Courier MCP Server

Courier MCP Server

The official Model Context Protocol (MCP) server for the Courier notification API. It gives AI agents full access to the Courier API — send messages, manage profiles, debug deliveries, configure lists, and more — through 124 tools backed by the @trycourier/courier Node SDK.

Install

Hosted (recommended)

Courier runs a hosted MCP server at https://mcp.courier.com. No local setup required.

Cursor — add to .cursor/mcp.json:

{
  "mcpServers": {
    "Courier": {
      "url": "https://mcp.courier.com",
      "headers": {
        "api_key": "YOUR_COURIER_API_KEY"
      }
    }
  }
}

Claude Code:

claude mcp add Courier --transport http --url https://mcp.courier.com --header "api_key: YOUR_COURIER_API_KEY"

Claude Desktop — add to claude_desktop_config.json:

{
  "mcpServers": {
    "Courier": {
      "url": "https://mcp.courier.com",
      "headers": {
        "api_key": "YOUR_COURIER_API_KEY"
      }
    }
  }
}

Local development

git clone https://github.com/trycourier/courier-mcp.git
cd courier-mcp
sh dev.sh

Then point your IDE at http://localhost:3000 with the same config format above.

Tools

123 default tools organized by API resource, plus 1 diagnostic tool available in local installs.

Default tools

Diagnostic tools (local only)

Safer defaults (optional client policies)

Tools that send live traffic, carry destructiveHint in MCP annotations, or mutate provider integrations are listed in code as RECOMMENDED_CLIENT_DISABLED_TOOLS (source). Export it from @trycourier/courier-mcp if you want to drive codegen or docs. Teams typically paste subsets into Claude Code (permissions.deny / mcp__<serverName>__<toolName>) or Codex ([mcp_servers.<name>.disabled_tools] in config.toml). This does not change hosted MCP behavior until each client applies its own policy.

Architecture

courier-mcp/
├── mcp/                    # MCP package (@trycourier/courier-mcp on npm)
│   └── src/
│       ├── index.ts        # CourierMcp server class
│       ├── policy/         # Optional client policy helpers (e.g. recommended disable list)
│       ├── tools/          # Tool definitions (one file per API resource)
│       └── utils/          # Config, error handling, registry
├── server/                 # Express server (hosts the MCP package via HTTP)
│   └── src/index.ts        # Stateless HTTP handler
└── dev.sh                  # Local development launcher

The MCP package uses the official @trycourier/courier Node SDK (Stainless-generated) for all API calls. The SDK stays in sync with the Courier API spec automatically, so tool implementations are thin wrappers with proper error handling.

Configuration

Development

# Install dependencies
cd mcp && npm install && cd ../server && npm install && cd ..

# Start development server
sh dev.sh

# Run tests
cd mcp && npm test

# Build
cd mcp && npm run build

SDK dependency updates

The @trycourier/courier SDK dependency in mcp/ is updated automatically via Dependabot. Dependabot checks npm daily and opens a PR when a new SDK version is available.

• Patch/minor bumps: review CI status, then merge.
• Major bumps (labeled breaking-review): check whether any tool input schemas or error handling need updates before merging.

After merging a Dependabot PR, the full pipeline runs automatically:

1. auto-version-bump.yml bumps the MCP package patch version and pushes to main.
2. publish-npm.yml publishes the new version to npm.
3. bump-services.yml opens a PR in trycourier/services to update the hosted MCP server.

Secrets required (set in repo Settings > Secrets and variables > Actions):

• REPO_TOKEN — PAT with Contents: Read and write on this repo. Used by auto-version-bump.yml to push to main and trigger downstream workflows.
• SERVICES_REPO_TOKEN — PAT with Contents: Read and write + Pull requests: Read and write on trycourier/services. Used by bump-services.yml to open dependency bump PRs.
• NPM_TOKEN — npm publish token. Used by publish-npm.yml.

Links

• Courier docs
• MCP documentation page
• AI developer tools overview
• Courier Node SDK
• MCP protocol spec