@ghostpaw/email

A standalone email engine for Node.js, built on SQLite.

Email treats IMAP sync, SMTP send, local caching, threading, search, and transport errors as one coherent model instead of a grab bag of protocol adapters. It ships as a single prebundled blob with zero runtime dependencies, designed for three audiences at once: human developers working directly in code, LLM agents operating through a structured soul / tools / skills runtime, and agent operators who want a ready-to-use email CLI binary without writing any wiring code.

MCP server

Every client below starts the same stdio server: npx -y @ghostpaw/email mcp. Cached messages live in ~/.ghostpaw/email.db unless the GHOSTPAW_EMAIL_DB environment variable (absolute path) or --db <path> says otherwise.

Claude Code

claude mcp add ghostpaw-email -- npx -y @ghostpaw/email mcp

or as a plugin, which also installs the skill:

/plugin marketplace add GhostPawJS/email
/plugin install ghostpaw-email@ghostpaw-email

Email CLI (~/.email/config.toml)

[mcp_servers.ghostpaw-email]
command = "npx"
args = ["-y", "@ghostpaw/email", "mcp"]

Cursor (.cursor/mcp.json), Claude Desktop (claude_desktop_config.json) or a project .mcp.json:

{
  "mcpServers": {
    "ghostpaw-email": {
      "command": "npx",
      "args": ["-y", "@ghostpaw/email", "mcp"]
    }
  }
}

Claude Desktop users can also install server.mcpb from the latest GitHub release. A Dockerfile is included for container hosts: docker build -t ghostpaw-email . && docker run -i --rm -v email:/data ghostpaw-email.

The server speaks MCP 2026-07-28 (stateless, server/discover) and the initialize-based revisions 2025-11-25, 2025-06-18, 2025-03-26 and 2024-11-05.

Network operations use the existing CLI account configuration (email account add) or EMAIL_IMAP_HOST, EMAIL_SMTP_HOST, EMAIL_USER and EMAIL_PASS (or EMAIL_ACCESS_TOKEN). Discovery and cached reads need no account or credentials. The surface database defaults to ~/.ghostpaw/email.db; point --db at an existing account cache to read it. Each network call opens and closes its IMAP session. Connection commands do not retain a session between calls.

Related MCP server: MailOKF MCP

Tool CLI

npx -y @ghostpaw/email tools
npx -y @ghostpaw/email call mail_read '{"view":"folders"}' --db :memory:
npx -y @ghostpaw/email call mail_search '{"query":"invoice"}'

Both email and ghostpaw-email run the same CLI. Existing account, read, search, compose, organize and sync commands remain available. The full guide is preserved in skills/email/references/cli.md.

Agent Skill: SKILL.md and skills/email/ ship in the package; print the skill with npx -y @ghostpaw/email skill.

Install

npm install @ghostpaw/email        # as a library
npm install -g @ghostpaw/email     # as a global CLI
npx @ghostpaw/email --help         # one-off, no install needed

Requires Node.js 24+ (uses the built-in node:sqlite module).

Quick Start

import { Mailbox } from '@ghostpaw/email';

const mailbox = new Mailbox({
  imap: { host: 'imap.example.com', port: 993, tls: true },
  smtp: { host: 'smtp.example.com', port: 465, tls: true },
  auth: { user: 'user@example.com', pass: 'secret' },
  storage: 'mail.db',
});

await mailbox.connect();

const folders = mailbox.read.folders();
await mailbox.network.sync();
const messages = mailbox.read.messages('INBOX', { limit: 20 });

await mailbox.write.send({
  to: [{ address: 'bob@example.com' }],
  subject: 'Hello',
  text: 'Sent from @ghostpaw/email.',
});

await mailbox.disconnect();

connect() opens the SQLite database, initialises the schema, upserts the account, and authenticates the IMAP session — one call does everything.

The Model

Seven stored concepts and three derived ones:

The model means each kind of mail state has its own home:

State is derived, not toggled. Thread IDs are computed from header chains at sync time, folder roles are detected from IMAP special-use attributes, and attachment metadata is extracted from BODYSTRUCTURE — all materialised during sync, never stored as manual status fields.

Two Audiences

Human developers

Use the Mailbox class with typed read, write, and network surfaces for direct-code access to every mail operation:

import { Mailbox } from '@ghostpaw/email';

const mailbox = new Mailbox(config);
await mailbox.connect();

const threads = mailbox.read.threads('INBOX', { limit: 20 });
const detail = await mailbox.read.getMessage('INBOX', uid);
await mailbox.write.reply('INBOX', uid, { text: 'Acknowledged.' });
await mailbox.write.archive('INBOX', [uid]);

See HUMAN.md for the full human-facing guide with worked examples.

LLM agents

Use the tools, skills, and soul namespaces for a structured runtime surface designed to minimise LLM cognitive load:

import { skills, soul, tools } from '@ghostpaw/email';

// 5 intent-shaped tools covering the full mailbox lifecycle
const allTools = tools.aligned.emailTools;
const readTool = tools.aligned.getEmailToolByName('mail_read');

// 8 reusable workflow skills for multi-step scenarios
const triageSkill = skills.getEmailSkillByName('triage-inbox');

// Thinking foundation for system prompts
const systemPrompt = soul.renderEmailSoulPromptFoundation();

The shared facade exposes name, description, whenToUse, whenNotToUse, inputSchema, readOnly, and sideEffects. Handlers take a context containing read, write, and network surfaces and the existing tool input. They return { ok, outcome, summary, next, data }; data.entities contains the message or mailbox references, and next contains follow-up hints. Errors map to ok: false. Read operations may refresh the local cache, so metadata conservatively marks all tools as writing state.

const definitions = tools.aligned.listEmailToolDefinitions();
const tool = tools.aligned.getEmailToolByName('mail_read');
if (!tool) throw new Error('mail_read is unavailable');
const result = await tool.handler(
  { read: mailbox.read, write: mailbox.write, network: mailbox.network },
  { view: 'folders' },
);
console.log(result.ok, result.summary);

The deprecated tools.emailTools and tools.getEmailToolByName() remain available with the original { outcome, summary, entities, nextSteps } result and unchanged inputs. Migrate to tools.aligned to use the shared shape.

See LLM.md for the full AI-facing guide covering soul, tools, and skills.

CLI (bash)

The package ships as a standalone email binary. Accounts are stored in ~/.config/email/accounts.json and every command accepts --json for machine-readable output.

# Add an account once
email account add --name work \
  --imap-host imap.example.com --smtp-host smtp.example.com \
  --user you@example.com --pass secret

# Then use it
email sync                              # pull latest from server
email read                             # check inbox
email search "invoice"                 # FTS5 search
email compose send --to bob@example.com --subject "Hi" --body "Hello"

# Machine-readable output for agents and scripts
email read queue --json | jq '.entities[].title'
echo "body text" | email compose send --to bob@example.com --subject "Hi"

All commands return the same { outcome, summary, entities, nextSteps } shape as the tool layer, with consistent exit codes (0 success, 1 user error, 2 config, 3 auth, 4 network, 5 tool error).

See SKILL.md for the complete CLI reference for agent operators and Claude Code / OpenClaw users.

Tools

Five tools shaped around operator intent, not raw protocol operations:

Key Properties

• Zero runtime dependencies. Only node:sqlite, node:tls, node:net, node:zlib, node:crypto (built into Node 24+).

• Single prebundled blob. One ESM + one CJS entry in dist/. No subpath exports, no code splitting.

• Pure SQLite storage. FTS5 full-text search, six tables, and deterministic derived reads. Mailbox creates and manages its own DatabaseSync instance.

• Full IMAP engine. Streaming tokenizer, response parser, COMPRESS=DEFLATE, IDLE (RFC 2177), CONDSTORE/QRESYNC (RFC 7162), XOAUTH2/OAUTHBEARER.

• Full SMTP client. TLS/STARTTLS/plaintext, PLAIN/LOGIN/XOAUTH2, dot stuffing, APPEND to Sent after send.

• Fetch-on-demand bodies. Initial sync pulls headers and BODYSTRUCTURE only. Message bodies and attachment bytes are fetched when actually read.

• JWZ threading. Conversation trees computed from References/In-Reply-To headers, with depth-ordered rendering and cross-folder support.

• Intention-shaped writes. send, reply, forward, archive, trash, saveDraft, sendDraft — operations that say what happened, not generic CRUD.

• Additive AI runtime. soul for posture, tools for actions, skills for workflow guidance — all optional, all structured.

• Colocated tests. Every non-type module has a colocated .test.ts file. The documented behaviour is backed by executable coverage.

Package Surface

import {
  Mailbox,      // porcelain class — the primary entry point
  initSchema,   // schema setup (called automatically by Mailbox.connect())
  read,         // read surface factory
  write,        // write surface factory
  network,      // network surface factory
  tools,        // LLM tool definitions + registry
  skills,       // LLM workflow skills + registry
  soul,         // thinking foundation for system prompts
} from '@ghostpaw/email';

All domain and runtime types are also available at the root for TypeScript consumers:

import type {
  EmailConfig,
  AuthConfig,
  EmailReadSurface,
  EmailWriteSurface,
  EmailNetworkSurface,
  EmailToolDefinition,
  EmailToolResult,
  EmailSkill,
  EmailSoul,
  ComposeInput,
  ReplyInput,
  ForwardInput,
  Message,
  MessageDetail,
  Thread,
  Folder,
  Attachment,
  AttachmentMeta,
  SyncResult,
  WatchEvent,
} from '@ghostpaw/email';

Documentation

Development

npm install
npm test            # node:test runner
npm run typecheck   # tsc --noEmit
npm run lint        # biome check
npm run build       # ESM + CJS + declarations via tsup

The repo is pinned to Node 24.14.0 via .nvmrc / .node-version / .tool-versions / mise.toml / Volta. Use whichever version manager you prefer.

Support

If this package helps your project, consider sponsoring its maintenance:

Anonyfox • MIT License