read-metadata
Extract and analyze metadata from images including EXIF, GPS, XMP, ICC, IPTC, JFIF, and IHDR segments for offline image analysis and data extraction.
Instructions
Read all or specified metadata segments from an image
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| image | Yes | ||
| segments | No |
Implementation Reference
- src/tools/index.ts:69-84 (handler)The core handler function for the 'read-metadata' tool. Loads image buffer using loadImage, builds exifr options from segments using buildOptions, parses metadata with exifr.parse, returns success response with metadata JSON or error.
async (args, extra) => { try { const { image, segments } = args; const buf = await loadImage(image); const opts = buildOptions(segments as any); const meta = await exifr.parse(buf, opts); if (!meta || Object.keys(meta).length === 0) { return createErrorResponse('No metadata found in image'); } return createSuccessResponse(meta); } catch (error) { return createErrorResponse(`Error reading metadata: ${error instanceof Error ? error.message : String(error)}`); } } - src/tools/index.ts:54-68 (schema)Input schema definition: ImageSourceSchema (zod object for image source kinds) and segments (optional array of specific metadata segments enum). Used in server.tool call.
const ImageSourceSchema = z.object({ kind: z.enum(['path', 'url', 'base64', 'buffer']), path: z.string().optional(), url: z.string().optional(), data: z.string().optional(), buffer: z.string().optional() }); // Tool 1: read-metadata - reads all or specified metadata segments from an image const readMetadataTool = server.tool('read-metadata', "Read all or specified metadata segments from an image", { image: ImageSourceSchema, segments: z.array(z.enum(['EXIF', 'GPS', 'XMP', 'ICC', 'IPTC', 'JFIF', 'IHDR'])).optional() }, - src/tools/index.ts:63-86 (registration)Registration of the 'read-metadata' tool via server.tool() with name, description, input schema, and handler function. Reference stored in tools object.
const readMetadataTool = server.tool('read-metadata', "Read all or specified metadata segments from an image", { image: ImageSourceSchema, segments: z.array(z.enum(['EXIF', 'GPS', 'XMP', 'ICC', 'IPTC', 'JFIF', 'IHDR'])).optional() }, async (args, extra) => { try { const { image, segments } = args; const buf = await loadImage(image); const opts = buildOptions(segments as any); const meta = await exifr.parse(buf, opts); if (!meta || Object.keys(meta).length === 0) { return createErrorResponse('No metadata found in image'); } return createSuccessResponse(meta); } catch (error) { return createErrorResponse(`Error reading metadata: ${error instanceof Error ? error.message : String(error)}`); } } ); tools['read-metadata'] = readMetadataTool; - src/tools/loaders.ts:11-72 (helper)loadImage helper: asynchronously loads image data from path, URL (http/file), base64 data URI or raw, or base64 buffer into Buffer/Uint8Array. Handles errors and size limits.
export async function loadImage(src: ImageSourceType): Promise<Buffer | Uint8Array> { try { switch (src.kind) { case 'path': if (!src.path) { throw new Error('Path is required for kind="path"'); } return await fs.promises.readFile(src.path); case 'url': if (!src.url) { throw new Error('URL is required for kind="url"'); } if (src.url.startsWith('file://')) { // Handle file:// URLs by converting to filesystem path const filePath = fileURLToPath(src.url); return await fs.promises.readFile(filePath); } else { // Handle HTTP/HTTPS URLs const response = await fetch(src.url); if (!response.ok) { throw new Error(`Failed to fetch URL: ${response.status} ${response.statusText}`); } return new Uint8Array(await response.arrayBuffer()); } case 'base64': if (!src.data) { throw new Error('Data is required for kind="base64"'); } // Check for potential oversized base64 string (>30MB) if (src.data.length > 40000000) { // ~30MB in base64 throw new Error('PayloadTooLarge: Base64 data exceeds 30MB limit'); } // Handle data URIs or raw base64 if (src.data.startsWith('data:')) { const base64Data = src.data.split(',')[1]; return Buffer.from(base64Data, 'base64'); } else { return Buffer.from(src.data, 'base64'); } case 'buffer': if (!src.buffer) { throw new Error('Buffer is required for kind="buffer"'); } return Buffer.from(src.buffer, 'base64'); default: // This should never happen due to type constraints, but TypeScript needs it throw new Error(`Unsupported image source kind: ${(src as any).kind}`); } } catch (error) { if (error instanceof Error) { throw new Error(`Failed to load image: ${error.message}`); } throw error; } } - src/tools/segments.ts:24-73 (helper)buildOptions helper: creates exifr.parse options enabling all segments by default or only specified ones (EXIF/GPS via 'tiff', XMP, ICC, IPTC, JFIF, IHDR).
export function buildOptions(segments?: SegmentType[]): ExifrOptions { // Default options - include everything if segments not specified if (!segments || segments.length === 0) { return { tiff: true, // Includes EXIF and GPS xmp: true, icc: true, iptc: true, jfif: true, ihdr: true, }; } // Start with all segments disabled const options: ExifrOptions = { tiff: false, xmp: false, icc: false, iptc: false, jfif: false, ihdr: false, }; // Enable requested segments segments.forEach(segment => { switch (segment) { case 'EXIF': case 'GPS': options.tiff = true; break; case 'XMP': options.xmp = true; break; case 'ICC': options.icc = true; break; case 'IPTC': options.iptc = true; break; case 'JFIF': options.jfif = true; break; case 'IHDR': options.ihdr = true; break; } }); return options; }