Toolkit Routing

mcp · proxy routes each tool call to the correct upstream using the toolkit field in the route condition. AI agents address tools with a toolkit prefix — bluesky__get_weather routes to the Bluesky toolkit, payments__charge routes to the payments toolkit — and Zilla dispatches accordingly.

Configuration

north_mcp_proxy:
  type: mcp
  kind: proxy
  routes:
    - exit: bluesky_mcp_client
      when:
        - toolkit: bluesky
    - exit: payments_mcp_client
      when:
        - toolkit: payments

Each routes[].when[].toolkit value matches the toolkit prefix in the tool name. Adding a new tool provider is one config entry — no code changes, no redeployments of existing upstreams.

How Agents Address Tools

When an agent calls a tool, it uses the double-underscore convention: <toolkit>__<tool>. For example:

Tool call	Routed to
bluesky__get_weather	bluesky_mcp_client
bluesky__search_posts	bluesky_mcp_client
payments__charge	payments_mcp_client
payments__refund	payments_mcp_client

The agent sees a unified tool list from all upstreams. Zilla strips the toolkit prefix before forwarding the call upstream, so each MCP server receives its own native tool names.