> ## Documentation Index
> Fetch the complete documentation index at: https://firecrawl-docs-agent-spark-2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Research Index

> Search papers, read paper passages, and find related work

Firecrawl Research is a purpose-built index for scientific and engineering research agents. It exposes a research-specific toolset for searching papers, inspecting paper metadata, reading relevant full-text passages, and discovering related papers through structural expansion.

The index covers roughly 43 million paper abstracts. The majority of the corpus is biomedical and life sciences — **PubMed**, **bioRxiv**, and **medRxiv** — alongside **arXiv** for physics, mathematics, and computer science. Papers are addressable by their source ids, so `pmid:`, `pmcid:`, and `doi:` references work the same way `arxiv:` ones do.

* Find papers by topic, method, benchmark, author, or category
* Inspect canonical paper metadata and source ids
* Read the passages in one paper that answer a specific question
* Expand from strong seed papers to related papers, citers, or references

<Note>
  To give your agent access to the Research Index, we strongly recommend using our [CLI](/sdks/cli) or [MCP](/mcp-server), combined with our [**dedicated research skill**](https://github.com/firecrawl/skills/blob/main/skills/firecrawl-research-index/SKILL.md), which you can install with:

  ```bash theme={null}
  npx skills add firecrawl/skills@firecrawl-research-index
  ```
</Note>

## How this relates to `/search`

Firecrawl has two things named "research", and they are not the same feature:

|                            | Research Index (this page)                                                                      | `/search` with `categories: ["research"]`                                                                  |
| :------------------------- | ----------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- |
| What it searches           | A paper index of \~43M abstracts — PubMed, bioRxiv, medRxiv, arXiv                              | The open web, restricted to \~14 academic **websites** (arxiv.org, nature.com, pubmed.ncbi.nlm.nih.gov, …) |
| What you get back          | Ranked paper records: canonical `paperId`, `primaryId`, source ids, title, full abstract, score | Ordinary web results: URL, title, snippet                                                                  |
| Can it read inside a paper | Yes — passage-level reads via `GET /search/research/papers/{id}`                                | No                                                                                                         |
| Can it expand by citations | Yes — `GET /search/research/papers/{id}/similar`                                                | No                                                                                                         |
| Endpoint                   | `GET /search/research/papers`                                                                   | `POST /search`                                                                                             |

Use the Research Index when you are doing literature work: finding papers, reading them, and following citations. Use [`categories: ["research"]`](/features/search#search-categories) when you want ordinary web pages that happen to live on academic domains.

## Endpoints

| Task                              | Endpoint                                                                                      |
| --------------------------------- | --------------------------------------------------------------------------------------------- |
| Search papers                     | [`GET /search/research/papers`](/api-reference/endpoint/research-search-papers)               |
| Inspect metadata or read passages | [`GET /search/research/papers/{id}`](/api-reference/endpoint/research-paper)                  |
| Find related papers               | [`GET /search/research/papers/{id}/similar`](/api-reference/endpoint/research-related-papers) |

## Search papers

Search paper abstracts with a natural-language query. The response returns ranked papers with canonical `paperId`, preferred `primaryId`, source ids, title, abstract, score, and optional ranking signals.

<CodeGroup>
  ```bash cURL theme={null}
  # No API key needed to get started; add -H "Authorization: Bearer $FIRECRAWL_API_KEY" for higher rate limits:
  curl -s "https://api.firecrawl.dev/v2/search/research/papers?query=diffusion%20image%20synthesis&k=20"
  ```

  ```bash CLI theme={null}
  firecrawl research search-papers "diffusion image synthesis" --limit 20
  ```

  ```python Python theme={null}
  from firecrawl import Firecrawl

  firecrawl = Firecrawl(
    # No API key needed to get started; add one for higher rate limits:
    # api_key="fc-YOUR-API-KEY",
  )

  result = firecrawl.v2.search_papers("diffusion image synthesis", k=20)
  print(result)
  ```

  ```js Node theme={null}
  import { Firecrawl } from "firecrawl";

  const firecrawl = new Firecrawl({
    // No API key needed to get started; add one for higher rate limits:
    // apiKey: "fc-YOUR-API-KEY",
  });

  const result = await firecrawl.research.searchPapers("diffusion image synthesis", {
    k: 20,
  });
  console.log(result);
  ```
</CodeGroup>

Optional filters:

* `authors`: author substring filter; all filters must match
* `categories`: paper category filter, such as `cs.LG`
* `from`: inclusive created/updated lower bound, `YYYY-MM-DD`
* `to`: inclusive created/updated upper bound, `YYYY-MM-DD`

### Biomedical example

Most of the index is life sciences, so clinical and molecular biology queries work the same way:

<CodeGroup>
  ```bash cURL theme={null}
  # No API key needed to get started; add -H "Authorization: Bearer $FIRECRAWL_API_KEY" for higher rate limits:
  curl -s "https://api.firecrawl.dev/v2/search/research/papers?query=CRISPR%20base%20editing%20off-target%20effects%20in%20primary%20human%20T%20cells&k=20"
  ```

  ```bash CLI theme={null}
  firecrawl research search-papers "CRISPR base editing off-target effects in primary human T cells" --limit 20
  ```

  ```python Python theme={null}
  from firecrawl import Firecrawl

  firecrawl = Firecrawl(
    # No API key needed to get started; add one for higher rate limits:
    # api_key="fc-YOUR-API-KEY",
  )

  result = firecrawl.v2.search_papers(
    "CRISPR base editing off-target effects in primary human T cells",
    k=20,
  )
  print(result)
  ```

  ```js Node theme={null}
  import { Firecrawl } from "firecrawl";

  const firecrawl = new Firecrawl({
    // No API key needed to get started; add one for higher rate limits:
    // apiKey: "fc-YOUR-API-KEY",
  });

  const result = await firecrawl.research.searchPapers(
    "CRISPR base editing off-target effects in primary human T cells",
    { k: 20 },
  );
  console.log(result);
  ```
</CodeGroup>

Results carry a `primaryId` in whichever namespace the source uses, so biomedical hits come back as `pmid:<id>`, `pmcid:<id>`, or `doi:<doi>`. Feed that value straight back into the inspect, read, and related endpoints below.

## Inspect a paper

Use a canonical `paperId` or a source-specific `primaryId`. Accepted `primaryId` forms are `arxiv:<id>`, `pmid:<id>`, `pmcid:<id>`, and `doi:<doi>` — for example `curl -s ".../v2/search/research/papers/pmid:<id>"` for a PubMed record.

<CodeGroup>
  ```bash cURL theme={null}
  # No API key needed to get started; add -H "Authorization: Bearer $FIRECRAWL_API_KEY" for higher rate limits:
  curl -s "https://api.firecrawl.dev/v2/search/research/papers/arxiv:1706.03762"
  ```

  ```bash CLI theme={null}
  firecrawl research inspect-paper arxiv:1706.03762
  ```

  ```python Python theme={null}
  from firecrawl import Firecrawl

  firecrawl = Firecrawl(
    # No API key needed to get started; add one for higher rate limits:
    # api_key="fc-YOUR-API-KEY",
  )

  paper = firecrawl.v2.inspect_paper("arxiv:1706.03762")
  print(paper)
  ```

  ```js Node theme={null}
  import { Firecrawl } from "firecrawl";

  const firecrawl = new Firecrawl({
    // No API key needed to get started; add one for higher rate limits:
    // apiKey: "fc-YOUR-API-KEY",
  });

  const paper = await firecrawl.research.getPaper("arxiv:1706.03762");
  console.log(paper);
  ```
</CodeGroup>

## Read paper passages

Add `query` to the same paper path to retrieve the top full-text passages for a question. This is useful for verifying whether a candidate paper actually contains a method, dataset, constraint, or result before you include it.

<CodeGroup>
  ```bash cURL theme={null}
  # No API key needed to get started; add -H "Authorization: Bearer $FIRECRAWL_API_KEY" for higher rate limits:
  curl -s "https://api.firecrawl.dev/v2/search/research/papers/arxiv:1706.03762?query=what%20is%20the%20attention%20mechanism&k=4"
  ```

  ```bash CLI theme={null}
  firecrawl research read-paper arxiv:1706.03762 --question "What is the attention mechanism?" --limit 4
  ```

  ```python Python theme={null}
  from firecrawl import Firecrawl

  firecrawl = Firecrawl(
    # No API key needed to get started; add one for higher rate limits:
    # api_key="fc-YOUR-API-KEY",
  )

  passages = firecrawl.v2.read_paper(
      "arxiv:1706.03762",
      "What is the attention mechanism?",
      k=4,
  )
  print(passages)
  ```

  ```js Node theme={null}
  import { Firecrawl } from "firecrawl";

  const firecrawl = new Firecrawl({
    // No API key needed to get started; add one for higher rate limits:
    // apiKey: "fc-YOUR-API-KEY",
  });

  const passages = await firecrawl.research.getPaper("arxiv:1706.03762", {
    query: "What is the attention mechanism?",
    k: 4,
  });
  console.log(passages);
  ```
</CodeGroup>

## Find related papers

Expand from one or more seed papers through semantic expansion and rank the candidates against a natural-language `intent`.

<CodeGroup>
  ```bash cURL theme={null}
  # No API key needed to get started; add -H "Authorization: Bearer $FIRECRAWL_API_KEY" for higher rate limits:
  curl -s "https://api.firecrawl.dev/v2/search/research/papers/arxiv:1706.03762/similar?intent=efficient%20transformers&mode=similar&k=20"
  ```

  ```bash CLI theme={null}
  firecrawl research related-papers arxiv:1706.03762 --intent "efficient transformers" --limit 20
  ```

  ```python Python theme={null}
  from firecrawl import Firecrawl

  firecrawl = Firecrawl(
    # No API key needed to get started; add one for higher rate limits:
    # api_key="fc-YOUR-API-KEY",
  )

  papers = firecrawl.v2.related_papers(
      "arxiv:1706.03762",
      "efficient transformers",
      mode="similar",
      k=20,
  )
  print(papers)
  ```

  ```js Node theme={null}
  import { Firecrawl } from "firecrawl";

  const firecrawl = new Firecrawl({
    // No API key needed to get started; add one for higher rate limits:
    // apiKey: "fc-YOUR-API-KEY",
  });

  const papers = await firecrawl.research.similarPapers("arxiv:1706.03762", {
    intent: "efficient transformers",
    mode: "similar",
    k: 20,
  });
  console.log(papers);
  ```
</CodeGroup>

Modes:

* `similar`: co-citation and bibliographic-coupling neighborhood
* `citers`: papers that cite the seed
* `references`: papers cited by the seed

## Search GitHub history

Issues, merged pull requests, and repository READMEs now live in the [Developer Index](/features/developer), which ranks them with the matched passages and adds curated documentation sources alongside them. Use [`GET` or `POST /search/developer`](/api-reference/endpoint/developer-search), or `/search` with `categories: ["developer"]`.