MCP

Connect a client

Kraterion is a Model Context Protocol server. Connect Claude Desktop, Cursor, Zed, or any MCP client and your assistant can browse buckets, search knowledge, and invoke agents directly.

Endpoint

The server lives at https://mcp.kraterion.com/mcp and speaks the Streamable HTTP transport. It's stateless — each request stands on its own, so there's no session to keep alive.

Authentication

Two ways to authenticate. Clients that support it can use OAuth 2.1 with dynamic client registration — the client registers itself and walks you through sign-in, no key to paste. Otherwise, pass a bearer token (kr_live_…). S3 keys are not accepted here.

Add to a client

In Claude Desktop, add Kraterion to your MCP servers config. The OAuth flow registers the client automatically.

{
  "mcpServers": {
    "kraterion": {
      "url": "https://mcp.kraterion.com/mcp",
      "auth": {
        "type": "oauth",
        "dcr": true
      }
    }
  }
}

The seven tools

The MCP server exposes seven tools. Note this set includes kraterion_invoke_agent — so a client can defer to a fully-configured agent rather than orchestrating retrieval itself.

Tool	Args	Does
`kraterion_list_buckets`	`—`	List your buckets.
`kraterion_list_objects`	`bucket, prefix?, limit?`	List object keys in a bucket.
`kraterion_search`	`bucket, query, top_k?`	Hybrid search over a knowledge bucket.
`kraterion_invoke_agent`	`agent_id, input, model?`	Call a configured agent and get its answer.
`kraterion_read_object`	`bucket, key`	Read an object (up to 1 MiB).
`kraterion_write_object`	`bucket, key, content, content_type?`	Write an object (up to 5 MiB).
`kraterion_get_manifest`	`bucket, key`	Fetch an object's knowledge manifest.

Example

Once connected, ask your assistant something that needs your data — it calls the tools for you. Under the hood, a tool call is a JSON-RPC request with a bearer token:

curl -X POST https://mcp.kraterion.com/mcp \
  -H "Authorization: Bearer kr_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": {
      "name": "kraterion_search",
      "arguments": { "bucket": "my-bucket", "query": "refund window", "top_k": 5 }
    }
  }'