canonical: https://jentic.com/apis/cancer.gov/cancer-gov

# Cancer Gov NCI Syndication API

Jentic publishes the only available OpenAPI specification for NCI Syndication API, keeping it validated and agent-ready. The National Cancer Institute Syndication API is the consolidated entry point for NCI's public services, including clinical-trial search, the medical glossary, the drug dictionary, sitewide search of cancer.gov, Best Bets editorial picks, and the R4R researcher-resource catalog. Seven GET endpoints expose these services across two host environments and are intended for research portals, oncology decision-support tools, and patient-information agents.

## For AI agents

Search NCI clinical trials, drug dictionary, glossary, sitewide search, Best Bets, and researcher resources from a single consolidated API.

## Scope

Does not handle patient EHR access, trial enrollment workflows, or clinician credentialing - use for searching NCI's public clinical-trial, drug, glossary, and content syndication services only.

## Capabilities

- Search active and completed cancer clinical trials by disease, intervention, location, and phase via /trials
- Retrieve a single trial's full record including eligibility criteria via `/trials/{nci_id}`
- Look up cancer-specific medical terminology via `/glossary/v1/Terms`
- Search the NCI drug dictionary for cancer-related medications via `/drugdictionary/v1/Drugs`
- Run sitewide search across cancer.gov content via `/sitewidesearch/v1/Search`
- Fetch curated Best Bets editorial selections for clinical topics via `/bestbets/v1/BestBets`
- Browse the R4R catalog of research resources via `/r4r/v1/Resources`

## Use cases

### Clinical Trial Matching for Patients

Patient advocacy and decision-support tools help cancer patients find relevant trials. /trials accepts disease, location, age, and intervention filters and returns matching trials with status and lead-organisation details, so a tool can shortlist candidates in seconds. `/trials/{nci_id}` then loads full eligibility criteria for the patient and clinician to review.

Example prompt: GET /trials with disease='breast cancer', location='Boston, MA', and recruitment_status='OPEN', then GET `/trials/{nci_id}` for the top result to retrieve eligibility criteria.

### Oncology Decision Support and Drug Lookup

Clinical decision-support agents need authoritative drug and term definitions tied to NCI nomenclature. `/drugdictionary/v1/Drugs` returns drug records including aliases and indications, and `/glossary/v1/Terms` returns definitions in plain English suitable for surfacing to patients or clinicians inline.

Example prompt: GET `/drugdictionary/v1/Drugs` filtered by name='pembrolizumab' to retrieve indications, then GET `/glossary/v1/Terms` for any unfamiliar pathology term referenced in the result.

### Patient-Education Content Surfacing

Cancer-information chatbots surface curated content from cancer.gov. `/sitewidesearch/v1/Search` returns content matches across the site, and `/bestbets/v1/BestBets` returns editorially-selected pages for high-traffic topics, giving a chatbot a high-quality fallback before generating freeform answers.

Example prompt: GET `/bestbets/v1/BestBets` for query='chemotherapy side effects' and surface the top editorially-curated link before falling back to `/sitewidesearch/v1/Search` results.

### AI Agent Cancer-Research Workflows via Jentic

Through Jentic, an agent searches for 'find cancer clinical trials', loads the input schema for /trials, and executes the call without managing the X-API-KEY header. Jentic's vault holds the NCI API key so it never enters the agent's prompt context.

Example prompt: Use the Jentic SDK to search 'find cancer clinical trials', load the /trials operation schema, and execute it with disease and location filters supplied by the patient.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/trials` | Search NCI clinical trials |
| GET | `/trials/{nci_id}` | Retrieve a single clinical trial by NCI ID |
| GET | `/drugdictionary/v1/Drugs` | Search the NCI drug dictionary |
| GET | `/glossary/v1/Terms` | Search NCI cancer terminology glossary |
| GET | `/sitewidesearch/v1/Search` | Sitewide search across cancer.gov |
| GET | `/bestbets/v1/BestBets` | Retrieve editorially-curated Best Bets |
| GET | `/r4r/v1/Resources` | Search Resources for Researchers |

## Key resources

- **Clinical Trials** — Search and retrieve NCI clinical trials by disease, intervention, location, and phase
- **Drug Dictionary** — Look up cancer-related drugs with names, aliases, and indications
- **Glossary** — Search NCI's medical terminology glossary for plain-language definitions
- **R4R** — Browse the Resources for Researchers catalog
- **Search** — Run sitewide search across cancer.gov and retrieve Best Bets editorial picks

## Why Jentic

- **Setup:** Wiring the NCI Syndication API by hand means setting its X-API-KEY header and learning the separate trials, drug dictionary, glossary, and search routes yourself. Through Jentic you install once, import the NCI Syndication API from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** This API exposes read-only search and lookup routes, with ids like `/trials/{nci_id}` in the URL path, so scope the agent to the operations it needs, such as trial search and drug lookups. You choose the operations it may call, so it stays limited to the read routes you enable.
- **Credential handling:** Your NCI API key is stored once, encrypted, by your own Jentic One instance and injected into the X-API-KEY header at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'find cancer clinical trials' or 'look up a cancer drug', and Jentic returns the matching NCI operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **ClinicalTrials.gov API** — ClinicalTrials.gov covers all U.S. and global clinical trials across diseases, where the NCI API focuses specifically on cancer trials with NCI-curated metadata.
- **openFDA API** — openFDA exposes FDA drug, device, and adverse-event data that complements NCI's drug dictionary and trial information.
- **NCBI Datasets API** — NCBI Datasets provides genomic and biomedical reference data that pair with NCI's clinical-research surface for translational workflows.

## FAQ

### Why is there no official OpenAPI spec for NCI Syndication API?

The National Cancer Institute documents its syndication services individually but does not publish a consolidated OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call NCI Syndication API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the NCI Syndication API use?

It uses an API key passed in the X-API-KEY header. Through Jentic, the key is stored in your Jentic One instance and injected into the X-API-KEY header at execution time, so the raw key never enters the agent's prompt context.

### Can I search for clinical trials by disease and location?

Yes. GET /trials accepts disease, location, recruitment_status, age, and phase filters and returns matching trials. Use the returned NCI ID with GET `/trials/{nci_id}` to retrieve the full record including eligibility criteria.

### How do I look up a cancer drug through Jentic?

Search 'look up a cancer drug' through the Jentic SDK. Jentic returns GET `/drugdictionary/v1/Drugs` with its input schema. Provide a name or partial-match term and execute the operation to retrieve drug records with aliases and indications.

### Are there separate hosts for clinical trials versus other services?

Yes. Clinical-trial endpoints live on https://clinicaltrialsapi.cancer.gov/api/v2 and the other syndication services live on https://webapis.cancer.gov. Both servers are listed in the OpenAPI spec; pick the one matching the operation's path.

### Is the NCI Syndication API free?

Yes. NCI provides the API free of charge with an API key obtained through the cancer.gov developer portal. Honour any rate limits or terms of use noted in your key registration.

### Can I limit what my agent is allowed to do with the NCI Syndication API?

Yes. Because you run your own self-hosted Jentic One instance, your rules decide which operations and credentials the agent may use. This API exposes only read-only search and lookup routes, so you can enable just the ones the agent needs, such as GET /trials and GET `/trials/{nci_id}` for clinical-trial search or GET `/drugdictionary/v1/Drugs` and GET `/glossary/v1/Terms` for drug and term lookups, while withholding the rest. The agent stays limited to the read operations you turn on and cannot call anything you have not enabled.