PR review surfaced a data-loss path: pingKey returned False on ANY exception,
so a VPN flap or DNS hiccup made Rules 1/2 (reuse existing valid key) fall
through to Rule 3 (mint new shadow), silently rotating the user's API key
and rewriting plugin-sync targets (~/.claude/settings.json, .zshrc).
Now pingKey returns False ONLY on a definitive auth failure (HTTP 401/403).
Network errors, timeouts, and 5xx responses return True so the existing key
is preferred over re-minting. Mirror change in both Python and Node.
Additional fixes from the same review pass:
- --agent-caller is now PATCHed to the backend when supplied on a Rule 1
or Rule 2 reuse path (previously silently dropped). Best-effort —
failures don't break reuse.
- bootstrap_via_backend / bootstrapViaBackend renames the `body` local on
the error path to `err_body` (no longer shadows the request payload).
Same rename in the claim flow.
- Bootstrap envelope is now validated for non-empty api_key +
default_user_id before mutation — defends against partial backend
responses silently persisting null/undefined into typed string fields.
- Stale docstrings in agent_detect.{py,ts} and bootstrap_via_backend no
longer claim env-var sniffing fills `agent_caller`; the field is
self-declared via --agent-caller only.
Tests (new file mirrored across runtimes):
- test_init_internals.py / init-internals.test.ts
- pingKey: 200/401/403/5xx/connect-error/timeout matrix
- plugin_sync.updateShellRc: trailing-newline preservation, no-create,
surrounding-content preservation, idempotency, missing-file no-op
- plugin_sync.updateClaudeSettings: no env-block creation, no
MEM0_API_KEY insertion into existing env, idempotency, malformed JSON
no-op
- Python only: bootstrap 403 "permission" → daily-limit translation
Python: 161 tests pass. Node: 112 tests pass. ruff + biome clean.
Learn more · Join Discord · Demo
📄 Benchmarking Mem0's token-efficient memory algorithm →
New Memory Algorithm (April 2026)
| Benchmark | Old | New | Tokens | Latency p50 |
|---|---|---|---|---|
| LoCoMo | 71.4 | 91.6 | 7.0K | 0.88s |
| LongMemEval | 67.8 | 94.8 | 6.8K | 1.09s |
| BEAM (1M) | — | 64.1 | 6.7K | 1.00s |
| BEAM (10M) | — | 48.6 | 6.9K | 1.05s |
All benchmarks run on the same production-representative model stack. Single-pass retrieval (one call, no agentic loops).
What changed:
- Single-pass ADD-only extraction -- one LLM call, no UPDATE/DELETE. Memories accumulate; nothing is overwritten.
- Agent-generated facts are first-class -- when an agent confirms an action, that information is now stored with equal weight.
- Entity linking -- entities are extracted, embedded, and linked across memories for retrieval boosting.
- Multi-signal retrieval -- semantic, BM25 keyword, and entity matching scored in parallel and fused.
- Temporal Reasoning -- time-aware retrieval that ranks the right dated instance for queries about current state, past events, and upcoming plans.
See the migration guide for upgrade instructions. The evaluation framework is open-sourced so anyone can reproduce the numbers.
Research Highlights
- 91.6 on LoCoMo -- +20 points over the previous algorithm
- 94.8 on LongMemEval -- +27 points, with +53.6 on assistant memory recall
- 64.1 on BEAM (1M) -- production-scale memory evaluation at 1M tokens
- Read the full paper
Introduction
Mem0 ("mem-zero") enhances AI assistants and agents with an intelligent memory layer, enabling personalized AI interactions. It remembers user preferences, adapts to individual needs, and continuously learns over time—ideal for customer support chatbots, AI assistants, and autonomous systems.
Key Features & Use Cases
Core Capabilities:
- Multi-Level Memory: Seamlessly retains User, Session, and Agent state with adaptive personalization
- Developer-Friendly: Intuitive API, cross-platform SDKs, and a fully managed service option
Applications:
- AI Assistants: Consistent, context-rich conversations
- Customer Support: Recall past tickets and user history for tailored help
- Healthcare: Track patient preferences and history for personalized care
- Productivity & Gaming: Adaptive workflows and environments based on user behavior
🚀 Quickstart Guide
Agent Mode — for AI agents setting up Mem0 autonomously. Run
mem0 init --agent --agent-caller <your-name> --json(afterpip install mem0-cliornpm install -g @mem0/cli), replacing<your-name>with your AI agent identity (e.g.claude-code,cursor,codex). This mints an evaluation Mem0 API key in <5 seconds — no email, no dashboard, no OTP. If you forgot to pass--agent-caller, runmem0 identify <your-name>after init. Use the key immediately against the Platform or the MCP server. The human owner can claim ownership later withmem0 init --email <their-email>: memories transfer, the same key keeps working, and the agent isn't disrupted.
| Library | Self-Hosted Server | Cloud Platform | |
|---|---|---|---|
| Best for | Testing, prototyping | Teams running on their own infrastructure | Zero-ops production use |
| Setup | pip install mem0ai |
docker compose up |
Sign up at app.mem0.ai |
| Dashboard | -- | Yes | Yes |
| Auth & API Keys | -- | Yes | Yes |
| Advanced Features | -- | Teasers | All included |
Just testing? Use the library. Building for a team? Self-hosted. Want zero ops? Cloud.
Library (pip / npm)
pip install mem0ai
For enhanced hybrid search with BM25 keyword matching and entity extraction, install with NLP support:
pip install mem0ai[nlp]
python -m spacy download en_core_web_sm
Install sdk via npm:
npm install mem0ai
Self-Hosted Server
Note: Self-hosted auth is on by default. Upgrading from a pre-auth build? Set
ADMIN_API_KEY, register an admin through the wizard, orAUTH_DISABLED=truefor local dev only. See upgrade notes.
# Recommended: one command — start the stack, create an admin, issue the first API key.
cd server && make bootstrap
# Manual: start the stack and finish setup via the browser wizard.
cd server && docker compose up -d # http://localhost:3000
See the self-hosted docs for configuration.
Cloud Platform
- Sign up on Mem0 Platform
- Embed the memory layer via SDK or API keys
CLI
Manage memories from your terminal:
npm install -g @mem0/cli # or: pip install mem0-cli
mem0 init
mem0 add "Prefers dark mode and vim keybindings" --user-id alice
mem0 search "What does Alice prefer?" --user-id alice
See the CLI documentation for the full command reference.
Agent Skills
Teach your AI coding assistant (Claude Code, Codex, Cursor, Windsurf, OpenCode, OpenClaw, and any tool that supports the skills standard) how to build with Mem0. Two categories:
Reference skills — always on (SDK knowledge loaded into the assistant's context):
npx skills add https://github.com/mem0ai/mem0 --skill mem0
npx skills add https://github.com/mem0ai/mem0 --skill mem0-cli
npx skills add https://github.com/mem0ai/mem0 --skill mem0-vercel-ai-sdk
Pipeline skills — run on demand (execute an end-to-end workflow in an existing repo):
npx skills add https://github.com/mem0ai/mem0 --skill mem0-integrate
npx skills add https://github.com/mem0ai/mem0 --skill mem0-test-integration
Use /mem0-integrate to wire Mem0 into an existing repo via a test-first pipeline, then /mem0-test-integration to verify. See the skills catalog or Vibecoding with Mem0 for the full picture.
Basic Usage
Mem0 requires an LLM to function, with gpt-5-mini from OpenAI as the default. However, it supports a variety of LLMs; for details, refer to our Supported LLMs documentation.
Mem0 uses text-embedding-3-small from OpenAI as the default embedding model. For best results with hybrid search (semantic + keyword + entity boosting), we recommend using at least Qwen 600M or a comparable embedding model. See Supported Embeddings for configuration details.
First step is to instantiate the memory:
from openai import OpenAI
from mem0 import Memory
openai_client = OpenAI()
memory = Memory()
def chat_with_memories(message: str, user_id: str = "default_user") -> str:
# Retrieve relevant memories
relevant_memories = memory.search(query=message, filters={"user_id": user_id}, top_k=3)
memories_str = "\n".join(f"- {entry['memory']}" for entry in relevant_memories["results"])
# Generate Assistant response
system_prompt = f"You are a helpful AI. Answer the question based on query and memories.\nUser Memories:\n{memories_str}"
messages = [{"role": "system", "content": system_prompt}, {"role": "user", "content": message}]
response = openai_client.chat.completions.create(model="gpt-5-mini", messages=messages)
assistant_response = response.choices[0].message.content
# Create new memories from the conversation
messages.append({"role": "assistant", "content": assistant_response})
memory.add(messages, user_id=user_id)
return assistant_response
def main():
print("Chat with AI (type 'exit' to quit)")
while True:
user_input = input("You: ").strip()
if user_input.lower() == 'exit':
print("Goodbye!")
break
print(f"AI: {chat_with_memories(user_input)}")
if __name__ == "__main__":
main()
For detailed integration steps, see the Quickstart and API Reference.
🔗 Integrations & Demos
- ChatGPT with Memory: Personalized chat powered by Mem0 (Live Demo)
- Browser Extension: Store memories across ChatGPT, Perplexity, and Claude (Chrome Extension)
- Langgraph Support: Build a customer bot with Langgraph + Mem0 (Guide)
- CrewAI Integration: Tailor CrewAI outputs with Mem0 (Example)
📚 Documentation & Support
- Full docs: https://docs.mem0.ai
- Community: Discord · X (formerly Twitter)
- Contact: founders@mem0.ai
Citation
We now have a paper you can cite:
@article{mem0,
title={Mem0: Building Production-Ready AI Agents with Scalable Long-Term Memory},
author={Chhikara, Prateek and Khant, Dev and Aryan, Saket and Singh, Taranjeet and Yadav, Deshraj},
journal={arXiv preprint arXiv:2504.19413},
year={2025}
}
⚖️ License
Apache 2.0 — see the LICENSE file for details.