Get AsyncAPI Spec Metadata

Instructions

Implementation Reference

• src/tools.ts:54-69 (handler)

  The handler function for the 'get_asyncapi_spec_metadata' tool. It calls fetchAsyncApiSpec(version) to retrieve the spec entry, then getSpecMetadata(entry) to extract metadata, and returns it as JSON.

  async ({ version }) => {
      try {
          const entry = await fetchAsyncApiSpec(version);
          const metadata = getSpecMetadata(entry);
  
          return {
              content: [{ type: 'text', text: JSON.stringify(metadata, null, 2) }],
              structuredContent: metadata,
          };
      } catch (error) {
          return {
              isError: true,
              content: [{ type: 'text', text: formatUnknownError(error) }],
          };
      }
  }

• src/tools.ts:47-52 (schema)

  Input schema for the 'get_asyncapi_spec_metadata' tool. It accepts an optional 'version' string parameter (e.g., '3.0.0').

  inputSchema: z.object({
      version: z
          .string()
          .optional()
          .describe('Optional spec version, for example "3.0.0". Defaults to latest from master.'),
  }),

• src/tools.ts:42-70 (registration)

  Registration of the 'get_asyncapi_spec_metadata' tool on the MCP server via mcpServer.registerTool().

  mcpServer.registerTool(
      'get_asyncapi_spec_metadata',
      {
          title: 'Get AsyncAPI Spec Metadata',
          description: 'Return source, version, cache, and size metadata for the latest AsyncAPI specification.',
          inputSchema: z.object({
              version: z
                  .string()
                  .optional()
                  .describe('Optional spec version, for example "3.0.0". Defaults to latest from master.'),
          }),
      },
      async ({ version }) => {
          try {
              const entry = await fetchAsyncApiSpec(version);
              const metadata = getSpecMetadata(entry);
  
              return {
                  content: [{ type: 'text', text: JSON.stringify(metadata, null, 2) }],
                  structuredContent: metadata,
              };
          } catch (error) {
              return {
                  isError: true,
                  content: [{ type: 'text', text: formatUnknownError(error) }],
              };
          }
      }
  );

• src/asyncapi-spec.ts:234-244 (helper)

  The getSpecMetadata() helper function that constructs a SpecMetadata object from a SpecCacheEntry, including sourceUrl, version, cache age, content size, etc.

  export const getSpecMetadata = (entry: SpecCacheEntry): SpecMetadata => ({
      sourceUrl: entry.sourceUrl,
      version: entry.version ?? null,
      requestedVersion: entry.requestedVersion ?? null,
      resolvedTag: entry.resolvedTag ?? null,
      fetchedAt: entry.fetchedAt.toISOString(),
      cacheAgeSeconds: Math.floor((Date.now() - entry.fetchedAt.getTime()) / 1000),
      hasEtag: Boolean(entry.etag),
      hasLastModified: Boolean(entry.lastModified),
      contentSizeBytes: new TextEncoder().encode(entry.text).byteLength,
  });