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c96c0400f3* feat: Add search transforms for tool discovery RegexSearchTransform and BM25SearchTransform collapse large tool catalogs into a search interface so LLMs discover tools on demand instead of receiving the full listing. * chore: Update SDK documentation * fix: call_tool recursion guard, atomic BM25 rebuild, hash includes descriptions * Extract CatalogTransform base class for catalog-aware transforms Transforms that replace list_tools() with synthetic components (like search) need to read the real catalog at call time without triggering their own replacement logic. CatalogTransform handles the re-entrant bypass via per-instance ContextVar, exposing transform_tools() as the subclass hook and get_tool_catalog() for catalog access. * Add search transform examples for regex and BM25 * Add README for search transform examples * Polish search example clients with rich output * Remove hardcoded tool counts from search example subtitles * Clarify that review bot feedback should be evaluated on its merits * Expand search transform docs with proper hierarchy --------- Co-authored-by: marvin-context-protocol[bot] <225465937+marvin-context-protocol[bot]@users.noreply.github.com>
82 lines
2.6 KiB
Python
82 lines
2.6 KiB
Python
"""Tests for CatalogTransform base class."""
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from __future__ import annotations
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from collections.abc import Sequence
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from mcp.types import TextContent
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from fastmcp import FastMCP
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from fastmcp.server.context import Context
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from fastmcp.server.transforms import GetToolNext
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from fastmcp.server.transforms.catalog import CatalogTransform
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from fastmcp.tools.tool import Tool
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from fastmcp.utilities.versions import VersionSpec
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class ReplacingTransform(CatalogTransform):
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"""Minimal subclass that replaces tools with a synthetic tool.
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Uses ``get_tool_catalog()`` to read the real catalog inside the
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synthetic tool's handler, verifying that the bypass mechanism works.
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"""
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async def transform_tools(self, tools: Sequence[Tool]) -> Sequence[Tool]:
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return [self._make_synthetic_tool()]
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async def get_tool(
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self, name: str, call_next: GetToolNext, *, version: VersionSpec | None = None
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) -> Tool | None:
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if name == "count_tools":
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return self._make_synthetic_tool()
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return await call_next(name, version=version)
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def _make_synthetic_tool(self) -> Tool:
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transform = self
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async def count_tools(ctx: Context = None) -> int: # type: ignore[assignment]
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"""Return the number of real tools in the catalog."""
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catalog = await transform.get_tool_catalog(ctx)
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return len(catalog)
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return Tool.from_function(fn=count_tools, name="count_tools")
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class TestCatalogTransformBypass:
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async def test_list_tools_replaced_by_subclass(self):
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mcp = FastMCP("test")
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@mcp.tool
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def add(a: int, b: int) -> int:
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return a + b
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@mcp.tool
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def multiply(x: float, y: float) -> float:
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return x * y
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mcp.add_transform(ReplacingTransform())
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tools = await mcp.list_tools()
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names = {t.name for t in tools}
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assert names == {"count_tools"}
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async def test_get_tool_catalog_returns_real_tools(self):
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mcp = FastMCP("test")
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@mcp.tool
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def add(a: int, b: int) -> int:
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return a + b
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@mcp.tool
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def multiply(x: float, y: float) -> float:
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return x * y
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mcp.add_transform(ReplacingTransform())
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result = await mcp.call_tool("count_tools", {})
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assert any("2" in c.text for c in result.content if isinstance(c, TextContent))
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async def test_multiple_instances_have_independent_bypass(self):
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"""Each CatalogTransform instance has its own bypass ContextVar."""
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t1 = ReplacingTransform()
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t2 = ReplacingTransform()
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assert t1._instance_id != t2._instance_id
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assert t1._bypass is not t2._bypass
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