microsoft/autogen · error · ValueError

Unsupported config type: {type(self._config)}

Error message

Unsupported config type: {type(self._config)}

What it means

During lazy initialization, ChromaDBVectorMemory selects a chromadb client by isinstance-dispatch on its config: PersistentChromaDBVectorMemoryConfig gets a PersistentClient, HttpChromaDBVectorMemoryConfig gets an HttpClient, and anything else raises ValueError with the offending type. The wrapper also logs 'Failed to initialize ChromaDB client' and re-raises the original exception for genuine client-creation failures.

Source

Thrown at python/packages/autogen-ext/src/autogen_ext/memory/chromadb/_chromadb.py:264

                if isinstance(self._config, PersistentChromaDBVectorMemoryConfig):
                    self._client = PersistentClient(
                        path=self._config.persistence_path,
                        settings=settings,
                        tenant=self._config.tenant,
                        database=self._config.database,
                    )
                elif isinstance(self._config, HttpChromaDBVectorMemoryConfig):
                    self._client = HttpClient(
                        host=self._config.host,
                        port=self._config.port,
                        ssl=self._config.ssl,
                        headers=self._config.headers,
                        settings=settings,
                        tenant=self._config.tenant,
                        database=self._config.database,
                    )
                else:
                    raise ValueError(f"Unsupported config type: {type(self._config)}")
            except Exception as e:
                logger.error(f"Failed to initialize ChromaDB client: {e}")
                raise

        if self._collection is None:
            try:
                # Create embedding function
                embedding_function = self._create_embedding_function()

                # Create or get collection with embedding function
                self._collection = self._client.get_or_create_collection(
                    name=self._config.collection_name,
                    metadata={"distance_metric": self._config.distance_metric},
                    embedding_function=embedding_function,
                )
            except Exception as e:
                logger.error(f"Failed to get/create collection: {e}")
                raise

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Use PersistentChromaDBVectorMemoryConfig or HttpChromaDBVectorMemoryConfig from the same autogen_ext.memory.chromadb module.
2. For a server setup, verify host/port/tenant/database are correct and the chroma server is reachable.
3. For persistent setup, verify persistence_path is writable.
4. Align autogen-ext versions across imports so isinstance dispatch matches.

Example fix

# before
memory = ChromaDBVectorMemory(config=some_custom_config)
# after
from autogen_ext.memory.chromadb import PersistentChromaDBVectorMemoryConfig
memory = ChromaDBVectorMemory(config=PersistentChromaDBVectorMemoryConfig(collection_name="docs", persistence_path="./chroma"))

from autogen_ext.memory.chromadb import (
    PersistentChromaDBVectorMemoryConfig,
    HttpChromaDBVectorMemoryConfig,
)
assert isinstance(config, (PersistentChromaDBVectorMemoryConfig, HttpChromaDBVectorMemoryConfig)), (
    f"unsupported config: {type(config).__name__}"
)

def is_supported_chromadb_config(cfg) -> bool:
    return isinstance(cfg, (PersistentChromaDBVectorMemoryConfig, HttpChromaDBVectorMemoryConfig))

try:
    memory = ChromaDBVectorMemory(config=config)
    await memory.update_context(ctx)  # triggers _ensure_initialized
except ValueError as e:
    if "Unsupported config type" in str(e):
        raise SystemExit("Use Persistent or Http ChromaDBVectorMemoryConfig") from e
    raise
except Exception:
    # genuine client init failure (network/path/tenant) is logged and re-raised as-is
    raise

When it happens

Trigger: Constructing ChromaDBVectorMemory with a config class other than the two supported ones (e.g. an in-memory config class from another module or a plain dict) and triggering the first query/update. Non-ValueError chromadb errors (bad path, unreachable host, bad tenant/database) surface from the same try block with the same log line.

Common situations: Version mismatch where the config classes were imported from a different autogen-ext version than the memory class; attempting an EphemeralClient-style config that this implementation does not support; HTTP configs pointing at a dead chroma server.

Related errors

• Unsupported embedding function config type: {type(config)}
• Failed to create custom embedding function. Error: {e}
• Please set OPENAI_API_KEY environment variable.
• Please set OPENAI_API_KEY environment variable.
• BING_API_KEY environment variable is not set

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/65be31f5f7b5afdd. Report an issue: GitHub.