Preliminary Checks
Reproduction
https://github.com/p9f/clerk-tanstack-start-quickstart
Publishable key
Description
It seems that the new release of @clerk/tanstack-react-start package is broken when used with bun and POST server function that contains a body.
My understanding is that the clerkMiddleware consume the body of the request, which makes it impossible for tanstack to use the body itself.
I am not sure why but i can only reproduce with bun.
Steps to reproduce:
Checkout the repo linked above.
Which is a minimal example of tanstack start (rc) + bun + clerk
Expected behavior:
No error
Actual behavior:
I get this error
Server Fn Error!
816 | if (method.toLowerCase() !== "post") {
817 | throw new Error("expected POST method");
818 | }
819 | let jsonPayload;
820 | if (contentType == null ? void 0 : contentType.includes("application/json")) {
821 | jsonPayload = await request.json();
^
error: Body already used
code: "ERR_BODY_ALREADY_USED"
Environment
System:
OS: macOS 15.6.1
CPU: (12) arm64 Apple M2 Pro
Memory: 66.14 MB / 32.00 GB
Shell: 4.1.1 - /opt/homebrew/bin/fish
Binaries:
Node: 24.9.0 - /opt/homebrew/bin/node
npm: 11.6.0 - /opt/homebrew/bin/npm
bun: 1.3.0 - /Users/p9f/.bun/bin/bun
Browsers:
Chrome: 141.0.7390.78
Firefox: 140.0.4
Safari: 18.6
npmPackages:
@eslint/compat: ^1.3.1 => 1.4.0
@eslint/js: ^9.31.0 => 9.37.0
@tanstack/nitro-v2-vite-plugin: ^1.133.3 => 1.133.3
@tanstack/react-router: ^1.132.47 => 1.133.3
@tanstack/react-router-devtools: ^1.133.1 => 1.133.3
@tanstack/react-start: ^1.132.56 => 1.133.6
@types/node: ^24.0.14 => 24.8.1
@types/react: ^19.1.8 => 19.2.2
@types/react-dom: ^19.1.6 => 19.2.2
@typescript-eslint/eslint-plugin: ^8.37.0 => 8.46.1
@typescript-eslint/parser: ^8.37.0 => 8.46.1
@vitejs/plugin-react: ^4.3.4 => 4.7.0
autoprefixer: ^10.4.21 => 10.4.21
eslint: ^9.31.0 => 9.37.0
eslint-plugin-react: ^7.37.5 => 7.37.5
eslint-plugin-react-hooks: ^5.2.0 => 5.2.0
eslint-plugin-react-refresh: ^0.4.20 => 0.4.24
prettier: ^3.6.2 => 3.6.2
react: ^19.1.0 => 19.2.0
react-dom: ^19.1.0 => 19.2.0
srvx: 0.8.15 => 0.8.15
typescript: ^5.8.3 => 5.9.3
typescript-eslint: ^8.37.0 => 8.46.1
vite: ^7.0.4 => 7.1.10
vite-tsconfig-paths: ^5.1.4 => 5.1.4
Preliminary Checks
I have reviewed the documentation: https://clerk.com/docs
I have searched for existing issues: https://github.com/clerk/javascript/issues
I have not already reached out to Clerk support via email or Discord (if you have, no need to open an issue here)
This issue is not a question, general help request, or anything other than a bug report directly related to Clerk. Please ask questions in our Discord community: https://clerk.com/discord.
Reproduction
https://github.com/p9f/clerk-tanstack-start-quickstart
Publishable key
Description
It seems that the new release of
@clerk/tanstack-react-startpackage is broken when used with bun and POST server function that contains a body.My understanding is that the
clerkMiddlewareconsume the body of the request, which makes it impossible for tanstack to use the body itself.I am not sure why but i can only reproduce with bun.
Steps to reproduce:
Checkout the repo linked above.
Which is a minimal example of tanstack start (rc) + bun + clerk
Expected behavior:
No error
Actual behavior:
I get this error
Environment