feat: distributed tracing - 3

[Udit-takkar]

What does this PR do?

This PR is on top of #24861

This PR displays the trace reference id on the frontend

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• N/A 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.

How should this be tested?

---

Summary by cubic

Adds end-to-end tracing for errors and shows a trace reference in the booking UI. Improves server error normalization across TRPC, Zod, Prisma, and Stripe, with tests.

• New Features
  • Server: getServerErrorFromUnknown now unwraps TracedError, maps TRPCError to HTTP status, and attaches traceId and traced data to HttpError responses. Adds clearer handling for Zod, Prisma (incl. P2025 -> 404), and Stripe errors.
  • UI: BookEventForm shows a “trace reference id” when available. Recurring booking errors scroll into view. Types updated to carry traceId.
  • Tests: Added coverage for TracedError, TRPCError, ZodError, Prisma errors, and unknown fallbacks.

^{Written for commit c176be2. Summary will update automatically on new commits.}

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Project	Deployment	Preview	Comments	Updated (UTC)
cal-companion	Ready	Preview	Comment	Dec 4, 2025 5:23am

2 Skipped Deployments

Project	Deployment	Preview	Comments	Updated (UTC)
cal	Ignored			Dec 4, 2025 5:23am
cal-eu	Ignored			Dec 4, 2025 5:23am

[cubic-dev-ai]

2 issues found across 5 files

Prompt for AI agents (all 2 issues)

Understand the root cause of the following 2 issues and fix them.


<file name="packages/features/bookings/Booker/components/BookEventForm/BookEventForm.tsx">

<violation number="1" location="packages/features/bookings/Booker/components/BookEventForm/BookEventForm.tsx:328">
`t(&quot;trace_reference_id&quot;)` uses a translation key that does not exist in the locale files, so users will see the raw key text instead of a localized label. Please add the corresponding translation entry before referencing it.</violation>
</file>

<file name="packages/lib/server/getServerErrorFromUnknown.ts">

<violation number="1" location="packages/lib/server/getServerErrorFromUnknown.ts:129">
This branch now returns a plain Error instead of an HttpError, so callers lose statusCode/message fields and will fail when a string cause is passed.</violation>
</file>

_{React with 👍 or 👎 to teach cubic. Mention @cubic-dev-ai to give feedback, ask questions, or re-run the review.}

[hariombalhara]

https://github.com/calcom/cal.com/blob/feat/dist-tracing-3/packages/lib/server/defaultResponder.ts#L64

We aren't passing tracedError and thus any uncaught error(e.g. I just did a throw new Error() in RegularBookingService) isn't sending the traceId back to client.

Also, if we make that change, we won't need to ensure to send traceId in HttpError data like this https://github.com/calcom/cal.com/blob/feat/dist-tracing-3/packages/features/bookings/lib/service/RegularBookingService.ts#L1852 as it would be automatically handled.

[hariombalhara]

Left a few small suggestions and a possible bug in functionality

[cubic-dev-ai]

No issues found across 6 files

[Udit-takkar]

https://github.com/calcom/cal.com/blob/feat/dist-tracing-3/packages/lib/server/defaultResponder.ts#L64

We aren't passing tracedError and thus any uncaught error(e.g. I just did a throw new Error() in RegularBookingService) isn't sending the traceId back to client.

Also, if we make that change, we won't need to ensure to send traceId in HttpError data like this https://github.com/calcom/cal.com/blob/feat/dist-tracing-3/packages/features/bookings/lib/service/RegularBookingService.ts#L1852 as it would be automatically handled

Done and removed traceId from HttpError

[hariombalhara]

Can we also remove existing code from RegularBookingService that passes traceId manually. That would simplify the service a bit and also won't set a wrong precedent that could be copied elsewhere.

[cubic-dev-ai]

No issues found across 7 files