MCP limits protect Cardzen accounts and keep automated assistants from creating accidental request loops. Limits apply across all connections for the same Cardzen account as well as to each individual grant.
Current Limits
| Account | Requests per minute | Weighted units per day | Writes per minute | Writes per day | Concurrent calls |
|---|---|---|---|---|---|
| Free or email-unverified | 10 | 50 | 10 | 10 | 2 |
| Pro | 50 | 200 | 20 | 50 | 10 |
The daily request cap uses weighted units rather than treating every operation as identical. Lightweight reads and updates use fewer units; bounded report, component, and wallet-history operations use more. Write operations also count toward separate per-minute and daily write caps. Cardzen may reject an oversized wallet, component set, history window, or response with result_too_large instead of continuing unbounded work.
Cardzen can temporarily lower limits, disable a tool, or disable MCP writes to protect customers and service reliability. A rate-limited response does not mean a write succeeded. Wait before retrying and never ask an assistant to loop until a request passes.
Connection Does Not Start
- Confirm the server address is exactly
https://mcp.cardzen.ai/mcp. - Confirm the client supports remote Streamable HTTP MCP and browser-based OAuth.
- Check whether custom apps or connectors are available for your assistant plan and workspace.
- Restart setup from the assistant so it creates a fresh authorization request.
Authorization Page Expired
Authorization requests are short-lived. Return to the assistant and start setup again. Do not reuse an old authorization-page URL or send it to another person.
Connected App Is Unavailable in Cardzen
If Cardzen cannot load Connected Apps, it shows an unavailable message instead of pretending that no apps are connected. Retry later. An unavailable list does not revoke existing grants.
Disconnect or Reconnect
Open Account & Settings -> MCP Integration, select the connected app, and choose Disconnect. To reconnect, return to the assistant and complete setup and authorization again.
A Tool Is Unavailable
The assistant may have cached an older tool list. Start a new conversation or reconnect if needed. The Cardzen server still enforces the current grant, plan capability, scope, and tool switch even if a client displays an outdated tool.
- Insufficient scope: reconnect and approve the access required by that tool. Cardzen does not silently expand an existing grant.
- Upgrade required: the requested tool is not included in the account's current Cardzen capability. The error names the minimum capability without exposing billing-provider details.
- Tool disabled: Cardzen has temporarily or permanently disabled that exact tool. Repeated retries will not override the switch.
- Rate limited: wait for the returned retry period. A rate-limit result does not prove that a write succeeded.
If an error shows a Support ID, include that non-secret identifier when contacting Cardzen support. Do not send an OAuth code, access token, Firebase credential, browser-session value, or full assistant conversation.
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