Healthcare Data APIs for Agents and Apps | FHIRfly

# FHIRfly > Healthcare reference data APIs for clinical coding, drug information, and provider lookup. FHIRfly provides real-time access to NDC, NPI, RxNorm, LOINC, ICD-10, CVX, MVX, FDA Labels, SNOMED CT, UCUM, RxClass, HCPCS, MS-DRG, POS, J-Code/NDC Crosswalk, HCC, OPCS-4, dm+d, Connectivity, Claims Intelligence, and State Medicaid Agency data. ## Authentication All API requests require an API key passed as `x-api-key` header or OAuth2 Bearer token. Free tier: 10,000 requests/month, no credit card required. Sign up: https://fhirfly.io/dashboard ## Quick Start (Node.js SDK) npm install @fhirfly-io/terminology import { Fhirfly } from "@fhirfly-io/terminology"; const client = new Fhirfly({ apiKey: "ffly_your_key" }); const med = await client.ndc.lookup("0069-0151-01"); ## Quick Start (REST API) curl -H "x-api-key: YOUR_KEY" https://api.fhirfly.io/v1/ndc/0069-0151-01 ## Quick Start (MCP for Claude Desktop) npx @fhirfly-io/mcp-server ## Resources - OpenAPI spec: https://fhirfly.io/openapi.yaml - SDK docs: https://fhirfly.io/docs/getting-started/quickstart - API reference: https://fhirfly.io/docs/api-reference - npm: https://www.npmjs.com/package/@fhirfly-io/terminology - GitHub: https://github.com/FHIRfly-io

openapi: 3.1.0 info: title: FHIRfly API version: 1.0.0 description: | Healthcare reference data APIs for clinical coding, drug information, and provider lookup. FHIRfly provides unified, developer-friendly access to: - **NDC** - National Drug Codes for medications - **NPI** - National Provider Identifier registry - **RxNorm** - Standardized drug nomenclature - **LOINC** - Laboratory and clinical observation codes - **ICD-10** - Diagnosis and procedure codes