feat(snap-account-service): add SnapAccountService

[ccharly]

Explanation

A new service where we will move the common logic of the current monolith SnapKeyring.

The idea is to be able to split this keyring into multiple ones and move the KeyringEvents logic in this service.

High-level architecture is the following:

For now, it's just an empty service, but we will move forward with more follow-up change as we are rewriting the existing SnapKeyring to use the new KeyringV2.

References

N/A

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Medium Risk
Adds a new atomic multi-keyring transaction API in KeyringController that can create/remove keyrings and persists or rolls back vault updates, which is a sensitive area for account storage consistency. The new @metamask/snap-account-service package is mostly scaffolding and low risk on its own.

Overview
Introduces a new workspace package, @metamask/snap-account-service, with initial service scaffolding (SnapAccountService) and basic test/config/docs, and wires it into the monorepo (tsconfigs, README, yarn workspace, CODEOWNERS/teams).

Extends @metamask/keyring-controller with a new withController messenger action/method to run atomic, mutex-protected operations across all keyrings via a RestrictedController that exposes a live read-only view plus staged addNewKeyring/removeKeyring; on success it commits + persists, and on error it rolls back and cleans up created/removed keyrings. Adds extensive tests for locking behavior, commit/rollback, immediate visibility, and unsafe direct keyring-return protection.

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[david0xd]

Can we have little bit more explanation here? For example, what is the main purpose of this service, what we should keep or implement here. So we build up some integrity of this package.

[david0xd]

When is this supposed to be implemented? Looks redundant at this moment.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

Overloads lose generic narrowing and expose phantom property

Medium Severity

The two public withKeyring overloads were refactored from { keyring: SelectedKeyring; metadata: KeyringMetadata } to KeyringEntry. This introduces two problems: (1) the callback's keyring is now typed as EthKeyring instead of SelectedKeyring, silently dropping the generic type narrowing that the filter type guard in KeyringSelector was designed to propagate; and (2) the callback type now includes keyringV2?: KeyringV2, but the implementation only passes { keyring, metadata }, so keyringV2 is always undefined at runtime — a misleading type that can lead to dead code branches.

Additional Locations (1)

• packages/keyring-controller/src/KeyringController.ts#L1821-L1822

 

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