issue: playwright-mcp not getting the request bodies

[mlaihk]

openwebui-log.txt

Check Existing Issues

• I have searched the existing issues and discussions.
• I am using the latest version of mcpo.

mcpo Version

0.3.11

Open WebUI Version (if applicable)

0.6.15

Operating System

Docker WSL

Browser (if applicable)

No response

Confirmation

• I have read and followed all instructions in README.md.
• I am using the latest version of both MCPO and Open WebUI.
• I have included the browser console logs.
• I have included the Docker container logs.
• I have listed steps to reproduce the bug in detail.

Expected Behavior

properly formatted api calls with url as request body like:

curl -X 'POST'
'http://mcpo:8000/playwright/browser_navigate'
-H 'accept: application/json'
-H 'Content-Type: application/json'
-d '{
"url": "https://www.hko.gov.hk"
}'

Actual Behavior

I got an error on tool call saying request body is empty:

From the Open WebUI chat with Qwen3 native tool call:
{
"arguments": {
"url": "https://www.hko.gov.hk"
},
"name": "tool_browser_navigate_post"
}
{
"error": "Request body expected for operation 'tool_browser_navigate_post' but none found."
}

Steps to Reproduce

1. Add official ms-playwright mcp to config.json:

   "playwright": {
   "command": "npx",
   "args": [
   "@playwright/mcp@latest",
   "--isolated",
   "--no-sandbox"
   ]
   }

2. Reboot mcpo

3. In OpenWebui add the mcpo:8000/playwright to tools.

4. Call tool with prompt: "Retrieve the html from this link https://www.hko.gov.hk"

Logs & Screenshots

Additional Information

`

openwebui-log.txt

`

[OnlineProxy-io]

Basically OpenWebUI sends requests wrapped in "name" and "arguments" format but Playwright MCP only expects expects raw JSON. Because of that it ends up with a request body expected error. So MCPO doesn’t unwrap the arguments before passing them on
You can throw a proxy in front that rewrites the request. It's a quick fix, but for long-term you can try patching MCPO so it does the unwrapping by default