Frequently Asked Questions

Differences from Node.js

Even though Membrane programs are written in TypeScript/JavaScript, they work differently from typical Node.js or browser programs in a few fundamental ways:

1. Membrane programs are durable. There’s no need to store data in external databases or files—use the state object instead. Actions can run indefinitely (e.g. await’ing an email reply).
2. Membrane programs are event-sourced. Each program has a write-ahead log that records all effects, which are then processed by membrane separately. That means all actions taken by a program are guaranteed to be in the logs—if it’s not in the logs, it didn’t happen.
3. All communication happens through the graph. Even fetch is implemented using graph nodes.

Do npm modules work?

In many cases, yes. To use an npm package:

1. Create a package.json file
2. Add any packages to dependencies
3. Save the program

Not all npm modules can be used in Membrane, especially if they depend on specific Node.js APIs that we don’t yet support.

Note

Please reach out to contact@membrane.io if you find a package that fails to load due to missing functionality—we’re working on closing runtime support gaps and would be happy to implement your request.