FoundationAgents/MetaGPT · error · Exception

Please install pymilvus first.

Error message

Please install pymilvus first.

What it means

MilvusStore.__init__ tries to import pymilvus.MilvusClient inside a try/except and raises 'Please install pymilvus first.' on ImportError. The dependency is optional: it is only declared in MetaGPT's rag/milvus extras, not the base install, so MilvusStore is unusable without it.

Source

Thrown at metagpt/document_store/milvus_store.py:24

@dataclass
class MilvusConnection:
    """
    Args:
        uri: milvus url
        token: milvus token
    """

    uri: str = None
    token: str = None


class MilvusStore(BaseStore):
    def __init__(self, connect: MilvusConnection):
        try:
            from pymilvus import MilvusClient
        except ImportError:
            raise Exception("Please install pymilvus first.")
        if not connect.uri:
            raise Exception("please check MilvusConnection, uri must be set.")
        self.client = MilvusClient(uri=connect.uri, token=connect.token)

    def create_collection(self, collection_name: str, dim: int, enable_dynamic_schema: bool = True):
        from pymilvus import DataType

        if self.client.has_collection(collection_name=collection_name):
            self.client.drop_collection(collection_name=collection_name)

        schema = self.client.create_schema(
            auto_id=False,
            enable_dynamic_field=False,
        )
        schema.add_field(field_name="id", datatype=DataType.VARCHAR, is_primary=True, max_length=36)
        schema.add_field(field_name="vector", datatype=DataType.FLOAT_VECTOR, dim=dim)

        index_params = self.client.prepare_index_params()

View on GitHub (pinned to 11cdf466d0)

Solutions

1. Install the dependency: pip install pymilvus (or pip install 'metagpt[milvus]' if you installed MetaGPT from PyPI with extras).
2. Pin a compatible version, e.g. pip install 'pymilvus>=2.4' — MilvusClient and create_schema require the 2.x client API.
3. For deployments, add pymilvus to requirements.txt / Dockerfile so the image is self-contained.

Example fix

# before
store = MilvusStore(MilvusConnection(uri="http://localhost:19530"))  # Exception: Please install pymilvus first.

# after
# shell: pip install pymilvus
store = MilvusStore(MilvusConnection(uri="http://localhost:19530"))

def milvus_available() -> bool:
    try:
        import pymilvus  # noqa: F401
        return True
    except ImportError:
        return False

if not milvus_available():
    raise SystemExit("Install with: pip install 'metagpt[milvus]' (or pip install pymilvus)")

try:
    store = MilvusStore(conn)
except Exception as e:
    if "install pymilvus" in str(e):
        raise SystemExit("missing dependency; run: pip install pymilvus") from e
    raise

When it happens

Trigger: Constructing MilvusStore(MilvusConnection(uri=..., token=...)) in an environment where the pymilvus package is not installed (no metagpt[milvus] extra).

Common situations: pip install metagpt without extras then using the Milvus document store; CI images trimmed of optional deps; a new team member following the base README; upgrading Python versions and losing the previously installed pymilvus.

Related errors

• To use the experience pool, you need to install the rag modu
• please check MilvusConnection, uri must be set.
• Missing fields: {missing_fields}
• use `review` after `fill`
• Data type not supported for metadata extraction.

AI-assisted analysis of FoundationAgents/MetaGPT@11cdf466d0 (2026-08-14). Data as JSON: /api/errors/af8bd4fada9ca141. Report an issue: GitHub.