Function●Since v0.1

loads

Revive a LangChain class from a JSON string.

Equivalent to load(json.loads(text)).

Only classes in the allowlist can be instantiated. The default allowlist includes core LangChain types (messages, prompts, documents, etc.). See langchain_core.load.mapping for the full list.

Do not use with untrusted input

This function instantiates Python objects and can trigger side effects during deserialization. Never call loads() on data from an untrusted or unauthenticated source. See the module-level security model documentation for details and best practices.

loads(
  text: str,
  *,
  allowed_objects: Iterable[AllowedObject] | Literal['all', 'core'] = 'core',
  secrets_map: dict[str, str] | None = None,
  valid_namespaces: list[str] | None = None,
  secrets_from_env: bool = False,
  additional_import_mappings: dict[tuple[str, ...], tuple[str, ...]] | None = None,
  ignore_unserializable_fields: bool = False,
  init_validator: InitValidator | None = default_init_validator
) -> Any

Parameters

Name	Type	Description
`text`*	`str`	The string to load.
`allowed_objects`	`Iterable[AllowedObject] \| Literal['all', 'core']`	Default:`'core'` Allowlist of classes that can be deserialized. `'core'` (default): Allow classes defined in the serialization mappings for `langchain_core`. `'all'`: Allow classes defined in the serialization mappings. This includes core LangChain types (messages, prompts, documents, etc.) and trusted partner integrations. See `langchain_core.load.mapping` for the full list. Explicit list of classes: Only those specific classes are allowed. `[]`: Disallow all deserialization (will raise on any object).
`secrets_map`	`dict[str, str] \| None`	Default:`None` A map of secrets to load. Only include the specific secrets the serialized object requires. If a secret is not found in the map, it will be loaded from the environment if `secrets_from_env` is `True`.
`valid_namespaces`	`list[str] \| None`	Default:`None` Additional namespaces (modules) to allow during deserialization, beyond the default trusted namespaces.
`secrets_from_env`	`bool`	Default:`False` Whether to load secrets from the environment. A crafted payload can name arbitrary environment variables in its `secret` fields, so enabling this on untrusted data can leak sensitive values. Keep this `False` (the default) unless the serialized data is fully trusted.
`additional_import_mappings`	`dict[tuple[str, ...], tuple[str, ...]] \| None`	Default:`None` A dictionary of additional namespace mappings. You can use this to override default mappings or add new mappings. When `allowed_objects` is `None` (using defaults), paths from these mappings are also added to the allowed class paths.
`ignore_unserializable_fields`	`bool`	Default:`False` Whether to ignore unserializable fields.
`init_validator`	`InitValidator \| None`	Default:`default_init_validator` Optional callable to validate kwargs before instantiation. If provided, this function is called with `(class_path, kwargs)` where `class_path` is the class path tuple and `kwargs` is the kwargs dict. The validator should raise an exception if the object should not be deserialized, otherwise return `None`. Defaults to `default_init_validator` which blocks jinja2 templates.

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loads

Revive a LangChain class from a JSON string.

Equivalent to load(json.loads(text)).

Only classes in the allowlist can be instantiated. The default allowlist includes core LangChain types (messages, prompts, documents, etc.). See langchain_core.load.mapping for the full list.

Do not use with untrusted input

loads( text: str, *, allowed_objects: Iterable[AllowedObject] | Literal['all', 'core'] = 'core', secrets_map: dict[str, str] | None = None, valid_namespaces: list[str] | None = None, secrets_from_env: bool = False, additional_import_mappings: dict[tuple[str, ...], tuple[str, ...]] | None = None, ignore_unserializable_fields: bool = False, init_validator: InitValidator | None = default_init_validator ) -> Any

Parameters

Name	Type	Description
`text`*	`str`	The string to load.
`allowed_objects`	`Iterable[AllowedObject] \| Literal['all', 'core']`	Default:`'core'` Allowlist of classes that can be deserialized. `'core'` (default): Allow classes defined in the serialization mappings for `langchain_core`. `'all'`: Allow classes defined in the serialization mappings. This includes core LangChain types (messages, prompts, documents, etc.) and trusted partner integrations. See `langchain_core.load.mapping` for the full list. Explicit list of classes: Only those specific classes are allowed. `[]`: Disallow all deserialization (will raise on any object).
`secrets_map`	`dict[str, str] \| None`	Default:`None` A map of secrets to load. Only include the specific secrets the serialized object requires. If a secret is not found in the map, it will be loaded from the environment if `secrets_from_env` is `True`.
`valid_namespaces`	`list[str] \| None`	Default:`None` Additional namespaces (modules) to allow during deserialization, beyond the default trusted namespaces.
`secrets_from_env`	`bool`	Default:`False` Whether to load secrets from the environment. A crafted payload can name arbitrary environment variables in its `secret` fields, so enabling this on untrusted data can leak sensitive values. Keep this `False` (the default) unless the serialized data is fully trusted.
`additional_import_mappings`	`dict[tuple[str, ...], tuple[str, ...]] \| None`	Default:`None` A dictionary of additional namespace mappings. You can use this to override default mappings or add new mappings. When `allowed_objects` is `None` (using defaults), paths from these mappings are also added to the allowed class paths.
`ignore_unserializable_fields`	`bool`	Default:`False` Whether to ignore unserializable fields.
`init_validator`	`InitValidator \| None`	Default:`default_init_validator` Optional callable to validate kwargs before instantiation. If provided, this function is called with `(class_path, kwargs)` where `class_path` is the class path tuple and `kwargs` is the kwargs dict. The validator should raise an exception if the object should not be deserialized, otherwise return `None`. Defaults to `default_init_validator` which blocks jinja2 templates.

loads

Parameters

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loads

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