0n3
MCP servers · .0n App Marketplace · connector · GPT action

Connect ChatGPT to .0n App Marketplace

One line gives ChatGPT your .0n App Marketplace account as tools: 5 endpoints, list apps, install app, checkout app, called with your own connection. No key in the prompt, a receipt for every call, revoke ChatGPT's access alone any time.

Get the line for ChatGPTConnect .0n App Marketplace first

Three steps

  1. Create a free 0n3 account and connect .0n App Marketplace. Paste a key or sign in; it lands in your vault, encrypted.
  2. Install 0n3 into ChatGPT. A custom connector in Developer mode, or an Action on a custom GPT from the OpenAPI spec.
  3. Ask ChatGPT: whoami. Then: "List apps in .0n App Marketplace".
Custom connector (needs Developer mode)
  1. Settings → Connectors (or Apps) → Advanced → Developer mode on
  2. Create → name 0n3 · MCP server URL https://0n3.app/mcp · Authentication: OAuth
  3. Finish the sign-in with your 0n account
  4. Enable the connector in a chat and ask: "whoami"

ChatGPT connectors cannot send a static header, so 0n3 signs you in through its OAuth door (dynamic client registration is on).

The line above carries a placeholder; 0n3.app/install mints a real key named for ChatGPT and fills it in.

What ChatGPT can then do in .0n App Marketplace

List apps · Browse the unified catalog (UCP products + apps)2
List appsGET /api/widgets/marketplace/catalog
List installedGET /api/marketplace/my-apps
Install app · Install a free app for the current location1
Install appPOST /api/widgets/marketplace/install
Checkout app · Stripe checkout for a paid app1
Checkout appPOST /api/widgets/marketplace/checkout
Execute app · Execute an installed .0n app1
Run an appPOST /api/marketplace/execute/{appId}
List installed · List apps installed on the current location0
List apps installed on the current location

.0n App Marketplace in other AI clients

Claude Code + .0n App MarketplaceMCP server + skillClaude (desktop & claude.ai) + .0n App MarketplaceconnectorCodex CLI + .0n App MarketplaceMCP serverGemini CLI + .0n App MarketplaceMCP serverCursor + .0n App MarketplaceMCP serverVS Code (Copilot) + .0n App MarketplaceMCP serverWindsurf + .0n App MarketplaceMCP server

ChatGPT with other apps

Hostinger363 endpointsTelegram132 endpointsPipedrive95 endpointsResend67 endpointsSquare57 endpointsLinkedIn50 endpointsSlack45 endpointsFigma32 endpointsCloudConvert32 endpointseBay25 endpointsQuickBooks21 endpointsCloudflare21 endpoints