Browse the CustomCat catalog, your products and designs; check shipping; create and cancel orders. Hosted by usefulapi — connect from Claude, ChatGPT, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"customcat": {
"url": "https://customcat.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"customcat": {
"type": "http",
"url": "https://customcat.usefulapi.io/mcp"
}
}
}No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run these commands. The second one opens the login page:
Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
The login page asks for your CustomCat API key.
Find it in the CustomCat app (customcat-beta.mylocker.net) → Settings: CustomCat creates two keys, a Read key and a Write key. Use the Read key for look-ups only; use the Write key if you want the assistant to place or cancel orders (an order charges the payment method on your CustomCat account). Your key is used only to call the CustomCat API on your behalf; it is never shown to anyone.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your CustomCat API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
Turn on the CustomCat connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
customcat_list_products | read | List your products List the products you set up in CustomCat (a design on one or more catalog items) with variants, SKUs, cost, price, stock flag and design images. Use the variant SKUs when placing an order for these products. GET /product. |
customcat_get_product | read | Get one of your products One of your CustomCat products by id (e.g. 22-2580581): variants, SKUs, cost, price, options, designs. GET /product/{product_id}. |
customcat_list_designs | read | List your designs List the designs uploaded to your CustomCat account: id, name, tags, image URLs, default product and last-updated time. GET /design. |
customcat_list_catalog_categories | read | List catalog categories The CustomCat catalog categories (Digisoft, Sublimation) and their subcategories (e.g. T-Shirts, Sweatshirts, Bags), to narrow customcat_list_catalog. GET /catalogcategory. |
customcat_list_catalog | read | List the blank-product catalog Browse the full CustomCat catalog of printable blank products (the items you can order with your own artwork). Filter by category and subcategory from customcat_list_catalog_categories. The reply carries the total in `total`. GET /catalog. |
customcat_get_catalog_product | read | Get a catalog product One catalog product by numeric id with its colors, sizes and SKUs. GET /catalog/{catalog_product_id}. |
customcat_get_catalog_sku | read | Get a catalog SKU (stock check) One catalog SKU with its price and stock status. Use it before ordering: a SKU that is out of stock, discontinued or invalid makes the order fail. GET /catalog/sku/{catalog_sku_id}. |
customcat_list_shipping_methods | read | List shipping methods The shipping methods CustomCat offers for a destination country (ids and names). The method name is required when placing an order. GET /shipping. |
customcat_get_shipping_cost | read | Get the shipping cost for items Calculate the shipping cost of one shipping method for a destination and a list of catalog SKUs with quantities. Read-only quote: it places nothing. POST /shipping/{shipping_id} (shipping_id from customcat_list_shipping_methods). |
customcat_get_order_status | read | Get order status Status of an order by YOUR order id: order status (Pending, Verified, Shipped), per-item production status, shipments with tracking ids, totals and the ship-to address. Set sandbox=true to look up a sandbox test order. GET /order/status/{order_id}. |
customcat_create_order | write | Place an order WRITE: place an order for CustomCat to print and ship. This CHARGES the payment method on file in your CustomCat account (product cost + shipping; a front+back print adds $5 per line item) unless sandbox=true, which only validates the order. A real order (sandbox=false) also needs confirm=true, set only after the user confirmed it. The order id is yours and must be new (a duplicate is rejected). Needs the Write API key. Check stock with customcat_get_catalog_sku and the method name with customcat_list_shipping_methods first, and confirm the details with the user before calling. POST /order/{order_id}. |
customcat_cancel_order | write | Cancel an order WRITE: cancel (delete) an order by YOUR order id. CustomCat can only cancel an order that has not gone into production; one already printed or shipped is refused. Needs the Write API key. Confirm with the user first. DELETE /order/{order_id}. |
customcat_usage_status | Usage status (free-tier meter) Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter. | |
customcat_request_feature | Request a missing feature Tell usefulapi that the user needs something the CustomCat tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
customcat_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on CustomCat (the free tier caps monthly usage). Plans: "monthly" — $9/month; "yearly" — $90/year (2 months free). Cancel any time: Pro then runs to the end of the paid period, so it also suits a one-time job. *A fair use limit applies. For heavy use (near Pro's limit): "plus" or "plus_yearly" — Pro+, $19/month or $190/year, unlimited tool calls (fair use limit: 100,000 a month); an existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Otherwise returns a short link to open in your browser (it opens Stripe Checkout); after payment the account upgrades automatically. Does not count against the meter. | |
customcat_cancel_subscription | Cancel the Pro subscription Cancel the caller's CustomCat Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run customcat_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this CustomCat server only. Subscribe with customcat_upgrade (it returns a Stripe Checkout link). Cancel any time with customcat_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running customcat_upgrade before then undoes the cancel. Or write to [email protected].
No. usefulapi is an independent service. It is not affiliated with or endorsed by CustomCat. The server calls the CustomCat API with your own CustomCat access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your CustomCat API key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your CustomCat API key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the CustomCat API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in CustomCat.
Yes, if you approve it. 2 of the 12 CustomCat tools can create or change data. The other 10 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this CustomCat server only. Cancel any time: Pro then runs to the end of the paid period. Run customcat_usage_status to see how many calls you used.
Ask the AI to run customcat_upgrade: it returns a Stripe Checkout link. To cancel, run customcat_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with customcat_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.