import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { z } from "zod";
import { getConfig } from "../config/index.js";
import { executeMultiEngineSearch } from "../domain/search/execution.js";
import { filterResultsWithSampling } from "../domain/search/filters.js";
import { createResponse } from "./utils/createResponse.js";
import { getSamplingStatus } from "../infrastructure/config/getSampling.js";
/**
* Register the search_web tool.
*/
export function registerSearchWebTool(
mcpServer: McpServer,
availableEngines: string[],
): void {
mcpServer.registerTool(
"search_web",
{
description:
"Search the web using multiple engines (e.g., Google, Bing, Brave), merge results, and optionally filter by relevance using an LLM (sampling).",
inputSchema: {
query: z.string().describe("The search query"),
engines: z
.array(z.string())
.optional()
.describe(
`Engines to use. Available: ${availableEngines.join(", ")}`,
),
max_results: z
.number()
.min(1)
.max(20)
.default(10)
.describe("Max results per engine"),
sampling: z
.boolean()
.optional()
.describe("Override global sampling setting for this request"),
},
},
async ({ query, engines, max_results, sampling }) => {
try {
const config = getConfig();
// 1. Validate engines
const selectedEngines = engines || config.defaultSearchEngines;
const validEngines = selectedEngines.filter((e) =>
availableEngines.includes(e),
);
if (validEngines.length === 0) {
return createResponse(
`No valid search engines provided. Available: ${availableEngines.join(
", ",
)}`,
true,
);
}
// Execute the search
let results = await executeMultiEngineSearch(
query,
validEngines,
max_results,
);
// Determine if sampling should be applied
// Parameter overrides global setting if provided
const samplingStatus = getSamplingStatus();
const shouldSample =
sampling !== undefined ? sampling : samplingStatus.sampling;
console.debug(
`Search: Global sampling=${samplingStatus.sampling}, Request override=${sampling}, Effective=${shouldSample}`,
);
// Apply sampling filter if enabled
if (shouldSample && results.length > 0) {
console.debug(
`Search: invoking sampling filter on ${results.length} results...`,
);
results = await filterResultsWithSampling({
query: query.trim(),
results,
maxResults: max_results,
server: mcpServer,
});
console.debug(
`Search: sampling complete. Returning ${results.length} results.`,
);
} else if (shouldSample && results.length === 0) {
console.debug(
"Search: verification enabled but no results to sample.",
);
} else {
console.debug("Search: sampling disabled, returning raw results.");
}
return createResponse(
JSON.stringify(
{
query: query.trim(),
engines: validEngines,
sampling_applied: shouldSample,
total_results: results.length,
results,
},
null,
2,
),
);
} catch (error) {
const errorMessage =
error instanceof Error ? error.message : "Unknown error";
return createResponse(`Search failed: ${errorMessage}`, true);
}
},
);
}
