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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>
74 lines
1.8 KiB
Python
74 lines
1.8 KiB
Python
"""Example: Search transforms with regex pattern matching.
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When a server has many tools, listing them all at once can overwhelm an LLM's
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context window. Search transforms collapse the full tool catalog behind a
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search interface — clients see only `search_tools` and `call_tool`, and
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discover the real tools on demand.
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This example registers a handful of tools and applies RegexSearchTransform.
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Clients use `search_tools` with a regex pattern to find relevant tools, then
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`call_tool` to execute them by name.
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Run with:
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uv run python examples/search/server_regex.py
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"""
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from fastmcp import FastMCP
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from fastmcp.server.transforms.search import RegexSearchTransform
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mcp = FastMCP("Regex Search Demo")
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# Register a variety of tools across different domains.
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# With the search transform active, none of these appear in list_tools —
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# they're only discoverable via search.
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@mcp.tool
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def add(a: int, b: int) -> int:
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"""Add two numbers together."""
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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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"""Multiply two numbers."""
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return x * y
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@mcp.tool
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def fibonacci(n: int) -> list[int]:
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"""Generate the first n Fibonacci numbers."""
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if n <= 0:
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return []
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seq = [0, 1]
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while len(seq) < n:
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seq.append(seq[-1] + seq[-2])
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return seq[:n]
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@mcp.tool
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def reverse_string(text: str) -> str:
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"""Reverse a string."""
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return text[::-1]
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@mcp.tool
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def word_count(text: str) -> int:
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"""Count the number of words in a text."""
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return len(text.split())
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@mcp.tool
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def to_uppercase(text: str) -> str:
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"""Convert text to uppercase."""
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return text.upper()
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# Apply the regex search transform.
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# max_results limits how many tools a single search returns.
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mcp.add_transform(RegexSearchTransform(max_results=3))
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if __name__ == "__main__":
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mcp.run()
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