SignWell MCP Server

Model Context Protocol server that orchestrates SignWell's e-signature workflows.

Prerequisites

• Node.js v18 or newer.
• A SignWell API key with document access (SIGNWELL_API_KEY environment variable).
• Optional overrides:
  • SIGNWELL_API_BASE_URL for non-production endpoints.
  • SIGNWELL_API_TIMEOUT_MS to tweak HTTP client timeouts (default 90000 ms; CLI flag --timeout on setup skips env prompts and writes this override).

Setup

Interactive Wizard (recommended)

1. Install dependencies if you have not already:

   npm install
   

2. Bundle the CLI so MCP clients point at the build output:

   npm run build
   

3. Run the wizard and follow the prompts:

   node build/index.js setup
   

   • Stores your SignWell secrets in ~/.config/signwell-mcp/env on Linux, ~/Library/Application Support/SignWell/MCP/env on macOS, or %APPDATA%/SignWell/MCP/env on Windows with 0700/0600 permissions.
   • Automatically updates Claude Desktop, Claude Code, Cursor, and OpenCode configuration files (backups are captured before each write) so you do not have to hunt for platform paths.
   • Client targets:
     • Claude Code: ~/.claude.json at mcpServers.signwell
     • Claude Desktop: claude_desktop_config.json at mcpServers.signwell
     • Cursor: ~/.cursor/mcp.json at mcpServers.signwell
     • OpenCode: ~/.config/opencode/opencode.json at mcp.signwell (Windows: %USERPROFILE%\.config\opencode\opencode.json)
   • Uses each client's documented JSON wrapper and STDIO/local server shape so the server is visible after the client restarts.
   • If a previous Claude Code install wrote the stale ~/.claude/mcp.json servers.signwell entry, rerunning setup backs up that legacy file and removes only the stale SignWell entry after writing the correct ~/.claude.json config.
   • Use --print (or -p) to preview outputs without writing to disk, and --yes --api-key=... for non-interactive runs (CI, devcontainers, etc.).
   • Pass --clients=claude-desktop,cursor to limit which MCP clients the wizard configures; omit for "all". Use --timeout=<ms> only if you need a non-default HTTP timeout.
   • After bundling (npm run build) and publishing the package, end users can invoke the same wizard with npx @signwell/mcp setup. Installing globally also enables invoking signwell-mcp setup directly.

Manual exports

Prefer to manage env vars yourself? Export the required values before running the server:

export SIGNWELL_API_KEY="your_api_key"
# export SIGNWELL_API_BASE_URL="https://www.signwell.com/api/v1"   # optional

Installation (npm)

Once the package is published to npm (GitHub: Bidsketch/signwell-mcp):

• Run the setup wizard without installing anything globally:

  npx @signwell/mcp setup
  

• Install globally if you prefer a persistent binary:

  npm install -g @signwell/mcp
  signwell-mcp setup
  

After configuration, start the MCP server via signwell-mcp (requires Node.js v18+).

The signwell-mcp.mcpb file is a separate Claude Desktop extension artifact. It uses the root manifest.json and should be rebuilt for releases after running npm run build.

Local Development Workflow

1. Install dependencies: npm install

2. Bundle the CLI entrypoint (required for MCP client configs): npm run build

3. Configure credentials: node build/index.js setup (or npx @signwell/mcp setup once published)

4. Start the MCP server locally: npm start (runs node build/index.js)

5. Open another terminal to run tests and linters before committing:

   npm test
   npm run typecheck
   npm run lint
   

6. When using MCP inspector or other clients, point them at npm start (stdio).

Running the Server

• Development entrypoint (stdio transport):

  SIGNWELL_API_KEY="$SIGNWELL_API_KEY" npm start
  # or run directly:
  SIGNWELL_API_KEY="$SIGNWELL_API_KEY" node build/index.js
  

• CLI helpers:

  • node build/index.js --help prints usage and env expectations.
  • node build/index.js --version prints the current build.
  • node build/index.js setup launches the setup wizard described above when working from source.
  • Once the package is bundled/published, npx @signwell/mcp setup runs the wizard and SIGNWELL_API_KEY=... npx @signwell/mcp starts the server via the packaged binary (global installs can call signwell-mcp ... directly).

MCP Inspector

Use the MCP inspector to exercise tools locally:

npx @modelcontextprotocol/inspector node build/index.js

Tests

Run the quality gates in order:

npm test
npm run typecheck
npm run lint
npm run format

Demo

Sample MCP inspector session (sanitized IDs):

1. Create Draft

   Tool: document_create
   Input: {
     "name": "Sales Agreement",
     "recipients": [{ "email": "alice@example.com" }],
     "files": [{ "name": "agreement.pdf", "file_url": "https://files.example.com/agreement.pdf" }]
   }
   Output:
   {
     "ok": true,
     "type": "document_create",
     "message": "Document draft created.",
     "data": {
       "id": "doc_123",
       "status": "draft"
     }
   }
   

2. Send Draft

   Tool: document_send_draft
   Input: { "document_id": "doc_123", "confirm_send": true }
   Output:
   {
     "ok": true,
     "type": "document_send_draft",
     "message": "Draft sent for signing.",
     "data": { "id": "doc_123", "status": "sent" }
   }
   

3. Check Status

   Tool: document_get
   Input: { "document_id": "doc_123" }
   Output:
   {
     "ok": true,
     "type": "document_get",
     "message": "Fetched document status.",
     "data": {
       "id": "doc_123",
       "status": "completed",
       "recipients": [{ "email": "alice@example.com", "status": "signed" }]
     }
   }
   

4. Completed PDF

   Tool: document_completed_pdf
   Input: { "document_id": "doc_123" }
   Output:
   {
     "ok": true,
     "type": "document_completed_pdf",
     "data": {
       "pdf_url": "https://signwell-downloads.example.com/doc_123.pdf"
     }
   }
   

Privacy Policy

This section describes the data practices of the SignWell MCP Server.

Data Collection

• The MCP server itself does not collect, transmit, or store any personal data or usage analytics.
• Your SignWell API key is stored locally on your machine with restrictive file permissions (0600) in platform-specific secure locations:
  • macOS: ~/Library/Application Support/SignWell/MCP/env
  • Linux: ~/.config/signwell-mcp/env
  • Windows: %APPDATA%/SignWell/MCP/env

Usage & Storage

• Files provided via file_store are held temporarily in memory with a 60-minute TTL and are cleared automatically.
• All in-memory file data is also cleared on server restart.
• No persistent data storage exists beyond the credential file created during setup.

Third-Party Sharing

• The MCP server does not share data with any third parties.
• All API communication goes directly between your machine and SignWell's servers (https://www.signwell.com/api/v1).

Telemetry & Analytics

• The server does not collect, transmit, or store usage analytics or telemetry of any kind.

Data Retention

• In-memory file storage is cleared on server restart or after the 60-minute TTL expires.
• No persistent data is retained beyond the local credential configuration file.

Contact

For privacy inquiries, contact support@signwell.com or open an issue at github.com/Bidsketch/signwell-mcp/issues.

See also the hosted privacy policy at https://www.signwell.com/privacy/.

Resources

• MCP resources: document://{id} and template://{id} expose read-only JSON snapshots that reuse the same normalization logic as the tools, so inspectors or other MCP clients can browse previously created assets quickly.

Attaching Files & Draft Safety

• document_create and template_create_document always set draft: true, ensuring nothing is emailed until you intentionally call document_send_draft.
• Supply files via the files array using either file_url (public URL or the link your MCP client provides when you @-attach a file in UIs like Claude Desktop), file_base64, or resource_uri. When a resource_uri is provided the MCP server automatically calls resources/read to pull the attachment bytes and forwards them to SignWell's /api/v1/documents/ endpoint.

Available Scripts

Script	Purpose
npm start	Execute the MCP server entrypoint over stdio (after npm run build).
npm test	Run the test suite.
npm run typecheck	Type-check the project with tsc --noEmit.
npm run lint	Lint source and tests using Biome.
npm run format	Apply repository formatting conventions via Biome.
npm run build	Produce an ESM bundle at build/index.js using esbuild.

Directory Layout

.
├── src/                # MCP server source (entrypoint + domain modules)
│   └── setup/          # Interactive setup wizard for MCP client configuration
├── test/               # Test suites
├── build/              # Bundled output (ignored in releases)
├── biome.json          # Biome lint/format configuration
└── tsconfig.json       # TypeScript compiler configuration