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Step 6

Test Your MCP Bridge

⏱ 3 min

Overview

With the bridge deployed, you’ll verify it’s working using Postman’s native MCP client. Postman supports the MCP protocol directly — you can connect to your bridge, discover tools, and invoke them interactively without writing any code.

Find your bridge URL

  1. Go to MCP Servers → PhotoMCPServer
  2. Click Instances → click the Instance ID
  3. Copy the Consumer Endpoint URL and append /mcp — it will look like: 
    https://<your-gateway-host>/<base-path>/mcp

Keep this URL handy for the steps below.

Step 1 — Connect Postman to the MCP Bridge

  1. Open Postman
  2. In the left sidebar, click New → MCP Request (or go to File → New MCP Request)
  3. In the Server URL field, paste your Consumer Endpoint URL with /mcp appended
  4. Set the Transport to Streamable HTTP
  5. Click Connect

Postman will establish an MCP session with the bridge. Once connected, you’ll see the session status change to Connected.

Step 2 — Discover available tools

Once connected, click the Tools tab in the Postman MCP view.

Postman automatically calls tools/list and displays each tool with its name, description, and input schema. You should see both tools listed:

Tool name Description
list_photos Returns a paginated list of photos in the catalog
get_photos_id Returns the full details of a single photo

Note: Tool names will match what you set during the MCP tools step. If you renamed them, they’ll appear under those names.

If you see both tools listed, your bridge is discoverable. ✓

Step 3 — Call the list photos tool

  1. Click list_photos in the Tools list
  2. Postman displays the tool’s input schema. Fill in the parameters:
    • album: 1
    • id: 1
  3. Click Run Tool

The bridge maps id to the ?id= query parameter, album to the ?album= parameter, and calls GET <upstream-url>/photos?album=1&id=1. Postman displays the response in the output panel.

Expected response shape:

[
  { "albumId": 1, "id": 1, "title": "...", "url": "...", "thumbnailUrl": "..." },
  { "albumId": 1, "id": 2, "title": "...", "url": "...", "thumbnailUrl": "..." },
  { "albumId": 1, "id": 3, "title": "...", "url": "...", "thumbnailUrl": "..." }
]

Step 4 — Call the get photo details tool

  1. Click get_photo in the Tools list
  2. Fill in the parameter:
    • id: 1
  3. Click Run Tool

The bridge maps id to the URI path and calls GET <upstream-url>/photos/1. You should see the full details for photo ID 1 returned.

Troubleshooting

Postman can’t connect

  • Confirm the Consumer Endpoint URL is correct (no trailing characters, correct base path)
  • Verify the MCP Server instance Status shows Active
  • Check Runtimes → Runtime Manager → Omni Gateways — your gateway should show Running

Tools tab is empty

  • The bridge may still be starting up — disconnect, wait 30 seconds, and reconnect
  • Check the instance Configuration Status — should show Up to date

Tool call returns an error

  • Verify the upstream URL in the bridge configuration is reachable
  • Check that the Target URL set during instance creation (https://jsonplaceholder.typicode.com/) is accessible

What you’ve verified

  • Postman connects to the MCP Bridge successfully
  • Both tools appear in the Tools tab
  • get_photos returns a list of photos
  • get_photos_id returns details for photo ID 1

All four checked? Your MCP Bridge is fully operational.

Continue to Securing the MCP Bridge →