How-To Guides
Register in ChatGPT (OpenAI)

Register your upstream connector in ChatGPT (OpenAI)

Your agentic SaaS—web app, accounts, billing, and MCP tools—is the product. ChatGPT is one distribution channel, not the thing Agentsyx wraps. This guide documents OpenAI’s flow for attaching your Agentsyx upstream MCP URL to a GPT (Apps / MCP steps as OpenAI presents them in their UI). Other MCP-capable hosts (Claude, etc.) use their own registration or connector flows.

Prerequisites

  • An Agentsyx upstream connector (see Create an Upstream MCP Connector)
  • Access to ChatGPT (ChatGPT Plus or Enterprise), per OpenAI’s requirements
  • MCP endpoint URL from your upstream connector

OpenAI ChatGPT: GPTs and MCP

In ChatGPT, custom GPTs can use tools and be shared. With MCP configured, the GPT can call your upstream endpoint. Typical capabilities:

  • Use custom tools and functions
  • Access external data and services
  • Provide specialized functionality
  • Be shared with other users (subject to OpenAI settings)

Your Agentsyx upstream connector exposes the MCP URL that ChatGPT connects to for those tool calls.

Step 1: Get Your MCP Endpoint URL

  1. Log in to your Agentsyx organization
  2. Navigate to your Upstream Connector
  3. Copy the MCP Endpoint URL - This is the URL you'll use in ChatGPT
  4. Save any API Keys or credentials if needed

Note: The MCP endpoint URL follows this shape: https://www.agentsyx.com/api/v1/flows/[org]/[project]/[deployment]/[connector]/mcp. The exact string is shown in Creator—use it as-is (production always uses www.agentsyx.com).

Step 2: Access ChatGPT GPT Creation

  1. Log in to ChatGPT
  2. Navigate to Explore GPTs or Create a GPT
  3. Click Create to start creating a new GPT

Step 3: Configure Your GPT

Configure the basic settings for your GPT:

  1. Name - Give your GPT a name (e.g., "My Agentsyx App")
  2. Description - Describe what your GPT does
  3. Instructions - Provide instructions for how your GPT should behave
  4. Conversation Starters - Add example prompts users can try

Step 4: Add MCP Connection

Add your Agentsyx MCP endpoint:

  1. Navigate to Configure tab
  2. Scroll down to Actions or Tools section
  3. Click Add Action or Add Tool
  4. Select MCP or Custom API option
  5. Enter your MCP Endpoint URL from Step 1
  6. Add Authentication if required (API key, OAuth, etc.)

MCP Configuration

  • Endpoint URL - Your Agentsyx MCP endpoint URL
  • Authentication - OAuth 2.0 (automatic) or API key if needed
  • Tools - Tools should be automatically discovered from your upstream connector

Step 5: Configure Tools

Configure which tools to use:

  1. Available Tools - Review tools discovered from your MCP endpoint
  2. Select Tools - Choose which tools your GPT should use
  3. Tool Descriptions - Add descriptions for each tool to help ChatGPT understand when to use them
  4. Tool Parameters - Configure default parameters if needed

Step 6: Test Your GPT

Test your GPT to ensure it works:

  1. Switch to Preview tab
  2. Test Tool Calls - Try using tools to verify they work
  3. Test Authentication - Verify that user authentication works
  4. Test Billing - Verify that credits are deducted correctly (if applicable)

Step 7: Publish Your GPT

Once testing is complete, publish your GPT:

  1. Review Settings - Make sure all settings are correct
  2. Set Visibility - Choose who can access your GPT (Only me, Anyone with a link, Public)
  3. Publish - Click Publish to make your GPT available

Step 8: Share Your GPT

Share your GPT with users:

  1. Get Share Link - Copy the share link for your GPT
  2. Share with Users - Share the link with your target users
  3. Monitor Usage - Track usage and billing in your Agentsyx dashboard

Troubleshooting

Connection Issues

  • MCP endpoint not accessible - Check your Agentsyx connector status and deployment
  • Authentication failing - Verify authentication configuration in both Agentsyx and ChatGPT
  • Tools not discovered - Check that your upstream connector is properly configured

Tool Issues

  • Tools not working - Verify tool mapping and downstream connector status
  • Tool calls failing - Check tool parameters and server response format
  • Billing not working - Verify billing configuration and subscription plans

ChatGPT Issues

  • GPT not responding - Check GPT instructions and tool configurations
  • Tools not being used - Improve tool descriptions and GPT instructions
  • User access issues - Verify GPT visibility settings and user permissions

Next Steps

Now that your GPT is registered:

  1. Monitor Usage - Track usage and billing in your Agentsyx dashboard
  2. Gather Feedback - Collect user feedback to improve your GPT
  3. Iterate - Make improvements based on usage and feedback
  4. Scale - Add more tools or features as needed

Related Concepts

Create an Upstream MCP ConnectorConnect to Your Stripe Account