# citation.is

> The open registry of verified scientific claims. Every claim is cross-referenced against authoritative databases and assigned a structured verdict. CC BY 4.0.

citation.is is a public scientific data registry that stores, indexes, and exposes verified claims extracted from peer-reviewed literature and preprints. Each claim is linked to its source document, assigned a verification verdict (Supported, Refuted, Inconclusive, or Needs Context), and cross-referenced against authoritative databases including UniProt, PubChem, NCBI Taxonomy, and PubMed.

The registry is fully open — no authentication required. All data is available via REST API, MCP (Model Context Protocol), OAI-PMH, and bulk download.

## Sub-contexts (read these for depth)

- [Registry](https://citation.is/registry/llms.txt) — Registry contents, statistics, and access methods
- [Developers](https://citation.is/developers/llms.txt) — API reference, MCP integration, code examples
- [Verticals](https://citation.is/verticals/llms.txt) — Research domain descriptions and coverage

## Key pages

- [Home](https://citation.is/) — Search and browse verified claims
- [Registry](https://citation.is/registry) — Full paginated claim registry with filters
- [Search](https://citation.is/search) — Full-text and semantic search across all claims
- [Verticals](https://citation.is/verticals) — Domain-specific claim collections (structural biology, salmon biotech, etc.)
- [Leaderboard](https://citation.is/leaderboard) — Most-cited papers and top-verified sources
- [Developers](https://citation.is/developers) — REST API docs, MCP integration guide, code examples
- [About](https://citation.is/about) — Mission, methodology, and data provenance

## Full content

- [llms-full.txt](https://citation.is/llms-full.txt) — Complete claim corpus as structured markdown (for LLM ingestion)
- [RSS feed](https://citation.is/rss.xml) — Recently verified claims (application/rss+xml)
- [sitemap.xml](https://citation.is/sitemap.xml) — XML sitemap
- [robots.txt](https://citation.is/robots.txt) — Crawler directives

## Data access

- REST API: `GET https://citation.is/api/external/public/claims` — paginated JSON list of all verified claims
- Search: `GET https://citation.is/api/external/public/claims?q={query}` — full-text search
- Verify: `POST https://citation.is/api/public/verify-claim` — submit a claim for verification
- OpenAPI spec: `GET https://citation.is/openapi.json`
- MCP endpoint: `GET https://citation.is/mcp` (Model Context Protocol)
- MCP server card: `GET https://citation.is/.well-known/mcp/server-card.json`
- OAI-PMH: `GET https://citation.is/oai?verb=ListRecords&metadataPrefix=oai_dc`
- Bulk download: `GET https://citation.is/api/public/claims.json`
- Knowledge graph: `GET https://citation.is/api/public/graph.json`

## Agent skills

- Search claims: `GET https://citation.is/api/external/public/claims?q={query}&verdict={verdict}`
- Verify a claim: `POST https://citation.is/api/public/verify-claim` with `{"claim": "..."}`
- Agent skills index: `GET https://citation.is/.well-known/agent-skills/index.json`

## Authentication

No authentication required. All endpoints are publicly accessible. See `/auth.md` for the full agent authentication guide.

## License

All data is published under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Attribution: citation.is.

## Contact

For questions about the registry, data quality, or API access, see the [Developers](https://citation.is/developers) page.