Smallest MCP Server

MCP server for the Smallest AI platform. Manage agents, debug calls, view analytics — directly from your IDE.

Quick start

Option A: npm (recommended)

Requires Node.js 18+. Add this to your MCP config (~/.cursor/mcp.json for Cursor, claude_desktop_config.json for Claude Desktop):

{
  "mcpServers": {
    "smallest": {
      "command": "npx",
      "args": ["-y", "@developer-smallestai/smallest-mcp-server"],
      "env": {
        "ATOMS_API_KEY": "sk_your_key_here"
      }
    }
  }
}

Auto-updates to the latest version every time your editor restarts.

Option B: One-line installer (no dependencies)

Mac / Linux:

curl -fsSL https://raw.githubusercontent.com/smallest-inc/mcp-server/main/install.sh | bash

Windows (PowerShell):

irm https://raw.githubusercontent.com/smallest-inc/mcp-server/main/install.ps1 | iex

Downloads a standalone binary, prompts for your API key, and configures Cursor + Claude Desktop automatically. Re-run to update.

Option C: One prompt

Open a chat in Cursor or Claude Desktop and type:

Set up the Smallest MCP server for me.
The npm package is @developer-smallestai/smallest-mcp-server.
My API key is: sk_paste_your_key_here

Verify

Reload your editor, then type: "List all my agents"

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Available tools

Read

Tool	Description
list_calls	Search and list calls with filters for status, type, date range, agent, phone number
debug_call	Get detailed info about a single call — status, transcript, errors, analytics, latency
get_agents	List agents with their configuration, voice, LLM model, and call stats
get_agent	Get full details for a single agent
get_agent_prompt	Read an agent's current system prompt and tools
get_usage_stats	Usage statistics — total calls, duration, costs, status breakdown
get_campaigns	List outbound calling campaigns with status and progress
get_phone_numbers	List phone numbers owned by your organization
get_voices	List available voices with gender, language, and model filters
get_playbooks	Read a multi-agent (Playbooks) agent's SOPs, intent router, and shared auth tools

Write

Tool	Description
create_agent	Create a new AI voice agent (single_prompt, or multi_agents for Playbooks)
update_agent_prompt	Update an agent's system prompt / instructions
add_playbooks	Add SOP playbooks (intent + prompt + scoped API tools + auth level) to a multi-agent
update_playbook	Edit, archive, or restore one playbook
configure_playbooks	Set the intent router, conversation guide, and shared weak/strong auth tools
configure_call_actions	Enable/disable end_call and set a transfer number — agent-level, applies across all playbooks
update_agent_config	Update agent settings — name, language, voice, STT, first message, etc.
add_agent_tool	Add or update an API-call tool the agent can invoke during a call
remove_agent_tool	Remove a tool from an agent by name
set_pre_call_api	Configure (or disable) the pre-call API that runs before a call to enrich variables
delete_agent	Archive (soft-delete) or unarchive an agent
publish_draft	Publish or discard a draft on a versioned agent

Act

Tool	Description
make_call	Initiate an outbound phone call using a specific agent

Resources

Resource	URI	Description
Platform Overview	atoms://docs/platform-overview	Key concepts, call types, statuses, and cost breakdown

---

Environment variables

Variable	Required	Description
ATOMS_API_KEY	Yes	Your Smallest AI API key

Development

npm install
npm run dev    # run with tsx
npm run build  # bundle to dist/

Releases

Merging to main automatically publishes a new version to npm and GitHub Releases.

Version bumps are automatic based on commit messages:

Commit message contains	Bump	Example
new tool, new resource, add tool, add resource	minor (0.2.0 → 0.3.0)	feat: add new tool for knowledge bases
BREAKING CHANGE or feat!:	major (0.2.0 → 1.0.0)	feat!: redesign agent config schema
Anything else	patch (0.2.0 → 0.2.1)	fix: handle empty call logs

License

MIT