---
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: 2026-10-15
---
# 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 memory API for products that runs as a managed service or, on an Enterprise agreement, in your own cloud. It accepts timestamped text and returns ranked documents with source excerpts. 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 | API for products: managed, or in your own cloud on an Enterprise agreement |
| Sharing model | Your assistants, your machine | Users, agents and services under key scoping |
| Time input | Memories with recency signals | Occurrence timestamps and optional query timestamp |
| Changed source | New memory accumulates | Stable source id replaces the prior revision |
| Evidence | Retrieved memories | Ranked, dated evidence with sources |
| Unanswerable | Empty or nearest results | Application evaluates returned documents |

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, waits until ingestion completes, and returns dated source excerpts. 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 timestamped input and source-backed recall. 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)