npi-providers-mcp-server
by cyanheads
README.md
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<h1>@cyanheads/npi-providers-mcp-server</h1>
<p><b>Search NPPES providers and resolve NUCC specialty codes via MCP over STDIO or Streamable HTTP.</b>
<div>3 Tools • 2 Resources</div>
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[](./CHANGELOG.md) [](./LICENSE) [](https://github.com/users/cyanheads/packages/container/package/npi-providers-mcp-server) [](https://modelcontextprotocol.io/) [](https://www.npmjs.com/package/@cyanheads/npi-providers-mcp-server) [](https://www.typescriptlang.org/) [](https://bun.sh/)
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[](https://github.com/cyanheads/npi-providers-mcp-server/releases/latest/download/npi-providers-mcp-server.mcpb) [](https://cursor.com/en/install-mcp?name=npi-providers-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvbnBpLXByb3ZpZGVycy1tY3Atc2VydmVyIl19) [](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22npi-providers-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads%2Fnpi-providers-mcp-server%22%5D%7D)
[](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)
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**Public Hosted Server:** [https://npi-providers.caseyjhand.com/mcp](https://npi-providers.caseyjhand.com/mcp)
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---
## Overview
US healthcare provider directory over the NPPES NPI Registry, with plain-language specialty terms resolved offline against a bundled NUCC taxonomy. Search providers by name, organization, location, and specialty; decode NPIs into professional-practice provider records; and resolve or browse the NUCC taxonomy directly. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.
### Tools
| 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 NPPES professional-practice record for up to 10 NPIs — taxonomies, practice addresses, credentials, identifiers, endpoints, and status. Only LOCATION address rows are kept for individual providers. |
| `npi_lookup_taxonomy` | Resolve, fetch, or browse the NUCC Healthcare Provider Taxonomy — fully offline. |
### Resources
| Resource | Description |
|:---|:---|
| `npi://provider/{npi}` | A single provider's decoded record by NPI — the resource twin of `npi_get_provider`. |
| `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.
## Capability reference
### `npi_search_providers` <sub>tool</sub>
- Inputs: `name_search` or `first_name` / `last_name` (individuals), `organization_name` (organizations), `provider_type`, `city` / `state` / `postal_code` (practice addresses only), and a plain-language `specialty` resolved through the bundled NUCC taxonomy, or an exact `taxonomy_description` (never both). At least one criterion is required, state alone is rejected, and individual and organization criteria can't be mixed. A trailing `*` needs at least 2 leading characters; `postal_code` takes 5 or 9 digits or a 2–9 digit prefix ending in `*`. `limit` 1–200 (default 10), `skip` 0–1000
- Output: compact rows (`npi`, name, primary taxonomy, primary practice `city` / `state` / `postalCode`, `status`), with `matchedLocation` / `matchedOtherName` naming the practice location or other name a row matched through, and `resolvedTaxonomies` / `appliedTaxonomyDescription` echoing the specialty resolution. No true total is reported: a full page names `nextPage`, and the terminal window (`skip` 1000, `limit` 200) returns `continuationPostalCodes` that continue the search
- Typed error reasons: `no_search_criteria`, `conflicting_specialty`, `mixed_provider_criteria`, `unresolved_specialty`, `invalid_search_field`
---
### `npi_get_provider` <sub>tool</sub>
- Accepts `npis`: a single NPI or up to 10, each exactly 10 digits and checked against its NPI check digit before any API call
- Partitions the batch into `found` (decoded records: taxonomies with license, practice addresses, credential, identifiers, FHIR/Direct endpoints, status — only LOCATION address rows for individual providers, so their mailing address is withheld), `notFound` (confirmed absence), `errored` (upstream failure — retry these), and `invalid` (failed the check digit, never looked up)
- Typed error reasons: `invalid_npi_format` (every NPI failed the check digit), `none_found` (every NPI looked up is a confirmed absence); an upstream failure surfaces as that underlying error instead
---
### `npi_lookup_taxonomy` <sub>tool</sub>
- Modes: `resolve` (`query` → matching active codes), `get` (exact `code` → full entry with NUCC's `notes`), `browse` (walk grouping → classification → specialization, filterable by `grouping` and NPI `section`); `resolve` / `browse` take `limit` (≤50, default 20) and `skip` (0–1000) and disclose `truncated`
- Every entry carries `status` (`active` / `inactive`) and an inactive code's `replacedBy`; `resolve` excludes inactive codes, while `get` and `browse` return them. A resolved entry's `specialization` (or `classification` when absent) is the exact value `npi_search_providers.taxonomy_description` accepts
- Typed error reasons: `no_match`, `missing_argument`
---
### `npi://provider/{npi}` <sub>resource</sub>
- Returns the same decoded record as `npi_get_provider`, for one NPI, as `application/json` — only LOCATION address rows are kept for individual providers
- `npi` must be a well-formed 10-digit NPI; `invalid_npi_format` when it fails the NPI check digit (no registry request), `no_record` when the registry has none (deactivated or never enumerated)
---
### `npi://taxonomy/{code}` <sub>resource</sub>
- Returns the same entry as `npi_lookup_taxonomy` mode `get` (NUCC `notes`, `status`, and `replacedBy` included; inactive codes stay readable), as `application/json`; cached publicly for 24 hours
- `code` must match `^\d{3}[A-Z0-9]{6}X$`; `no_match` when no entry exists for the code
## Features
Built on [`@cyanheads/mcp-ts-core`](https://github.com/cyanheads/mcp-ts-core): stdio and Streamable HTTP transports, pluggable auth (`none` / `jwt` / `oauth`), swappable storage (`in-memory`, `filesystem`, `Supabase`, `Cloudflare KV/R2/D1`), structured logging with optional OpenTelemetry tracing.
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 883-code Healthcare Provider Taxonomy (v26.1) 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; a full page names the exact next page, and a broad query that hits the 1200-match reachable ceiling gets the postal-code prefixes that continue it
- Graceful partial failure — `npi_get_provider` returns per-NPI `found` / `notFound` / `errored` / `invalid` rows instead of failing the whole batch
## 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
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:
```sh
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp
```
### Prerequisites
- [Bun v1.4.0](https://bun.sh/) 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
1. **Clone the repository:**
```sh
git clone https://github.com/cyanheads/npi-providers-mcp-server.git
```
2. **Navigate into the directory:**
```sh
cd npi-providers-mcp-server
```
3. **Install dependencies:**
```sh
bun install
```
4. **Configure environment (optional):**
```sh
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_SESSION_MODE` | HTTP session handling: `stateless`, `stateful`, or `auto`. This server pins `stateless`; the schema default `auto` resolves to `stateful`. | `stateless` |
| `MCP_LOG_LEVEL` | Log level (RFC 5424). | `info` |
| `LOG_TOOL_FAILURE_PAYLOADS` | Log each failed tool call's arguments and result, redacted by key name and capped at `LOG_TOOL_FAILURE_PAYLOAD_MAX_BYTES` (default `16384`). A secret inside a free-form value is not redacted. | `false` |
| `STORAGE_PROVIDER_TYPE` | Storage backend. | `in-memory` |
| `OTEL_ENABLED` | Enable [OpenTelemetry instrumentation](https://github.com/cyanheads/mcp-ts-core/tree/main/docs/telemetry) (spans, metrics, completion logs). | `false` |
See [`.env.example`](./.env.example) for the full list of optional overrides.
## Running the server
### Local development
- **Build and run:**
```sh
# One-time build
bun run rebuild
# Run the built server
bun run start:stdio
# or
bun run start:http
```
- **Run checks and tests:**
```sh
bun run devcheck # Lint, format, typecheck, security
bun run test # Vitest test suite
bun run lint:mcp # Validate MCP definitions against spec
```
### Docker
```sh
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`](./CLAUDE.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
## Data attribution
Provider data from the [CMS NPPES NPI Registry](https://npiregistry.cms.hhs.gov/) (public domain). The bundled specialty codes are the [NUCC Health Care Provider Taxonomy](https://www.nucc.org/index.php/code-sets-mainmenu-41/provider-taxonomy-mainmenu-40), © American Medical Association on behalf of the National Uniform Claim Committee (NUCC), redistributed unmodified beyond formatting under the [NUCC permission](https://www.nucc.org/index.php/nucc-structure-mainmenu-36/contact-us-mainmenu-34?id=111). See [`NOTICE`](NOTICE).
## Contributing
Issues are welcome. Run checks and tests before submitting:
```sh
bun run devcheck
bun run test
```
## License
Apache-2.0 — see [LICENSE](LICENSE) for details.
This server cannot be deployed
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