This code generator creates pydantic v1 and v2 model, dataclasses.dataclass, typing.TypedDict and msgspec.Struct from an openapi file and others.
See documentation for more details.
To install datamodel-code-generator:
$ pip install datamodel-code-generatorYou can generate models from a local file.
$ datamodel-codegen --input api.yaml --output model.pyapi.yaml
openapi: "3.0.0"
info:
version: 1.0.0
title: Swagger Petstore
license:
name: MIT
servers:
- url: http://petstore.swagger.io/v1
paths:
/pets:
get:
summary: List all pets
operationId: listPets
tags:
- pets
parameters:
- name: limit
in: query
description: How many items to return at one time (max 100)
required: false
schema:
type: integer
format: int32
responses:
'200':
description: A paged array of pets
headers:
x-next:
description: A link to the next page of responses
schema:
type: string
content:
application/json:
schema:
$ref: "#/components/schemas/Pets"
default:
description: unexpected error
content:
application/json:
schema:
$ref: "#/components/schemas/Error"
x-amazon-apigateway-integration:
uri:
Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
passthroughBehavior: when_no_templates
httpMethod: POST
type: aws_proxy
post:
summary: Create a pet
operationId: createPets
tags:
- pets
responses:
'201':
description: Null response
default:
description: unexpected error
content:
application/json:
schema:
$ref: "#/components/schemas/Error"
x-amazon-apigateway-integration:
uri:
Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
passthroughBehavior: when_no_templates
httpMethod: POST
type: aws_proxy
/pets/{petId}:
get:
summary: Info for a specific pet
operationId: showPetById
tags:
- pets
parameters:
- name: petId
in: path
required: true
description: The id of the pet to retrieve
schema:
type: string
responses:
'200':
description: Expected response to a valid request
content:
application/json:
schema:
$ref: "#/components/schemas/Pets"
default:
description: unexpected error
content:
application/json:
schema:
$ref: "#/components/schemas/Error"
x-amazon-apigateway-integration:
uri:
Fn::Sub: arn:aws:apigateway:${AWS::Region}:lambda:path/2015-03-31/functions/${PythonVersionFunction.Arn}/invocations
passthroughBehavior: when_no_templates
httpMethod: POST
type: aws_proxy
components:
schemas:
Pet:
required:
- id
- name
properties:
id:
type: integer
format: int64
name:
type: string
tag:
type: string
Pets:
type: array
items:
$ref: "#/components/schemas/Pet"
Error:
required:
- code
- message
properties:
code:
type: integer
format: int32
message:
type: string
apis:
type: array
items:
type: object
properties:
apiKey:
type: string
description: To be used as a dataset parameter value
apiVersionNumber:
type: string
description: To be used as a version parameter value
apiUrl:
type: string
format: uri
description: "The URL describing the dataset's fields"
apiDocumentationUrl:
type: string
format: uri
description: A URL to the API console for each APImodel.py
# generated by datamodel-codegen:
# filename: api.yaml
# timestamp: 2020-06-02T05:28:24+00:00
from __future__ import annotations
from typing import List, Optional
from pydantic import AnyUrl, BaseModel, Field
class Pet(BaseModel):
id: int
name: str
tag: Optional[str] = None
class Pets(BaseModel):
__root__: List[Pet]
class Error(BaseModel):
code: int
message: str
class Api(BaseModel):
apiKey: Optional[str] = Field(
None, description='To be used as a dataset parameter value'
)
apiVersionNumber: Optional[str] = Field(
None, description='To be used as a version parameter value'
)
apiUrl: Optional[AnyUrl] = Field(
None, description="The URL describing the dataset's fields"
)
apiDocumentationUrl: Optional[AnyUrl] = Field(
None, description='A URL to the API console for each API'
)
class Apis(BaseModel):
__root__: List[Api]- OpenAPI 3 (YAML/JSON, OpenAPI Data Type);
- JSON Schema (JSON Schema Core/JSON Schema Validation);
- JSON/YAML/CSV Data (it will be converted to JSON Schema);
- Python dictionary (it will be converted to JSON Schema);
- GraphQL schema (GraphQL Schemas and Types);
- pydantic.BaseModel;
- pydantic_v2.BaseModel;
- dataclasses.dataclass;
- typing.TypedDict;
- msgspec.Struct;
- Custom type from your jinja2 template;
JetBrains |
Astral |
Datadog, Inc. |
These OSS projects use datamodel-code-generator to generate many models. See the following linked projects for real world examples and inspiration.
- airbytehq/airbyte
- apache/iceberg
- argoproj-labs/hera
- awslabs/aws-lambda-powertools-python
- Recommended for advanced-use-cases in the official documentation
- DataDog/integrations-core
- hashintel/hash
- IBM/compliance-trestle
- Netflix/consoleme
- Nike-Inc/brickflow
- open-metadata/OpenMetadata
- PostHog/posthog
- SeldonIO/MLServer
To install datamodel-code-generator:
$ pip install datamodel-code-generatorIf you want to resolve $ref for remote files then you should specify http extra option.
$ pip install 'datamodel-code-generator[http]'If you want to generate data model from a GraphQL schema then you should specify graphql extra option.
$ pip install 'datamodel-code-generator[graphql]'The docker image is in Docker Hub
$ docker pull koxudaxi/datamodel-code-generatorYou can generate models from a URL.
$ datamodel-codegen --url https://<INPUT FILE URL> --output model.pyThis method needs the http extra option
The datamodel-codegen command:
usage:
datamodel-codegen [options]
Generate Python data models from schema definitions or structured data
Options:
--http-headers HTTP_HEADER [HTTP_HEADER ...]
Set headers in HTTP requests to the remote host.
(example: "Authorization: Basic dXNlcjpwYXNz")
--http-ignore-tls Disable verification of the remote host's TLS
certificate
--http-query-parameters QUERY_PARAMETER [QUERY_PARAMETER ...]
Set query parameters in HTTP requests to the remote host.
(example: "ref=branch")
--input INPUT Input file/directory (default: stdin)
--input-file-type {auto,openapi,graphql,jsonschema,json,yaml,dict,csv}
Input file type (default: auto)
--output OUTPUT Output file (default: stdout)
--output-model-type {pydantic.BaseModel,pydantic_v2.BaseModel,dataclasses.dataclass,typing.TypedDict,msgspec.Struct}
--url URL Input file URL. `--input` is ignored when `--url` is
used
Typing customization:
--base-class BASE_CLASS
Base Class (default: pydantic.BaseModel)
--enum-field-as-literal {all,one}
Parse enum field as literal. all: all enum field type
are Literal. one: field type is Literal when an enum
has only one possible value
--field-constraints Use field constraints and not con* annotations
--set-default-enum-member
Set enum members as default values for enum field
--strict-types {str,bytes,int,float,bool} [{str,bytes,int,float,bool} ...]
Use strict types
--use-annotated Use typing.Annotated for Field(). Also, `--field-
constraints` option will be enabled.
--use-generic-container-types
Use generic container types for type hinting
(typing.Sequence, typing.Mapping). If `--use-standard-
collections` option is set, then import from
collections.abc instead of typing
--use-non-positive-negative-number-constrained-types
Use the Non{Positive,Negative}{FloatInt} types instead
of the corresponding con* constrained types.
--use-one-literal-as-default
Use one literal as default value for one literal field
--use-standard-collections
Use standard collections for type hinting (list, dict)
--use-subclass-enum Define Enum class as subclass with field type when
enum has type (int, float, bytes, str)
--use-union-operator Use | operator for Union type (PEP 604).
--use-unique-items-as-set
define field type as `set` when the field attribute
has `uniqueItems`
Field customization:
--capitalise-enum-members, --capitalize-enum-members
Capitalize field names on enum
--empty-enum-field-name EMPTY_ENUM_FIELD_NAME
Set field name when enum value is empty (default: `_`)
--field-extra-keys FIELD_EXTRA_KEYS [FIELD_EXTRA_KEYS ...]
Add extra keys to field parameters
--field-extra-keys-without-x-prefix FIELD_EXTRA_KEYS_WITHOUT_X_PREFIX [FIELD_EXTRA_KEYS_WITHOUT_X_PREFIX ...]
Add extra keys with `x-` prefix to field parameters.
The extra keys are stripped of the `x-` prefix.
--field-include-all-keys
Add all keys to field parameters
--force-optional Force optional for required fields
--original-field-name-delimiter ORIGINAL_FIELD_NAME_DELIMITER
Set delimiter to convert to snake case. This option
only can be used with --snake-case-field (default: `_`
)
--remove-special-field-name-prefix
Remove field name prefix if it has a special meaning
e.g. underscores
--snake-case-field Change camel-case field name to snake-case
--special-field-name-prefix SPECIAL_FIELD_NAME_PREFIX
Set field name prefix when first character can't be
used as Python field name (default: `field`)
--strip-default-none Strip default None on fields
--use-default Use default value even if a field is required
--use-default-kwarg Use `default=` instead of a positional argument for
Fields that have default values.
--use-field-description
Use schema description to populate field docstring
--use-pendulum
Use pendulum instead of `datetime` for `date`,
`datetime`, and `time` data types
Model customization:
--allow-extra-fields Allow to pass extra fields, if this flag is not
passed, extra fields are forbidden.
--allow-population-by-field-name
Allow population by field name
--class-name CLASS_NAME
Set class name of root model
--collapse-root-models
Models generated with a root-type field will be
mergedinto the models using that root-type model
--disable-appending-item-suffix
Disable appending `Item` suffix to model name in an
array
--disable-timestamp Disable timestamp on file headers
--enable-faux-immutability
Enable faux immutability
--enable-version-header
Enable package version on file headers
--keep-model-order Keep generated models' order
--reuse-model Reuse models on the field when a module has the model
with the same content
--target-python-version {3.6,3.7,3.8,3.9,3.10,3.11}
target python version (default: 3.7)
--use-schema-description
Use schema description to populate class docstring
--use-title-as-name use titles as class names of models
--use-exact-imports Import exact types instead of modules, for example:
`from .foo import Bar` instead of
`from . import foo` with `foo.Bar`
Template customization:
--aliases ALIASES Alias mapping file
--custom-file-header CUSTOM_FILE_HEADER
Custom file header
--custom-file-header-path CUSTOM_FILE_HEADER_PATH
Custom file header file path
--custom-template-dir CUSTOM_TEMPLATE_DIR
Custom template directory
--encoding ENCODING The encoding of input and output (default: UTF-8)
--extra-template-data EXTRA_TEMPLATE_DATA
Extra template data
--use-double-quotes Model generated with double quotes. Single quotes or
your black config skip_string_normalization value will
be used without this option.
--wrap-string-literal
Wrap string literal by using black `experimental-
string-processing` option (require black 20.8b0 or
later)
--additional-imports Custom imports for output (delimited list input).
For example "datetime.date,datetime.datetime"
--custom-formatters List of modules with custom formatter (delimited list input).
--custom-formatters-kwargs A file with kwargs for custom formatters.
OpenAPI-only options:
--openapi-scopes {schemas,paths,tags,parameters} [{schemas,paths,tags,parameters} ...]
Scopes of OpenAPI model generation (default: schemas)
--strict-nullable Treat default field as a non-nullable field (Only
OpenAPI)
--use-operation-id-as-name
use operation id of OpenAPI as class names of models
--validation Deprecated: Enable validation (Only OpenAPI). this
option is deprecated. it will be removed in future
releases
General options:
--debug show debug message (require "debug". `$ pip install 'datamodel-code-generator[debug]'`)
--disable-warnings disable warnings
--no-color disable colorized output
--version show version
-h, --help show this help message and exitThis code generator creates FastAPI app from an openapi file.
https://github.com/koxudaxi/fastapi-code-generator
A JetBrains PyCharm plugin for pydantic.
https://github.com/koxudaxi/pydantic-pycharm-plugin
https://pypi.org/project/datamodel-code-generator
See docs/development-contributing.md for how to get started!
datamodel-code-generator is released under the MIT License. http://www.opensource.org/licenses/mit-license