Bubble MCP on Free With No Limits and No Agent Credits, but Cursor Has No CIMD: Which Sidecar to Use This Week
Bubble's official MCP server is in beta, with no request limits on the Free plan and no Agent credit usage. Cursor can't connect to it because it doesn't support CIMD. Here's the sidecar I'd connect today if I were a non-technical founder building an MVP.
On October 6, 2026, Bubble shipped two things at once. Agent 2 went to General Availability (GA), and the official Bubble MCP server opened in beta. If you're an early-stage founder or vibe coder without a deep engineering background, your job is to get an MVP in front of users and pick up early traction or angel interest fast. Nocode plus AI is the default stack for that now. But this release has a billing and compatibility split in it, and it changes how you should build this week. Worth reading next: Bubble, Reverse.dev for Teams, and.
Two Diverging AI Workflows: Native Agent vs External MCP
Bubble now gives you two separate ways to use AI on your app.
- Bubble AI Agent 2 inside the editor. It's pinned into the visual builder and runs on per-app Bubble AI credits. Free gives you 500 credits per month per app. Starter Web includes 1,000 per month. Starting October 20, 2026, Web-only Starter goes up to $39/month, or $32/month billed annually. A double-credits promotion runs through October 31 for eligible apps. Even so, rapid prototyping burns through 500 credits very quickly.
- External clients via Bubble MCP. The official MCP server is live in beta. According to Bubble's docs and the October community update, there are no Bubble-side request limits, even on Free, and it does not consume Bubble AI credits. You only pay for your model usage or subscription with your external provider, such as Anthropic or OpenAI. That means you can keep prototyping without running into Bubble's credit ceiling. Same topic: Bubble MCP server: Three Meanings. Same topic: Agent 2 GA, MCP Beta,.
| Workflow | What it is for | What it is not for |
|---|---|---|
| Bubble AI Agent 2 (in editor) | AI pinned in the visual builder; runs on per-app Bubble AI credits (Free: 500/month/app; Starter Web: 1,000/month) | Heavy rapid prototyping without hitting Bubble’s credit ceiling (500 credits burn through quickly) |
| External clients via Bubble MCP | Official MCP server (beta); use external providers (e.g. Anthropic, OpenAI) with no Bubble-side request limits (including Free) and no Bubble AI credit consumption | Relying on Bubble AI credits instead of your external model subscription or usage billing |
The Blocker: Cursor Lacks CIMD Support
A lot of non-technical builders doing vibe coding use Cursor as their main editor. The obvious move is to plug Cursor straight into Bubble's new MCP server.
Right now that fails. Bubble built authentication on CIMD (Client ID Metadata Documents, which Bubble describes as a newer sign-in standard). Cursor supports MCP OAuth through Dynamic Client Registration (DCR) and static credentials. It doesn't support CIMD. When you try to connect, authentication fails with: “Incompatible auth server: does not support dynamic client registration.”
Bubble staff confirmed they're working on support. Updates on the Cursor community forum say there's no public timeline for CIMD yet. Composio is also listed among clients without CIMD support. Nobody has committed to a date. Same topic: Bubble Community on Price Transparency.
What Sidecar to Set Up This Week for Your MVP
I wouldn't wait for Cursor. If you want to validate an MVP now without losing momentum or burning through credits, use the clients that are officially verified to work with Bubble MCP:
- Claude and Claude Code
- ChatGPT and Codex
- VS Code with GitHub Copilot
Hook Claude or VS Code up to Bubble's MCP server and you can inspect your app's structure and do dev-level work without touching your app's 500 monthly Bubble AI credits.
Guardrails and Beta Boundaries
The beta has real limits. Know them before your first request:
- Development database only. Bubble MCP can only work with the development database. It can't read or write live production data, so your active users are shielded from side effects.
- No deploys, branch merges, or logs. The MCP server can't deploy your app, merge branches, or read server logs. Deploying is still a manual action you take in the Bubble visual editor.
- Dev edits are real. MCP runs with your authenticated account's permissions. If it changes or deletes development data, that's real and you can't undo it. I'd start on a dedicated scratch app before letting it near anything that matters.
- Editor sidecar, not end-user MCP. What's shipping now is an editor sidecar for you, the builder. It's not the end-user MCP the founders hinted at in Bubble's September AMA, where deployed apps would expose actions to end users' own AI tools at some point in the future. Same topic: What Bubble Really Costs for.
Bottom Line for Early Builders
Don't get stuck on Cursor's auth wall. Keep the Bubble visual editor open for manual checks, save your native AI credits, and connect Claude or VS Code to Bubble MCP to do the heavy lifting on your MVP. This week, that's the cheapest way to vibe code a prototype on Bubble.