import logger from '@src/logger/logger.js';
import type { ClientInfo, ContextNamespace, EnvironmentContext, UserContext } from '@src/types/context.js';
import type { Request } from 'express';
// Header constants for context transmission (now only for session ID)
export const CONTEXT_HEADERS = {
SESSION_ID: 'mcp-session-id', // Use standard streamable HTTP header
} as const;
/**
* Type guard to check if a value is a valid ContextData
*/
function isContextData(value: unknown): value is {
project: ContextNamespace;
user: UserContext;
environment: EnvironmentContext;
timestamp?: string;
version?: string;
sessionId?: string;
} {
return (
typeof value === 'object' &&
value !== null &&
'project' in value &&
'user' in value &&
'environment' in value &&
typeof (value as { project: unknown }).project === 'object' &&
typeof (value as { user: unknown }).user === 'object' &&
typeof (value as { environment: unknown }).environment === 'object'
);
}
/**
* Extract context data from _meta field in request body (from STDIO proxy)
*/
export function extractContextFromMeta(req: Request): {
project?: ContextNamespace;
user?: UserContext;
environment?: EnvironmentContext;
timestamp?: string;
version?: string;
sessionId?: string;
transport?: {
type: string;
connectionId?: string;
connectionTimestamp?: string;
client?: ClientInfo;
};
} | null {
try {
// Check if request body exists and has params with _meta
const body = req.body as {
params?: {
_meta?: {
context?: unknown;
};
};
};
if (!body?.params?._meta?.context) {
return null;
}
const contextData = body.params._meta.context;
// Validate that the context has the correct structure
if (!isContextData(contextData)) {
logger.warn('Invalid context structure in _meta field, ignoring context');
return null;
}
logger.info(`📊 Extracted context from _meta field: ${contextData.project.name} (${contextData.sessionId})`);
const result: {
project?: ContextNamespace;
user?: UserContext;
environment?: EnvironmentContext;
timestamp?: string;
version?: string;
sessionId?: string;
transport?: {
type: string;
connectionId?: string;
connectionTimestamp?: string;
client?: ClientInfo;
};
} = {
project: contextData.project,
user: contextData.user,
environment: contextData.environment,
timestamp: contextData.timestamp,
version: contextData.version,
sessionId: contextData.sessionId,
};
// Include transport info if present
if (
'transport' in contextData &&
contextData.transport &&
typeof contextData.transport === 'object' &&
'type' in contextData.transport
) {
result.transport = contextData.transport as {
type: string;
connectionId?: string;
connectionTimestamp?: string;
client?: ClientInfo;
};
}
return result;
} catch (error) {
logger.error(
'Failed to extract context from _meta field:',
error instanceof Error ? error : new Error(String(error)),
);
return null;
}
}
