This subdomain (mcp.gtm.assay.wiki) will host the Model Context Protocol server — read-only JSON-RPC interface to the Truth Graph for AI agents (n8n flows, Slack handlers, partner integrations).
Tools to expose: truth_graph.get_node, truth_graph.find, truth_graph.list_personas, truth_graph.confidence, truth_graph.cascade_status, plus POST /mcp/resolve for wikilink transclusions.
Real service lands in: Phase 1 task P1-MCP-01 (#22) — read-only MCP server. Wikilink resolver in #23, Postgres LISTEN/NOTIFY event subscription in #24.
Auth: JWT only. No Caddy-level basicauth — the agent authenticates itself.