# LegiScan MCP Server
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[](LICENSE)
[](package.json)
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A Model Context Protocol (MCP) server that gives terminal agents structured access to the [LegiScan API](https://legiscan.com/) for legislative data from all 50 US states and Congress.
Built for research workflows where you direct an agent (Codex, Claude Code, Claude Desktop, etc.) to gather bill history, sponsor context, and voting records quickly.
## Features
- **10 Streamlined MCP Tools** optimized for legislative research workflows
- **Composite tools** that batch multiple API calls (90%+ reduction in API usage)
- Full TypeScript type definitions for all API responses
- Bill number normalization (handles AB 858, AB858, AB-858 formats)
- Input validation guardrails for state codes, legislator name queries, and large bill batches
## Installation
### From npm (Recommended)
```bash
npm install -g legiscan-mcp-server
```
### From Source
```bash
git clone https://github.com/sh-patterson/legiscan-mcp.git
cd legiscan-mcp
npm install
npm run build
```
## Setup
### 1. Get a LegiScan API Key
1. Create a free account at [LegiScan](https://legiscan.com/)
2. Register for API access at https://legiscan.com/legiscan
3. Copy your API key
### 2. Add to Your MCP-Capable Agent
Add this server to whatever MCP host your terminal agent uses.
Claude Desktop config paths:
- macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`
- Windows: `%APPDATA%\Claude\claude_desktop_config.json`
For other MCP clients (Codex CLI, Claude Code, etc.), add the same `mcpServers.legiscan` entry in that client's MCP config file.
#### Using npx (Recommended)
```json
{
"mcpServers": {
"legiscan": {
"command": "npx",
"args": ["-y", "legiscan-mcp-server"],
"env": {
"LEGISCAN_API_KEY": "your_api_key_here"
}
}
}
}
```
#### Using local installation
```json
{
"mcpServers": {
"legiscan": {
"command": "node",
"args": ["/path/to/legiscan-mcp-server/dist/index.js"],
"env": {
"LEGISCAN_API_KEY": "your_api_key_here"
}
}
}
}
```
## Available Tools
### Composite Tools (High-Level Research)
| Tool | Description |
|------|-------------|
| `legiscan_find_legislator` | Find a legislator's people_id by name. Supports partial matching. |
| `legiscan_get_legislator_votes` | Get how a legislator voted on multiple bills in one call. |
| `legiscan_get_primary_authored` | Get only bills where legislator is primary author (not co-sponsor). |
### Bills
| Tool | Description |
|------|-------------|
| `legiscan_get_bill` | Get detailed bill info (sponsors, history, votes, texts) |
| `legiscan_find_bill_by_number` | Find bill by number (handles AB 858, AB858, AB-858) |
| `legiscan_get_roll_call` | Get vote details with individual legislator votes |
### People
| Tool | Description |
|------|-------------|
| `legiscan_get_person` | Get legislator info with third-party IDs (VoteSmart, OpenSecrets, etc.) |
| `legiscan_get_session_people` | Get all legislators active in a session |
### Search
| Tool | Description |
|------|-------------|
| `legiscan_search` | Full-text search across legislation |
### Sessions
| Tool | Description |
|------|-------------|
| `legiscan_get_session_list` | List available legislative sessions by state |
## Researcher Workflow (Terminal Agent)
### 1. Start with a scoped request
Give your agent a goal, state, timeframe, and output format.
Example prompt:
```text
Use the LegiScan MCP tools to find major California housing bills in the current session.
Return: bill number, title, latest action date, top sponsors, and whether there was a close roll-call vote (margin <= 5).
```
### 2. Ask the agent to follow a tool sequence
For high-quality results, tell the agent to do this order:
1. `legiscan_get_session_list` to identify the correct session.
2. `legiscan_search` or `legiscan_find_bill_by_number` to locate target bills.
3. `legiscan_get_bill` for sponsor/history/vote references.
4. `legiscan_get_roll_call` for individual vote details.
5. `legiscan_get_person` only when legislator enrichment is needed.
### 3. Reuse composite tools for analyst workflows
These cut tool-call volume and simplify instructions to your agent:
- `legiscan_find_legislator`: get `people_id` from a name query.
- `legiscan_get_primary_authored`: separate primary-authored from co-sponsored bills.
- `legiscan_get_legislator_votes`: pull vote positions across many bills in one request.
## Prompt Templates
### A) Opposition research on one legislator
```text
Use LegiScan MCP for Texas.
1) Find legislator "Jane Smith".
2) List all primary-authored bills in the current session.
3) For these bills, summarize topic area and latest status.
4) Then check votes on SB 12, HB 301, and SB 455, and show how the legislator voted.
```
### B) Bill tracking brief for an issue area
```text
Use LegiScan MCP to track "climate resilience" bills in New York.
Focus on current session only.
Return top 15 bills by relevance with bill number, title, last action, sponsor party, and any recorded roll calls.
```
### C) Scorecard support workflow
```text
For California session 2172, resolve bill numbers AB 858, SB 525, SB 616, SB 399.
For each bill, fetch details and any roll calls.
Then report vote positions for people_id values 21719, 23214, and 25359.
Output as a table suitable for CSV export.
```
## API Call Reduction
The composite tools dramatically reduce API calls for common workflows:
| Workflow | Without Composites | With Composites |
|----------|-------------------|-----------------|
| Get votes for 1 legislator on 10 bills | ~80 calls | 1 call |
| Filter primary authored from 150 sponsored | ~150 calls | 1 call |
| Find legislator by name | 2 calls | 1 call |
## Research Tips
- State codes are validated as two-letter strings and uppercased automatically (`ca` → `CA`). Invalid codes like `ZZ` pass local validation but return an API error from LegiScan.
- Always pin state and session in your prompt to reduce ambiguous results.
- Ask the agent to show `bill_id`, `roll_call_id`, and `people_id` in intermediate output so you can audit traceability.
- For legislator search, provide at least a first and last name (name input must be at least 2 characters).
- `legiscan_get_legislator_votes` accepts up to 100 `bill_ids` per request; split larger jobs into chunks.
- Ask for final outputs in a table/CSV-ready shape if you plan downstream analysis.
## Development
```bash
npm run build # Compile TypeScript
npm run typecheck # Type-check src + tests
npm test # Run deterministic unit tests (no API key)
npm run test:live # Run live API integration tests (requires API key)
npm run lint # Check for lint errors
npm run format # Format code with Prettier
```
## Testing Modes
- `npm test` / `npm run test:unit`: Fast deterministic tests with mocked network calls.
- `npm run test:live`: Real LegiScan API integration tests. Requires `LEGISCAN_API_KEY`.
## API Limits
- Free public API keys have a **30,000 queries per month** limit
- Composite tools batch requests (10 concurrent max) to avoid rate limits
- The composite tools help you stay within limits by reducing total API calls
## License
MIT - see [LICENSE](LICENSE) for details.
