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Snaps lifecycle

Just like service workers or AWS lambda functions, snaps are designed to wake up in response to messages/events, and shut down when idle. Snaps have an ephemeral lifecycle: they're here one moment, gone the next. Also, if MetaMask detects that a snap becomes unresponsive, it shuts the snap down. This doesn't mean that you can't create long-running snaps, but it does mean that your snaps must handle being shut down, especially when they're not within the JSON-RPC request/response cycle.

A snap is considered unresponsive if:

  1. It hasn't received a JSON-RPC request for 30 seconds.
  2. It takes more than 60 seconds to process a JSON-RPC request.

Stopped snaps start whenever they receive a JSON-RPC request, unless they're disabled. If a snap is disabled, the user must re-enable it before it can start again.