mail-index

# mail-index

[![npm version](https://img.shields.io/npm/v/mail-index?logo=npm&color=cb3837)](https://www.npmjs.com/package/mail-index)
[![npm downloads](https://img.shields.io/npm/dm/mail-index?logo=npm&color=cb3837)](https://www.npmjs.com/package/mail-index)
[![GitHub stars](https://img.shields.io/github/stars/unsoldgroup/mail-index?logo=github)](https://github.com/unsoldgroup/mail-index/stargazers)
[![GitHub forks](https://img.shields.io/github/forks/unsoldgroup/mail-index?logo=github)](https://github.com/unsoldgroup/mail-index/network/members)
[![CI](https://github.com/unsoldgroup/mail-index/actions/workflows/ci.yml/badge.svg)](https://github.com/unsoldgroup/mail-index/actions/workflows/ci.yml)
[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
![Node](https://img.shields.io/badge/node-%E2%89%A524-3c873a)
![deps](https://img.shields.io/badge/native%20deps-none-brightgreen)

mail-index downloads a **preview of your whole inbox** to your machine, then
smartly fetches the full text of the messages that matter as you use it. That
local index lets your AI agent run **true summarization and recall over your
entire mailbox** — instead of being trapped behind Gmail's search bar.

It works through a **local MCP server**, so any agent (Claude, Codex, any MCP
client) can query it. Local-first — the default index never leaves your machine.
Operators who need an always-on connector can instead deploy the optional,
single-tenant [remote Worker Deployment](docs/INSTALL-worker.md) in their own
Cloudflare account; mail-index operates no hosting service.
Read-only by default — it never sends or mutates your mail unless you
explicitly opt into archive + label edits (a least-privilege `gmail.modify`
re-auth; never send or delete). See [ADR-0007](docs/adr/0007-opt-in-mailbox-writes.md).

<p align="center">
  <a href="docs/demo/mcp-demo.html">
    <img src="docs/demo/mcp-demo.gif" width="720"
         alt="Claude answering a vague inbox question through the mail-index MCP server, locally, with zero network calls" />
  </a>
  <br />
  <sub>Ask a vague question → one local MCP call → ranked, snippet-first answer.
  <a href="docs/demo/mcp-demo.html">Interactive version →</a></sub>
</p>

> **Status: v1.5 — published.** Progressive sync, the correspondence graph, the
> interest engine, curation, the full 23-tool MCP surface, and the write-back
> loops are built and tested — and `mail-index` is live on
> **[npm](https://www.npmjs.com/package/mail-index)** with a
> **[`.mcpb` bundle](https://github.com/unsoldgroup/mail-index/releases/latest)**.
> Still in progress: the bundled Option A OAuth client and signed one-click
> installers. Architecture lives in
> **[docs/PLAN.md](docs/PLAN.md)**; start with **[docs/INSTALL.md](docs/INSTALL.md)**;
> every release is recorded in **[CHANGELOG.md](CHANGELOG.md)**.

> [!TIP]
> **New in v1.5 — the optional remote Deployment.** mail-index can now also run
> as a **single-tenant Cloudflare Worker in your own account**: always-on, synced
> on a cron, and reachable by remote agents over authenticated MCP (plus a small
> A2A surface). It serves the _same_ tool registry as the local server, backed by
> a **D1** storage driver that passes the same FTS ranking conformance suite, and
> it can **push** — Trigger rules match new mail as it lands and fire signed
> webhooks. Long O(N) work becomes a queued **Job** instead of a command
> handback. You can seed a fresh Deployment straight from your existing local
> index with `mail-index export` → D1 import, so it starts with your history
> already indexed. **The local CLI + stdio path is unchanged and stays the
> default**, and mail-index still operates no hosting service — the Worker is
> code you deploy to infrastructure you own.
> See **[docs/INSTALL-worker.md](docs/INSTALL-worker.md)**,
> **[docs/WORKER-SEED.md](docs/WORKER-SEED.md)**,
> **[ADR-0008](docs/adr/0008-self-hosted-remote-deployment.md)**.
>
> Also new locally: every MCP response carries a **freshness block** and any
> stale read now auto-triggers a background sync (previously only the digest
> composites did).

> [!TIP]
> **From v1.4 — opt-in mailbox writes + human-readable labels.**
> mail-index can **archive** a message and **edit its labels** directly on
> Gmail — via the `archive` / `label` CLI commands and the `archive_message` /
> `modify_labels` MCP tools, on both the gog and gws adapters. It stays
> **read-only by default**: writes are unreachable until you opt in with a
> _least-privilege_ `gmail.modify` grant (**never** send or delete) — enable per
> account with `mail-index setup --account <email> --enable-writes` or the
> bundled `scripts/enable-writes.sh`. Labels render as their **human names**
> everywhere (the index caches Gmail's label catalogue and resolves
> `Label_3546…` → _"Expedition Insure"_ in both directions), and you can pass a
> friendly label name to `label --add/--remove`.
> See **[ADR-0007](docs/adr/0007-opt-in-mailbox-writes.md)**.

---

## How it works

1. **Progressive sync** — metadata for the whole mailbox in minutes; bodies
   fetched selectively.
2. **Graph** — contacts, domains, threads; centrality + communities over your
   _human_ (non-bulk) mail.
3. **Interest** — an engagement score per contact from read/reply/star/importance
   signals. A _seed for your curation_, not an autonomous decision.
4. **Curate** — you (via your agent, or a CLI wizard) confirm who/what matters;
   that profile drives which bodies get fetched.
5. **Query** — your agent searches, traverses the graph, and reads the messages
   that matter, all locally via MCP.

<p align="center">
  <a href="docs/demo/sync-flow.html">
    <img src="docs/demo/sync-flow.gif" width="720"
         alt="mail-index prewarms a local SQLite index with the important messages, then the MCP server serves the agent from it, fetching from Gmail again only on a miss" />
  </a>
  <br />
  <sub>Important messages prewarm a local index; the MCP reads from it, touching
  Gmail again only when a needed body isn't there yet.
  <a href="docs/demo/sync-flow.html">Interactive version →</a></sub>
</p>

## Quick start

Requires **Node 24+** and a Gmail `MailSource` adapter — **`gog`** (recommended)
or **`gws`**. Reading Gmail needs a Google OAuth client, and you get one **two
ways**: use the **mail-index beta client** (skip Google Cloud entirely;
[request access](https://github.com/unsoldgroup/mail-index/issues/new?template=beta_access.yml)
to join the ~100-user test list) or **bring your own** Google Cloud client (no
cap, no request — we walk you through it). See
[docs/INSTALL.md §2](docs/INSTALL.md#2-connect-a-mailbox-pick-an-oauth-path)
and [docs/oauth-and-verification.md](docs/oauth-and-verification.md).

```sh
npm install -g mail-index                    # or: pnpm add -g mail-index

mail-index init                              # scaffold the config
# …connect a mailbox (own OAuth client, read-only) — see docs/INSTALL.md §2 / agent-install.md…
mail-index sync  --account personal --since 6mo
mail-index graph build --account personal
mail-index search "that contract we discussed"
```

_(Prefer source? `git clone …`, `pnpm install && pnpm build`, then run the bins
as `node dist/cli/index.js …`.)_

### Add to Claude

The MCP server registers in one step, but it still needs a mailbox connected
first (see the walkthrough). A `.mcpb`/`claude mcp add` only **adds the server** —
it doesn't install the adapter, sign you in, or sync.

- **Claude Code:** `claude mcp add --transport stdio mail-index -- npx -y -p mail-index mail-index-mcp`
  (on **Windows**, prefix with `cmd /c`: `… -- cmd /c npx -y -p mail-index mail-index-mcp` —
  bare `npx`/`.cmd` won't spawn. See [docs/INSTALL.md §7](docs/INSTALL.md).)
- **Any MCP client (manual):**
  ```jsonc
  { "mcpServers": { "mail-index": { "command": "mail-index-mcp" } } }
  ```
- **Claude Desktop:** download the **[`.mcpb` bundle](https://github.com/unsoldgroup/mail-index/releases/latest/download/mail-index.mcpb)**
  and double-click it (unsigned during beta — you may need to allow it in System
  Settings / Windows SmartScreen). The bundle is **self-contained** (ships its own
  dependencies, run by Claude Desktop's bundled Node — no npx, network, or system
  Node needed) so it installs identically on Windows/macOS/Linux. A signed
  all-in-one installer that _also_ installs the adapter, signs you in, and syncs is
  still in progress; there is no `claude://` install link.

**Teach your agent the common moves.** The MCP server already tells the agent
_when_ to reach for it (purchases, receipts, bookings, "who said what", "catch me
up"), and the repo ships a Claude **[Agent Skill](skills/mail-index/SKILL.md)**
with the typical recipes (find purchases, catch up, find a contact's mail,
summarize a sender). Drop it in for Claude Code/Desktop:

```sh
mkdir -p ~/.claude/skills && cp -R skills/mail-index ~/.claude/skills/
```

Full walkthrough (auth, curation, enrichment, scheduled sync, desktop-app
gotchas) → **[docs/INSTALL.md](docs/INSTALL.md)**. Driving setup with an agent →
**[docs/agent-install.md](docs/agent-install.md)**.

## What to expect — time & storage

The index keeps metadata for every message and full text only where it earns it,
so it grows with message _count_, not mailbox size — about **1.5% of your Gmail**.
First sync runs ~50 messages/min (one-time, incremental after); search is instant.
Start with `--since 1mo` for value in minutes, then expand. Sizing table & growth
path → **[docs/INSTALL.md §9](docs/INSTALL.md#9-grow-your-index-intelligently)**.

## Why it's lighter than Gmail search

Stock Gmail-API MCPs are query-based **lookup** tools — exact query, a network
round-trip per call, raw payloads dumped into the model's context. mail-index
answers _vague_ questions from a local **recall** index. Across a 100-question
suite on a real mailbox it answered every question for **15× fewer tokens** — and
the gap widens exactly where a query-based MCP ha