%% Enterprise MCP tool hub: request journey and team handoffs. Generated.
sequenceDiagram
  autonumber
  actor n_clients as Agent clients
  participant n_mcp_gateway as MCP policy gateway
  participant n_authz as Authorization server
  participant n_catalog_ui as Tool catalog and consent
  participant n_edge as Edge protection
  participant n_registry as Tool registry
  participant n_guardrail as Content guardrail
  participant n_servers as Domain MCP servers
  participant n_broker as Credential broker
  participant n_systems as Systems of record
  participant n_audit as Audit ledger
  participant n_owners as Tool owners
  participant n_traces as Traces and alerts
  participant n_contracts as Tool contract tests
  Note over n_clients: Discover and consent
  n_clients->>n_mcp_gateway: List tools
  n_clients-->>n_authz: OAuth consent, audience-bound token
  n_catalog_ui-->>n_authz: Grant or revoke scopes
  Note over n_clients: Admit the call
  n_clients->>n_edge: Tool call with token
  n_edge->>n_mcp_gateway: Rate-checked call
  n_mcp_gateway-->>n_registry: Scope and version lookup
  Note over n_mcp_gateway: Scan what goes in and out
  n_mcp_gateway-->>n_guardrail: Input and output scan
  Note over n_mcp_gateway: Act as the person, not as a robot
  n_mcp_gateway->>n_servers: Authorized call
  n_servers-->>n_broker: Token exchange
  n_servers->>n_systems: Backend call as the user
  Note over n_mcp_gateway: Record and govern
  n_mcp_gateway->>n_audit: Call record
  n_owners-->>n_registry: Approve tool or scope change
  n_mcp_gateway-->>n_traces: Latency and errors
  Note over n_contracts: Test every tool version
  n_contracts-->>n_servers: Contract tests per version