feat: expose request session setter

[onmax]

Bearer-authenticated H3 requests can resolve a complete AppSession, but the module only exposed readers for its request cache. Integrations therefore had to assign event.context.requestSession directly, which also allowed an older in-flight cookie-session lookup to overwrite the supplied value.

This adds the server-only setRequestSession(event, session) helper so trusted authentication middleware can pass an AppSession | null to existing getRequestSession, getUserSession, and requireUserSession consumers.

Request-session contract

• The explicit value becomes authoritative for the current request without creating, updating, or clearing a session cookie.
• When a lookup is already running, later session readers join the setter while it waits. The older lookup only writes or clears state while it still owns the in-flight marker.
• null is an authoritative negative cache value.
• Rejected earlier lookups do not prevent trusted middleware from supplying its resolved session.
• Context-less/narrowed H3 events continue through the existing request-session fallback.

The helper intentionally does not verify bearer tokens or interpret claims. The API reference requires callers to authenticate the value and enforce OAuth audience and scope restrictions before injection.

Closes #408

Verification

• corepack pnpm exec vitest run test/get-request-session.test.ts test/require-user-session-typing.test.ts test/public-skill.test.ts — 24 tests passed on 19c4f83
• Full corepack pnpm test with a temporary Corepack pnpm shim — 317 tests passed
• corepack pnpm lint
• corepack pnpm typecheck
• corepack pnpm build:docs
• git diff --check

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
nuxt-better-auth-docs	Ready	Preview	Aug 21, 2026 3:03pm

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@nuxtjs/better-auth@409

commit: a1f338f

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

The latest updates on your project. Learn more about integrating Git with Workers.

Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	better-auth	a1f338f	Commit Preview URL Branch Preview URL	Aug 21 2026, 03:05 PM