Clinical Data APIs Overview

FHIRfly provides instant access to healthcare reference data through simple REST APIs.

Available APIs

API	Description	Data Source
NDC	National Drug Codes	FDA NDC Directory
NPI	Provider Identifiers	CMS NPPES
RxNorm	Drug Terminology	NLM RxNorm
LOINC	Lab Codes	Regenstrief LOINC
ICD-10	Diagnosis Codes	CMS ICD-10
CVX	Vaccine Codes	CDC CVX
MVX	Manufacturer Codes	CDC MVX
FDA Labels	Drug Labels	FDA DailyMed

Common Patterns

All Clinical Data APIs follow consistent patterns:

Single Lookup

GET /v1/{api}/{code}

Batch Lookup

POST /v1/{api}/_batch
Content-Type: application/json
{"codes": ["code1", "code2", "code3"]}

Response Shapes

GET /v1/{api}/{code}?shape=compact|standard|full

See Response Shapes for details on each format.

Authentication

All Clinical Data API requests require authentication via API key or OAuth token.

# API Key
curl -H "x-api-key: YOUR_API_KEY" https://api.fhirfly.io/v1/ndc/0069-0151-01

# OAuth Token
curl -H "Authorization: Bearer TOKEN" https://api.fhirfly.io/v1/ndc/0069-0151-01

Response Format

All responses follow a consistent structure:

{
  "data": { /* resource data */ },
  "meta": {
    "source": { /* provenance (full shape only) */ },
    "legal": { /* licensing info */ }
  }
}

Error Responses

Status	Description
400	Invalid request (bad code format)
401	Missing or invalid authentication
403	Insufficient permissions (scope)
404	Code not found
429	Rate limit exceeded
500	Server error

{
  "error": "not_found",
  "error_description": "NDC code not found: 0000-0000-00"
}