> ## Documentation Index
> Fetch the complete documentation index at: https://docs.consensus.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Consensus API compared with PubMed, Europe PMC, OpenAlex and Semantic Scholar

> Why teams build on the Consensus API, how it works alongside PubMed, Europe PMC, OpenAlex, Semantic Scholar and Crossref, and how the APIs compare on coverage, search, evidence metadata, full text, pricing and rate limits.

The Consensus API searches the scholarly literature by meaning and returns papers with the evidence details already attached. Its research agent goes further: it crawls citations, traces authors and plans multi-step searches, the way a researcher would. This page explains what it's built for, how teams use it alongside the free scholarly APIs (PubMed, Europe PMC, OpenAlex, Semantic Scholar and Crossref), and how they compare. The pages under **Compare scholarly APIs** go deeper on each topic.

## Why teams choose the Consensus API

> [card] [400M+ papers across every field](https://docs.consensus.app/get-started/where-papers-come-from.md)
>
> 400 million scholarly articles, 350 million of them peer-reviewed, from astronomy to sociology. Includes all of PubMed. Updated weekly.

> [card] [Full text from publisher partners](https://docs.consensus.app/get-started/full-text-access.md)
>
> Search reaches into the full text of open-access papers and of paywalled papers from 7 of the 10 largest academic publishers.

> [card] [Ask in plain language](https://docs.consensus.app/get-started/how-search-works.md)
>
> Hybrid semantic and keyword search, ranked for scientific relevance. Send the question as written. Boolean queries work too.

> [card] [First-party evidence filters](https://docs.consensus.app/api-reference/search.md)
>
> Filter by study type, sample size, journal quartile, human or animal studies, country of study, study duration, citations and more.

> [card] [Full-text snippets for grounding](https://docs.consensus.app/api-full-text.md)
>
> Get the passages from each paper that answer your query, labeled by section, ready to put in front of an LLM.

> [card] [A research agent, not just search](https://docs.consensus.app/api-quickstart-threads.md)
>
> The Threads API plans a search strategy, crawls citations, looks up authors and reads full papers, then writes an answer with numbered citations and the quotes behind them.

Publisher partners whose full text Consensus searches include:

![Wiley](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/wiley.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=89f93113e74bb0090ce94a5b4f55c24a)

![Taylor & Francis](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/taylor-and-francis.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=2075ac1161cb69642ac53438254b2aae)

![SAGE](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/sage.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=da227aff27e194e0395d10dddb992ece)

![Wolters Kluwer](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/wolters-kluwer.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=8d67fdc3b4fa013aa8cc8429b49de5f7)

![Oxford University Press](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/oxford-university-press.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=4159326ee81748817a0c41594c71c17d)

![American Chemical Society](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/acs.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=6b8e12edf4b83daef036c2aa4b8c14a9)

![De Gruyter Brill](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/de-gruyter-brill.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=efed8f09bb4ea863bfa97cc33566c933)

![BMJ](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/bmj.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=73f5754cbec30c1ad3ef2ce20a71d81c)

![American Psychological Association](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/apa.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=29cfd1c4ea69e51519e5a8edda1081a5)

![AAAS](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/aaas.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=6ebd3cc659c6f52f1f4e95d8af2b8aec)

![JAMA Network](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/jama.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=d9a7d8740a81df20c319564a003723bd)

![American Society for Microbiology](https://mintcdn.com/consensus-f7e6ffce/wHajK_wM4l0mxqJf/logo/publishers/asm.png?fit=max\&auto=format\&n=wHajK_wM4l0mxqJf\&q=85\&s=b0ea127517100a30f2a38ca56eb60467)

Partner full text improves which papers rank and powers analysis in the Consensus app. The snippets the API returns come from open-access papers. See [Full text in the API](https://docs.consensus.app/api-full-text.md).

Every paper in a response carries the details you'd otherwise have to dig for: `study_type`, `sample_size`, `sjr_best_quartile`, `population_type`, `countries_of_study`, `citation_count`, `is_preprint` and a one-sentence `takeaway`. Your code, or your model, can weigh the evidence without opening the paper.

## How teams combine Consensus with open APIs

Most teams don't pick one API. They use Consensus to find the evidence, then call the free APIs for what those do best.

**1. Find and rank the papers with Consensus**

Send the research question as written. Filter to the study designs and sample sizes you trust, and pull full-text snippets for the papers your model will read.

**2. Enrich the results with open metadata**

Every Consensus result has a DOI. Use it to pull citation graphs and similar papers from Semantic Scholar, author, institution and funder data from OpenAlex, or registration metadata from Crossref.

**3. Run a Boolean strategy where a protocol requires one**

For the search you report in a systematic review, run a reproducible Boolean query in PubMed or Europe PMC, and use Consensus to check you haven't missed the strongest studies.

This works smoothly because Consensus builds on the same open records: its index aggregates Semantic Scholar, OpenAlex and PubMed, then adds its own crawl of the scholarly web, publisher full text, evidence classification and ranking.

## At a glance

A dash (—) means we didn't find the feature in that provider's API documentation as of November 2026.

### Coverage and search

| | Coverage | How you search |
| - | - | - |
| **Consensus** | <ul><li>400M+ scholarly articles, 350M peer-reviewed</li><li>Every field, including all of PubMed</li><li>Updated weekly</li></ul> | <ul><li>Hybrid semantic and keyword search</li><li>Natural-language questions or Boolean</li><li>Ranked for scientific relevance</li></ul> |
| **PubMed** | <ul><li>40M+ biomedical citations and abstracts<sup>[1](#source-1)</sup></li></ul> | <ul><li>Boolean keywords, field tags and MeSH<sup>[2](#source-2)</sup></li><li>Best Match relevance sort<sup>[3](#source-3)</sup></li></ul> |
| **Europe PMC** | <ul><li>49.2M abstracts, 12.5M full-text articles<sup>[4](#source-4)</sup></li><li>Life sciences, including preprints</li></ul> | <ul><li>Boolean keywords over abstracts and full text<sup>[4](#source-4)</sup></li></ul> |
| **OpenAlex** | <ul><li>320M+ works in the core catalog<sup>[5](#source-5)</sup></li></ul> | <ul><li>Keyword search over title, abstract and full text<sup>[6](#source-6)</sup></li><li>Semantic search, up to 50 results per query<sup>[7](#source-7)</sup></li></ul> |
| **Semantic Scholar** | <ul><li>214M papers<sup>[8](#source-8)</sup></li></ul> | <ul><li>Relevance and Boolean bulk search</li><li>Snippet search over body text<sup>[9](#source-9)</sup></li></ul> |
| **Crossref** | <ul><li>About 188M DOI records<sup>[10](#source-10)</sup></li></ul> | <ul><li>Queries and filters over bibliographic metadata<sup>[11](#source-11)</sup></li></ul> |

### Evidence metadata and full text

| | Evidence metadata per paper | Full text |
| - | - | - |
| **Consensus** | <ul><li>Study type, sample size, journal quartile</li><li>Human or animal, country, duration</li><li>Filter on every one of them</li></ul> | <ul><li>Searches open-access and partner full text</li><li>Returns query-relevant snippets from open-access papers (paid plans)</li></ul> |
| **PubMed** | <ul><li>NLM publication types, such as Randomized Controlled Trial<sup>[12](#source-12)</sup></li></ul> | <ul><li>None in PubMed<sup>[1](#source-1)</sup></li><li>PubMed Central holds 10M+ full-text records<sup>[13](#source-13)</sup></li></ul> |
| **Europe PMC** | <ul><li>Publication type, such as clinical trial or preprint<sup>[4](#source-4)</sup></li></ul> | <ul><li>Open-access XML through `fullTextXML`<sup>[14](#source-14)</sup></li></ul> |
| **OpenAlex** | <ul><li>7 study designs, tagged from title and abstract<sup>[15](#source-15)</sup></li><li>Citation counts</li></ul> | <ul><li>Open-access PDF and TEI XML for 60M+ works<sup>[16](#source-16)</sup></li></ul> |
| **Semantic Scholar** | <ul><li>Publication types, such as ClinicalTrial and MetaAnalysis<sup>[9](#source-9)</sup></li><li>Citation counts</li></ul> | <ul><li>Passages of about 500 words through snippet search<sup>[9](#source-9)</sup></li></ul> |
| **Crossref** | <ul><li>Work type, funding and licence<sup>[11](#source-11)</sup></li></ul> | <ul><li>Metadata only, with abstracts where deposited<sup>[11](#source-11)</sup></li></ul> |

### Pricing and rate limits

| | Pricing | Rate limits |
| - | - | - |
| **Consensus** | <ul><li>Free: 30 calls a month</li><li>Pro and Teams: 500. Deep: 2,000</li><li>\$0.05 per extra call. Enterprise: custom</li></ul> | <ul><li>1 request a second on self-serve plans</li><li>Custom on Enterprise</li></ul> |
| **PubMed** | <ul><li>Free<sup>[1](#source-1)</sup></li></ul> | <ul><li>3 a second without a key</li><li>10 a second with a free key<sup>[17](#source-17)</sup></li></ul> |
| **Europe PMC** | <ul><li>Free<sup>[4](#source-4)</sup></li></ul> | <ul><li>10 a second per IP, no key<sup>[18](#source-18)</sup></li></ul> |
| **OpenAlex** | <ul><li>Data is free (CC0)</li><li>\$1 of API usage a day with a free key</li><li>Annual plans from \$5,000 a year<sup>[19](#source-19)</sup></li></ul> | <ul><li>10 a second without a key</li><li>30 with a free key<sup>[20](#source-20)</sup></li></ul> |
| **Semantic Scholar** | <ul><li>No published price</li><li>Free key on request<sup>[8](#source-8)</sup></li></ul> | <ul><li>Shared pool without a key</li><li>1 a second with a new key<sup>[8](#source-8)</sup></li></ul> |
| **Crossref** | <ul><li>Free public API</li><li>Paid Metadata Plus tier<sup>[21](#source-21)</sup></li></ul> | <ul><li>5 to 150 a second, by pool<sup>[21](#source-21)</sup></li></ul> |

A Consensus call covers up to 100 papers, and the API and MCP server share one monthly pool. See [plans and access](https://docs.consensus.app/api-plans-and-access.md).

## Compare in depth

> [card] [Biomedical search: Consensus, PubMed and Europe PMC](https://docs.consensus.app/api-comparison/pubmed-europe-pmc.md)
>
> Semantic search over PubMed's records, study-design filters, and when a Boolean strategy is the right tool.

> [card] [Open metadata: OpenAlex, Semantic Scholar and Crossref](https://docs.consensus.app/api-comparison/openalex-semantic-scholar-crossref.md)
>
> What each open API does best, and how to enrich Consensus results with it.

> [card] [Retrieval for RAG and AI agents](https://docs.consensus.app/api-comparison/rag-and-ai-agents.md)
>
> What a RAG pipeline needs from a search API, and when web search APIs like Exa and Tavily fit.

> [card] [Pricing, rate limits and data privacy](https://docs.consensus.app/api-comparison/pricing-and-privacy.md)
>
> Costs, limits and interfaces side by side, and what each provider does with your queries.

> [card] [Search quality evaluations](https://docs.consensus.app/api-comparison/evaluations.md)
>
> Two blind relevance studies: more relevant than Google Scholar, and more relevant than GPT-5.5 and Opus 4.8 in a fraction of the time.

## FAQ

> [accordion] Is Consensus built on PubMed, OpenAlex and Semantic Scholar?
>
> Partly. Consensus aggregates metadata and abstracts from Semantic Scholar, OpenAlex and PubMed, crawls the scholarly web to fill the gaps, and adds full text from open-access papers and publisher partners. On top of that it classifies each paper's study design and sample size and ranks results for scientific relevance. See [where the papers come from](https://docs.consensus.app/get-started/where-papers-come-from.md).

> [accordion] Is there a free Consensus API?
>
> Yes. Every plan includes API access. The Free plan has 30 calls a month and up to 20 papers per request, without pagination or full-text snippets. See [plans and access](https://docs.consensus.app/api-plans-and-access.md).

> [accordion] Does the Consensus API return full text?
>
> Every search matches against full text where it's available. On paid plans, `include_full_text_chunks=true` adds up to 3 query-relevant passages per paper from open-access papers. See [Full text in the API](https://docs.consensus.app/api-full-text.md).

> [accordion] Does Consensus train AI models on my queries?
>
> No. Customer data isn't used to train AI models, and the LLM providers Consensus uses keep no data from requests. See [Pricing, rate limits and data privacy](https://docs.consensus.app/api-comparison/pricing-and-privacy.md).

> [accordion] What's the difference between the Consensus API and the Consensus MCP server?
>
> The API is a REST interface for your own code. The [MCP server](https://docs.consensus.app/consensus-mcp.md) gives AI assistants and agents, such as Claude, ChatGPT and Cursor, the same search and research agent as tools. Both draw on one monthly pool of calls.

> [accordion] Is Consensus related to goconsensus.com?
>
> No. goconsensus.com is an unrelated sales-demo software company that also publishes a "Consensus MCP". Consensus, the AI search engine for research, is at [consensus.app](https://consensus.app), with its API at `api.consensus.app` and its MCP server at `mcp.consensus.app`.

## Sources

Facts about other providers were checked against their official documentation on 5 November 2026. Limits and prices change, so check the source before you build on a number.

1. [About PubMed](https://pubmed.ncbi.nlm.nih.gov/about/): "more than 40 million citations and abstracts of biomedical literature"; "does not include full text journal articles"; a free resource.
2. [PubMed User Guide](https://pubmed.ncbi.nlm.nih.gov/help/): Boolean operators, field tags, MeSH and Best Match sorting.
3. [E-utilities in depth, ESearch](https://www.ncbi.nlm.nih.gov/books/NBK25499/): `sort=relevance` is the default Best Match order on web PubMed.
4. [About Europe PMC](https://europepmc.org/About): 49.2 million abstracts and 12.5 million full-text articles; searches abstracts and full text; searches can be limited to clinical trials, preprints or article sections such as Methods; free to anyone.
5. [OpenAlex works](https://help.openalex.org/data/works/): more than 320 million works in the core catalog.
6. [OpenAlex search](https://help.openalex.org/api/searching/): `search=` matches works by title, abstract, full text and keywords; Boolean and phrase searches are supported.
7. [OpenAlex semantic search](https://help.openalex.org/api/semantic-search/): embeds title, abstract and venue name; up to 50 results per query; 1 request a second; 17 supported filters, and others such as `cited_by_count` return a 400 error.
8. [Semantic Scholar API overview](https://www.semanticscholar.org/product/api): 214 million papers; unauthenticated requests share 1,000 requests a second across all users and may be throttled under heavy use; the introductory limit for an API key is 1 request a second. The API also serves SPECTER2 embeddings and a Recommendations service for similar papers.
9. [Semantic Scholar Academic Graph API reference](https://api.semanticscholar.org/api-docs/graph): `/paper/search` (up to 1,000 relevance-ranked results), `/paper/search/bulk` (Boolean), `/snippet/search` (passages of about 500 words from title, abstract and body), and the `publicationTypes`, `minCitationCount` and `venue` filters.
10. `total-results` from `https://api.crossref.org/works?rows=0` on 5 November 2026: 188,499,975.
11. [Crossref REST API](https://www.crossref.org/documentation/retrieve-metadata/rest-api/): bibliographic metadata including funding, licence and abstracts; no sign-up required; most metadata isn't subject to copyright.
12. [NLM publication types](https://www.nlm.nih.gov/mesh/pubtypes.html).
13. [About PMC](https://pmc.ncbi.nlm.nih.gov/about/intro/): "more than 10 million full-text article records".
14. [Europe PMC developer resources](https://europepmc.org/developers): REST, SOAP, OAI-PMH and FTP access to open-access content and metadata; automated bulk download of other content isn't allowed. The [Articles RESTful API](https://europepmc.org/RestfulWebService) includes `/{id}/fullTextXML`.
15. [OpenAlex study designs](https://help.openalex.org/data/study-designs/): seven designs tagged automatically from title and abstract; each value right at least 96% of the time.
16. [OpenAlex full text](https://help.openalex.org/access/fulltext/): cached PDF and TEI XML for more than 60 million open-access works.
17. [A General Introduction to the E-utilities](https://www.ncbi.nlm.nih.gov/books/NBK25497/): more than 3 requests a second without an API key returns an error; with a key, up to 10 a second by default; higher rates by request. Requests without registered `tool` and `email` values may be blocked.
18. Europe PMC team on the [Europe PMC web services forum](https://groups.google.com/a/ebi.ac.uk/g/epmc-webservices/c/x3PLL09mels), 1 October 2024: the rate limit is 10 requests a second (500 a minute), and no API key is required.
19. [OpenAlex pricing](https://help.openalex.org/access/pricing/): all data CC0; \$1 of free API usage a day with a key; annual plans from \$5,000 a year; the whole database can be downloaded as a snapshot refreshed every quarter. A keyless response notes that it shares a \$0.10 daily budget per IP address.
20. [OpenAlex authentication and rate limits](https://help.openalex.org/api/authentication/): 10 requests a second with no key, 30 with a free key or prepaid usage, 50 on an annual plan; semantic search is limited to 1 a second.
21. [Crossref access and authentication](https://www.crossref.org/documentation/retrieve-metadata/rest-api/access-and-authentication/): public pool 5 requests a second, polite pool 10, Metadata Plus 150.


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