Document restyling job with MCP verification in Node.js

import express from 'express';
import { z } from 'zod';
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';

// Stand-in for your checks. The first defined-terms check reports one violation, the next one is clean.
let definedTermsCalls = 0;

function createServer() {
	const server = new McpServer( { name: 'filing-style-checks', version: '1.0.0' } );
	const inputSchema = { document: z.string().describe( 'The full HTML of the filing, with data-id attributes.' ) };

	server.registerTool( 'check_defined_terms', {
		description: 'Checks that every defined term is introduced once, in quotes and bold, and used consistently afterwards. ' +
			'Returns the violations, each with the data-id of the element.',
		inputSchema
	}, async () => {
		definedTermsCalls++;
		const violations = definedTermsCalls === 1 ? [ { dataId: 'e4', term: 'Credit Agreement', problem: 'used before definition' } ] : [];

		return { content: [ { type: 'text', text: JSON.stringify( { violations } ) } ] };
	} );

	server.registerTool( 'check_number_format', {
		description: 'Checks that amounts are in thousands with the unit stated once per table, negatives in parentheses, ' +
			'and percentages to one decimal. Returns the violations, each with the data-id of the element.',
		inputSchema
	}, async () => ( { content: [ { type: 'text', text: JSON.stringify( { violations: [] } ) } ] } ) );

	server.registerTool( 'check_cross_references', {
		description: 'Checks that every "see Item 7" and "Note 12" points at a heading that exists. ' +
			'Returns the violations, each with the data-id of the element.',
		inputSchema
	}, async () => ( { content: [ { type: 'text', text: JSON.stringify( { violations: [] } ) } ] } ) );

	return server;
}

const app = express();
app.use( express.json( { limit: '32mb' } ) );

app.use( '/mcp', ( req, res, next ) => {
	if ( req.headers.authorization !== `Bearer ${ process.env.MCP_TOKEN }` ) {
		res.sendStatus( 401 );
		return;
	}
	next();
} );

app.post( '/mcp', async ( req, res ) => {
	const server = createServer();
	const transport = new StreamableHTTPServerTransport( { sessionIdGenerator: undefined } );

	res.on( 'close', () => {
		transport.close();
		server.close();
	} );

	await server.connect( transport );
	await transport.handleRequest( req, res, req.body );
} );

app.get( '/mcp', ( req, res ) => res.sendStatus( 405 ) );
app.delete( '/mcp', ( req, res ) => res.sendStatus( 405 ) );

app.listen( 3020, () => console.log( 'Checks server listening on http://localhost:3020/mcp' ) );

import { readFile, writeFile, readdir } from 'node:fs/promises';

const HOST = process.env.CKEDITOR_AI_HOST;	// your on-premises CKEditor AI
const TOKEN = process.env.CKEDITOR_AI_TOKEN;  // from your token endpoint
const STYLE_GUIDE = await readFile( './style-guide.txt', 'utf8' );

for ( const file of await readdir( './inbox' ) ) {
	const html = await readFile( `./inbox/${ file }`, 'utf8' );

	const response = await fetch( `${ HOST }/v1/documents/process`, {
		method: 'POST',
		headers: { 'Authorization': `Bearer ${ TOKEN }`, 'Content-Type': 'application/json' },
		body: JSON.stringify( {
			content: [ { type: 'document', content: html } ],
			prompt: STYLE_GUIDE,
			model: 'agent-1'
		} ),
		signal: AbortSignal.timeout( 10 * 60 * 1000 ) // the service allows up to 10 minutes per call
	} );

	if ( !response.ok ) {
		console.error( `${ file }: ${ response.status } ${ await response.text() }` );
		continue;
	}

	const { documents: [ result ] } = await response.json();

	await writeFile( `./review/${ file }`, result.document );
	await writeFile( `./review/${ file }.summary.txt`, result.summary );
	console.log( `${ file }: ${ result.summary.split( '\n' )[ 0 ] }` );
}

import { readFile } from 'node:fs/promises';

const HOST = process.env.CKEDITOR_AI_HOST;	// your on-premises CKEditor AI
const TOKEN = process.env.CKEDITOR_AI_TOKEN;  // from your token endpoint

async function stream( path, body ) {
	const response = await fetch( `${ HOST }${ path }`, {
		method: 'POST',
		headers: { 'Authorization': `Bearer ${ TOKEN }`, 'Content-Type': 'application/json', 'Accept': 'text/event-stream' },
		body: JSON.stringify( body )
	} );

	if ( !response.ok ) {
		throw new Error( `${ response.status } ${ await response.text() }` );
	}

	const decoder = new TextDecoder();
	let buffer = '';

	for await ( const chunk of response.body ) {
		buffer += decoder.decode( chunk, { stream: true } );

		let end;
		while ( ( end = buffer.indexOf( '\n\n' ) ) >= 0 ) {
			const lines = buffer.slice( 0, end ).split( '\n' );
			buffer = buffer.slice( end + 2 );

			const event = lines.find( line => line.startsWith( 'event: ' ) )?.slice( 7 );
			const data = lines.find( line => line.startsWith( 'data: ' ) )?.slice( 6 );

			console.log( `event: ${ event }\ndata: ${ data }\n` );
		}
	}
}

await stream( '/v1/documents/process/stream', JSON.parse( await readFile( './request.json', 'utf8' ) ) );