--- title: "Open Targets Platform API" description: "**GraphQL API (primary, recommended):** ``` https://api.platform.opentargets.org/api/v4/graphql ```" type: skill canonical_url: https://claudary.paisolsolutions.com/skills/opentargets source: "Claudary" difficulty: intermediate author: "Claude Code Knowledge Pack" date: 2026-07-10T11:31:31.999Z license: CC-BY-4.0 attribution: "Open Targets Platform API — Claudary (https://claudary.paisolsolutions.com/skills/opentargets)" --- # Open Targets Platform API **GraphQL API (primary, recommended):** ``` https://api.platform.opentargets.org/api/v4/graphql ``` ## Overview # Open Targets Platform API ## Base URLs **GraphQL API (primary, recommended):** ``` https://api.platform.opentargets.org/api/v4/graphql ``` **Important:** The GraphQL endpoint requires HTTP POST with `Content-Type: application/json`. WebFetch (GET-only) will not work — use `curl` via shell instead: ```bash curl -s -X POST -H "Content-Type: application/json" \\ -d '{"query":"{ target(ensemblId: \\"ENSG00000157764\\") { approvedSymbol approvedName } }"}' \\ https://api.platform.opentargets.org/api/v4/graphql ``` **REST API (simpler queries):** ``` https://api.platform.opentargets.org/api/v4 ``` ## Authentication No API key required. All endpoints are public. ## GraphQL API All GraphQL queries are sent as POST requests to the GraphQL endpoint. ``` POST https://api.platform.opentargets.org/api/v4/graphql Content-Type: application/json { "query": "...", "variables": { ... } } ``` ### 1. Target information (by Ensembl Gene ID) ```graphql query TargetInfo($ensemblId: String!) { target(ensemblId: $ensemblId) { id approvedSymbol approvedName biotype proteinIds { id source } tractability { label modality value } safetyLiabilities { event effects { direction dosing } } pathways { pathway pathwayId } functionDescriptions subcellularLocations { location } } } ``` **Variables:** `{ "ensemblId": "ENSG00000141510" }` **Example as URL (GET also supported for simple queries):** ``` https://api.platform.opentargets.org/api/v4/graphql?query={target(ensemblId:"ENSG00000141510"){id approvedSymbol approvedName biotype functionDescriptions}} ``` --- ### 2. Disease information (by EFO ID) ```graphql query DiseaseInfo($efoId: String!) { disease(efoId: $efoId) { id name description therapeuticAreas { id name } synonyms { terms } } } ``` **Variables:** `{ "efoId": "EFO_0000311" }` (cancer) **Example as URL:** ``` https://api.platform.opentargets.org/api/v4/graphql?query={disease(efoId:"EFO_0000311"){id name description therapeuticAreas{id name}}} ``` --- ### 3. Target-Disease associations ```graphql query Associations($ensemblId: String!, $page: Pagination!) { target(ensemblId: $ensemblId) { approvedSymbol associatedDiseases(page: $page) { count rows { disease { id name } score datasourceScores { id score } } } } } ``` **Variables:** ```json { "ensemblId": "ENSG00000141510", "page": { "index": 0, "size": 10 } } ``` **Example as URL:** ``` https://api.platform.opentargets.org/api/v4/graphql?query={target(ensemblId:"ENSG00000141510"){approvedSymbol associatedDiseases(page:{index:0,size:5}){count rows{disease{id name}score}}}} ``` --- ### 4. Disease-Target associations (from disease side) ```graphql query DiseaseAssociations($efoId: String!, $page: Pagination!) { disease(efoId: $efoId) { name associatedTargets(page: $page) { count rows { target { id approvedSymbol } score datasourceScores { id score } } } } } ``` **Variables:** ```json { "efoId": "EFO_0000311", "page": { "index": 0, "size": 10 } } ``` --- ### 5. Evidence for a target-disease pair ```graphql query Evidence($ensemblId: String!, $efoId: String!, $size: Int!) { disease(efoId: $efoId) { evidences(ensemblIds: [$ensemblId], size: $size) { count rows { id score datasourceId datatypeId literature diseaseFromSource targetFromSourceId resourceScore urls { niceName url } } } } } ``` **Variables:** ```json { "ensemblId": "ENSG00000141510", "efoId": "EFO_0000311", "size": 10 } ``` --- ### 6. Drug/molecule information ```graphql query DrugInfo($chemblId: String!) { drug(chemblId: $chemblId) { id name drugType maximumClinicalTrialPhase hasBeenWithdrawn mechanismsOfAction { rows { mechanismOfAction targets { id approvedSymbol } } } indications { rows { disease { id name } maxPhaseForIndication } } linkedDiseases { count rows { id name } } linkedTargets { count rows { id approvedSymbol } } } } ``` **Variables:** `{ "chemblId": "CHEMBL25" }` (aspirin) **Example as URL:** ``` https://api.platform.opentargets.org/api/v4/graphql?query={drug(chemblId:"CHEMBL25"){id name drugType maximumClinicalTrialPhase mechanismsOfAction{rows{mechanismOfAction targets{id approvedSymbol}}}}} ``` --- ### 7. Search across targets, diseases, and drugs ```graphql query Search($queryString: String!, $entityNames: [String!], $page: Pagination!) { search(queryString: $queryString, entityNames: $entityNames, page: $page) { total hits { id entity name description score } } } ``` **Variables:** ```json { "queryString": "BRAF melanoma", "entityNames": ["target", "disease", "drug"], "page": { "index": 0, "size": 10 } } ``` **Example as URL:** ``` https://api.platform.opentargets.org/api/v4/graphql?query={search(queryString:"BRAF",entityNames:["target"],page:{index:0,size:5}){total hits{id entity name description}}} ``` --- ### 8. Known drugs for a target ```graphql query KnownDrugs($ensemblId: String!, $size: Int!) { target(ensemblId: $ensemblId) { approvedSymbol knownDrugs(size: $size) { count rows { drug { id name drugType maximumClinicalTrialPhase } disease { id name } phase status mechanismOfAction urls { niceName url } } } } } ``` **Variables:** ```json { "ensemblId": "ENSG00000157764", "size": 10 } ``` (ENSG00000157764 = BRAF) --- ### 9. Tractability (druggability) Included in the target query (see endpoint 1 above). Modalities include: - `SM` (small molecule) - `AB` (antibody) - `PR` (PROTAC) - `OC` (other clinical) --- ## REST API Endpoints These are simpler alternatives for common operations. ### Search ``` GET /api/v4/search?q={query}&page=0&size=10 ``` **Example:** ``` https://api.platform.opentargets.org/api/v4/search?q=TP53&size=5 ``` **Response:** ```json { "total": 15, "data": [ { "id": "ENSG00000141510", "entity": "target", "name": "TP53", "description": "Cellular tumor antigen p53", "score": 142.5 } ] } ``` --- ## Key Identifiers | Entity | ID Format | Example | |---------|-----------|---------| | Target | Ensembl Gene ID | `ENSG00000141510` (TP53) | | Disease | EFO/Mondo/HP/Orphanet | `EFO_0000311` (cancer), `MONDO_0007254` | | Drug | ChEMBL ID | `CHEMBL25` (aspirin) | ## Datasource IDs (for filtering evidence) - `ot_genetics_portal` -- Open Targets Genetics - `eva` -- ClinVar (via EVA) - `cancer_gene_census` -- COSMIC Cancer Gene Census - `chembl` -- ChEMBL (clinical trials) - `europepmc` -- Literature mining - `expression_atlas` -- Expression Atlas - `gene2phenotype` -- Gene2Phenotype - `genomics_england` -- Genomics England PanelApp - `intogen` -- IntOGen (cancer drivers) - `ot_crispr` -- Open Targets CRISPR screens - `progeny` -- PROGENy (pathway activity) - `reactome` -- Reactome pathways - `slapenrich` -- SLAPenrich - `sysbio` -- Systems biology - `uniprot_literature` -- UniProt literature ## Pagination GraphQL uses `page: { index: Int, size: Int }` (0-based index). REST uses `page` and `size` query parameters. ## Rate Limits - No API key required. - Fair-use rate limiting applies. No hard published limit. - For bulk data, use the Open Targets data downloads (Parquet files on GCS/FTP) rather than API. - Respect HTTP 429 and `Retry-After` headers. ## Error Format GraphQL errors: ```json { "errors": [ { "message": "Variable '$ensemblId' expected value of type 'String!' but got: null", "locations": [{"line": 1, "column": 7}] } ] } ``` REST errors return appropriate HTTP status codes with JSON error bodies. ## Tips - Use the GraphQL API for maximum flexibility -- request only the fields you need. - The GET method for GraphQL works for simple queries but POST is required for complex ones with variables. - Combine target + disease queries to get association scores with evidence breakdown. - Use `datasourceScores` in association queries to see which evidence sources contribute most. - The Open Targets Platform web UI at `https://platform.opentargets.org` has a GraphQL playground for testing queries. --- Source: [Claudary](https://claudary.paisolsolutions.com/skills/opentargets) · https://claudary.paisolsolutions.com