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research by fourzerotwo
Crossref DOI Metadata
Crossref REST API metadata (abstracts excluded where publisher-copyrighted).
- endpoints
- 5
- from
- $0.002 / call
- free tier
- yes
DOI lookup
Title, authors, journal, dates, references count and licence for a DOI.
- price
- $0.002 / call
- free tier
- free allowance
- MCP tool
- crossref__doi
- method
- GET
GET https://fourzerotwo.si/v1/crossref/doi
| Param | Type | Description |
|---|---|---|
| doi | string | DOI |
# unpaid: returns 402 with the price curl -i "https://fourzerotwo.si/v1/crossref/doi?doi=10.1038%2Fnature14539" # free tier: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/crossref/doi?doi=10.1038%2Fnature14539"
Search works
Bibliographic search across Crossref works.
- price
- $0.003 / call
- free tier
- free allowance
- MCP tool
- crossref__search
- method
- GET
GET https://fourzerotwo.si/v1/crossref/search
| Param | Type | Description |
|---|---|---|
| q | string | Query |
# unpaid: returns 402 with the price curl -i "https://fourzerotwo.si/v1/crossref/search?q=deep%20learning%20review" # free tier: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/crossref/search?q=deep%20learning%20review"
Journal by ISSN
Journal title, publisher and DOI counts by ISSN.
- price
- $0.002 / call
- free tier
- free allowance
- MCP tool
- crossref__journal
- method
- GET
GET https://fourzerotwo.si/v1/crossref/journal
| Param | Type | Description |
|---|---|---|
| issn | string | ISSN |
# unpaid: returns 402 with the price curl -i "https://fourzerotwo.si/v1/crossref/journal?issn=0028-0836" # free tier: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/crossref/journal?issn=0028-0836"
Search funders
Research funders by name, with Funder Registry ids.
- price
- $0.002 / call
- free tier
- free allowance
- MCP tool
- crossref__funders
- method
- GET
GET https://fourzerotwo.si/v1/crossref/funders
| Param | Type | Description |
|---|---|---|
| q | string | Funder |
# unpaid: returns 402 with the price curl -i "https://fourzerotwo.si/v1/crossref/funders?q=Wellcome" # free tier: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/crossref/funders?q=Wellcome"
Search publishers
Crossref member publishers by name.
- price
- $0.002 / call
- free tier
- free allowance
- MCP tool
- crossref__members
- method
- GET
GET https://fourzerotwo.si/v1/crossref/members
| Param | Type | Description |
|---|---|---|
| q | string | Publisher |
# unpaid: returns 402 with the price curl -i "https://fourzerotwo.si/v1/crossref/members?q=Elsevier" # free tier: send a free key from https://fourzerotwo.si/free curl -H "X-API-Key: fzt_…" "https://fourzerotwo.si/v1/crossref/members?q=Elsevier"
Metadata from Crossref (crossref.org).