MetaMask Snaps Explained: Extending Your Wallet's Features

MetaMask Snaps are third-party plugins that extend the MetaMask wallet with additional functionality — most notably support for non-EVM blockchains that MetaMask doesn't natively handle — running in an isolated environment inside the wallet rather than requiring a separate application. They let developers add features to MetaMask without those features needing to be built into MetaMask's own core code.

This plugin-style architecture mirrors how browser extensions add capabilities to a web browser: MetaMask provides the platform and a permission system, and independent developers build Snaps that plug into it.

What Snaps can add

Before Snaps, MetaMask was limited to Ethereum and other EVM-compatible chains. Snaps have expanded that scope considerably, enabling things like:

• Support for managing accounts on non-EVM networks directly within the same MetaMask interface, rather than needing an entirely separate wallet.
• Additional transaction insight tools that analyze a pending transaction and warn about suspicious patterns before you sign.
• Custom notification systems, alternative security checks, and specialized interfaces for particular protocols.

The goal is turning MetaMask from a single-purpose EVM wallet into more of a platform that a wider set of blockchain ecosystems and tools can build on top of.

How Snaps run in isolation

Each Snap runs in its own sandboxed environment, separate from MetaMask's core wallet code and separate from other installed Snaps. This is meant to contain the impact of any single Snap having a bug or behaving unexpectedly, and it means a Snap must explicitly request permission for specific capabilities — such as network access or the ability to display custom UI — rather than having unrestricted access to everything MetaMask can do.

This permission model is similar in spirit to how mobile apps must request specific device permissions rather than having blanket access by default.

Why the permission model matters

When installing a Snap, MetaMask displays what permissions it's requesting. Reading these carefully matters because:

• A Snap requesting broad or unusual permissions relative to its stated purpose is a warning sign worth investigating before installing.
• Permissions, once granted, generally persist until you manually remove the Snap, so periodic review of installed Snaps is a reasonable habit.
• Because Snaps are built by third-party developers rather than MetaMask itself, the security and reliability of a given Snap depends on that specific developer's code quality, not on MetaMask's own audit history.

Comparing life before and after Snaps

Aspect	MetaMask without Snaps	MetaMask with Snaps
Supported networks	EVM-compatible chains only	EVM chains plus non-EVM chains via Snaps
Extensibility	Fixed feature set	Plugin-style, developer-extensible
Added attack surface	Limited to MetaMask's own code	Includes each installed Snap's code
Permission granularity	N/A	Per-Snap, explicitly requested
Isolation	N/A	Sandboxed per Snap

Risks worth understanding

The core risk with any plugin ecosystem is that not every third-party developer has the same security rigor as the core platform. A poorly coded or malicious Snap could, within the scope of permissions you grant it, mishandle sensitive data or behave in unexpected ways. This is analogous to the risk of browser extension wallets generally — see browser extension wallet risks for the broader category of concerns.

Practical mitigations:

• Only install Snaps from developers and projects you recognize and trust, ideally verified through MetaMask's own official directory rather than an external link.
• Review the specific permissions requested before installing, and question anything that seems broader than the Snap's stated purpose requires.
• Periodically review and remove Snaps you're no longer actively using, reducing the ongoing attack surface.
• Keep the core MetaMask application itself updated, since security patches to the sandboxing model benefit every installed Snap.

Who benefits most from Snaps

Users who want to manage assets across a wider range of blockchains — including non-EVM ecosystems — without juggling multiple separate wallet applications benefit most from Snaps, since they consolidate account management into one interface. Users focused purely on a single EVM chain and prioritizing the smallest possible attack surface may reasonably choose to avoid installing additional Snaps beyond what's strictly necessary.

Bottom line

MetaMask Snaps extend the wallet with plugin-style features, most notably support for non-EVM blockchains, by running third-party code in a sandboxed, permission-gated environment inside MetaMask. They add real utility for multi-chain users, but because each Snap is built by an independent developer, the security of any given Snap depends on that developer's code — review permissions carefully, install only from trusted sources, and periodically prune Snaps you no longer use.