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fix: revert actor correlation changes for session identification #12

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fix: revert actor correlation changes for session identification #12

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2 changes: 1 addition & 1 deletion src/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -179,7 +179,7 @@ function track(
identify: options.identify,
redactSensitiveInformation: options.redactSensitiveInformation,
},
sessionSource: "mcpcat", // Initially MCPCat-generated, will change to "mcp" if MCP sessionId is provided
sessionSource: "mcpcat", // Initially MCPCat-generated, will change to "mcp" if MCP sessionId is provided in requests
};

setServerTrackingData(lowLevelServer, mcpcatData);
Expand Down
122 changes: 0 additions & 122 deletions src/modules/internal.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,6 @@ import { PublishEventRequestEventTypeEnum } from "mcpcat-api";
import { publishEvent } from "./eventQueue.js";
import { getMCPCompatibleErrorMessage } from "./compatibility.js";
import { writeToLog } from "./logging.js";
import { INACTIVITY_TIMEOUT_IN_MINUTES } from "./constants.js";

/**
* Simple LRU cache for session identities.
Expand Down Expand Up @@ -66,66 +65,6 @@ class IdentityCache {
// This prevents duplicate identify events when server objects are recreated
const _globalIdentityCache = new IdentityCache(1000);

/**
* Maps userId to recent session IDs for reconnection support.
* When a user reconnects (new initialize without MCP sessionId),
* we can reuse their previous session if it's recent enough.
*/
class UserSessionCache {
private cache: Map<string, { sessionId: string; lastSeen: number }>;
private maxSize: number;

constructor(maxSize: number = 1000) {
this.cache = new Map();
this.maxSize = maxSize;
}

getRecentSession(userId: string, timeoutMs: number): string | undefined {
const entry = this.cache.get(userId);
if (!entry) return undefined;

// Check if session has expired
if (Date.now() - entry.lastSeen > timeoutMs) {
this.cache.delete(userId);
return undefined;
}

return entry.sessionId;
}

set(userId: string, sessionId: string): void {
// Remove if already exists (to re-add at end for LRU)
this.cache.delete(userId);

// Evict oldest if at capacity
if (this.cache.size >= this.maxSize) {
const oldestKey = this.cache.keys().next().value;
if (oldestKey !== undefined) {
this.cache.delete(oldestKey);
}
}

this.cache.set(userId, { sessionId, lastSeen: Date.now() });
}
}

// Global user session cache for reconnection support
const _globalUserSessionCache = new UserSessionCache(1000);

/**
* FOR TESTING ONLY: Manually set a user session cache entry with custom lastSeen timestamp
*/
export function _testSetUserSession(
userId: string,
sessionId: string,
lastSeenMs: number,
): void {
(_globalUserSessionCache as any).cache.set(userId, {
sessionId,
lastSeen: lastSeenMs,
});
}

// Internal tracking storage
const _serverTracking = new WeakMap<MCPServerLike, MCPCatData>();

Expand Down Expand Up @@ -224,64 +163,6 @@ export async function handleIdentify(
try {
const identityResult = await data.options.identify(request, extra);
if (identityResult) {
// Check for session reconnection (if no MCP sessionId provided in extra)
// If this user had a recent session, switch to it instead of creating new one
if (!extra?.sessionId && identityResult.userId) {
const timeoutMs = INACTIVITY_TIMEOUT_IN_MINUTES * 60 * 1000;
const previousSessionId = _globalUserSessionCache.getRecentSession(
identityResult.userId,
timeoutMs,
);

if (previousSessionId && previousSessionId !== data.sessionId) {
// User has a previous session - reconnect to it
const currentSessionIdentity = _globalIdentityCache.get(
data.sessionId,
);

if (!currentSessionIdentity) {
// Current session is brand new (no identity) - reconnect to previous session
data.sessionId = previousSessionId;
data.lastActivity = new Date();
setServerTrackingData(server, data);

writeToLog(
`Reconnected user ${identityResult.userId} to previous session ${previousSessionId} (current session was new)`,
);
} else if (currentSessionIdentity.userId !== identityResult.userId) {
// Current session belongs to different user - reconnect to user's previous session
data.sessionId = previousSessionId;
data.lastActivity = new Date();
setServerTrackingData(server, data);

writeToLog(
`Reconnected user ${identityResult.userId} to previous session ${previousSessionId}`,
);
}
// If current session already belongs to this user, no need to do anything
} else if (!previousSessionId) {
// User has NO previous session - check if current session belongs to someone else
const currentSessionIdentity = _globalIdentityCache.get(
data.sessionId,
);
if (
currentSessionIdentity &&
currentSessionIdentity.userId !== identityResult.userId
) {
// Current session belongs to different user - create new session
const { newSessionId } = await import("./session.js");
data.sessionId = newSessionId();
data.sessionSource = "mcpcat";
data.lastActivity = new Date();
setServerTrackingData(server, data);

writeToLog(
`Created new session ${data.sessionId} for user ${identityResult.userId} (previous session belonged to ${currentSessionIdentity.userId})`,
);
}
}
}

// Now use the (possibly updated) sessionId for all subsequent operations
const currentSessionId = data.sessionId;

Expand All @@ -302,9 +183,6 @@ export async function handleIdentify(
// Per-server cache: used by getSessionInfo() for fast local access
data.identifiedSessions.set(data.sessionId, mergedIdentity);

// Track userId → sessionId mapping for reconnection support
_globalUserSessionCache.set(mergedIdentity.userId, currentSessionId);

if (hasChanged) {
writeToLog(
`Identified session ${currentSessionId} with identity: ${JSON.stringify(mergedIdentity)}`,
Expand Down
19 changes: 8 additions & 11 deletions src/modules/session.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -69,17 +69,14 @@ export function getServerSessionId(

// If MCP sessionId is provided
if (mcpSessionId) {
// Check if it's a new or changed MCP sessionId
if (mcpSessionId !== data.lastMcpSessionId) {
// Derive deterministic KSUID from MCP sessionId
data.sessionId = deriveSessionIdFromMCPSession(
mcpSessionId,
data.projectId || undefined,
);
data.lastMcpSessionId = mcpSessionId;
data.sessionSource = "mcp";
setServerTrackingData(server, data);
}
// Derive deterministic KSUID from MCP sessionId
data.sessionId = deriveSessionIdFromMCPSession(
mcpSessionId,
data.projectId || undefined,
);
data.lastMcpSessionId = mcpSessionId;
data.sessionSource = "mcp";
setServerTrackingData(server, data);
// If MCP sessionId hasn't changed, continue using the existing derived KSUID
setLastActivity(server);
return data.sessionId;
Expand Down
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