Paper Finder in ChatGPT
Find papers, get abstracts. The MCP server is https://papers.openkrill.app/mcp. No key. The steps below are only for ChatGPT. A call to get_paper was checked against that server on 2026-10-01.
What this server answers
Find research papers on a topic, search arXiv preprints, and get a paper's abstract and free full-text link from its DOI, PubMed id or arXiv id.
Ask "find recent open-access papers on retrieval-augmented generation evaluation", "search arXiv for speculative decoding papers from this year" or "get the abstract and open-access link for DOI 10.1038/s41586-021-03819-2".
It reads three public indexes: Europe PMC (life sciences and biomedicine, with PubMed and PubMed Central), Crossref (publisher records from all fields) and arXiv (preprints in physics, mathematics, computer science and more). A topic search asks Europe PMC and Crossref together and returns one merged list, each paper with its authors, year, venue, DOI, citation count and the index it came from.
A paper's open-access link is shown only when the index confirms a free full text: a Europe PMC or PubMed Central copy, an arXiv PDF, or a Crossref record that lists a Creative Commons or public-domain license. A missing link means the index does not confirm one, not that none exists.
It does not check whether a paper was retracted and does not verify reference lists: use the Citation Checker plugin for that. It lists papers and abstracts only. It does not read or summarize full texts, and it gives no medical advice.
It stores nothing about you: answers are cached for a few hours and the only lasting record is a daily count of calls per tool.
What it can do
- Searches Europe PMC and Crossref together for papers on a topic, with an optional start year and an open-access filter
- Searches arXiv preprints by topic, with optional category, start year and newest-first order
- Returns authors, year, venue, DOI, citation count and the index each paper came from
- Shows a free full-text link only when the index confirms one, with its license when stated
- Gets one paper's abstract by DOI, PubMed id or arXiv id
- Names the sources and the date they were read in every answer
Tools
search_papers, Search papers. Use this when the user wants papers on a topic, such as "find recent open-access papers on retrieval-augmented generation evaluation" or "systematic reviews on intermittent fasting". Pass topic words, and optionally from_year, open_access_only and a limit of up to 10. Asks Europe PMC and Crossref together and returns one merged list with each paper's authors, year, venue, DOI, citation count, free full-text link when the index confirms one, and the index it came from. Does not search arXiv: use search_arxiv for preprints. Not for retraction or reference checks: use the Citation Checker plugin.search_arxiv, Search arXiv. Use this when the user wants preprints from arXiv, such as "search arXiv for speculative decoding" or "newest cs.CL papers on tokenization". Pass topic words, and optionally an arXiv category such as cs.CL, from_year, sort (relevance or newest) and a limit of up to 10. Returns each preprint's title, authors, year, the start of its abstract, its arXiv page and its PDF link. Preprints are not peer reviewed.get_paper, Get a paper. Use this when the user gives a DOI, PubMed id or arXiv id and wants the paper's abstract or a free full-text link, such as "get the abstract for DOI 10.1038/s41586-021-03819-2". Pass exactly one of doi, pmid or arxiv_id. Returns the title, authors, year, venue, the start of the abstract, the free full-text link and license when the index confirms them, and the index it came from. It does not say whether the paper was retracted or whether a reference is correct: use the Citation Checker plugin for that.
Add Paper Finder in ChatGPT
ChatGPT does not read a local config file. A custom MCP server is added in the product, and only after developer mode is on. These steps were checked against OpenAI's plugin connect guide and the ChatGPT MCP guide on 2026-10-01. Developer mode can be hidden by a workspace policy, so a Team or Enterprise admin may have to allow it first.
- Open ChatGPT settings, then Security and login, and turn on Developer mode.
- Open ChatGPT plugins and select the plus button.
- Enter a name such as "Paper Finder" and a one-line description of what you want it to answer.
- Under Connection, choose the public endpoint and paste
https://papers.openkrill.app/mcp. Include the/mcppath. Do not add a tunnel id: this server is already public. - Create the connection and review the tools ChatGPT lists. You should see
search_papers,search_arxiv,get_paper. The feedback tools on the same server are optional and not required for the lookup. - Start a new conversation, add the connection from the tools menu, and ask: Find recent open-access papers on retrieval-augmented generation evaluation
No API key and no OAuth client id are required. The server answers without a login. Calls are limited per network and per day, and a limit comes back as a tool error rather than a partial answer. If the tool list is stale after a server change, open the connection and select Refresh, then start a new conversation.
The ChatGPT desktop app, Codex CLI and IDE extension share a different config. In the desktop app, open Settings, then MCP servers, choose Add server, select Streamable HTTP, and paste the same URL. In ~/.codex/config.toml the equivalent is a table named mcp_servers.papers with url = "https://papers.openkrill.app/mcp". ChatGPT on the web does not read that file. A published directory listing is also a different path: this page is the developer-mode connection, not a claim that Paper Finder is already in the ChatGPT directory.
Treat the server as untrusted until you have read a few answers. A remote MCP server sees the arguments the model sends. Paper Finder is read-only and documents what it sends onward on the privacy page.
A call checked on 2026-10-01
This DOI is the paper in the plugin's starter prompts. A missing full-text link is not proof that no free copy exists. The request below was posted to https://papers.openkrill.app/mcp as tools/call. HTTP 200. Source: the Paper Finder server, read 2026-10-01.
{
"method": "tools/call",
"params": {
"name": "get_paper",
"arguments": {
"doi": "10.1038/s41586-021-03819-2"
}
}
}- status. ok
- asOf. 2026-10-01
- source. Europe PMC (https://europepmc.org)
- notice. These are records from public indexes, not endorsements. To check whether a paper was retracted or to verify a reference list, use the Citation Checker plugin.
Repeat the call yourself if you need a newer reading. Cached answers expire. A rate limit is not a result: wait and try again. Nothing in the call is a ranking, a filing, or advice.