Module mcp 

MCP (Model Context Protocol) integration — JSON-RPC client, tool bridging, lazy loading.

Modules

descriptors

Task 19 (Commit A) — safe local MCP descriptor cache and dormant deferred-tool integration (spec §7.4).

lease

Task 19 (Commit B) — session-scoped exact MCP runtime leases (spec §7.4).

Structs

McpConfig

MCP config file format: { “mcpServers”: { “name”: { command, args, env } } }

McpConnectTool

A tool that lazily connects to MCP servers on demand. Instead of spawning all servers at startup (burning tokens on 65 tool schemas), this registers ONE tool that the model calls to activate a specific server.

McpLeaseCapability

Typed per-session lease capability handed to tool contexts: the exact session identity plus the shared manager. Never widens to a server grant — every call re-validates the exact tool and fingerprint.

McpRuntimeManager

Session-scoped exact MCP runtime lease manager. See module docs.

McpServerConfig

MCP server configuration — matches claude-code/gemini-cli format.

McpSessionEndGuard

Durable last-owner session scope. The Runtime mints ONE of these per tool session (wrapped in an Arc shared by every runtime clone and in-flight stream); streams HOLD it, never construct or drop their own. Leases therefore survive across provider turns, and only the drop of the LAST owner — true session end — terminates the session’s leases.

McpTool

A dynamic tool backed by an MCP server connection. The connection is shared (Arc<Mutex<>>) across all tools from the same server.

Constants

MCP_CONFIG_MAX_ARGS

MCP_CONFIG_MAX_ARG_BYTES

MCP_CONFIG_MAX_BYTES

Hard byte bound on mcp.json.

MCP_CONFIG_MAX_COMMAND_BYTES

MCP_CONFIG_MAX_ENV_ENTRIES

MCP_CONFIG_MAX_ENV_KEY_BYTES

MCP_CONFIG_MAX_ENV_VALUE_BYTES

MCP_CONFIG_MAX_SERVERS

Structural bounds on mcp.json (Task 19 review): the 1 MiB byte cap alone leaves server/env counts and string shapes unbounded. Violations fail the WHOLE config closed with a static reason.

MCP_CONFIG_MAX_SERVER_NAME_BYTES

Functions

connect_mcp_servers

Connect to all configured MCP servers and register their tools. Returns the number of tools registered.

load_mcp_config

Load MCP config from ~/.synaps-cli/mcp.json (or profile variant).

setup_lazy_mcp

Set up MCP loading at engine boot, before any session tool set exists.

validate_mcp_config

Validate config structure before ANY use. Static reasons only — no config content is ever echoed.