KosmoKrator

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Weaviate MCP Integration for LangChain

Connect Weaviate to LangChain through the local KosmoKrator MCP gateway with scoped tools, credentials, and write policy.

7 functions 5 read 2 write API key auth
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Connect Weaviate to LangChain

Bridge LangChain agents to local KosmoKrator integration tools through MCP or headless CLI calls.

Use the MCP gateway when the agent should discover tools, or wrap kosmo integrations:call for fixed chains. The gateway is local, scoped to this integration, and starts with --write=deny so LangChain can inspect read-capable tools without receiving write access by default.

Weaviate MCP Config for LangChain

Keep the gateway scoped to the integration and operation class needed by the chain.

{
  "mcpServers": {
    "kosmokrator-weaviate": {
      "type": "stdio",
      "command": "kosmo",
      "args": [
        "mcp:serve",
        "--integration=weaviate",
        "--write=deny"
      ]
    }
  }
}

Run the Gateway Manually

kosmokrator mcp:serve --integration=weaviate --write=deny

Why Use KosmoKrator Here

Scoped tools

Expose only Weaviate instead of a broad multi-service tool list.

Local credentials

Reuse credentials already configured for the KosmoKrator CLI and Lua runtime.

Write policy

Start read-only, then opt into ask or allow for trusted workspaces.

Weaviate Tools Visible to LangChain

LangChain sees stable MCP tool names generated from the Weaviate integration catalog.

MCP toolSource functionTypeDescription
integration__weaviate__weaviate_list_schemas weaviate.weaviate_list_schemas Read List all schemas (collections/classes) defined in the Weaviate instance. Returns the full schema including all classes and their properties.
integration__weaviate__weaviate_get_schema weaviate.weaviate_get_schema Read Get the schema definition for a specific class (collection) in Weaviate. Returns the class name, properties, vectorizer config, and module settings.
integration__weaviate__weaviate_create_class weaviate.weaviate_create_class Write Create a new class (collection) in the Weaviate schema. Provide a class definition with the class name and an array of property definitions (name, dataType, etc.).
integration__weaviate__weaviate_search_objects weaviate.weaviate_search_objects Read Search and query objects in Weaviate using GraphQL. Supports Get, Aggregate, and Explore queries with filters, sorting, and vector/nearVector/nearText search.
integration__weaviate__weaviate_create_object weaviate.weaviate_create_object Write Create a new data object in a Weaviate class. Provide the class name and a properties object with the data fields. Optionally specify a UUID for the object.
integration__weaviate__weaviate_get_object weaviate.weaviate_get_object Read Retrieve a specific data object from Weaviate by its class name and UUID. Returns the full object including all properties and metadata.
integration__weaviate__weaviate_get_health weaviate.weaviate_get_health Read Check the health and liveness of the Weaviate instance. Returns a status indicating whether the service is alive and responsive.

Related Weaviate Pages

Weaviate CLIUse direct JSON commands instead of MCP discovery. Weaviate MCPFull gateway reference and MCP tool names. KosmoKrator for LangChainClient-level gateway setup.