Customnia API
Print on Demand API for Custom Apparel
Send orders from your store, app or AI agent straight to our print shops in New York and Los Angeles. We print or embroider every order, pack it under your brand if you like, ship it anywhere in the US and keep your system posted at every step.
- Test key included
- Print shops in NY and LA
- 4.9 on Google
{
"reference": "brooklyn-tees:1001",
"items": [{"design_id": 57, "color_id": 1,
"size_id": 3, "quantity": 2}],
"seller": {"packing_name": "Brooklyn Tees"},
"shipping_address": {"city": "New York", …}
}- received
- printing
- ready
- shipped
- delivered
An order.updated webhook at every step, with tracking once it ships.
Who it's for
Anyone who sells custom apparel and would rather not run a print shop.
Online stores
Your website sells the shirt, we make it. Send each paid order with one call and get the tracking number back.
Apps and marketplaces
Give your sellers a print shop: our catalog at your wholesale prices, mockups for their listings, and every order tagged with the seller it came from.
Shopify sellers
Make products from our mockups, upload them to your Shopify store, and send paid orders from your app. Tracking comes back by webhook.
AI agents
Plug our MCP server into Claude Code, Cursor or VS Code. Your agent searches the catalog, makes designs and mockups, and quotes orders.
What the API does
Everything between "a customer paid" and "the parcel arrived", in one API.
Catalog with your prices
Blanks with their colors, sizes, photos and print areas, and your wholesale price for every color and size. Filter by category, brand, color or size.
Designs your way
Upload a PNG, send the layers from your own editor, or just send words in one of the designer's fonts. Backgrounds can come off automatically.
Mockups for every color
See any design on every color of its blank, front and back, as a 1000 × 1000 JPEG ready for your product pages.
Quotes before you charge
Know what an order will cost, items and shipping, before you take your customer's money.
Orders in your name
One call per paid order, safe to retry. With white label, your name is on the label and the parcel; your logo and a note go on the packing slip.
Status and tracking
Signed webhooks whenever an order starts printing, is ready, ships or is delivered. Cancel or change the address until printing starts.
How to start
Three steps from the first call to the first real order.
Ask for your keys
Email hello@customnia.com and tell us what you are connecting. You get a live key and a test key; keep them on your server.
Build with the test key
Every call works and is priced like a real one, but test orders are never printed or charged. Walk them through shipping to test your webhooks.
Go live
Switch to the live key. Each order is made in 4 business days in New York or Los Angeles and ships to any US address.
Connect an AI agent
The API is also an MCP server. Add it to your coding tool with your key, and the agent works with exactly what your key can see.
- Search the catalog and open any blank
- Create designs from a picture link, layers or words
- See mockups and quote orders
- Read orders, cancel them or change the address
- Place test orders with the test key
Real store orders are placed from your own server. Start the agent with the test key.
claude mcp add --transport http customnia \ https://api.customnia.com/mcp \ --header "Authorization: Bearer cn_test_…"
Cursor, VS Code and other tools take the same URL and header.
Request an API key
Write to us and tell us a little about your project:
- Your company or store and its website
- What you are connecting: a store, an app, a Shopify store or an AI agent
- About how many orders a month you expect
- The URL for order webhooks, if you have it
- Whether parcels should ship under your brand
The button opens an email with these questions already in it. You get a live key and a test key.
Questions about the Customnia API
Anything else? Email hello@customnia.com.
How do I get an API key?
Email hello@customnia.com with your company, your website and what you are connecting. Keys are issued by Customnia: you get a live key and a test key. Keep them on your server, never in a browser or a mobile app.
Can I test without placing real orders?
Yes. With the test key every call is checked and priced like a real one, but test orders are kept apart and are never printed, packed or charged. You can move a test order through printing, shipping and delivery to see your webhooks work. Designs and mockups made with the test key can later be ordered with the live key.
How do prices and payment work?
Your wholesale price for every color and size of a blank is in the catalog, and every quote and order shows it again. Placing an order means you will pay its total; Customnia invoices partners as agreed.
How fast are orders made and shipped?
Production takes 4 business days (weekends and US holidays excluded), and orders placed after 3 PM count from the next business day. Every order tells you its ready-by date. Orders to western states are made in Los Angeles, the rest in New York. We ship to US addresses, usually by UPS Ground.
Can orders ship under my brand?
Yes. When your account ships white label, your name goes on the shipping label and the parcel, with no Customnia branding. Your logo and a short note can go on the packing slip of every order.
Can an AI agent use the API?
Yes. The API is also an MCP server at api.customnia.com/mcp for Claude Code, Cursor, VS Code and other tools that take a server URL with a header. It sees exactly what your key sees. With the test key the agent can also place test orders; real store orders are placed from your own server.
I want to order for myself, not for my customers.
Then see Order with AI: tell ChatGPT, Claude or another AI assistant what you want printed. It makes the design, shows you a mockup and the price, and places the order only when you say yes.
We use the old design API. What changes?
The old API at design.customnia.com/api had no keys and is being retired. Everything it did is in the Partner API, with your key. Claim your existing designs first, so they keep the ids your database already uses; the migration steps walk you or your coding agent through the rest.
Documentation
Written for developers and for the coding agents that work with them.
- GuideKeys, test mode, catalog, designs, orders and webhooks, with examples
- API referenceEvery endpoint, field and error
- OpenAPI schemaGenerate a client or import it into Postman
- ChangelogVersions and what changed in each
- MCP serverConnect Claude Code, Cursor or VS Code
- llms.txtThe whole API in one page for AI agents
- REST and JSON
- Bearer keys
- Test mode
- Signed webhooks
- 240 requests a minute
- Version 1
Plug a print shop into your product
Ask for your keys, build with test orders, and go live when you are ready.