[remix]: wrap the request handler to support middleware by carbonrobot · Pull Request #15189 · vercel/vercel

carbonrobot · 2026-02-20T22:12:50Z

Summary

Added support for the future.v8_middleware option in @vercel/remix-builder, allowing projects to opt into React Router's v8 middleware features.
Updated the default server handler (server-react-router.mjs) to detect and wrap request handling with RouterContextProvider when v8_middleware is enabled, ensuring middleware context is available during request processing.
Adds a test fixture with probe for verification

Background

React Router introduced middleware under a future flag in their configuration. When enabled, the request handler has a different function signature.

Since older versions of React Router do not export the new RouterContextProvider class, we use a namespace import (RR) to ensure we don't break the application module when loading.

- import { createRequestHandler } from 'react-router';
+ import * as RR from 'react-router';

// existing code

      return (request) =>
        build.future.v8_middleware
          ? handler(request, new RR.RouterContextProvider())
          : handler(request);

See: https://github.com/vercel/vercel/pull/15189/changes#diff-0e6934640b150a57cf9803aa548f1533f57bef4a7f61ac65f4346b1de27104ccR13-R23

Test Plan

Added integration test probe to verify page loads with the correct context information
Verified on production deployment for RR@latest here
Verified on production deployment for RR@7.1.5 here

Note

Low Risk Change

This PR adds feature flag support for React Router v8 middleware by conditionally wrapping the request handler, plus adds a test fixture - no security-sensitive changes.

Modifies server handler to conditionally pass RouterContextProvider based on v8_middleware flag
Adds complete test fixture with middleware demo app
Changes import style from named to namespace import for react-router

^{Risk assessment for commit c0dbdac.}

changeset-bot · 2026-02-20T22:12:54Z

🦋 Changeset detected

Latest commit: c0dbdac

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@vercel/remix-builder	Minor
vercel	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

github-actions · 2026-02-20T22:13:02Z

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github-actions · 2026-02-20T22:14:19Z

🧪 Unit Test Strategy

Comparing: 984d448 → c0dbdac (view diff)

Strategy: Affected packages only

✅ Only testing packages that have been modified or depend on modified packages.

Affected packages - 2 (5%)

@vercel/remix-builder
vercel

Unaffected packages - 38 (95%)

@vercel-internals/get-package-json
@vercel/backends
@vercel/build-utils
@vercel/cervel
@vercel/cli-auth
@vercel/client
@vercel/config
@vercel/detect-agent
@vercel/edge
@vercel/elysia
@vercel/error-utils
@vercel/express
@vercel/fastify
@vercel/firewall
@vercel/frameworks
@vercel/fs-detectors
@vercel/functions
@vercel/gatsby-plugin-vercel-builder
@vercel/go
@vercel/h3
@vercel/hono
@vercel/hydrogen
@vercel/koa
@vercel/nestjs
@vercel/next
@vercel/node
@vercel/oidc
@vercel/oidc-aws-credentials-provider
@vercel/python
@vercel/python-analysis
@vercel/redwood
@vercel/related-projects
@vercel/routing-utils
@vercel/ruby
@vercel/rust
@vercel/static-build
@vercel/static-config
examples

Results

Unit tests: Only affected packages will run unit tests
E2E tests: Running in parallel via E2E Tests workflow
Type checks: Only affected packages will run type checks

This comment is automatically generated based on the affected testing strategy

This PR was opened by the [Changesets release](https://github.com/changesets/action) GitHub action. When you're ready to do a release, you can merge this and the packages will be published to npm automatically. If you're not ready to do a release yet, that's fine, whenever you add more changesets to main, this PR will be updated. # Releases ## @vercel/routing-utils@6.0.0 ### Major Changes - Allow `routes` to coexist with `rewrites`, `headers`, `redirects`, `cleanUrls`, and `trailingSlash`. ([#15020](#15020)) This is part of our efforts to undeprecate `routes`, which had previously been deprecated for a few years and replaced by the properties above. Now that we are undeprecating `routes` in favor of a more focused deprecation of properties within it, it is now allowed to coexist with the new properties. When used together, `routes` are inserted after `cleanUrls` and `trailingSlash` but before `redirects`, `headers`, and `rewrites` in the routing order. - Deprecate `handle`, `important`, and `override` properties in `routes` schema ([#15015](#15015)) ## @vercel/build-utils@13.6.0 ### Minor Changes - Find entrypoints for django projects. ([#15167](#15167)) ### Patch Changes - Rename fetch to nodeFetch in cases where it is an import from node-fetch ([#15234](#15234)) - [@vercel/build-utils] fix uncaught exception in streamToBuffer when stream exceeds max Buffer size ([#15276](#15276)) - Remove source and destination typo suggestions for routes schema ([#15014](#15014)) - Support function overrides in backends builder ([#15214](#15214)) - Updated dependencies \[[`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc)]: - @vercel/python-analysis@0.8.0 ## vercel@50.25.0 ### Minor Changes - Launch auto-provision flow as default for `vercel integration add` and `vercel install`. The `FF_AUTO_PROVISION_INSTALL` flag is now a kill-switch (`=0` to revert) instead of opt-in. ([#15265](#15265)) - [services] make the `experimentalServices` config the primary marker for the services flow ([#15246](#15246)) - Added command to fetch a development OIDC token ([#14785](#14785)) ### Patch Changes - Rename fetch to nodeFetch when importing from node-fetch ([#15232](#15232)) - Add setup/destroy hooks and context handling to the CLI eval runner. ([#15247](#15247)) - [services] fix dev server hang when FastAPI CLI is used ([#15274](#15274)) - Fix `--help` flag to return exit code 0 instead of 2 for the `metrics` command, aligning with standard CLI conventions. ([#15259](#15259)) - Rename fetch to nodeFetch in cases where it is an import from node-fetch ([#15234](#15234)) - Change `vercel metrics` default query output from CSV to rich text with metadata, summary tables, sparklines, and optional raw values via `--raw-values`. ([#15178](#15178)) - Removes the legacy SSO redirect flow code. ([#15228](#15228)) - Updated dependencies \[[`ad86425c3e0a1d1738cef8464dd767dd1d9a0e9a`](ad86425), [`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269), [`d9e3a570a9c6ee47afa3446ec611b6a9e4b4feec`](d9e3a57), [`2db57840669ca2fa8dadf492bd38c21bf9e3cfeb`](2db5784), [`0d42acfd22e51e51cb0e4a5aea7c19f3886ed496`](0d42acf), [`8404a7315260851495d708f1c7c6e870d7ffa007`](8404a73), [`fbf649223e6fa8b509295a85784347dcebd4a0b0`](fbf6492), [`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc), [`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585)]: - @vercel/remix-builder@5.6.0 - @vercel/python@6.17.0 - @vercel/next@4.15.35 - @vercel/node@5.6.8 - @vercel/static-build@2.8.42 - @vercel/build-utils@13.6.0 - @vercel/go@3.4.3 - @vercel/backends@0.0.38 - @vercel/elysia@0.1.41 - @vercel/express@0.1.50 - @vercel/fastify@0.1.44 - @vercel/h3@0.1.50 - @vercel/hono@0.2.44 - @vercel/koa@0.1.24 - @vercel/nestjs@0.2.45 - @vercel/redwood@2.4.9 - @vercel/rust@1.0.5 - @vercel/hydrogen@1.3.5 - @vercel/ruby@2.3.2 ## @vercel/python@6.17.0 ### Minor Changes - Find entrypoints for django projects. ([#15167](#15167)) ### Patch Changes - Rename fetch to nodeFetch when importing from node-fetch ([#15232](#15232)) - [services] fix dev server hang when FastAPI CLI is used ([#15274](#15274)) - [python] fix dev server crash on relative imports ([#15269](#15269)) - Updated dependencies \[[`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc)]: - @vercel/python-analysis@0.8.0 ## @vercel/python-analysis@0.8.0 ### Minor Changes - Find entrypoints for django projects. ([#15167](#15167)) ## @vercel/remix-builder@5.6.0 ### Minor Changes - [remix] Support future.v8_middleware option ([#15189](#15189)) ## @vercel/backends@0.0.38 ### Patch Changes - Support function overrides in backends builder ([#15214](#15214)) - Updated dependencies \[[`2db57840669ca2fa8dadf492bd38c21bf9e3cfeb`](2db5784), [`0d42acfd22e51e51cb0e4a5aea7c19f3886ed496`](0d42acf), [`8404a7315260851495d708f1c7c6e870d7ffa007`](8404a73), [`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc), [`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585)]: - @vercel/build-utils@13.6.0 ## @vercel/cervel@0.0.25 ### Patch Changes - Updated dependencies \[[`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585)]: - @vercel/backends@0.0.38 ## @vercel/client@17.2.48 ### Patch Changes - rename fetch to fetchApi ([#15231](#15231)) - Updated dependencies \[[`e64a85daec784b4fe571abe7405a80aca150007a`](e64a85d), [`2db57840669ca2fa8dadf492bd38c21bf9e3cfeb`](2db5784), [`0d42acfd22e51e51cb0e4a5aea7c19f3886ed496`](0d42acf), [`8404a7315260851495d708f1c7c6e870d7ffa007`](8404a73), [`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc), [`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585), [`af6a651229cad4ddb7fcc15bd14d06355c2b77ee`](af6a651)]: - @vercel/routing-utils@6.0.0 - @vercel/build-utils@13.6.0 ## @vercel/config@0.0.35 ### Patch Changes - Updated dependencies \[[`e64a85daec784b4fe571abe7405a80aca150007a`](e64a85d), [`af6a651229cad4ddb7fcc15bd14d06355c2b77ee`](af6a651)]: - @vercel/routing-utils@6.0.0 ## @vercel/elysia@0.1.41 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/express@0.1.50 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 - @vercel/cervel@0.0.25 ## @vercel/fastify@0.1.44 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/frameworks@3.19.1 ### Patch Changes - Rename fetch to nodeFetch when importing from node-fetch ([#15232](#15232)) ## @vercel/fs-detectors@5.8.12 ### Patch Changes - Support function overrides in backends builder ([#15214](#15214)) - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269), [`e64a85daec784b4fe571abe7405a80aca150007a`](e64a85d), [`af6a651229cad4ddb7fcc15bd14d06355c2b77ee`](af6a651)]: - @vercel/frameworks@3.19.1 - @vercel/routing-utils@6.0.0 ## @vercel/gatsby-plugin-vercel-builder@2.0.140 ### Patch Changes - Updated dependencies \[[`2db57840669ca2fa8dadf492bd38c21bf9e3cfeb`](2db5784), [`0d42acfd22e51e51cb0e4a5aea7c19f3886ed496`](0d42acf), [`8404a7315260851495d708f1c7c6e870d7ffa007`](8404a73), [`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc), [`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585)]: - @vercel/build-utils@13.6.0 ## @vercel/go@3.4.3 ### Patch Changes - Rename fetch to nodeFetch in cases where it is an import from node-fetch ([#15234](#15234)) ## @vercel/h3@0.1.50 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/hono@0.2.44 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/koa@0.1.24 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/nestjs@0.2.45 ### Patch Changes - Updated dependencies \[[`3d872692c601abeec98743d2af3a3ea19587e799`](3d87269)]: - @vercel/node@5.6.8 ## @vercel/next@4.15.35 ### Patch Changes - Rename fetch to nodeFetch when importing from node-fetch ([#15232](#15232)) ## @vercel/node@5.6.8 ### Patch Changes - Rename fetch to nodeFetch when importing from node-fetch ([#15232](#15232)) - Updated dependencies \[[`2db57840669ca2fa8dadf492bd38c21bf9e3cfeb`](2db5784), [`0d42acfd22e51e51cb0e4a5aea7c19f3886ed496`](0d42acf), [`8404a7315260851495d708f1c7c6e870d7ffa007`](8404a73), [`b3a96cc4f276ce8d16c695eabd499d3a17e73aa8`](b3a96cc), [`9a6358529f0737415110cf03d626dc9ee8e99126`](9a63585)]: - @vercel/build-utils@13.6.0 ## @vercel/static-build@2.8.42 ### Patch Changes - Rename fetch to nodeFetch in cases where it is an import from node-fetch ([#15234](#15234)) - Updated dependencies \[]: - @vercel/gatsby-plugin-vercel-builder@2.0.140 ## @vercel/python-runtime@0.5.2 ### Patch Changes - fix ASGI lifecycle events in non-IPC codepath ([#15268](#15268)) ## @vercel/python-workers@0.0.11 ### Patch Changes - Add a version bump for `@vercel/python-workers` so previously merged changes are included in the next release. ([#15254](#15254))  > [!NOTE] > Low Risk Change > > This PR is an automated Changesets release that only updates version numbers in package.json files and CHANGELOG.md files across multiple packages, with no logic or schema changes. > > - Version bumps across ~30 packages (package.json version fields) > - CHANGELOG.md updates documenting previously merged changes > - Deletion of .changeset/*.md files consumed by release automation > > <sup>Risk assessment for [commit 9b78e59](https://github.com/vercel/vercel/commit/9b78e59c7c4716d10beac3a0228e767c8565f65a).</sup>  Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

[remix]: wrap the request handler to support middleware

cd84802

fix: lint

c0dbdac

vercel bot deployed to Preview February 20, 2026 22:31 View deployment

carbonrobot marked this pull request as ready for review February 23, 2026 16:58

carbonrobot requested a review from a team as a code owner February 23, 2026 16:58

jeffsee55 approved these changes Feb 25, 2026

View reviewed changes

carbonrobot merged commit ad86425 into main Feb 25, 2026
270 of 274 checks passed

carbonrobot deleted the carbonrobot/react-router-middleware branch February 25, 2026 17:49

vercel-release-bot mentioned this pull request Feb 25, 2026

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[remix]: wrap the request handler to support middleware#15189

[remix]: wrap the request handler to support middleware#15189
carbonrobot merged 2 commits intomainfrom
carbonrobot/react-router-middleware

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