/* eslint-disable */
/**
* Stdio silencer and stdout mirror for MCP stdio mode (container-only).
* - Silences all console methods to prevent non-JSON stdout contamination
* - Mirrors process stdout to /app/logs/stdout-raw.log (diagnostics only)
* - Mirrors process stdin to /app/logs/stdin-raw.log (diagnostics only)
* - Does NOT alter or gate protocol output (avoids interfering with SDK framing)
* - Does nothing when not in stdio mode
*/
(function main() {
try {
const fs = require('fs');
const path = require('path');
const stripQuotes = (value) => typeof value === 'string'
? value.toLowerCase().replace(/^["']|["']$/g, '')
: '';
const matchesKeyword = (arg, keyword) => {
const normalized = stripQuotes(arg);
if (!normalized) {
return false;
}
if (normalized === keyword) {
return true;
}
if (normalized.endsWith('=' + keyword) || normalized.endsWith(':' + keyword)) {
return true;
}
if (normalized.startsWith('--transport') && normalized.includes('=' + keyword)) {
return true;
}
return false;
};
const argvValues = Array.isArray(process.argv) ? process.argv : [];
const shouldSilence = argvValues.some(arg => matchesKeyword(arg, 'stdio')) ||
argvValues.some(arg => matchesKeyword(arg, 'sse')) ||
process.env.CONSOLE_OUTPUT_SILENCED === '1';
if (!shouldSilence) {
return;
}
// Silence console methods to avoid any non-protocol output on stdout/stderr
const noop = () => {};
console.log = noop;
console.error = noop;
console.warn = noop;
console.info = noop;
console.debug = noop;
console.trace = noop;
// Suppress process warnings as an extra precaution
try {
process.removeAllListeners('warning');
} catch (_) {}
process.on('warning', noop);
// Prepare logs directory
const logsDir = '/app/logs';
try {
fs.mkdirSync(logsDir, { recursive: true });
} catch (_) {}
// Mirror stdin raw for diagnostics (what the server receives)
try {
const stdinLogPath = path.join(logsDir, 'stdin-raw.log');
const stdinLogStream = fs.createWriteStream(stdinLogPath, { flags: 'a' });
if (process.stdin && typeof process.stdin.on === 'function') {
process.stdin.on('data', (chunk) => {
try {
stdinLogStream.write(chunk);
} catch (_) {}
});
}
} catch (_) {}
// Mirror stdout to a file for diagnostics (non-invasive: do not modify content or gating)
try {
const stdoutLogPath = path.join(logsDir, 'stdout-raw.log');
const stdoutLogStream = fs.createWriteStream(stdoutLogPath, { flags: 'a' });
const origWrite = process.stdout.write.bind(process.stdout);
process.stdout.write = function(chunk, encoding, callback) {
try {
// Write exactly what would be sent to client without any modification
stdoutLogStream.write(chunk);
} catch (_) {}
return origWrite(chunk, encoding, callback);
};
} catch (err) {
try {
fs.appendFileSync(path.join(logsDir, 'stdio-silencer-error.log'),
`Failed to setup stdout mirror: ${err.message}\n`);
} catch (_) {}
}
} catch (e) {
// Never throw from preloader
}
})();
