Presets¶
Presets are immutable named groups of CLI options. A preset name never changes behavior; new recommendations are published as new dated preset names.
Every preset name includes its Python target, so generated Python syntax is pinned without an extra --target-python-version argument. Choose the preset name instead of adding a separate target option to normal preset commands; if an explicit target is already present in CLI or pyproject configuration, it must match the preset name.
See also: CLI Reference, --preset, --target-python-version, --output-model-type, --profile, --generate-pyproject-config, --generate-cli-command, pyproject.toml configuration, and CI/CD integration.
Usage¶
Use a preset by passing its immutable name:
datamodel-codegen \
--input schema.json \
--input-file-type jsonschema \
--output-model-type pydantic_v2.BaseModel \
--preset standard-py312-20260619 \
--output model.py
Use standard-py312-20260619 for the project-recommended modern Python 3.12 baseline. Use practical-py312-20260619 when you also want schema-authored names, model reuse, and schema descriptions embedded in the generated code.
Override Preset Options¶
Preset options are defaults, not locks. Explicit options override preset-supplied values.
datamodel-codegen \
--input schema.json \
--preset standard-py312-20260619 \
--no-snake-case-field \
--no-use-annotated \
--enum-field-as-literal none
Use documented --no-* options for boolean settings that support negation. For value options, pass the replacement value explicitly, such as --enum-field-as-literal none.
Add Options On Top¶
You can add any normal CLI option to a preset command. This is the recommended way to start from a preset and make a project-specific choice:
datamodel-codegen \
--input schema.json \
--preset standard-py312-20260619 \
--extra-fields forbid \
--use-title-as-name \
--output model.py
Use Presets With Profiles¶
Presets can live in [tool.datamodel-codegen] or in a named profile. Profiles are useful when one repository generates several model sets:
pyproject.toml
[tool.datamodel-codegen]
output-model-type = "pydantic_v2.BaseModel"
preset = "standard-py312-20260619"
[tool.datamodel-codegen.profiles.api]
input = "schemas/api.json"
output = "src/models/api.py"
preset = "practical-py312-20260619"
extra-fields = "forbid"
[tool.datamodel-codegen.profiles.events]
input = "schemas/events.json"
output = "src/models/events.py"
use-title-as-name = true
If --preset is passed on the CLI, it overrides pyproject preset settings and pyproject options unless the same option is also explicit on the CLI. If preset is configured in pyproject.toml, pyproject/profile options and CLI options override preset-supplied values.
Export Configuration¶
To convert a working preset command into pyproject.toml, use --generate-pyproject-config:
datamodel-codegen \
--input schema.json \
--output model.py \
--output-model-type pydantic_v2.BaseModel \
--preset practical-py312-20260619 \
--extra-fields forbid \
--generate-pyproject-config
To inspect the effective CLI command for an existing pyproject profile, use --generate-cli-command:
Use --ignore-pyproject when you want to test a preset command without loading project configuration.
Built-in Presets¶
Target Matrix¶
| Python target | Standard preset | Practical preset |
|---|---|---|
| 3.10 | standard-py310-20260619 |
practical-py310-20260619 |
| 3.11 | standard-py311-20260619 |
practical-py311-20260619 |
| 3.12 | standard-py312-20260619 |
practical-py312-20260619 |
| 3.13 | standard-py313-20260619 |
practical-py313-20260619 |
| 3.14 | standard-py314-20260619 |
practical-py314-20260619 |
Each preset name includes its Python target. Do not add --target-python-version just to use a preset; only expanded configuration without --preset needs a separate target option.
Preset Reference¶
standard-py310-20260619¶
Recommended modern Python 3.10 output for new projects.
This immutable preset enables the project-recommended Python output style for new code targeting Python 3.10. It is output-model aware and keeps stdlib dataclass and TypedDict keys compatible with their input names.
- Requires separate target Python version: no
- Target Python version: 3.10
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.10. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.10"
use-annotated = true
use-frozen-field = true
use-standard-collections = true
use-subclass-enum = true
use-union-operator = true
datamodel-codegen --allow-population-by-field-name --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --output model.py --output-model-type pydantic_v2.BaseModel --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.10 --use-annotated --use-frozen-field --use-standard-collections --use-subclass-enum --use-union-operator
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
standard-py311-20260619¶
Recommended modern Python 3.11 output for new projects.
This immutable preset enables the project-recommended Python output style for new code targeting Python 3.11. It is output-model aware and keeps stdlib dataclass and TypedDict keys compatible with their input names.
- Requires separate target Python version: no
- Target Python version: 3.11
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.11. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.11"
use-annotated = true
use-frozen-field = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-union-operator = true
datamodel-codegen --allow-population-by-field-name --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --output model.py --output-model-type pydantic_v2.BaseModel --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.11 --use-annotated --use-frozen-field --use-specialized-enum --use-standard-collections --use-subclass-enum --use-union-operator
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
standard-py312-20260619¶
Recommended modern Python 3.12 output for new projects.
This immutable preset enables the project-recommended Python output style for new code targeting Python 3.12. It is output-model aware and keeps stdlib dataclass and TypedDict keys compatible with their input names.
- Requires separate target Python version: no
- Target Python version: 3.12
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.12. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.12"
use-annotated = true
use-frozen-field = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-union-operator = true
datamodel-codegen --allow-population-by-field-name --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --output model.py --output-model-type pydantic_v2.BaseModel --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.12 --use-annotated --use-frozen-field --use-specialized-enum --use-standard-collections --use-subclass-enum --use-union-operator
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
standard-py313-20260619¶
Recommended modern Python 3.13 output for new projects.
This immutable preset enables the project-recommended Python output style for new code targeting Python 3.13. It is output-model aware and keeps stdlib dataclass and TypedDict keys compatible with their input names.
- Requires separate target Python version: no
- Target Python version: 3.13
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.13. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.13"
use-annotated = true
use-frozen-field = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-union-operator = true
datamodel-codegen --allow-population-by-field-name --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --output model.py --output-model-type pydantic_v2.BaseModel --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.13 --use-annotated --use-frozen-field --use-specialized-enum --use-standard-collections --use-subclass-enum --use-union-operator
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
standard-py314-20260619¶
Recommended modern Python 3.14 output for new projects.
This immutable preset enables the project-recommended Python output style for new code targeting Python 3.14. It is output-model aware and keeps stdlib dataclass and TypedDict keys compatible with their input names.
- Requires separate target Python version: no
- Target Python version: 3.14
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.14. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.14"
use-annotated = true
use-frozen-field = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-union-operator = true
datamodel-codegen --allow-population-by-field-name --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --output model.py --output-model-type pydantic_v2.BaseModel --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.14 --use-annotated --use-frozen-field --use-specialized-enum --use-standard-collections --use-subclass-enum --use-union-operator
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
practical-py310-20260619¶
Standard Python 3.10 output plus practical naming, deduplication, and schema documentation.
This immutable preset extends standard-py310-20260619 with options that make generated models easier to read and use in real projects. It favors schema-authored names, model reuse, and embedded schema documentation over the most conservative output-shape stability.
- Requires separate target Python version: no
- Target Python version: 3.10
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.10. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-reuse-models = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
naming-strategy = "primary-first"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
reuse-model = true
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.10"
use-annotated = true
use-default-kwarg = true
use-field-description = true
use-field-description-example = true
use-frozen-field = true
use-object-type = true
use-schema-description = true
use-single-line-docstring = true
use-standard-collections = true
use-subclass-enum = true
use-title-as-name = true
use-tuple-for-fixed-items = true
use-union-operator = true
use-unique-items-as-set = true
datamodel-codegen --allow-population-by-field-name --collapse-reuse-models --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --naming-strategy primary-first --output model.py --output-model-type pydantic_v2.BaseModel --reuse-model --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.10 --use-annotated --use-default-kwarg --use-field-description --use-field-description-example --use-frozen-field --use-object-type --use-schema-description --use-single-line-docstring --use-standard-collections --use-subclass-enum --use-title-as-name --use-tuple-for-fixed-items --use-union-operator --use-unique-items-as-set
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
| Practical model structure and names | --reuse-model, --collapse-reuse-models, --use-title-as-name, --naming-strategy primary-first |
Deduplicate identical models without empty inheritance wrappers, prefer schema titles for class names, and keep primary definitions ahead of inline duplicate names. |
| Practical typing and defaults | --use-default-kwarg, --use-object-type, --use-tuple-for-fixed-items, --use-unique-items-as-set, --use-single-line-docstring |
Render defaults explicitly, prefer object for unconstrained values, preserve fixed and unique arrays, and keep short docstrings concise. |
| Schema documentation | --use-schema-description, --use-field-description, --use-field-description-example |
Preserve schema and field descriptions, including examples, in generated model documentation. |
practical-py311-20260619¶
Standard Python 3.11 output plus practical naming, deduplication, and schema documentation.
This immutable preset extends standard-py311-20260619 with options that make generated models easier to read and use in real projects. It favors schema-authored names, model reuse, and embedded schema documentation over the most conservative output-shape stability.
- Requires separate target Python version: no
- Target Python version: 3.11
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.11. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-reuse-models = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
naming-strategy = "primary-first"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
reuse-model = true
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.11"
use-annotated = true
use-default-kwarg = true
use-field-description = true
use-field-description-example = true
use-frozen-field = true
use-object-type = true
use-schema-description = true
use-single-line-docstring = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-title-as-name = true
use-tuple-for-fixed-items = true
use-union-operator = true
use-unique-items-as-set = true
datamodel-codegen --allow-population-by-field-name --collapse-reuse-models --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --naming-strategy primary-first --output model.py --output-model-type pydantic_v2.BaseModel --reuse-model --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.11 --use-annotated --use-default-kwarg --use-field-description --use-field-description-example --use-frozen-field --use-object-type --use-schema-description --use-single-line-docstring --use-specialized-enum --use-standard-collections --use-subclass-enum --use-title-as-name --use-tuple-for-fixed-items --use-union-operator --use-unique-items-as-set
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
| Practical model structure and names | --reuse-model, --collapse-reuse-models, --use-title-as-name, --naming-strategy primary-first |
Deduplicate identical models without empty inheritance wrappers, prefer schema titles for class names, and keep primary definitions ahead of inline duplicate names. |
| Practical typing and defaults | --use-default-kwarg, --use-object-type, --use-tuple-for-fixed-items, --use-unique-items-as-set, --use-single-line-docstring |
Render defaults explicitly, prefer object for unconstrained values, preserve fixed and unique arrays, and keep short docstrings concise. |
| Schema documentation | --use-schema-description, --use-field-description, --use-field-description-example |
Preserve schema and field descriptions, including examples, in generated model documentation. |
practical-py312-20260619¶
Standard Python 3.12 output plus practical naming, deduplication, and schema documentation.
This immutable preset extends standard-py312-20260619 with options that make generated models easier to read and use in real projects. It favors schema-authored names, model reuse, and embedded schema documentation over the most conservative output-shape stability.
- Requires separate target Python version: no
- Target Python version: 3.12
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.12. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-reuse-models = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
naming-strategy = "primary-first"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
reuse-model = true
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.12"
use-annotated = true
use-default-kwarg = true
use-field-description = true
use-field-description-example = true
use-frozen-field = true
use-object-type = true
use-schema-description = true
use-single-line-docstring = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-title-as-name = true
use-tuple-for-fixed-items = true
use-union-operator = true
use-unique-items-as-set = true
datamodel-codegen --allow-population-by-field-name --collapse-reuse-models --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --naming-strategy primary-first --output model.py --output-model-type pydantic_v2.BaseModel --reuse-model --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.12 --use-annotated --use-default-kwarg --use-field-description --use-field-description-example --use-frozen-field --use-object-type --use-schema-description --use-single-line-docstring --use-specialized-enum --use-standard-collections --use-subclass-enum --use-title-as-name --use-tuple-for-fixed-items --use-union-operator --use-unique-items-as-set
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
| Practical model structure and names | --reuse-model, --collapse-reuse-models, --use-title-as-name, --naming-strategy primary-first |
Deduplicate identical models without empty inheritance wrappers, prefer schema titles for class names, and keep primary definitions ahead of inline duplicate names. |
| Practical typing and defaults | --use-default-kwarg, --use-object-type, --use-tuple-for-fixed-items, --use-unique-items-as-set, --use-single-line-docstring |
Render defaults explicitly, prefer object for unconstrained values, preserve fixed and unique arrays, and keep short docstrings concise. |
| Schema documentation | --use-schema-description, --use-field-description, --use-field-description-example |
Preserve schema and field descriptions, including examples, in generated model documentation. |
practical-py313-20260619¶
Standard Python 3.13 output plus practical naming, deduplication, and schema documentation.
This immutable preset extends standard-py313-20260619 with options that make generated models easier to read and use in real projects. It favors schema-authored names, model reuse, and embedded schema documentation over the most conservative output-shape stability.
- Requires separate target Python version: no
- Target Python version: 3.13
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.13. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-reuse-models = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
naming-strategy = "primary-first"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
reuse-model = true
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.13"
use-annotated = true
use-default-kwarg = true
use-field-description = true
use-field-description-example = true
use-frozen-field = true
use-object-type = true
use-schema-description = true
use-single-line-docstring = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-title-as-name = true
use-tuple-for-fixed-items = true
use-union-operator = true
use-unique-items-as-set = true
datamodel-codegen --allow-population-by-field-name --collapse-reuse-models --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --naming-strategy primary-first --output model.py --output-model-type pydantic_v2.BaseModel --reuse-model --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.13 --use-annotated --use-default-kwarg --use-field-description --use-field-description-example --use-frozen-field --use-object-type --use-schema-description --use-single-line-docstring --use-specialized-enum --use-standard-collections --use-subclass-enum --use-title-as-name --use-tuple-for-fixed-items --use-union-operator --use-unique-items-as-set
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
| Practical model structure and names | --reuse-model, --collapse-reuse-models, --use-title-as-name, --naming-strategy primary-first |
Deduplicate identical models without empty inheritance wrappers, prefer schema titles for class names, and keep primary definitions ahead of inline duplicate names. |
| Practical typing and defaults | --use-default-kwarg, --use-object-type, --use-tuple-for-fixed-items, --use-unique-items-as-set, --use-single-line-docstring |
Render defaults explicitly, prefer object for unconstrained values, preserve fixed and unique arrays, and keep short docstrings concise. |
| Schema documentation | --use-schema-description, --use-field-description, --use-field-description-example |
Preserve schema and field descriptions, including examples, in generated model documentation. |
practical-py314-20260619¶
Standard Python 3.14 output plus practical naming, deduplication, and schema documentation.
This immutable preset extends standard-py314-20260619 with options that make generated models easier to read and use in real projects. It favors schema-authored names, model reuse, and embedded schema documentation over the most conservative output-shape stability.
- Requires separate target Python version: no
- Target Python version: 3.14
Included Options¶
These snippets show the equivalent expanded configuration without --preset for JSON Schema input, Pydantic v2 BaseModel output, and Python 3.14. Replace the input and output paths for your project.
[tool.datamodel-codegen]
allow-population-by-field-name = true
collapse-reuse-models = true
collapse-root-models = true
disable-timestamp = true
enum-field-as-literal = "one"
input = "schema.json"
input-file-type = "jsonschema"
naming-strategy = "primary-first"
output = "model.py"
output-model-type = "pydantic_v2.BaseModel"
reuse-model = true
set-default-enum-member = true
snake-case-field = true
strict-nullable = true
target-python-version = "3.14"
use-annotated = true
use-default-kwarg = true
use-field-description = true
use-field-description-example = true
use-frozen-field = true
use-object-type = true
use-schema-description = true
use-single-line-docstring = true
use-specialized-enum = true
use-standard-collections = true
use-subclass-enum = true
use-title-as-name = true
use-tuple-for-fixed-items = true
use-union-operator = true
use-unique-items-as-set = true
datamodel-codegen --allow-population-by-field-name --collapse-reuse-models --collapse-root-models --disable-timestamp --enum-field-as-literal one --input schema.json --input-file-type jsonschema --naming-strategy primary-first --output model.py --output-model-type pydantic_v2.BaseModel --reuse-model --set-default-enum-member --snake-case-field --strict-nullable --target-python-version 3.14 --use-annotated --use-default-kwarg --use-field-description --use-field-description-example --use-frozen-field --use-object-type --use-schema-description --use-single-line-docstring --use-specialized-enum --use-standard-collections --use-subclass-enum --use-title-as-name --use-tuple-for-fixed-items --use-union-operator --use-unique-items-as-set
| Scope | Options | Notes |
|---|---|---|
| All output model types | --use-standard-collections, --use-union-operator, --use-annotated, --enum-field-as-literal one, --use-subclass-enum, --collapse-root-models, --strict-nullable, --set-default-enum-member, --disable-timestamp |
Use built-in collection syntax, PEP 604 unions, Annotated constraints, single-value enum Literals, typed enum subclasses, enum-member defaults, inline root wrappers, schema-accurate nullability, and reproducible file headers. |
| Python 3.11+ targets | --use-specialized-enum |
Use StrEnum or IntEnum only when the selected target Python version supports it. |
| Pydantic v2 BaseModel and dataclass output | --snake-case-field, --allow-population-by-field-name, --use-frozen-field |
Generate Pythonic field names while preserving input aliases and readOnly immutability metadata. |
| msgspec Struct output | --snake-case-field, --use-standard-primitive-types |
Generate Pythonic field names with aliases and stdlib primitive types for schema formats. |
| stdlib dataclass output | --use-standard-primitive-types |
Use stdlib primitive types without renaming input keys because dataclasses do not carry aliases. |
| TypedDict output | --use-standard-primitive-types, --use-frozen-field |
Use stdlib primitive types and ReadOnly metadata without renaming dictionary keys. |
| Practical model structure and names | --reuse-model, --collapse-reuse-models, --use-title-as-name, --naming-strategy primary-first |
Deduplicate identical models without empty inheritance wrappers, prefer schema titles for class names, and keep primary definitions ahead of inline duplicate names. |
| Practical typing and defaults | --use-default-kwarg, --use-object-type, --use-tuple-for-fixed-items, --use-unique-items-as-set, --use-single-line-docstring |
Render defaults explicitly, prefer object for unconstrained values, preserve fixed and unique arrays, and keep short docstrings concise. |
| Schema documentation | --use-schema-description, --use-field-description, --use-field-description-example |
Preserve schema and field descriptions, including examples, in generated model documentation. |