@mdgate/core

The mdgate converter contract.

@mdgate/core is create(), the Converter interface, and ConvertError. Format packages implement this contract. Applications compose readers with it.

Works in Node.js, Cloudflare Workers, Edge runtimes, and browsers.

npm install @mdgate/core

Why @mdgate/core

Each format package can be used alone. create() is how you build a reader from more than one of them.

Converters compete by sniff score. Content signatures outrank extension hints. Nested converters (ZIP, PDF images, OneNote packages) call back into the same registry.

• Pure TypeScript
• No Python runtime
• No native addons
• No WASM runtime
• Zero third-party runtime dependencies

Compose a reader

import { create } from '@mdgate/core';
import { pdf } from '@mdgate/pdf';
import { docx } from '@mdgate/docx';
import { xlsx } from '@mdgate/xlsx';

const read = create([
  pdf(),
  docx(),
  xlsx(),
]);

const markdown = await read(bytes);

The optional second argument is a format hint:

const markdown = await read(bytes, {
  path: 'records.csv',
});

path is never used to read a file from disk.

Write a converter

A converter identifies its input and returns Markdown:

import type { Converter } from '@mdgate/core';
import { documentToMarkdown } from '@mdgate/document';

export function myFormat(): Converter {
  return {
    id: 'my-format',

    sniff(bytes) {
      return looksLikeMyFormat(bytes) ? 2 : 0;
    },

    convert(bytes) {
      return {
        markdown: documentToMarkdown(
          parseMyFormat(bytes),
        ),
      };
    },
  };
}

Content signatures should return 2. Extension hints should return 1.

Errors

A conversion throws when meaningful Markdown cannot be produced.

import { ConvertError, create } from '@mdgate/core';

try {
  const markdown = await read(bytes);
} catch (error) {
  if (error instanceof ConvertError) {
    console.error(error.code);
  }
}

| Code | Meaning | | --------------- | ------------------------------------------- | | unsupported | The format is unknown or unsupported | | malformed | No meaningful content could be extracted | | encrypted | The file is encrypted or password-protected | | missingPart | Required document data is missing | | io | The input could not be read | | resourceLimit | Reserved for resource-limit failures |

Need a complete reader?

npm install @mdgate/converters

import { toMarkdown } from '@mdgate/converters';

const markdown = await toMarkdown(bytes, {
  path: filename,
});

@mdgate/core is part of the open-source mdgate/converters project.

For AI agents, the same converter architecture can be used to extend read_file from text files to real-world document formats.

License

MIT