---
title: "OpenMemory and past.dev: local memory vs memory API"
description: "OpenMemory is mem0's local memory with an MCP server. Compare its deployment, browser-extension status and time model with the past.dev API."
canonical: https://past.dev/compare/openmemory
last-updated: 2026-08-31
---
# OpenMemory and past.dev

Source: https://past.dev/compare/openmemory

OpenMemory stores personal memories on a local machine and exposes them to assistants through an MCP server. past.dev is a managed or self-hosted memory API for products. It provides temporal storage, entity resolution, dated evidence and explicit response status through four endpoints. Choose based on personal use or shared application infrastructure.

## What OpenMemory is

[OpenMemory](https://mem0.ai/openmemory) stores memories on the user's device. An MCP server makes them available to MCP-compatible assistants. The [browser extension repository](https://github.com/mem0ai/mem0-chrome-extension) is archived. Evaluate the current local product and MCP server instead.

## Product comparison

| Property | OpenMemory | past.dev |
| --- | --- | --- |
| Deployment | Local-first, personal | Managed or self-hosted API for products |
| Sharing model | Your assistants, your machine | Users, agents and services under key scoping |
| Time model | Memories with recency signals | Validity windows, supersession, point-in-time recall |
| Changed facts | New memory accumulates | Old fact superseded, history kept queryable |
| Evidence | Retrieved memories | Ranked, dated evidence with sources |
| Unanswerable | Empty or nearest results | Explicit NoKnownSupport |

Applications that require current and historical facts need [supersession](/glossary/fact-supersession) and [point-in-time recall](/glossary/point-in-time-recall). Evaluate whether approximate recency is sufficient for the intended use case.

## When to use each product

- **Choose OpenMemory** for a personal memory you own locally and share across your own assistants over MCP, especially if you already run mem0.
- **Choose past.dev** when the memory belongs to a product: many users, changing facts, dates and sources on every answer, deletion and scoping as API operations.

[past.dev vs mem0](/vs/mem0) compares the two services and deployment options. [What is agent memory?](/what-is-agent-memory) describes the main memory architectures.

## Testing the API

The [quickstart](/docs/memory-api/quickstart) ingests timestamped text and returns dated evidence in four calls. The [benchmarks page](/benchmarks) documents recall, update handling and abstention tests.

## Frequently asked questions

### Can past.dev serve as a personal memory too?

Yes. MCP-capable assistants can use past.dev for personal memory. The product is designed for shared application and team memory with temporal structure, evidence, and explicit response status. A local-first tool may be a better fit for a private store used on one machine.

## Related

- [past.dev vs mem0](https://past.dev/vs/mem0)
- [past.dev and claude-mem](https://past.dev/compare/claude-mem)
- [Fact supersession](https://past.dev/glossary/fact-supersession)
- [What is agent memory?](https://past.dev/what-is-agent-memory)
- [Quickstart](https://past.dev/docs/memory-api/quickstart)