. For instance, if your server fails to return a response within a specified time, you may want your users to retry their request without clobbering your server.

To add retries to SDKs generated by Speakeasy, add a top-level x-speakeasy-retries schema to your OpenAPI spec. You can also override the retry strategy per operation by adding x-speakeasy-retries to each operation.

Adding Global Retries

To add global retries, we need to customize the schema generated by the FastAPI get_openapi function.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


from fastapi import FastAPI
from fastapi.openapi.utils import get_openapi
app = FastAPI(
    summary="A simple API to manage burgers and orders",
    description="This API is used to manage burgers and orders in a restaurant",
    version="0.1.0",
    title="Apitizing Burger API",
)
@app.get("/")
def root():
    return {"message": "Root"}
def custom_openapi():
    if app.openapi_schema:
        return app.openapi_schema
    openapi_schema = get_openapi(
        title=app.title,
        version=app.version,
        summary=app.summary,
        description=app.description,
        routes=app.routes,
    )
    # Add retries
    openapi_schema["x-speakeasy-retries"] = {
        "strategy": "backoff",
        "backoff": {
            "initialInterval": 500,
            "maxInterval": 60000,
            "maxElapsedTime": 3600000,
            "exponent": 1.5,
        },
        "statusCodes": [
            "5XX",
        ],
        "retryConnectionErrors": True,
    }
    app.openapi_schema = openapi_schema
    return app.openapi_schema
app.openapi = custom_openapi

Keep in mind you'll need to add this customization after declaring your operation routes.

This change adds the following top-level section to openapi.yaml.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


x-speakeasy-retries:
  backoff:
    exponent: 1.5
    initialInterval: 500
    maxElapsedTime: 3600000
    maxInterval: 60000
  retryConnectionErrors: true
  statusCodes:
  - 5XX
  strategy: backoff

Adding Retries per Request

To add x-speakeasy-retries to a single operation, update the operation and add the openapi_extra parameter as follows.

main.py

openapi.yaml

sdkconfiguration.py

sdk.py

burger.py


from fastapi import FastAPI
app = FastAPI()
@app.get(
    "/burger/",
    openapi_extra={
        "x-speakeasy-retries": {
            "strategy": "backoff",
            "backoff": {
                "initialInterval": 500,
                "maxInterval": 60000,
                "maxElapsedTime": 3600000,
                "exponent": 1.5,
            },
            "statusCodes": [
                "5XX",
            ],
            "retryConnectionErrors": True,
        }
    },
)
def list_burgers():
    return []

Add a List of Servers to Your FastAPI App

However, when generating SDKs, your OpenAPI spec needs to list servers.

In our app/main.py, we added our local server as shown.

This leads to the following generated output in openapi.yaml.

Add a Title, Summary, Description, and Version to Your FastAPI App

In our app/main.py, if we have the following.

FastAPI generates the following yaml in our openapi.yaml file.

Route-Level Customizations: Enhancing Usability

With the basics out of the way, let's look at a few more substantial recommendations.

Add Typed Additional Responses to FastAPI Routes

When developers use your generated SDK, they may wish to see what all the possible responses for an API call could be.

With FastAPI, you can add additional responses to each route by specifying a response type.

In our app/main.py, we added this abbreviated code.

FastAPI adds a schema for our specific error message to openapi.yaml.

Group FastAPI Operations With OpenAPI Tags and Tag Metadata

Add Tags to Operations

The most straightforward way to add tags is to edit each operation and add a list of tags. This example highlights the tags list.

Add Metadata to Tags

You can add metadata to your tags to further improve the developer experience.

FastAPI accepts a parameter called openapi_tags, which we can use to add metadata, such as a description and a list of external documentation links.

Here's how to add metadata to tags.

How Tags Are Added to the OpenAPI Spec

When we add metadata to tags, FastAPI adds a top-level tags section to our OpenAPI spec.

Each tagged path in our OpenAPI spec also gets a list of tags.

Customize the OpenAPI `operationId` Generated by FastAPI

When FastAPI outputs an OpenAPI spec, it generates a unique OpenAPI operationId for each path. By default, this unique ID is generated by the FastAPI generate_unique_id function.

This can often lead to cumbersome and unintuitive names. To improve usability, we have two methods of customizing these generated strings.

Option 1: Customize the FastAPI `generate_unique_id_function` Function

The preferred method is to use a custom function when you generate unique IDs for paths.

Option 2: Add an Operation ID per Operation

With FastAPI, you can specify the operationId per operation. For our example, we'll add a new parameter called operation_id to the operation decorator.

Add Webhooks for Real-Time Notifications

Starting with OpenAPI version 3.1.0, it is possible to specify webhooks for your application in OpenAPI.

Here's how to add a webhook to FastAPI:

FastAPI generates the following top-level webhooks section in openapi.yaml.

Integrating Speakeasy

Server Information

After we added our local server information, this is how it generates in the openapi.yaml file.

After Speakeasy generates the SDK, this leads to the following abbreviated code in sdk/src/sdk/sdkconfiguration.py.

You'll find calls to SDKConfiguration.get_server_details() when the SDK builds API URLs.

Title, Summary, and Description

Speakeasy adds the version to the SDKConfiguration in sdk/src/sdk/sdkconfiguration.py.

This way, your server logs will include the FastAPI App version along with other helpful details about the SDK.

Customizing FastAPI `operation_id`

The unique operation_id generated by FastAPI does not translate well into an SDK. We need to customize the unique operation_id that FastAPI generates for better readability.

Here's a usage example after generating an SDK without customizing the operationId.

However, after using the custom function we defined previously, the read_burger operation gets a much friendlier operation ID: readBurger. And the usage example becomes much easier to read.

To add this extension, follow the Speakeasy guide on changing method names.

Add Retries to Your SDK With `x-speakeasy-retries`

Adding Global Retries

To add global retries, we need to customize the schema generated by the FastAPI get_openapi function.

Keep in mind you'll need to add this customization after declaring your operation routes.

This change adds the following top-level section to openapi.yaml.

Adding Retries per Request

To add x-speakeasy-retries to a single operation, update the operation and add the openapi_extra parameter as follows.

main.py


from fastapi import FastAPI
app = FastAPI(
    servers=[
        {"url": "http://127.0.0.1:8000", "description": "Local server"},
    ],
)

Summary

In this post, we've explored how you can set up a FastAPI-based SDK generation pipeline without hand-editing or updating OpenAPI specifications. By using existing FastAPI methods for extending and customizing OpenAPI specifications, you can improve the usability of your generated client SDKs.

How To Generate an OpenAPI Spec With FastAPI

Generating an OpenAPI Spec With FastAPI

Our FastAPI Example App: APItizing Burgers

Basic FastAPI Setup

Add a List of Servers to Your FastAPI App

Add a Title, Summary, Description, and Version to Your FastAPI App

Route-Level Customizations: Enhancing Usability

Add Typed Additional Responses to FastAPI Routes

Group FastAPI Operations With OpenAPI Tags and Tag Metadata

Add Tags to Operations

Add Metadata to Tags

How Tags Are Added to the OpenAPI Spec

Customize the OpenAPI operationId Generated by FastAPI

Option 1: Customize the FastAPI generate_unique_id_function Function

Option 2: Add an Operation ID per Operation

Add Webhooks for Real-Time Notifications

Integrating Speakeasy

Server Information

Title, Summary, and Description

Customizing FastAPI operation_id

Add Retries to Your SDK With x-speakeasy-retries

Adding Global Retries

Adding Retries per Request

Add a List of Servers to Your FastAPI App

Add a Title, Summary, Description, and Version to Your FastAPI App

Route-Level Customizations: Enhancing Usability

Add Typed Additional Responses to FastAPI Routes

Group FastAPI Operations With OpenAPI Tags and Tag Metadata

Add Tags to Operations

Add Metadata to Tags

How Tags Are Added to the OpenAPI Spec

Customize the OpenAPI operationId Generated by FastAPI

Option 1: Customize the FastAPI generate_unique_id_function Function

Option 2: Add an Operation ID per Operation

Add Webhooks for Real-Time Notifications

Integrating Speakeasy

Server Information

Title, Summary, and Description

Customizing FastAPI operation_id

Add Retries to Your SDK With x-speakeasy-retries

Adding Global Retries

Adding Retries per Request

Summary

Customize the OpenAPI `operationId` Generated by FastAPI

Option 1: Customize the FastAPI `generate_unique_id_function` Function

Customizing FastAPI `operation_id`

Add Retries to Your SDK With `x-speakeasy-retries`

Customize the OpenAPI `operationId` Generated by FastAPI

Option 1: Customize the FastAPI `generate_unique_id_function` Function

Customizing FastAPI `operation_id`

Add Retries to Your SDK With `x-speakeasy-retries`