# paper-lookup

> Search 10 academic paper databases via REST APIs for research papers, preprints, and scholarly articles — covering PubMed, PMC, bioRxiv, medRxiv, arXiv, OpenAlex, Crossref, Semantic Scholar, CORE, and Unpaywall.

**Use case**: Search ten academic databases in one command

**Canonical URL**: https://agentcookbooks.com/skills/paper-lookup/

**Topics**: claude-code, skills, science, scientific-writing

**Trigger phrases**: "find papers on", "look up this DOI", "search PubMed for", "find this paper", "get the abstract for"

**Source**: [K-Dense AI](https://github.com/K-Dense-AI/scientific-agent-skills/tree/main/scientific-skills/paper-lookup)

**License**: MIT

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## What it does

`paper-lookup` is a Claude Code skill from K-Dense AI's [scientific-agent-skills repo](https://github.com/K-Dense-AI/scientific-agent-skills). It turns Claude into a multi-database paper retrieval agent that queries up to 10 academic databases via REST APIs in a single session: PubMed, PMC (full text), bioRxiv, medRxiv, arXiv, OpenAlex, Crossref, Semantic Scholar, CORE, and Unpaywall.

A session produces structured results — abstracts, full-text links, open-access availability, citation graphs, and author metadata — depending on which databases have coverage. For DOI or PMID lookups the result is immediate; for topic searches the skill returns a ranked list you can narrow.

## When to use it

Reach for it when:

- You have a DOI, PMID, or arXiv ID and want the full metadata record
- You're looking for preprints on a specific topic across bioRxiv, medRxiv, and arXiv simultaneously
- You want to check whether a paywalled article has an open-access version via Unpaywall

When *not* to reach for it:

- You need a synthesized literature review — use `literature-review`
- You want to interact with full-text experimental data extracted from papers — use `bgpt-paper-search`

## Install

Copy the `SKILL.md` from K-Dense AI's [paper-lookup folder](https://github.com/K-Dense-AI/scientific-agent-skills/tree/main/scientific-skills/paper-lookup) into `.claude/skills/paper-lookup/` in your project.

Trigger phrases: "find papers on", "look up this DOI", "search PubMed for", "find this paper".

## What a session looks like

A typical session has three phases:

1. **Query specification.** Provide a DOI, PMID, arXiv ID, or search terms. Optionally specify which databases to query and any date filters.
2. **Parallel API retrieval.** Claude queries the relevant databases concurrently and de-duplicates results by DOI where records overlap.
3. **Structured output.** Results are returned with title, authors, abstract, journal/venue, publication date, DOI, and open-access link when available. Citation counts from Semantic Scholar or OpenAlex are included where present.

## Receipts

**Where it works well:**
- DOI and PMID direct lookups — resolution is fast and metadata is complete for indexed records
- Cross-server preprint searches where the same work may appear on bioRxiv, medRxiv, and arXiv

**Where it backfires:**
- Books, book chapters, and conference proceedings have lower coverage across these APIs than journal articles
- Unpaywall links are only as current as their crawler; some recent open-access versions lag by days to weeks

**Pattern that works:** use paper-lookup for targeted retrieval, then hand the results to `citation-management` to format them for your bibliography.

## Source and attribution

Originally authored by [K-Dense Inc.](https://github.com/K-Dense-AI). The canonical SKILL.md lives in the [`paper-lookup` folder](https://github.com/K-Dense-AI/scientific-agent-skills/tree/main/scientific-skills/paper-lookup) of their public scientific-agent-skills repository.

License: MIT. Install, adapt, and redistribute with attribution preserved.

This page documents the skill from a practitioner's perspective. For the formal spec and any updates, defer to the source repo.