Skip to content

ref(core)!: Split browser/server-only exports out of the default entrypoint - #23762

Merged
mydea merged 6 commits into
developfrom
fn/split-core-exports
Sep 1, 2026
Merged

ref(core)!: Split browser/server-only exports out of the default entrypoint#23762
mydea merged 6 commits into
developfrom
fn/split-core-exports

Conversation

@mydea

@mydea mydea commented Aug 31, 2026

Copy link
Copy Markdown
Member

Splits the browser- and server-only exports out of @sentry/core's default entrypoint. @sentry/core now exposes only isomorphic code, and the @sentry/core/browser and @sentry/core/server entrypoints now contain only their platform-specific exports instead of also re-exporting the shared surface on top.

Previously the default entrypoint re-exported everything (via shared-exports.ts), and both /browser and /server re-exported that shared surface plus their platform extras. That meant importing anything from @sentry/core could drag server-only code (http server/client instrumentation, ANR, postgres/sql helpers, …) into browser bundles, and the platform entrypoints were never cleanly separable.

After this change:

  • @sentry/core — isomorphic exports only (the former shared-exports.ts, inlined into index.ts).
  • @sentry/core/browser — browser-only exports, e.g. the guarded startSpan/startInactiveSpan variants that install spanStreamingIntegration.
  • @sentry/core/server — server-only exports: ServerRuntimeClient, ServerRuntimeOptions, trpcMiddleware, wrapMcpServerWithSentry, the http client/server subscription APIs, flushIfServerless, loadModule, node stack-trace helpers, postgres/sql instrumentation, and more.

Consumer packages were updated to import platform-specific symbols from the matching entrypoint rather than from @sentry/core.

Root cause of the guarded-span split: the browser SDK's init() deliberately omits spanStreamingIntegration — referencing it would keep the whole span-streaming graph in every bundle, including error-only ones. Because the plain and guarded span-start APIs share their names, importing the plain variant in browser code compiles fine but produces spans that are then never sent. The new no-unguarded-span-apis lint rule is the only thing that catches this, and enforces that browser-facing code imports the span-start APIs from @sentry/core/browser.

Decisions

  • The three entrypoints are kept disjoint rather than having /browser and /server re-export the isomorphic surface. Consumers import isomorphic code from @sentry/core and platform code from the matching subpath — this is what makes the separation meaningful for tree-shaking and bundle size.
  • Marked breaking (!): symbols previously reachable from @sentry/core (e.g. trpcMiddleware, wrapMcpServerWithSentry) now live under @sentry/core/server.

@cursor cursor Bot left a comment

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

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

Fix All in Cursor

❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.

Want reviews to match your repository better? Bugbot Learning can learn team-specific rules from PR activity. A team admin can enable Learning in the Cursor dashboard.

Reviewed by Cursor Bugbot for commit e32bdf9. Configure here.

Comment thread packages/browser/src/index.ts
@github-actions

github-actions Bot commented Aug 31, 2026

Copy link
Copy Markdown
Contributor

size-limit report 📦

Path Size % Change Change
@sentry/browser 28.56 kB - -
@sentry/browser - with treeshaking flags 26.92 kB - -
@sentry/browser - with treeshaking flags tracing without tracing 26.82 kB - -
@sentry/browser (incl. Tracing) 48.86 kB - -
@sentry/browser (incl. Tracing + Span Streaming) 48.87 kB - -
@sentry/browser (incl. Tracing, Profiling) 51.79 kB - -
@sentry/browser (incl. Tracing, Replay) 88.35 kB - -
@sentry/browser (incl. Tracing, Replay) - with treeshaking flags 77.75 kB - -
@sentry/browser (incl. Tracing, Replay with Canvas) 93.04 kB - -
@sentry/browser (incl. Tracing, Replay, Feedback) 106 kB - -
@sentry/browser (incl. Feedback) 46.05 kB - -
@sentry/browser (incl. sendFeedback) 33.62 kB - -
@sentry/browser (incl. FeedbackAsync) 38.73 kB - -
@sentry/browser (incl. Metrics) 29.51 kB - -
@sentry/browser (incl. Logs) 29.8 kB - -
@sentry/browser (incl. Metrics & Logs) 30.43 kB - -
@sentry/react 30.3 kB - -
@sentry/react (incl. Tracing) 51.06 kB - -
@sentry/vue 35.73 kB - -
@sentry/vue (incl. Tracing) 51.13 kB - -
@sentry/svelte 28.59 kB - -
CDN Bundle 30.35 kB - -
CDN Bundle (incl. Tracing) 49.5 kB - -
CDN Bundle (incl. Logs, Metrics) 32.58 kB - -
CDN Bundle (incl. Tracing, Logs, Metrics) 51.41 kB - -
CDN Bundle (incl. Replay, Logs, Metrics) 73.17 kB - -
CDN Bundle (incl. Tracing, Replay) 87 kB - -
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) 88.86 kB - -
CDN Bundle (incl. Tracing, Replay, Feedback) 92.93 kB - -
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) 94.83 kB - -
CDN Bundle - uncompressed 89.95 kB - -
CDN Bundle (incl. Tracing) - uncompressed 147.56 kB - -
CDN Bundle (incl. Logs, Metrics) - uncompressed 96.24 kB - -
CDN Bundle (incl. Tracing, Logs, Metrics) - uncompressed 153.25 kB - -
CDN Bundle (incl. Replay, Logs, Metrics) - uncompressed 225.41 kB - -
CDN Bundle (incl. Tracing, Replay) - uncompressed 267.05 kB - -
CDN Bundle (incl. Tracing, Replay, Logs, Metrics) - uncompressed 272.73 kB - -
CDN Bundle (incl. Tracing, Replay, Feedback) - uncompressed 280.75 kB - -
CDN Bundle (incl. Tracing, Replay, Feedback, Logs, Metrics) - uncompressed 286.42 kB - -
@sentry/nextjs (client) 53.68 kB - -
@sentry/sveltekit (client) 49.29 kB - -
@sentry/core/server 40.72 kB -38.14% -25.1 kB 🔽
@sentry/core/browser 13.42 kB -74.16% -38.51 kB 🔽
@sentry/node 123.83 kB +0.01% +5 B 🔺
@sentry/node/import (ESM hook with diagnostics-channel injection) 81.4 kB -0.26% -206 B 🔽
@sentry/node - without tracing 88.13 kB +0.02% +10 B 🔺
@sentry/node - without channel injection 103.26 kB +0.01% +1 B 🔺
@sentry/aws-serverless 96.48 kB +0.01% +7 B 🔺
@sentry/cloudflare (withSentry) - minified 201.21 kB - -
@sentry/cloudflare (withSentry) 500.7 kB - -

View base workflow run

@mydea
mydea force-pushed the fn/split-core-exports branch from e32bdf9 to e787ccb Compare August 31, 2026 12:35
@mydea
mydea force-pushed the fn/split-core-exports branch from 096dba7 to 8813722 Compare September 1, 2026 08:34
@mydea
mydea marked this pull request as ready for review September 1, 2026 08:34
@mydea
mydea requested review from a team as code owners September 1, 2026 08:34
@mydea
mydea requested review from JPeer264, isaacs, logaretm, msonnb, nicohrubec and s1gr1d and removed request for a team September 1, 2026 08:34
mydea and others added 5 commits September 1, 2026 10:35
…ypoint

`@sentry/core` now exposes only isomorphic code. The `/browser` and `/server`
entrypoints contain only their platform-specific exports instead of also
re-exporting the full shared surface, and consumer packages import
platform-specific symbols from the matching entrypoint.

A `no-unguarded-span-apis` lint rule enforces that browser-facing code imports
the span-start APIs from `@sentry/core/browser` (the guarded variant), never
from `@sentry/core`/`@sentry/core/server`.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Point browser-facing tests at `@sentry/core` for isomorphic symbols (keeping
only the guarded span-start APIs on `@sentry/core/browser`), and point
server-facing tests at `@sentry/core/server` for the moved server-only symbols
(`flushIfServerless`, `loadModule`, `isNodeEnv`, `vercelWaitUntil`,
`nodeStackLineParser`, `trpcMiddleware`, `ServerRuntimeClient`, ...) so mocks and
spies intercept the same binding the source imports.

Update `core`'s `exports.test.ts` to the disjoint entrypoint contract: the root
entry serves the plain span-start APIs and `spanStreamingIntegration`, the
browser entry serves the guarded span-start variants, and the server entry
re-exports neither (server code imports the isomorphic APIs from the root entry).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The postgres/postgresjs tracing scenarios imported `uuid4` from
`@sentry/core/server`, which only serves server-specific exports and does not
provide `uuid4` — the ESM import crashed each scenario at load. `uuid4` is
isomorphic and lives on the root `@sentry/core` entry.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
@mydea
mydea force-pushed the fn/split-core-exports branch from 8813722 to 64417fb Compare September 1, 2026 08:36

@JPeer264 JPeer264 left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM. Tests are failing but they seem to be flaky. I'll rerun

Comment thread packages/effect/src/server/tracer.ts Outdated
* Effect `Tracer` that records Effect spans as Sentry spans on the server.
*
* Deliberately the plain `@sentry/core` variant, not `@sentry/core/browser`: the browser one guards
* Deliberately the plain `@sentry/core` variant, not `@sentry/core`: the browser one guards

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

l: This comment doesn't make sense anymore when /browser got removed. I guess this block can be removed now

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

we still need the block, but the comment is wrong indeeed :D

import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
import { z } from 'zod';
import { wrapMcpServerWithSentry } from '@sentry/core';
import { wrapMcpServerWithSentry } from '@sentry/node';

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

l: The @sentry/core dependency can then also be removed if this switches to @sentry/node

Copy link
Copy Markdown
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

we still use a type from this somewhere 🤔

@mydea
mydea merged commit d99cacd into develop Sep 1, 2026
284 of 285 checks passed
@mydea
mydea deleted the fn/split-core-exports branch September 1, 2026 10:07
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants