YAADMINThe connection model#
MCP connects YAADMIN to independently implemented external tool servers. YAADMIN supports STDIO and HTTP tool operations without requiring YAADMIN-specific code in the remote server for those supported operations.
- MCP server
- initialize / tools/list
- Tool descriptions and schemas
- YAADMIN registry
- RBAC
- Approval if required
- Execution
STDIO and HTTP#
STDIO launches a configured command and arguments with inherited environment plus configured environment values. The client exchanges JSON-RPC messages through the process streams.
HTTP sends JSON-RPC over POST, accepts JSON/SSE response envelopes and retains Mcp-Session-Id. Initialization advertises protocol version 2025-06-18; the HTTP client retains the returned version for subsequent requests.
Discovery and invocation#
Startup uses initialize, notifications/initialized and tools/list. Discovered names, descriptions and inputSchema become registry descriptors. Invocation uses tools/call with the exact remote tool name and arguments.
One failing server can be skipped while its startup error is retained. A configured profile alone does not prove that its tools were successfully registered.
OAuth and personal connections#
OAuth discovery, dynamic registration, pre-registered client credentials, authorization-code flow and S256 PKCE exist. Administrators own server profiles. HTTP profiles in per_user mode let users connect their own OAuth identity; STDIO uses shared mode.
Personal execution uses the current actor's protected credential and does not fall back to an administrator's shared bearer. Some credential statements in the audit snapshot are redacted.
MCP Registry#
Registry search and installation plans can populate server metadata and connection settings. A generated plan is not proof that an external package runtime was installed successfully.
Current implementation notes#
Continue with Add a server, Custom servers and MCP tool permissions.