feat: Sink url shortner for sms workflow reminders

[Amit91848]

For dub fallback, add the following to .env before merging

What does this PR do?

Uses https://github.com/miantiao-me/sink hosted on cloudflare workers.

Fixes GTM-239

For testing you can add this in .env
SINK_API_URL=https://sink.amit-b43.workers.dev

SINK_API_KEY=(present in bitwarden under name Sink url shortner)

Dashboard: https://sink.amit-b43.workers.dev/dashboard/login
Pass: same as SINK_API_KEY present in bitwarden

Follow https://github.com/miantiao-me/Sink/blob/master/docs/deployment/workers.md for prod setup

• Fixes #XXXX (GitHub issue number)
• Fixes CAL-XXXX (Linear issue number - should be visible at the bottom of the GitHub issue description)

Visual Demo (For contributors especially)

Screen.Recording.2026-01-09.at.4.09.46.PM.mov

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. If N/A, write N/A here and check the checkbox.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

---

Summary by cubic

Adds a pluggable, user/team-aware URL shortener for SMS workflow reminders that prefers Sink (feature-flagged), then Dub, then original URLs. Removes hardcoded Dub settings and aligns with Linear GTM-239.

• New Features

  • UrlShortenerFactory selects SinkShortener when sink-shortener is enabled (globally, per user, or per team via FeaturesRepository); else DubShortener; else NoopShortener. Used in ee/workflows/lib/reminders/utils, ee/workflows/api/scheduleSMSReminders, and smsReminderManager (now passes userId/teamId).
  • Shortening forwards optional DUB_SMS_DOMAIN/DUB_SMS_FOLDER_ID to Dub; .env.example documents SINK_API_URL/SINK_API_KEY and optional Dub SMS vars; lib/constants exports both Dub SMS values.
  • Adds sink-shortener flag to AppFlags/useFlags; seeds via migration. New @calcom/features/url-shortener module with SinkClient, providers, and factory; broad test coverage for shorteners, factory, reminder utils, and scheduleSMSReminders.

• Migration

  • To use Sink, set SINK_API_URL and SINK_API_KEY, then enable the sink-shortener feature globally, per user, or per team.
  • If Dub is configured, it’s used; otherwise original URLs are sent. Optionally set DUB_SMS_DOMAIN and DUB_SMS_FOLDER_ID.

^{Written for commit ffbeac0. Summary will update on new commits.}

---

[cubic-dev-ai]

No issues found across 7 files

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4 Skipped Deployments

Project	Deployment	Review	Updated (UTC)
api-v2	Ignored	Preview	Jan 11, 2026 1:41am
cal	Ignored		Jan 11, 2026 1:41am
cal-companion	Ignored	Preview	Jan 11, 2026 1:41am
cal-eu	Ignored		Jan 11, 2026 1:41am

[github-actions]

This PR has been marked as stale due to inactivity. If you're still working on it or need any help, please let us know or update the PR to keep it active.

[linear]

GTM-239 Sink url shortner for sms workflow reminders

[Udit-takkar]

I am getting this error

b:dev: 09:26:09:241 [ERROR] sink-url-shortener Sink API error: 401 - {
@calcom/web:dev:   "error": true,
@calcom/web:dev:   "url": "https://sink.amit-b43.workers.dev/api/link/create",
@calcom/web:dev:   "statusCode": 401,
@calcom/web:dev:   "statusMessage": "Unauthorized",
@calcom/web:dev:   "message": ""
@calcom/web:dev: }

[Udit-takkar]

We should use a combination of strategy + factory pattern here and we should use global feature flags to decide which one to use and it would be easier to add more/ replace with another url shortner service.

For eg:-

export class SinkShortener implements IUrlShortenerProvider {
  constructor(private client: SinkClient) {}

  async shortenMany(urls: string[]) {
    const results = await this.client.createMany(urls);
    return results.map(r => ({
      shortLink: r.shortLink || r.url
    }));
  }
}

export class UrlShortenerFactory {
  static create(): IUrlShortenerProvider {
// Check feature flag here instead of env vars
    if (process.env.SINK_API_KEY) {
      return new SinkShortener(new SinkClient());
    }

    if (process.env.DUB_API_KEY) {
      return new DubShortener();
    }

    return new NoopShortener();
  }
}

[Udit-takkar]

There is also

Circular dependency violation — packages/lib imports from @calcom/features/auth/lib/dub, violating the rule that packages/lib must never import from packages/features

[github-actions]

Devin AI is resolving merge conflicts

This PR has merge conflicts with the main branch. A Devin session has been created to automatically resolve them.

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[devin-ai-integration]

Merge conflicts resolved and pushed. The single conflicted file (packages/features/ee/workflows/api/scheduleSMSReminders.test.ts) was resolved by combining both test suites - the PR branch's comprehensive handler tests and main's smsReminderNumber fallback tests - using shared UrlShortenerFactory mocks. All 39 tests pass.

Note: Unable to remove the devin-conflict-resolution label due to API authentication limitations. Please remove it manually.

[github-actions]

E2E results are ready!

• Workflow #106586.1 latest results

[keithwillcode]

We discussed internally and @Amit91848 is going to add a TeamFeatureFlag for this so we can slowly roll out.