## Summary
Splits the Stack Auth MCP server out of `apps/backend` and into a
dedicated Next.js app at `apps/mcp/`, served on port `:42` (suffixed via
`NEXT_PUBLIC_STACK_PORT_PREFIX`) and exposed in production at
`https://mcp.stack-auth.com/mcp`. The backend no longer carries the MCP
transport route; clients now point at the new host.
Base: `dev` → Head: `chore/move-mcp-to-a-sep-app`
Scope: 34 files, +1425 / −353
## What changed
- **New app** `apps/mcp/` — standalone Next.js + `@vercel/mcp-adapter`,
with:
- `src/app/api/internal/[transport]/route.ts` — MCP transport handler
(moved from backend)
- `src/app/mcp/route.ts`, `src/app/route.ts` — public landing + setup
page
- `src/app/health/route.ts` — health check
- `src/mcp-handler.ts`, `src/setup-page.ts`, `src/analytics.ts`
- **Backend** drops
`apps/backend/src/app/api/internal/[transport]/route.ts` (−105) — MCP
code is gone from the backend image.
- **Dashboard** install hint updated to point at
`https://mcp.stack-auth.com/mcp` (was `/`).
- **Dev launchpad** gets an MCP tile so the new service shows up
alongside the rest of the local stack.
- **CI** workflows (`db-migration-backwards-compatibility`,
`e2e-api-tests*`) start the MCP service in the background before running
tests.
- **Docs** (`docs-mintlify`, `docs/`) and `init-stack` / `init-prompt`
updated to reference the new URL.
- **E2E** `apps/e2e/tests/backend/endpoints/api/v1/internal/mcp.test.ts`
reworked to hit the new host; `helpers.ts` and env files gain an MCP
base-URL var.
## Visuals
### New `apps/mcp` setup page (`https://mcp.stack-auth.com/`)
The standalone app's root now serves a self-contained MCP setup guide
with per-client instructions (Cursor, VS Code, Codex, Claude Code,
Claude Desktop, Windsurf, ChatGPT, Gemini CLI):
### Dev launchpad now lists the MCP service
New tile at port suffix `:42`, importance 2, alongside Backend /
Dashboard / Demo app:
## Notes for reviewers
- The MCP transport endpoint moved path: it was mounted under
`/api/internal/[transport]` in the backend; in the new app it's at the
same path but on the dedicated host. The public-facing URL is
`https://mcp.stack-auth.com/mcp`.
- `apps/mcp` ships its own PostHog analytics client (`src/analytics.ts`)
so the backend doesn't have to proxy events for it anymore.
- Port allocation: `${PORT_PREFIX}42` (default `8142` in dev). Picked to
fit the existing dev-launchpad importance-2 row.
- No DB migrations.
## Test plan
- [x] `apps/mcp` builds and `pnpm dev` serves on `:8142`
- [x] Dev launchpad renders the new MCP tile (screenshot above)
- [x] MCP setup page renders client tabs (screenshot above)
- [x] E2E `mcp.test.ts` updated to hit the new host
- [ ] CI green on `e2e-api-tests*` and
`db-migration-backwards-compatibility` workflows (they were touched to
start the MCP service)
- [ ] `init-stack` / `mcp.ts` install flow lands users on the new URL
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Standalone MCP app added with a public /mcp endpoint and health check.
* MCP appears in the dev-launchpad apps list.
* **Documentation**
* MCP endpoint updated to https://mcp.stack-auth.com/mcp in all setup
guides and installer snippets.
* Setup page enhanced with detailed client install tabs and
instructions.
* **Chores**
* MCP service integrated into CI/e2e workflows and local env configs.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
DB migration compat / Back-compat — Current branch migrations with ${{ needs.check-migrations-changed.outputs.base_branch }} branch code (push) Has been cancelled
DB migration compat / Forward-compat — Current branch code with ${{ needs.check-migrations-changed.outputs.base_branch }} branch migrations (push) Has been cancelled
<!--
Make sure you've read the CONTRIBUTING.md guidelines:
https://github.com/stack-auth/stack-auth/blob/dev/CONTRIBUTING.md
-->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Provision local-emulator projects from a local config file and return
emulator credentials via a new internal endpoint.
* Dashboard: "Open config file" flow to open local projects and refresh
owned projects.
* **Changes**
* Branch config can prefer/read/write local files for emulator projects.
* Environment config updates/resets are blocked for local-emulator
projects.
* Dashboard UI shows read-only notices and disables project creation in
emulator mode.
* Added DB mapping and a standard env flag to identify local-emulator
projects.
* **Tests**
* New E2E tests covering provisioning and config restrictions.
* **Chores**
* Removed legacy emulator docs and compose; added CI workflow for
local-emulator E2E runs.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Konstantin Wohlwend <n2d4xc@gmail.com>
