# nonprofit-explorer-mcp-server [Health: Active]
**Category:** 💻 Developer Tools
**Repository:** https://github.com/cyanheads/nonprofit-explorer-mcp-server
**GitHub Stars:** 2
**Views:** 0
**Installs:** 0
**Upvotes:** 0
**Directory Page:** https://allmcps.com/mcp/nonprofit-explorer-mcp-server
## Description
MCP server for nonprofit financials via ProPublica — IRS Form 990 data for 1.8M+ nonprofits.
## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `bunx` (confidence: high):
```json
"mcpServers": {
"nonprofit-explorer-mcp-server": {
"command": "bunx",
"args": ["@cyanheads/nonprofit-explorer-mcp-server@latest"]
}
}
```
## Documentation & README
@cyanheads/nonprofit-explorer-mcp-server
Search and explore 1.8M+ US nonprofits, fetch Form 990 financials, and access IRS filing history via MCP. STDIO or Streamable HTTP.
3 Tools
[](./CHANGELOG.md) [](./LICENSE) [](https://github.com/users/cyanheads/packages/container/package/nonprofit-explorer-mcp-server) [](https://modelcontextprotocol.io/) [](https://www.npmjs.com/package/@cyanheads/nonprofit-explorer-mcp-server) [](https://www.typescriptlang.org/) [](https://bun.sh/)
[](https://github.com/cyanheads/nonprofit-explorer-mcp-server/releases/latest/download/nonprofit-explorer-mcp-server.mcpb) [](https://cursor.com/en/install-mcp?name=nonprofit-explorer-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvbm9ucHJvZml0LWV4cGxvcmVyLW1jcC1zZXJ2ZXIiXX0=) [](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22nonprofit-explorer-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads%2Fnonprofit-explorer-mcp-server%22%5D%7D)
[](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)
**Public Hosted Server:** [https://nonprofit-explorer.caseyjhand.com/mcp](https://nonprofit-explorer.caseyjhand.com/mcp)
---
## Tools
3 tools for working with US nonprofit and IRS Form 990 data:
| Tool | Description |
|:---|:---|
| `nonprofit_search` | Search 1.8M+ IRS-recognized tax-exempt organizations by name, keyword, city, or phrase with optional state, NTEE sector, and 501(c) filters |
| `nonprofit_get_organization` | Full profile for one org by EIN: legal identity, IRS classification, ruling date, and a financial snapshot from the most recent Form 990 |
| `nonprofit_get_filings` | All Form 990 filings for an org by EIN: year-by-year financials, revenue breakdown, executive compensation, and source PDF links |
### `nonprofit_search`
Search for tax-exempt organizations across the IRS Nonprofit Explorer dataset.
- Full-text search across org name, the IRS Business Master File secondary name line, and city with relevance ranking
- Supports quoted phrases (`"Red Cross"`), required terms (`+evanston`), excluded terms (`-dental`)
- Filter by US state, territory, or military postal code (`ZZ` for foreign entities); case-insensitive, and a code outside that set is rejected rather than silently returning national results
- Filter by NTEE major sector (Arts, Education, Health, Human Services, etc., 1–10)
- Filter by 501(c) subsection code (e.g., `3` = charitable organization — both public charities and private foundations, `4` = social welfare)
- Paginated at 25 per page; use `page` (zero-indexed) with `num_pages`, `per_page`, and `page_offset` to walk large result sets
- Zero matches and a page past the last one are both successful searches with an empty `organizations` array and a `notice` explaining which case it is
- API caps total results at 10,000; `total_results === 10000` means the actual count may be higher, and a `page` whose offset reaches 10,000 is refused with the `pagination_ceiling` error
- Returns EINs — pass to `nonprofit_get_organization` or `nonprofit_get_filings` for details
---
### `nonprofit_get_organization`
Fetch the full profile for a single tax-exempt org by EIN.
- Accepts EIN as integer (`530196605`) or string with or without hyphen (`"53-0196605"`)
- Returns legal name, address, NTEE code, 501(c) type, and IRS ruling date
- IRS Business Master File standing: whether contributions are deductible (including the deductible-by-treaty case), exemption status, and public-charity vs. private-foundation classification — each decoded from its IRS code with the raw code retained
- Financial snapshot from the most recent Form 990: revenue, expenses, assets, liabilities, net assets
- Includes source 990 PDF link and IRS Business Master File summary figures
- `filing_count` shows how many filings with extracted data are on record
- Data lags 1–2 years; `tax_prd_yr` in the snapshot is the fiscal year of the filing, not the current year
- Use `nonprofit_search` first if you only have an org name
---
### `nonprofit_get_filings`
Fetch the full filing history for an org by EIN.
- All Form 990 filings with extracted financial data, sorted newest first
- Per-filing: revenue, expenses, assets, liabilities, net assets, revenue breakdown (contributions, program service, investment income)
- `program_expense_ratio` is always `null` — ProPublica returns no Form 990 Part IX program-service expense total, so the program/management/fundraising split is only in the source PDF
- Executive compensation summary with field-name transparency and a note pointing to Schedule J for per-officer detail
- Source 990 PDF link per filing
- An EIN that resolves to a real org with no 990 on record returns an empty `filings` array plus a `notice` — a successful lookup, not an error
- `filings_pdf_only` lists older filings with a PDF but no extracted data
- Data lags 1–2 years; always cite `tax_prd_yr` (fiscal year) when presenting figures
## Features
Built on [`@cyanheads/mcp-ts-core`](https://www.npmjs.com/package/@cyanheads/mcp-ts-core):
- Declarative tool definitions — single file per tool, 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
ProPublica Nonprofit Explorer / IRS-specific:
- Keyless access — ProPublica Nonprofit Explorer API requires no API key
- Covers 1.8M+ IRS-recognized tax-exempt organizations
- IRS Form 990 data: annual filings for public charities (990), small orgs (990-EZ), and private foundations (990-PF)
- Source filing PDF link on every filing record, except where IRS PDF processing lags the extracted data and `pdf_url` is still null
- Data sourced from ProPublica Nonprofit Explorer, derived from IRS Form 990 filings; data lags 1–2 years
Agent-friendly output:
- Provenance on every response — `data_source` attribution on all tool outputs, ProPublica URL for direct verification
- Filing-year clarity — `tax_prd_yr` prominently labeled as fiscal year with explicit lag caveat in every financial response
- Null values are rendered, not dropped — the formatted text names why a value is absent (never recorded by the IRS, not extracted from the filing, not carried by that form type), and `structuredContent` keeps an explicit `null` rather than omitting the key
- Field-name transparency on compensation — `field_name` and `form_type` exposed so agents know exactly which IRS field was read
## Getting started
### Public Hosted Instance
A public instance is available at `https://nonprofit-explorer.caseyjhand.com/mcp` — no installation required. Point any MCP client at it via Streamable HTTP, with this client config:
```json
{
"mcpServers": {
"nonprofit-explorer-mcp-server": {
"type": "streamable-http",
"url": "https://nonprofit-explorer.caseyjhand.com/mcp"
}
}
}
```
Or, install locally and add the following to your MCP client configuration file.
```json
{
"mcpServers": {
"nonprofit-explorer-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/nonprofit-explorer-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with npx (no Bun required):
```json
{
"mcpServers": {
"nonprofit-explorer-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/nonprofit-explorer-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with Docker:
```json
{
"mcpServers": {
"nonprofit-explorer-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"ghcr.io/cyanheads/nonprofit-explorer-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 v1.3.14](https://bun.sh/) or higher (or Node.js v24+).
- No API key required — ProPublica Nonprofit Explorer is a keyless public API.
### Installation
1. **Clone the repository:**
```sh
git clone https://github.com/cyanheads/nonprofit-explorer-mcp-server.git
```
2. **Navigate into the directory:**
```sh
cd nonprofit-explorer-mcp-server
```
3. **Install dependencies:**
```sh
bun install
```
4. **Configure environment:**
```sh
cp .env.example .env
# edit .env as needed (no required vars — server works out of the box)
```
## Configuration
All configuration is validated at startup. Key environment variables:
| Variable | Description | Default |
|:---------|:------------|:--------|
| `MCP_TRANSPORT_TYPE` | Transport: `stdio` or `http` | `stdio` |
| `MCP_HTTP_PORT` | HTTP server port | `3010` |
| `MCP_HTTP_HOST` | HTTP server hostname | `127.0.0.1` |
| `MCP_HTTP_ENDPOINT_PATH` | HTTP endpoint path | `/mcp` |
| `MCP_PUBLIC_URL` | Public origin override for TLS-terminating reverse-proxy deployments | — |
| `MCP_AUTH_MODE` | Authentication: `none`, `jwt`, or `oauth` | `none` |
| `MCP_LOG_LEVEL` | Log level (`debug`, `info`, `warning`, `error`, etc.) | `info` |
| `LOGS_DIR` | Directory for log files (Node.js only) | `/logs` |
| `STORAGE_PROVIDER_TYPE` | Storage backend: `in-memory`, `filesystem`, `supabase`, `cloudflare-kv/r2/d1` | `in-memory` |
| `OTEL_ENABLED` | Enable [OpenTelemetry instrumentation](https://github.com/cyanheads/mcp-ts-core/tree/main/docs/telemetry) | `false` |
No server-specific required variables. ProPublica Nonprofit Explorer is a keyless public API.
See [`.env.example`](https://github.com/cyanheads/nonprofit-explorer-mcp-server/blob/HEAD/.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 nonprofit-explorer-mcp-server .
docker run --rm -p 3010:3010 nonprofit-explorer-mcp-server
```
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to `/var/log/nonprofit-explorer-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 inits the service. |
| `src/mcp-server/tools` | Tool definitions (`*.tool.ts`). Three tools for search and financial data. |
| `src/services/nonprofit-explorer` | ProPublica Nonprofit Explorer API client and domain types. |
| `tests/` | Unit and integration tests mirroring `src/`. |
## Development guide
See [`CLAUDE.md`/`AGENTS.md`](https://github.com/cyanheads/nonprofit-explorer-mcp-server/blob/HEAD/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 via the arrays in `createApp()` in `src/index.ts`
- 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:
```sh
bun run devcheck
bun run test
```
## License
Apache-2.0 — see [LICENSE](https://github.com/cyanheads/nonprofit-explorer-mcp-server/blob/HEAD/LICENSE) for details.