chroma-core/chroma · error · ValueError

Invalid configuration type: {parameter.value}

Error message

Invalid configuration type: {parameter.value}

What it means

Raised in ConfigurationInternal.__init__ (chromadb/api/configuration.py:112) when a parameter value is a dict (i.e. a nested, recursive configuration) whose "_type" key does not resolve to a known ConfigurationInternal subclass in this module's globals. The _type discriminator is what from_json uses to pick the concrete class for the nested value; an unknown, misspelled, or renamed _type means the nested configuration cannot be reconstructed.

Source

Thrown at chromadb/api/configuration.py:112

    # All expected parameters must be present with defaults or None values at initialization
    parameter_map: Dict[str, ConfigurationParameter]
    definitions: ClassVar[Dict[str, ConfigurationDefinition]]

    def __init__(self, parameters: Optional[List[ConfigurationParameter]] = None):
        """Initializes a new instance of the Configuration class. Respecting defaults and
        validators."""
        self.parameter_map = {}
        if parameters is not None:
            for parameter in parameters:
                if parameter.name not in self.definitions:
                    raise ValueError(f"Invalid parameter name: {parameter.name}")

                definition = self.definitions[parameter.name]
                # Handle the case where we have a recursive configuration definition
                if isinstance(parameter.value, dict):
                    child_type = globals().get(parameter.value.get("_type", None))
                    if child_type is None:
                        raise ValueError(
                            f"Invalid configuration type: {parameter.value}"
                        )
                    parameter.value = child_type.from_json(parameter.value)
                if not isinstance(parameter.value, type(definition.default_value)):
                    raise ValueError(f"Invalid parameter value: {parameter.value}")

                parameter_validator = definition.validator
                if not parameter_validator(parameter.value):
                    raise ValueError(f"Invalid parameter value: {parameter.value}")
                self.parameter_map[parameter.name] = parameter
        # Apply the defaults for any missing parameters
        for name, definition in self.definitions.items():
            if name not in self.parameter_map:
                self.parameter_map[name] = ConfigurationParameter(
                    name=name, value=definition.default_value
                )

        self.configuration_validator()

View on GitHub (pinned to aecdd12c8a)

Solutions

1. Set _type to the exact class name of a ConfigurationInternal subclass defined in chromadb.api.configuration (e.g. "HNSWConfigurationInternal")
2. If the JSON came from another version, regenerate it with the current chromadb or upgrade to the version that knows that class
3. Drop the nested dict and pass the value in its already-constructed form

Example fix

# before
raw = {"hnsw": {"_type": "HNSWConfiguration", "M": 16}}   # wrong _type
# after
raw = {"hnsw": {"_type": "HNSWConfigurationInternal", "M": 16}}

import chromadb.api.configuration as cfgmod
from chromadb.api.configuration import ConfigurationInternal

def known_config_types():
    return {name for name in dir(cfgmod)
            if isinstance(getattr(cfgmod, name, None), type)
            and issubclass(getattr(cfgmod, name), ConfigurationInternal)}

def valid_nested(value: dict) -> bool:
    return value.get("_type") in known_config_types()

When it happens

Trigger: Nested config JSON like {"_type": "HNSWConfiguration", ...} when the class is actually named HNSWConfigurationInternal; _type missing entirely (globals().get(None) returns None); loading nested config produced by another chromadb version where the class was renamed or did not yet exist.

Common situations: Persisted collection or system configuration replayed after a chromadb upgrade or downgrade; hand-authored JSON configs with a guessed _type value; cross-environment moves (dev config applied in prod with different chromadb versions).

Related errors

• Trying to instantiate configuration of type {cls.__name__} f
• Invalid parameter name: {parameter.name}
• Invalid parameter value: {parameter.value}
• Invalid parameter name: {name} for configuration {self.__cla
• Invalid parameter name: {name}

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/bf215e36e72dc772. Report an issue: GitHub.