handler() — mcp Function Reference

Architecture documentation for the handler() function in symbol-context.ts from the mcp codebase.

Function typescript AnalysisTools SymbolSearch calls 6

Entity Profile

AnalysisTools→ SymbolSearch→ handler() — mcp Function Reference

Dependency Diagram

graph TD
  f6b4d8d8_12fd_640f_c545_748d0e260bf0["handler()"]
  ca77ccf4_30df_6b5c_22dc_f7ba42fd0765["symbol-context.ts"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|defined in| ca77ccf4_30df_6b5c_22dc_f7ba42fd0765
  cbd676af_ec21_66d2_a9cd_83a383d7bc5b["asErrorResult()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| cbd676af_ec21_66d2_a9cd_83a383d7bc5b
  0c2dbb97_347e_7226_4d31_fbdcb85ac22b["resolveOrFetchGraph()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| 0c2dbb97_347e_7226_4d31_fbdcb85ac22b
  1595e523_decc_c3ce_72e9_f77eb66bef69["classifyApiError()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| 1595e523_decc_c3ce_72e9_f77eb66bef69
  acad5452_c49c_a5b9_12f1_5263dd556260["findSymbol()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| acad5452_c49c_a5b9_12f1_5263dd556260
  4d61d2d9_1e21_bfa3_9ab1_b3a87cf498d7["asTextContentResult()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| 4d61d2d9_1e21_bfa3_9ab1_b3a87cf498d7
  fd98a844_5daf_fa4c_d573_003b6d89b6be["renderSymbolContext()"]
  f6b4d8d8_12fd_640f_c545_748d0e260bf0 -->|calls| fd98a844_5daf_fa4c_d573_003b6d89b6be
  style f6b4d8d8_12fd_640f_c545_748d0e260bf0 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

src/tools/symbol-context.ts lines 60–118

export const handler: HandlerFunction = async (client, args, defaultWorkdir) => {
  const symbol = typeof args?.symbol === 'string' ? args.symbol.trim() : '';
  const rawDir = args?.directory as string | undefined;
  const directory = (rawDir && rawDir.trim()) || defaultWorkdir || process.cwd();

  if (!symbol) {
    return asErrorResult({
      type: 'validation_error',
      message: 'Missing required "symbol" parameter.',
      code: 'MISSING_SYMBOL',
      recoverable: false,
      suggestion: 'Provide the name of a function, class, or method to look up.',
    });
  }

  if (!directory || typeof directory !== 'string') {
    return asErrorResult({
      type: 'validation_error',
      message: 'No directory provided and no default workdir configured.',
      code: 'MISSING_DIRECTORY',
      recoverable: false,
      suggestion: 'Provide a directory parameter or start the MCP server with a workdir argument.',
    });
  }

  let graph: IndexedGraph;
  try {
    graph = await resolveOrFetchGraph(client, directory);
  } catch (error: any) {
    return asErrorResult(classifyApiError(error));
  }

  // Find the symbol
  const matches = findSymbol(graph, symbol);

  if (matches.length === 0) {
    return asTextContentResult(
      `No symbol matching "${symbol}" found in the code graph.\n\n` +
      `Try:\n` +
      `- A different spelling or casing\n` +
      `- Just the function name without the class prefix\n` +
      `- Use the \`overview\` tool to see available domains and key functions`
    );
  }

  // Render results for top matches (usually 1, sometimes a few)
  const renderedParts = await Promise.all(
    matches.slice(0, 3).map(node => renderSymbolContext(graph, node, directory))
  );
  const rendered = renderedParts.join('\n---\n\n');

  if (matches.length > 3) {
    return asTextContentResult(
      rendered + `\n\n*... and ${matches.length - 3} more matches. Use a more specific name to narrow results.*`
    );
  }

  return asTextContentResult(rendered);
};