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feat: enable Bun runtime on Vercel Functions#22

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sergical wants to merge 3 commits intomainfrom
sergical/bun-runtime
Open

feat: enable Bun runtime on Vercel Functions#22
sergical wants to merge 3 commits intomainfrom
sergical/bun-runtime

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@sergical
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@sergical sergical commented Feb 10, 2026

Summary

  • Adds vercel.json with bunVersion: 1.x to run Vercel Functions under Bun (blog post)
  • Updates dev/build/start scripts to use bun --bun next so Next.js runs under Bun locally (docs)
  • Removes 4 stale pnpm.overrides that are no longer needed (all dependencies already resolve to the constrained versions upstream)

Removed overrides (all no-ops)

Override Pulled by Current version Why safe to drop
mdast-util-to-hast ^13.2.1 shiki, streamdown 13.2.1 Already at target
@modelcontextprotocol/sdk ^1.24.0 shadcn (dev) 1.26.0 Already above target
js-yaml ^4.1.1 shadcn → cosmiconfig (dev) 4.1.1 Already at target
body-parser ^2.2.1 shadcn → express (dev) 2.2.2 Already above target

Things to verify

  • bun --bun next dev works locally (requires bun installed)
  • Sentry tracing works under Bun (import-in-the-middle, require-in-the-middle are Node.js module hooks)
  • AI SDK streaming endpoints work correctly
  • Cold start performance on Vercel (Bun cold starts are currently slower than Node.js)
  • No regressions from removed overrides

Rollback

  • Remove vercel.json to revert Vercel Functions to Node.js
  • Remove bun --bun prefix from scripts to revert local dev to Node.js

🤖 Generated with Claude Code

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vercel bot commented Feb 10, 2026

The latest updates on your projects. Learn more about Vercel for GitHub.

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webvitals-com Ready Ready Preview, Comment Feb 10, 2026 10:37pm
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sergical and others added 3 commits February 10, 2026 17:33
Adds vercel.json with bunVersion: 1.x to switch serverless functions
from Node.js to Bun runtime. This is currently in public beta.

Note: Sentry instrumentation packages (import-in-the-middle,
require-in-the-middle) may need testing under Bun.

Co-Authored-By: Claude <noreply@anthropic.com>
- Prepend `bun --bun` to dev/build/start scripts so Next.js runs
  under the Bun runtime locally
- Remove 4 pnpm overrides that are now no-ops (dependencies already
  resolve to the constrained versions upstream)

Co-Authored-By: Claude <noreply@anthropic.com>
Replace pnpm-lock.yaml with bun.lock so Vercel uses bun for both
package installation and runtime.

Co-Authored-By: Claude <noreply@anthropic.com>
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