MCP - Invalid JSON: EOF while parsing a string at line 1 column 51268

[Arik-LT]

I'm using the brightdata MCP, In particular binding it to a ReAct langgraph agent in python to run research tasks. I had a working implementation however since this morning I've started seeing these errors, both with the SSE and Streamable HTTP connections.

ERROR:mcp.client.sse:Error parsing server message pydantic_core._pydantic_core.ValidationError: 1 validation error for JSONRPCMessage Invalid JSON: EOF while parsing a string at line 1 column 51268 input_value='{"result":{"content":[{"...\\u000e�uF�z��'

ERROR:mcp.client.sse:Error in sse_reader httpcore.ReadError -> httpx.ReadError

Account support mentioned there is a potential problem when scraping pdfs, however I have an example where it is working where the extension is:[&formatType=PDF"]

Any info and advice would be greatly appreciated

[meirk-brd]

Hi Arik,

Thanks for reaching out!

You’re correct-we don’t currently support PDF parsing. We only have a Markdown parser, and when it’s used on PDFs it can produce messy, incomplete output like what you received. This also explains why you might see the issue with SSE but not STDIO: the error is tied to buffer size, and the SSE response format can exacerbate it.

If you can share one URL that works and another that fails, we can investigate further. That will help us understand the conditions that trigger the problem, and it may even enable us to add PDF support to the same tool (scrape_as_markdown).

Looking forward to hearing from you!