RxDB
Firebase
PouchDB
GUN
SignalDB
Supabase
FeathersJS
Realm.io
Emisar.dev
RxDB, which stands for Reactive Database, is a JavaScript-based NoSQL database designed for a wide range of applications such as websites, hybrid apps, Electron apps, progressive web apps, and Node.js. The "reactive" aspect of RxDB allows you not only to retrieve the current state of the database but also to subscribe to all changes in the state, including query results or specific fields within a document. This feature is particularly advantageous for real-time user interface applications, as it facilitates development and offers notable performance benefits. Additionally, RxDB can be utilized to build efficient backends in Node.js.
Emisar is the last MCP server youโll need to install: a Zero-Trust gateway connecting Claude, Cursor, ChatGPT, and any AI agent to your infrastructure. One server handles production access, debugging, alerts, and internal operations, with new capabilities added as packs. Agents can inspect real production state, debug what they shipped, and help resolve incidents. Safe reads run automatically; policy allows, blocks, or routes risky actions for approval. No SSH keys, VPNs, remote shells, or standing shell access โ and every call is recorded.
RxDB Emisar.devNo features have been listed yet.
Emisar.dev's answer:
emisar is for SRE, DevOps, platform engineering, infrastructure, and security teams that want AI agents to inspect and operate production systems. It is especially relevant to teams managing multiple Linux hosts, clusters, databases, cloud services, or regulated environments where unrestricted shell access and incomplete audit records are unacceptable.
Emisar.dev's answer:
The hosted control plane and operator interface use Elixir, Phoenix, LiveView, PostgreSQL, and Tailwind CSS. The host runner and MCP bridge are written in Go. Action packs use YAML and JSON Schema, while production infrastructure is managed with Terraform on Google Cloud. The system communicates through MCP, OAuth 2.1, TLS, and WebSockets.
Emisar.dev's answer:
Emisar.dev's answer:
Founder Andrii Dryga spent a decade working as a CTO, full-stack engineer, SRE, and DevOps engineer. He experienced the cost of running the wrong command on the wrong cluster, while also seeing AI solve operational problems in seconds. emisar grew from the need to preserve both truths: AI agents are useful, and production access must remain bounded. Its answer is to give agents a reviewed catalog of operations instead of a blank terminal.
Emisar.dev's answer:
emisar lets AI agents work on real infrastructure without giving them a shell. Agents choose from a finite catalog of typed, versioned actions. Policy decides what runs, what requires approval, and what is denied, while an outbound-only runner verifies the action again on the host. New capabilities arrive as packs behind the same MCP integration, and every request is recorded in both a searchable audit trail and a tamper-evident host journal. [
Emisar.dev's answer:
Choose emisar when you want an agent to keep investigating and handling routine operations without handing it SSH credentials or supervising every call. Compared with raw shell access, copy-paste workflows, or one-off MCP servers, emisar provides reviewed action contracts, host-level enforcement, risk-based policy, scoped access, approvals, pack integrity checks, and a durable audit trail. It is built specifically for governed infrastructure access rather than generic automation.
Based on our record, RxDB seems to be more popular. It has been mentiond 14 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Iโm doing offline-first apps at work and want to emphasize that youโre constraining yourself a lot trying to do this. As mentioned, everything fast(ish) is using SQLite under the hood. If you donโt already know, SQLite has a limited set of types, and some funky defaults. How are you going to take this loosey-goosey typed data and store it in a backend database when you sync? What about foreign key... - Source: Hacker News / 11 months ago
> I'm thinking to give it a try in one of my React Native apps that face very uncertain connectivity. Some similar stuff you may want to investigate (no real opinion, just sharing since I've investigated this space a bit): - https://rxdb.info. - Source: Hacker News / over 1 year ago
Looks like it could be a more batteries-included/opinionated alternative to RxDB (https://rxdb.info). The relational queries might help some people who tend to think in SQL as opposed to documents (as in CouchDB or MongoDB) and the WebSockets for synchronization will help people get started more quickly. (RxDB provides interfaces for those who want to implement their own storage engine and/or synchronization... - Source: Hacker News / about 2 years ago
Some years ago "offline-first" was a thing: https://web.archive.org/web/20170720174332/http://hood.ie/initiatives/#offline-first Primarily based on PouchDB/CouchDB. Now the site redirects to RxDB. https://rxdb.info/ There's still a site by that name but I don't quite understand what's the intention https://offlinefirst.org/. - Source: Hacker News / about 2 years ago
I'm interested in this problem also! I think there is a large overlap with projects that market/focus on offline-first experiences. AFAIK this problem can be solved by: 1) Considering a client-side copy of the database that gets synced with the remote DB. This is an approach [PowerSync](https://www.powersync.com/) and [ElectricSql](https://electric-sql.com/) and [rxdb](https://rxdb.info/) take! - Source: Hacker News / over 2 years ago
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
PouchDB - Open-source JavaScript database inspired by Apache CouchDB that's designed to run well within the browser
GUN - Self-hosted Firebase.
SignalDB - SignalDB is a reactive, local-first JavaScript database designed for modern web applications. It combines signal-based reactivity with powerful local data management and real-time synchronization capabilities.
Supabase - An open source Firebase alternative
FeathersJS - Wow your users. Build incredible real-time applications in record time.