CLI Reference¶

This page is generated from the current fastapi-codegen --help output. Run tox run -e cli-docs after changing CLI options.

Usage: fastapi-codegen [OPTIONS]

Options:
  -e, --encoding TEXT             [default: utf-8]
  -i, --input TEXT                [required]
  -o, --output PATH               [required]
  -m, --model-file TEXT
  -t, --template-dir PATH
  --model-template-dir PATH
  --enum-field-as-literal [all|one]
  -r, --generate-routers
  --specify-tags TEXT
  -c, --custom-visitor PATH
  --disable-timestamp
  -d, --output-model-type [pydantic.BaseModel|pydantic_v2.BaseModel|dataclasses.dataclass|typing.TypedDict|msgspec.Struct]
                                  [default: pydantic.BaseModel]
  -p, --python-version [3.9|3.10|3.11|3.12|3.13|3.14]
                                  [default: 3.10]
  -V, --version
  --install-completion            Install completion for the current shell.
  --show-completion               Show completion for the current shell, to
                                  copy it or customize the installation.
  --help                          Show this message and exit.

Tested CLI Scenarios¶

--help¶

Show the CLI help message.

fastapi-codegen --help

--version¶

Show the installed fastapi-codegen version.

fastapi-codegen --version

--input, --output¶

Generate a FastAPI application from an OpenAPI input file.

fastapi-codegen --input openapi/default_template/simple.yaml --output app

Input schema: openapi/default_template/simple.yaml

--template-dir¶

Render generated files with a custom template directory.

fastapi-codegen --input openapi/custom_template_security/custom_security.yaml --output app --template-dir custom_template/security

Input schema: openapi/custom_template_security/custom_security.yaml

--encoding¶

Read the input schema using an explicit text encoding.

fastapi-codegen --input openapi/default_template/simple.yaml --output app --encoding utf-16

Input schema: openapi/default_template/simple.yaml

--disable-timestamp¶

Omit the generated timestamp header from output files.

fastapi-codegen --input openapi/disable_timestamp/simple.yaml --output app --disable-timestamp

Input schema: openapi/disable_timestamp/simple.yaml

--generate-routers¶

Generate modular router files from tagged OpenAPI operations.

fastapi-codegen --input openapi/using_routers/using_routers_example.yaml --output app --template-dir modular_template --generate-routers

Input schema: openapi/using_routers/using_routers_example.yaml

--specify-tags¶

Regenerate only the routers matching a comma-separated tag list.

fastapi-codegen --input openapi/using_routers/using_routers_example.yaml --output app --template-dir modular_template --generate-routers --specify-tags Wild Boars, Fat Cats

Input schema: openapi/using_routers/using_routers_example.yaml

--enum-field-as-literal¶

Render enum fields as Literal annotations.

fastapi-codegen --input openapi/default_template/duplicate_anonymus_parameter.yaml --output app --enum-field-as-literal all

Input schema: openapi/default_template/duplicate_anonymus_parameter.yaml

--model-file¶

Write generated models to a custom module path.

fastapi-codegen --input openapi/default_template/body_and_parameters.yaml --output app --model-file custom_models.py --model-template-dir model_templates --output-model-type pydantic_v2.BaseModel --python-version 3.13

Input schema: openapi/default_template/body_and_parameters.yaml

Related options: --model-template-dir, --output-model-type, --python-version

--model-template-dir¶

Use a custom datamodel-code-generator template directory.

fastapi-codegen --input openapi/default_template/body_and_parameters.yaml --output app --model-file custom_models.py --model-template-dir model_templates --output-model-type pydantic_v2.BaseModel --python-version 3.13

Input schema: openapi/default_template/body_and_parameters.yaml

Related options: --model-file, --output-model-type, --python-version

--output-model-type¶

Choose the datamodel-code-generator output backend.

fastapi-codegen --input openapi/default_template/body_and_parameters.yaml --output app --model-file custom_models.py --model-template-dir model_templates --output-model-type pydantic_v2.BaseModel --python-version 3.13

Input schema: openapi/default_template/body_and_parameters.yaml

Related options: --model-file, --model-template-dir, --python-version

--python-version¶

Target a specific Python version when formatting generated code.

fastapi-codegen --input openapi/default_template/body_and_parameters.yaml --output app --model-file custom_models.py --model-template-dir model_templates --output-model-type pydantic_v2.BaseModel --python-version 3.13

Input schema: openapi/default_template/body_and_parameters.yaml

Related options: --model-file, --model-template-dir, --output-model-type

--custom-visitor¶

Load a custom visitor module and expose additional template variables.

fastapi-codegen --input openapi/default_template/simple.yaml --output app --template-dir template --generate-routers --custom-visitor visitor.py

Input schema: openapi/default_template/simple.yaml