"""Registering a connected (or schema-cached) MCP server's tools into the tool registry: include/exclude filtering, trust-tier metadata capture, utility-tool selection, name-collision resolution and the schema-cache write-through. Both entry points (``_register_server_tools`` live, ``_register_from_cache_sync`` lazy) build ``_Candidate`` records for ``_register_candidates``.""" import logging from dataclasses import dataclass from types import SimpleNamespace from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, List, Optional from tools.mcp_tool_common import _parse_boolish, _core, _resolve_tool_timeout, mcp_field from tools import mcp_tool_handlers as _handlers from tools import mcp_tool_schema as _schema from tools.mcp_tool_handlers import ( _make_check_fn, _make_get_prompt_handler, _make_list_prompts_handler, _make_list_resources_handler, _make_read_resource_handler) from tools.mcp_tool_schema import ( _UTILITY_CAPABILITY_ATTRS, _build_utility_schemas, _normalize_name_filter, matches_name_filter) if TYPE_CHECKING: # pragma: no cover from tools.mcp_tool import MCPServerTask logger = logging.getLogger("tools.mcp_tool") _UTILITY_ORIGIN_PREFIX = "generated utility " # Utility tool key -> handler factory; each takes (server_name, tool_timeout). _UTILITY_HANDLER_FACTORIES = { "list_resources": _make_list_resources_handler, "read_resource": _make_read_resource_handler, "list_prompts": _make_list_prompts_handler, "get_prompt": _make_get_prompt_handler} def _normalize_server_trust(value: Any) -> str: """Config ``trust`` -> tier. None -> ``full`` (compat default); unrecognized -> ``untrusted`` (fail closed).""" if value is None: return _core._TRUST_FULL text = str(value).strip().lower() if text in (_core._TRUST_FULL, _core._TRUST_UNTRUSTED): return text logger.warning("MCP trust: unrecognized trust value %r — treating as 'untrusted' (valid values: full, untrusted)", value) return _core._TRUST_UNTRUSTED def _annotation_read_only_hint(mcp_tool: Any) -> bool: """True only when annotations (SDK object or cache dict) carry ``readOnlyHint is True``; unknown = write-capable.""" annotations = getattr(mcp_tool, "annotations", None) hint = annotations.get("readOnlyHint") if isinstance(annotations, dict) else getattr(annotations, "readOnlyHint", None) return hint is True def _record_tool_trust_metadata(server_name: str, config: dict, tools: List[Any]) -> None: """Capture per-server trust and per-tool readOnlyHint at discovery — the security boundary: the call-time gate classifies from data we control, never re-read server-supplied state.""" with _core._lock: _core._server_trust_levels[server_name] = _normalize_server_trust((config or {}).get("trust")) hints = _core._tool_read_only_hints.setdefault(server_name, {}) hints.update({t.name: _annotation_read_only_hint(t) for t in tools if getattr(t, "name", None)}) def _track_mcp_tool_server(tool_name: str, server_name: str) -> None: """Remember the exact raw MCP server that registered *tool_name*.""" with _core._lock: _core._mcp_tool_server_names[tool_name] = server_name def _forget_mcp_tool_server(tool_name: str) -> None: """Forget MCP server provenance for a deregistered tool.""" with _core._lock: _core._mcp_tool_server_names.pop(tool_name, None) def _select_utility_schemas(server_name: str, server: "MCPServerTask", config: dict) -> List[dict]: """Utility schemas allowed by config (``tools.resources``/``tools.prompts``) and advertised capabilities. ``initialize_result.capabilities`` is the truth (sub-object non-None iff the family is served); without it fall back to the legacy session-method check, which never filters anything since ClientSession defines all four methods.""" tools_filter = config.get("tools") or {} enabled = {f: _parse_boolish(tools_filter.get(f), default=True) for f in ("resources", "prompts")} advertised = getattr(getattr(server, "initialize_result", None), "capabilities", None) def _skip_reason(handler_key: str) -> Optional[str]: family = _UTILITY_CAPABILITY_ATTRS[handler_key] if not enabled[family]: return f"{family} disabled" if advertised is not None: if getattr(advertised, family, None) is None: return f"server does not advertise '{family}' capability" return None # Legacy gate (no initialize_result): the ClientSession method shares the handler key. return None if hasattr(server.session, handler_key) else f"session lacks {handler_key}" selected: List[dict] = [] for entry in _build_utility_schemas(server_name): reason = _skip_reason(entry["handler_key"]) if reason: logger.debug("MCP server '%s': skipping utility '%s' (%s)", server_name, entry["handler_key"], reason) else: selected.append(entry) return selected def _existing_tool_names() -> List[str]: """Tool names for all connected servers plus lazy (cache-registered) servers, whose tools live only in the registry.""" names: List[str] = [] for server in _core._servers.values(): names.extend(server._registered_tool_names if hasattr(server, "_registered_tool_names") else (_schema._convert_mcp_schema(server.name, t)["name"] for t in server._tools)) with _core._lock: names.extend(n for sname, tool_names in _core._lazy_server_tool_names.items() if sname not in _core._servers for n in tool_names) return names def _make_tool_filter(name: str, config: dict) -> Callable[[str], bool]: """Include/exclude predicate for a server's tool names: ``tools.include`` is a whitelist (``[]`` = register nothing), ``tools.exclude`` a blacklist; entries are exact names or fnmatch globs; include wins over exclude.""" tools_filter = config.get("tools") or {} # Selective tool loading: honour include/exclude lists from config. Rules (matching issue #690 spec, # extended with glob support): tools.include — whitelist: only matching tool names are registered # tools.exclude — blacklist: all tools EXCEPT matching ones are registered entries may be exact names or # fnmatch globs (e.g. "*_radar_*") include takes precedence over exclude include: [] → register nothing # (an explicit empty whitelist, as written by the install checklist's "uncheck everything" path) Neither # set → register all tools (backward-compatible default) include_raw = tools_filter.get("include") include_set = _normalize_name_filter(include_raw, f"mcp_servers.{name}.tools.include") exclude_set = _normalize_name_filter(tools_filter.get("exclude"), f"mcp_servers.{name}.tools.exclude") if isinstance(include_raw, (str, list, tuple, set)): return lambda tool_name: matches_name_filter(tool_name, include_set) return lambda tool_name: not (exclude_set and matches_name_filter(tool_name, exclude_set)) def _cached_tools(raws: Iterable[Any]) -> List[SimpleNamespace]: """Schema-cache rows -> stand-ins for MCP Tool objects; rows that are not dicts or lack a name are dropped. Missing or non-dict ``annotations`` (older cache files) fail closed to write-capable.""" return [SimpleNamespace(name=raw["name"], description=raw.get("description") or "", inputSchema=raw["inputSchema"] if isinstance(raw.get("inputSchema"), dict) else {}, annotations=raw["annotations"] if isinstance(raw.get("annotations"), dict) else None) for raw in raws if isinstance(raw, dict) and raw.get("name")] @dataclass class _Candidate: """One registration attempt (native tool or generated utility); ``origin`` is the provenance text in diagnostics.""" registry_name: str origin: str schema: dict handler: Callable @property def is_utility(self) -> bool: return self.origin.startswith(_UTILITY_ORIGIN_PREFIX) def _tool_candidates(name: str, tools: Iterable[Any], should_register: Callable[[str], bool], tool_timeout) -> List[_Candidate]: """Native tools (live SDK objects or cache stand-ins) -> candidates. The injection scan runs on BOTH paths: the cache file is user-writable JSON.""" out: List[_Candidate] = [] for t in tools: if not should_register(t.name): logger.debug("MCP server '%s': skipping tool '%s' (filtered by config)", name, t.name) continue _schema._scan_mcp_description(name, t.name, t.description or "") schema = _schema._convert_mcp_schema(name, t) handler = _handlers._make_tool_handler(name, t.name, tool_timeout) out.append(_Candidate(schema["name"], f"tool {t.name!r}", schema, handler)) return out def _utility_candidates(name: str, entries: Iterable[Any], tool_timeout) -> List[_Candidate]: """``{schema, handler_key}`` rows (live selection or cache) -> candidates; malformed rows dropped.""" out: List[_Candidate] = [] for raw in entries: schema, key = (raw.get("schema"), raw.get("handler_key")) if isinstance(raw, dict) else (None, None) if isinstance(schema, dict) and key in _UTILITY_HANDLER_FACTORIES and schema.get("name"): out.append(_Candidate(schema["name"], f"{_UTILITY_ORIGIN_PREFIX}{key!r}", schema, _UTILITY_HANDLER_FACTORIES[key](name, tool_timeout))) return out def _resolve_name_collisions(name: str, candidates: List[_Candidate]) -> List[_Candidate]: """Preflight name collisions: exact duplicates dropped silently; a utility normalizing onto a native tool's name is shadowed (native wins); any other multi-origin collision skips every colliding entry (fail closed). Returns survivors in order.""" unique: List[_Candidate] = [] origins_by_name: Dict[str, set[str]] = {} for c in candidates: origins = origins_by_name.setdefault(c.registry_name, set()) if c.origin in origins: logger.debug("MCP server '%s': duplicate registration candidate %s for '%s'; keeping one", name, c.origin, c.registry_name) continue origins.add(c.origin) unique.append(c) ambiguous: Dict[str, List[str]] = {} shadowed: set[tuple[str, str]] = set() # A generated resource/prompt utility that normalizes onto a server-native tool's name must not knock # that native tool out of the registry: the native tool is the capability the user connected the server # for, while the generated utility (read_resource/list_resources/list_prompts/get_prompt) is optional # sugar that only matters when the server exposes no such tool of its own (#87112). Resolve that # specific collision in favour of the native tool — keep it, drop the shadowed utility — and fall back # to the conservative skip-everything only for genuinely ambiguous collisions (two or more native tools # normalizing to one name, which we cannot disambiguate). The four utility keys are distinct, so a # colliding set holds at most one utility origin. for registry_name, origins in origins_by_name.items(): if len(origins) <= 1: continue utility_origins = sorted(o for o in origins if o.startswith(_UTILITY_ORIGIN_PREFIX)) native_origins = sorted(origins - set(utility_origins)) if len(native_origins) == 1 and utility_origins: shadowed.update((registry_name, o) for o in utility_origins) logger.info( "MCP server '%s': generated utility %s normalizes onto server-native %s — keeping the native tool " "and dropping the utility (the utility only applies when the server has no such tool of its own)", name, ", ".join(utility_origins), native_origins[0]) else: ambiguous[registry_name] = sorted(origins) for registry_name, origins in sorted(ambiguous.items()): logger.error("MCP server '%s': name normalization collision for '%s' from %s; skipping every colliding " "entry instead of choosing an arbitrary handler", name, registry_name, ", ".join(origins)) return [c for c in unique if c.registry_name not in ambiguous and (c.registry_name, c.origin) not in shadowed] def _register_candidates(name: str, candidates: List[_Candidate], *, check_fn: Callable, scope: Callable[[], Optional[str]], lazy: bool) -> List[str]: """Register candidates under toolset ``mcp-{name}``; returns the names that landed. The ownership pre-check is advisory (servers connect in parallel): ``registry.register()`` is the atomic gate and its verdict is re-read after every call.""" from tools.registry import registry toolset_name = f"mcp-{name}" registered: List[str] = [] for c in candidates: existing_toolset = registry.get_toolset_for_tool(c.registry_name) if existing_toolset and existing_toolset != toolset_name: # foreign owner: skip, preserve it if lazy: if not c.is_utility: logger.warning("MCP server '%s' (lazy): cached tool '%s' collides with toolset '%s' — skipping", name, c.registry_name, existing_toolset) elif existing_toolset.startswith("mcp-"): logger.error("MCP server '%s': %s normalizes to '%s', already owned by MCP toolset '%s' — skipping to " "preserve the existing owner", name, c.origin, c.registry_name, existing_toolset) else: logger.warning("MCP server '%s': %s (→ '%s') collides with built-in tool in toolset '%s' — skipping to " "preserve built-in", name, c.origin, c.registry_name, existing_toolset) continue registry.register( name=c.registry_name, toolset=toolset_name, schema=c.schema, handler=c.handler, check_fn=check_fn, is_async=False, description=c.schema.get("description") or "", scope=scope()) if registry.get_toolset_for_tool(c.registry_name) == toolset_name: _track_mcp_tool_server(c.registry_name, name) registered.append(c.registry_name) elif not lazy: logger.error("MCP server '%s': registration of %s as '%s' was rejected by the registry; " "skipping provenance/count updates", name, c.origin, c.registry_name) if registered: registry.register_toolset_alias(name, toolset_name) return registered def _write_schema_cache(name: str, server: "MCPServerTask", config: dict, should_register) -> None: """Write-through: persist the manifest so the next startup registers this server lazily (no spawn). Never raises.""" try: # Write-through (#56832): refresh the on-disk schema cache after a live connect so the next startup # can lazily register this server without spawning it. Cache failures never break registration. from tools.mcp_schema_cache import config_fingerprint, write_cache_entry tools_payload = [] for t in server._tools: if not should_register(t.name): continue # mcp 2.0 renamed every Tool model field to snake_case and left camelCase as a # *serialization* alias only, which pydantic does not apply to attribute access: a bare # camelCase getattr returns None on 2.x instead of raising. That silently wrote an empty # ``inputSchema`` into the schema cache on every write-through, so a ``lazy: true`` server # registered from cache with every parameter stripped. ``mcp_field`` reads both spellings. schema_obj = mcp_field(t, "input_schema", "inputSchema") tools_payload.append({ "name": t.name, "description": t.description or "", "inputSchema": schema_obj if isinstance(schema_obj, dict) else {}, "annotations": {"readOnlyHint": _annotation_read_only_hint(t)}, # lazy path trust-gates identically }) utility_payload = [{"schema": e["schema"], "handler_key": e["handler_key"]} for e in _select_utility_schemas(name, server, config)] cache_meta = getattr(server, "_list_cache_meta", None) or {} write_cache_entry(name, config_fingerprint(config), tools=tools_payload, utility_tools=utility_payload, ttl_ms=cache_meta.get("ttl_ms"), cache_scope=cache_meta.get("cache_scope")) except Exception as exc: logger.debug("MCP schema cache write failed for '%s': %s", name, exc) def _register_server_tools(name: str, server: "MCPServerTask", config: dict) -> List[str]: """Register a connected server's tools plus utilities (initial discovery and list_changed refresh); returns the names. Toolset aliases derive from the live registry, not ``toolsets.TOOLSETS``; lossy normalization collisions (``read-file``/``read_file``) fail closed.""" should_register = _make_tool_filter(name, config) _record_tool_trust_metadata(name, config, server._tools) candidates = _tool_candidates(name, server._tools, should_register, server.tool_timeout) candidates += _utility_candidates(name, _select_utility_schemas(name, server, config), server.tool_timeout) registered = _register_candidates( name, _resolve_name_collisions(name, candidates), check_fn=_make_check_fn(name), scope=lambda: _core._server_registry_scope(name), lazy=False) if registered: _write_schema_cache(name, server, config, should_register) return registered def _register_from_cache_sync(name: str, config: dict, entry: dict) -> List[str]: """Lazy startup: register from a cached manifest with no child process (first real call goes through ``_ensure_lazy_server_connected``). Trust metadata is recorded first so the call-time gate is identical for live and cached registrations. Lazy startup (#56832, design by Vansh5632): tools appear in the registry immediately; the first real call routes through ``_get_connected_server_for_call`` → ``_ensure_lazy_server_connected``. """ from tools.mcp_schema_cache import config_fingerprint, tools_from_cache_entry, utility_tools_from_cache_entry tool_timeout = _resolve_tool_timeout(config) cached_tools = _cached_tools(tools_from_cache_entry(entry)) _record_tool_trust_metadata(name, config, cached_tools) candidates = _tool_candidates(name, cached_tools, _make_tool_filter(name, config), tool_timeout) candidates += _utility_candidates(name, utility_tools_from_cache_entry(entry), tool_timeout) registered = _register_candidates( name, candidates, check_fn=_make_check_fn(name), scope=_core._mcp_registry_scope, lazy=True) if registered: with _core._lock: _core._lazy_server_configs[name] = dict(config) _core._lazy_server_fingerprints[name] = config_fingerprint(config) _core._lazy_server_tool_names[name] = list(registered) logger.info("MCP server '%s' (lazy): registered %d tool(s) from schema cache", name, len(registered)) return registered