io.github.cyanheads/npi-providers-mcp-server

Official

by cyanheads · TypeScript

Look up US healthcare providers in the NPPES NPI registry and resolve NUCC specialty codes.

Search US healthcare providers in NPPES NPI registry and resolve medical specialty codes.

Topics

cmscyanheadshealth-techhealthcaremcpmcp-servermodel-context-protocolnpinppesnuccprovider-directorytypescriptai-agentsproviders

README.md13 KBView on GitHub

<div align="center"> <h1>@cyanheads/npi-providers-mcp-server</h1> <p><b>Look up US healthcare providers in the NPPES NPI registry and resolve NUCC specialty codes via MCP. STDIO or Streamable HTTP.</b> <div>3 Tools • 2 Resources</div> </p> </div> <div align="center">

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Public Hosted Server: https://npi-providers.caseyjhand.com/mcp

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Tools

Three tools covering the provider directory — search the registry, decode an NPI to its full record, and resolve plain-language specialties through the bundled taxonomy:

Tool	Description
`npi_search_providers`	Search the NPPES registry by name, organization, location, provider type, and specialty. Plain-language specialties resolve through the bundled NUCC taxonomy before searching.
`npi_get_provider`	Fetch the complete NPPES record for up to 10 NPIs — taxonomies, addresses, credentials, identifiers, endpoints, and status.
`npi_lookup_taxonomy`	Resolve, fetch, or browse the NUCC Healthcare Provider Taxonomy — fully offline.

`npi_search_providers`

Search the registry for individual practitioners and organizations, with specialty resolution and honest pagination disclosure.

Search by name_search shortcut, explicit first_name / last_name, organization_name, city / state / postal_code, and provider_type (individual / organization)
Plain-language specialty (e.g. "cardiologist") resolves through the bundled NUCC taxonomy to the registry's exact descriptions before searching; the resolved taxonomy is echoed back so you can see what was actually searched
taxonomy_description escape hatch for callers who already hold an exact NUCC description (mutually exclusive with specialty)
Trailing-wildcard (*) name matching, with the registry's ≥2-leading-character rule documented inline
Discloses that the returned count is the page size — never a grand total — and that only the first 1200 matches are reachable, steering broad queries toward narrower filters

`npi_get_provider`

Decode one or more NPIs into fully populated provider profiles — the tool to turn an NPI from a claim, prescription, or another health data source into a known provider.

Batch fetch up to 10 NPIs per call; the 10-digit format is validated before any API call
Returns every taxonomy (with its primary flag, license number and state), all practice and mailing addresses, credential, sex, sole-proprietor flag, enumeration and last-updated dates, secondary identifiers (Medicaid, etc.), and FHIR/Direct endpoints
Partial-success reporting — well-formed NPIs with no registry record (deactivated or never enumerated) land in notFound rather than failing the whole call

`npi_lookup_taxonomy`

Resolve and browse the NUCC Healthcare Provider Taxonomy — the specialty code set NPPES uses — fully offline from the bundled code set.

resolve — turn a plain-language specialty into matching taxonomy codes and canonical descriptions (the value the search tools filter on)
get — return the full entry for an exact taxonomy code
browse — walk the hierarchy (grouping → classification → specialization), filterable by grouping and by NPI section (Individual/NPI-1 vs Non-Individual/NPI-2)

Resources and prompts

Type	Name	Description
Resource	`npi://provider/{npi}`	A single provider's full decoded record by NPI — the resource twin of `npi_get_provider`.
Resource	`npi://taxonomy/{code}`	A single NUCC taxonomy entry by code — the resource twin of `npi_lookup_taxonomy` mode `get`.

All resource data is also reachable via tools. The resources are convenience twins for resource-capable clients; tool-only clients lose nothing.

Features

Built on @cyanheads/mcp-ts-core:

Declarative tool and resource definitions — single file per primitive, framework handles registration and validation
Unified error handling — handlers throw, framework catches, classifies, and formats
Pluggable auth: none, jwt, oauth
Swappable storage backends: in-memory, filesystem, Supabase, Cloudflare KV/R2/D1
Structured logging with optional OpenTelemetry tracing
STDIO and Streamable HTTP transports

NPI/NPPES-specific:

Keyless — runs against the public CMS NPPES NPI Registry API (v2.1) with no API key or account
Bundled NUCC taxonomy — the 879-code Healthcare Provider Taxonomy (v25.0) ships in the image and loads into an in-memory index at startup, so specialty resolution and code lookups work fully offline with no second upstream
Specialty resolution turns a vague term ("heart doctor") into the precise taxonomy description the registry filters on, and echoes the match back for the agent to verify
Detects the registry's quirk of returning HTTP 200 with an Errors[] body on validation failure and maps it to typed, recoverable error reasons

Agent-friendly output:

Provenance on search — the resolved taxonomy and the exact taxonomy_description sent to the registry are echoed back, so agents can see what was actually searched and re-run with a different code
Honest pagination — the returned count is disclosed as the page size, never a fabricated grand total, with the 1200-match reachable ceiling surfaced when a broad query is capped
Graceful partial failure — npi_get_provider returns per-NPI found / notFound rows instead of failing the whole batch when some NPIs are deactivated or never enumerated

Getting started

Public Hosted Instance

A public instance is available at https://npi-providers.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP, with this client config:

json

{
  "mcpServers": {
    "npi-providers-mcp-server": {
      "type": "streamable-http",
      "url": "https://npi-providers.caseyjhand.com/mcp"
    }
  }
}

Self-hosted / local install

Add the following to your MCP client configuration file. No API key is required — the upstream NPPES registry is keyless.

json

{
  "mcpServers": {
    "npi-providers-mcp-server": {
      "type": "stdio",
      "command": "bunx",
      "args": ["@cyanheads/npi-providers-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with npx (no Bun required):

json

{
  "mcpServers": {
    "npi-providers-mcp-server": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@cyanheads/npi-providers-mcp-server@latest"],
      "env": {
        "MCP_TRANSPORT_TYPE": "stdio",
        "MCP_LOG_LEVEL": "info"
      }
    }
  }
}

Or with Docker:

json

{
  "mcpServers": {
    "npi-providers-mcp-server": {
      "type": "stdio",
      "command": "docker",
      "args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "ghcr.io/cyanheads/npi-providers-mcp-server:latest"]
    }
  }
}

For Streamable HTTP, set the transport and start the server:

MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp

Prerequisites

Bun v1.3.2 or higher (or Node.js v24+).
No API key — the NPPES NPI Registry API is public and keyless. The NUCC taxonomy is bundled, so there is no second data source to provision.

Installation

Clone the repository:

git clone https://github.com/cyanheads/npi-providers-mcp-server.git

Navigate into the directory:

cd npi-providers-mcp-server

Install dependencies:

bun install

Configure environment (optional):

cp .env.example .env
# edit .env only if you need to override the NPPES base URL or timeout

Configuration

No required variables — the server runs out of the box against the keyless NPPES registry. All variables below are optional overrides.

Variable	Description	Default
`NPPES_API_BASE_URL`	NPPES NPI Registry API base URL. Override for a private mirror or testing.	`https://npiregistry.cms.hhs.gov/api`
`NPPES_TIMEOUT_MS`	Per-request HTTP timeout for NPPES calls, in milliseconds.	`15000`
`MCP_TRANSPORT_TYPE`	Transport: `stdio` or `http`.	`stdio`
`MCP_HTTP_PORT`	Port for the HTTP server.	`3010`
`MCP_AUTH_MODE`	Auth mode: `none`, `jwt`, or `oauth`.	`none`
`MCP_LOG_LEVEL`	Log level (RFC 5424).	`info`
`STORAGE_PROVIDER_TYPE`	Storage backend.	`in-memory`
`OTEL_ENABLED`	Enable OpenTelemetry instrumentation (spans, metrics, completion logs).	`false`

See .env.example for the full list of optional overrides.

Running the server

Local development

Build and run:

# One-time build
bun run rebuild

# Run the built server
bun run start:stdio
# or
bun run start:http

Run checks and tests:

bun run devcheck   # Lint, format, typecheck, security
bun run test       # Vitest test suite
bun run lint:mcp   # Validate MCP definitions against spec

Docker

docker build -t npi-providers-mcp-server .
docker run --rm -e MCP_TRANSPORT_TYPE=http -p 3010:3010 npi-providers-mcp-server

The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/npi-providers-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.

Project structure

Directory	Purpose
`src/index.ts`	`createApp()` entry point — registers tools and resources, inits services.
`src/config`	Server-specific environment variable parsing and validation with Zod.
`src/mcp-server/tools`	Tool definitions (`*.tool.ts`).
`src/mcp-server/resources`	Resource definitions (`*.resource.ts`).
`src/services/nppes`	NPPES NPI Registry API client — query building, `Errors[]`-on-200 detection, normalization.
`src/services/taxonomy`	Bundled NUCC taxonomy service — in-memory index for resolve / get / browse.
`tests/`	Unit and integration tests mirroring `src/`.

Development guide

See CLAUDE.md/AGENTS.md for development guidelines and architectural rules. The short version:

Handlers throw, framework catches — no try/catch in tool logic
Use ctx.log for request-scoped logging, ctx.state for tenant-scoped storage
Register new tools and resources in the createApp() arrays
Wrap external API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields

Contributing

Issues and pull requests are welcome. Run checks and tests before submitting:

bun run devcheck
bun run test

License

Apache-2.0 — see LICENSE for details.

Provider data from the CMS NPPES NPI Registry (public domain). Specialty codes from the NUCC Health Care Provider Taxonomy (NUCC, bundled).

Install

Configuration

Environment variables

MCP_LOG_LEVELdefault info

Sets the minimum log level for output (e.g., 'debug', 'info', 'warn').

NPPES_API_BASE_URLdefault https://npiregistry.cms.hhs.gov/api

NPPES NPI Registry API base URL. Override for a private mirror or testing.

NPPES_TIMEOUT_MSdefault 15000

Per-request HTTP timeout for NPPES calls, in milliseconds.

MCP_HTTP_HOSTdefault 127.0.0.1

The hostname for the HTTP server.

MCP_HTTP_PORTdefault 3010

The port to run the HTTP server on.

MCP_HTTP_ENDPOINT_PATHdefault /mcp

The endpoint path for the MCP server.

MCP_AUTH_MODEdefault none

Authentication mode to use: 'none', 'jwt', or 'oauth'.

claude_desktop_config.json

{
  "mcpServers": {
    "npi-providers-mcp-server": {
      "command": "npx",
      "args": [
        "-y",
        "@cyanheads/npi-providers-mcp-server@0.1.3",
        "run",
        "start:stdio"
      ],
      "env": {
        "MCP_LOG_LEVEL": "info",
        "NPPES_API_BASE_URL": "https://npiregistry.cms.hhs.gov/api",
        "NPPES_TIMEOUT_MS": "15000"
      }
    }
  }
}