Control

[dferber90]

Refactors the internals of vercel-flags-core:

• adds a controller which does no I/O itself and only controls the various data sources
  • renames the original dataSource to controller
• adds blackbox tests (currently two variants, one with a mocked fetch, one with msw)
  • i added both so we can decide which one is easier to work with before adding more tests
  • goal would be that all tests are black box tests so we can refactor internals without rewriting tests going forward

As part of this PR we should tighten the fallback behavior

• if steam is not reachable, do we fall back to polling or fall back to embedding?
• ensure polling stops if stream re-connects
• always retry stream in 60s+jitter intervals if we fell back
• transport information about data source
  • store whether current in-memory data came from streaming, polling, fallback
  • store whether data is considered stale
    • if stream is disconnected it's considered stale?
    • would polling always count as stale even if stream was disabled?
• should the init timeout be configured on the client (current state) or on the .initialize({ timeout: number }) call?

Transactions concept where we guarantee the same definitions are used while handling as single request to avoid situations like this where flagA and flagB are handled as part of the same request but potentially use different underlying configuration:

await flagA()
// stream receives updated configuration
await flagB()

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
flags-sdk-dev	Ready	Preview, Comment, Open in v0	Feb 17, 2026 7:31am
shirt-shop	Ready	Preview, Comment, Open in v0	Feb 17, 2026 7:31am
shirt-shop-api	Ready	Preview, Comment, Open in v0	Feb 17, 2026 7:31am

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	@​vercel/​edge@​1.2.2
	@​fetch-mock/​vitest@​0.2.18
	fetch-mock@​12.6.0
	react@​19.3.0-canary-6066c782-20260212 ⏵ 19.3.0-canary-03ca38e6-20260213
	flags@​4.0.1

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