How every AI tool handles memory, and where each one loses it

33 tools, one page each. What the tool stores today per its own docs, what it forgets between sessions and after compaction, and the exact fix. No tool-name swapping; every page is built from that tool's real memory model.

Start with your tool below, or read the problem pages at /fix and the honest comparisons at /compare.

Coding agents and editors

Tools where the agent writes code in your repository. Most connect over hooks or MCP.

Claude Code by Anthropic

Keep project decisions across sessions and compaction with the published hook package.

Codex by OpenAI

Persistent project context for Codex sessions, with a published hooks package.

Cursor by Anysphere

Connect the vault as a remote MCP server so new chats open with project decisions.

Windsurf by Windsurf (Cascade)

Workspace memories plus a shared vault over MCP for Cascade sessions.

Cline by Cline

Memory Bank discipline plus a shared vault over MCP for cross-session recall.

Aider by Aider

Drop-in OpenAI-compatible endpoint that recalls and stores automatically.

Zed by Zed Industries

Agent panel threads plus a shared vault over a remote context server.

Continue by Continue

Rules for behavior plus a shared vault over MCP for agent sessions.

Sourcegraph Cody by Sourcegraph

MCP bridge from Cody to the MemoryRouter vault on enterprise instances.

GitHub Copilot by GitHub

Repository instructions plus Copilot memory, and where a portable vault fits.

Gemini CLI by Google

GEMINI.md context files plus a remote MCP server for durable memory.

Roo Code by Roo Code

Custom instructions and MCP tools for memory that outlives a task.

Kilo Code by Kilo Code

AGENTS.md is now the memory path, with MCP for a durable vault.

OpenCode by SST

AGENTS.md for instructions, MCP for a vault that outlives sessions.

Goose by Block

.goosehints plus an MCP memory extension for cross-session context.

Amp by Sourcegraph

AGENTS.md discovery plus MCP, where policy allows, for durable recall.

Chat apps and builders

Products where memory lives inside the vendor, and where the boundary actually sits.

ChatGPT by OpenAI

Saved memories and chat history, plus a Developer mode connector for one shared vault.

Claude by Anthropic

Claude memory across chats and Cowork, plus a connector for a shared vault.

Perplexity by Perplexity

Memory and Brain for answers, and what that means for build work.

OpenClaw by OpenClaw

Workspace files plus the mr-memory plugin for sessions that keep their context.

Hermes Agent by Hermes

Swap the memory provider to MemoryRouter with a published Python package.

DeepSeek Harness by DeepSeek Harness

Install the dsh-memoryrouter plugin for durable profile-scoped memory.

Devin by Cognition

Knowledge items with trigger descriptions, and where project memory lives.

Replit Agent by Replit

Memories, custom instructions, and skills, and what stays on the platform.

Bolt by StackBlitz

Project knowledge versus working context, and the handoff problem.

Lovable by Lovable

Workspace knowledge and skills, and where cross-tool memory goes.

v0 by Vercel

Chat context per conversation, knowledge uploads, and the repo handoff.

Agent frameworks and SDKs

Tools for building your own product, where memory has to work per user at scale.

LangGraph by LangChain

Checkpointers for threads plus a published package for durable, per-user memory.

CrewAI by CrewAI

A unified memory class for crews, and where durable per-user memory fits.

AutoGen by Microsoft

A Memory protocol for agents, plus a durable store behind it.

Mastra by Mastra

Working memory, semantic recall, and a managed store behind them.

LlamaIndex by LlamaIndex

Memory blocks and chat stores, with a managed vault behind them.

Vercel AI SDK by Vercel

Agents and message persistence, with a memory provider behind them.

Problem pages

The exact failure in the exact words people search: lost context after compaction, forgotten decisions, sessions that ask you to explain the codebase again.

Claude Code lost context after compaction

Free fixes first, then the durable fix.

Cursor forgets project context

Free fixes first, then the durable fix.

Codex memory between sessions

Free fixes first, then the durable fix.

context window exceeded

Free fixes first, then the durable fix.

conversation too long

Free fixes first, then the durable fix.

AI forgets what I told it yesterday

Free fixes first, then the durable fix.

See every problem page

Comparisons

MemoryRouter against the real alternatives, with dated pricing and sources. Including where the other option is the better choice.

MemoryRouter vs Mem0