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ede8ff6703* Simplify Provider interface and consolidate docket registration - Remove get_http_routes from Provider (unused) - Remove ProviderLifespanConfig, _base_lifespan, _register_tasks - Remove supports_tasks flag from Provider.__init__ - Consolidate all docket registration in server._docket_lifespan() - Simplify lifespan() to take no parameters - Move MountedProvider to separate module * Fix control flow in ComponentService resource methods * Move providers to server/providers * Ensure MountedProvider get_* methods go through middleware * Fix get_resource to only return concrete resources Reverts template-checking in get_resource that broke task execution. Tasks need access to the original template, not instantiated resources. * Move prefix utilities into mounted.py, deprecate import_server - Add resource prefix functions (add/remove/has_resource_prefix) to mounted.py - Deprecate import_server with warning to use mount() instead - Add tool_names uniqueness validation in MountedProvider * Fix provider iteration order and remove dead _is_mounted flag - Remove unused _is_mounted flag (MountedProvider.lifespan() calls _lifespan not _lifespan_manager, so the flag was never checked) - Fix provider iteration: change reversed() to forward order in execution methods (_call_tool, _read_resource_middleware, _get_prompt_content_middleware) to match documented "first non-None wins" semantics - Fix ComponentService to handle prefix-less mounted servers using _strip_tool_prefix()/_strip_resource_prefix() methods - Update conflict resolution tests to expect first-registered provider wins - Add regression tests for Docket behavior and prefix-less ComponentService * Add TaskComponents type and exception handling for provider task registration - Create TaskComponents dataclass with FunctionTool/FunctionResource/etc. types for proper typing of get_tasks() return value - Add try/except wrapper around provider.get_tasks() in _docket_lifespan for consistent error handling (warn + continue or raise based on settings) - Remove type: ignore comments from server.py task registration loop
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1.8 KiB
Dynamic Tools from SQLite
This example demonstrates serving MCP tools from a database. Tools can be added, modified, or disabled by updating the database - no server restart required.
Structure
tools.db- SQLite database with tool configurations (committed for convenience)setup_db.py- Script to create/reset the databaseserver.py- MCP server that loads tools from the database
Usage
# Reset the database (optional - tools.db is pre-seeded)
uv run examples/providers/sqlite/setup_db.py
# Run the server
uv run fastmcp run examples/providers/sqlite/server.py
How It Works
The SQLiteToolProvider queries the database on every list_tools and call_tool request:
class SQLiteToolProvider(BaseToolProvider):
async def list_tools(self) -> list[Tool]:
# Query database for enabled tools
...
async def get_tool(self, name: str) -> Tool | None:
# Efficient single-tool lookup
...
Tools are defined as ConfigurableTool subclasses that combine schema and execution:
class ConfigurableTool(Tool):
operation: str # "add", "multiply", etc.
async def run(self, arguments: dict[str, Any]) -> ToolResult:
# Execute based on configured operation
...
Modifying Tools at Runtime
While the server is running, you can modify tools in the database:
# Add a new tool
sqlite3 examples/providers/sqlite/tools.db "INSERT INTO tools VALUES ('subtract_numbers', 'Subtract two numbers', '{\"type\":\"object\",\"properties\":{\"a\":{\"type\":\"number\"},\"b\":{\"type\":\"number\"}},\"required\":[\"a\",\"b\"]}', 'subtract', 0, 1)"
# Disable a tool
sqlite3 examples/providers/sqlite/tools.db "UPDATE tools SET enabled = 0 WHERE name = 'divide_numbers'"
The next list_tools or call_tool request will reflect these changes.