Research Index - Firecrawl Docs

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 or MCP, combined with our dedicated research skill, which you can install with:

npx skills add firecrawl/skills@firecrawl-research-index

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"] when you want ordinary web pages that happen to live on academic domains.

Endpoints#

Task	Endpoint
Search papers	`GET /search/research/papers`
Inspect metadata or read passages	`GET /search/research/papers/{id}`
Find related papers	`GET /search/research/papers/{id}/similar`

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.

# 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"

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:

# 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"

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.

# 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"

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.

# 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"

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

# 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"

Modes:

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