# Mail Index > A local, agent-queryable mail intelligence layer — progressive mailbox index + MCP server that gives AI agents recall over your email without handing them the keys. - **Type:** MCP server - **Install:** `agentstack add mcp-alunsoldantarctica-mail-index` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [unsoldgroup](https://agentstack.voostack.com/s/unsoldgroup) - **Installs:** 0 - **Category:** [Databases](https://agentstack.voostack.com/c/databases) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [unsoldgroup](https://github.com/unsoldgroup) - **Source:** https://github.com/unsoldgroup/mail-index - **Website:** https://unsoldgroup.github.io/mail-index/ ## Install ```sh agentstack add mcp-alunsoldantarctica-mail-index ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # mail-index [](https://www.npmjs.com/package/mail-index) [](https://www.npmjs.com/package/mail-index) [](https://github.com/alunsoldantarctica/mail-index/stargazers) [](https://github.com/alunsoldantarctica/mail-index/network/members) [](https://github.com/alunsoldantarctica/mail-index/actions/workflows/ci.yml) [](LICENSE) 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 index never leaves your machine. 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). Ask a vague question → one local MCP call → ranked, snippet-first answer. Interactive version → > **Status: v1.0 — 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/alunsoldantarctica/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)**. > [!TIP] > **New in v1.4 — opt-in mailbox writes + human-readable labels.** > mail-index can now **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 --enable-writes` or the > bundled `scripts/enable-writes.sh`. Labels now 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`. The local-only / zero-egress > guarantee is unchanged. 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. Important messages prewarm a local index; the MCP reads from it, touching Gmail again only when a needed body isn't there yet. Interactive version → ## 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/alunsoldantarctica/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/alunsoldantarctica/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 has no primitive at all: summarizing, relationships, and commitments. Per-category tables, the read-one-message comparison, the tool-by-tool landscape, and how to reproduce it all → **[docs/COMPARISON.md](docs/COMPARISON.md)**. ## Stack TypeScript · `node:sqlite` (no native deps) · SQLite FTS5 · Graphology · `@modelcontextprotocol/sdk`. Node 24+. Pluggable `MailSource` adapters; ships two Gmail transports — [`gog`](https://github.com/openclaw/gogcli) (recommended) and Google's [`gws`](https://github.com/googleworkspace/cli). ## CLI Two bins ship: `mail-index` (CLI) and `mail-index-mcp` (the stdio MCP server). ``` mail-index init Scaffold the operator config + data dir mail-index sync --account [--since 30d|1mo] [--all] [--query ] [--limit N] mail-index sync --all-accounts Sync every account by its policy presets mail-index enrich --account [--profile | --rule direct|all] [--sender ] [--match ] [--limit N] mail-index graph build [--account | --all-accounts] mail-index curate [--account ] Interactive curation wizard (no-agent fallback) mail-index compact [--account ] [--now] Demote summarized bulk bodies (ADR-0003) mail-index search [--account ] [--limit N] [--enrich] mail-index show Print a message (auto-enriches a meta row) mail-index open Print the provider web URL (no fetch) mail-index archive Archive (drop INBOX) — opt-in write; needs gmail.modify mail-index label [--add ]... [--remove ]... Opt-in write; needs gmail.modify mail-index status [--json] Per-account freshness + counts ``` Writes are off by default. Enable archive + label edits for an account with `mail-index setup --account --enable-writes` (or the bundled `scripts/enable-writes.sh `) — a least-privilege `gmail.modify` grant (never send or delete). See [ADR-0007](docs/adr/0007-opt-in-mailbox-writes.md). ## Documentation - **[docs/INSTALL.md](docs/INSTALL.md)** — generic onboarding (install, authenticate a MailSource, init, sync, curate, enrich, add the MCP server, scheduled-sync snippet). - **[docs/MCP.md](docs/MCP.md)** — the 18-tool MCP reference for agent integrators: args, compact result shapes, the `index_as_of` freshness + command-handback contracts. - **[docs/ADAPTERS.md](docs/ADAPTERS.md)** — the `MailSource` contract and how to write + contract-test a new adapter. - **[docs/PLAN.md](docs/PLAN.md)** — architecture, data model, and the key decisions (ADR digest). - **[SECURITY.md](.github/SECURITY.md)** + **[docs/THREAT-MODEL.md](docs/THREAT-MODEL.md)** — privacy posture, trust boundaries, prompt-injection stance, and a "verify our claims yourself" runbook. The local-only promise is enforced in CI by an [egress guard test](test/egress-guard.test.ts) — the core (`src/`) makes no network calls; the one exception is the opt-out launch-shim self-updater (`bin/selfupdate.mjs`, throttled npm-version check, `MAIL_INDEX_NO_AUTOUPDATE=1` to disable), audited by the same guard. ## About Built by **[Unsold Group](https://unsold.group/al)** — a travel & insurtech company building the groundwork to operate as an AI-native business: local-first, agent-native infrastructure that gives AI real, queryable context to work from. mail-index is one piece of that — giving agents durable memory of a mailbox without handing them the keys to it. More: **[unsold.group/al](https://unsold.group/al)** ## Project growth [](https://star-history.com/#alunsoldantarctica/mail-index&Date) ## Feedback & contact There's **no telemetry** — we only know what you tell us, so feedback is genuinely welcome: - 💬 **[Discussions](https://github.com/alunsoldantarctica/mail-index/discussions)** — questions, ideas, how you use it - 🐞 **[Report a bug](https://github.com/alunsoldantarctica/mail-index/issues/new?template=bug_report.yml)** · 💡 **[Request a feature](https://github.com/alunsoldantarctica/mail-index/issues/new?template=feature_request.yml)** - 🔒 Security/privacy issues → **[SECURITY.md](.github/SECURITY.md)** (private) - 🌐 **[unsold.group/al](https://unsold.group/al)** Inside your agent you can also just say *"report a mail-index bug"* — the MCP server points the agent to a GitHub link for you to submit (it never sends anything itself). See **[SUPPORT.md](.github/SUPPORT.md)**. ## License [MIT](LICENSE) ## Source & license This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [unsoldgroup](https://github.com/unsoldgroup) - **Source:** [unsoldgroup/mail-index](https://github.com/unsoldgroup/mail-index) - **License:** MIT - **Homepage:** https://unsoldgroup.github.io/mail-index/ Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/mcp-alunsoldantarctica-mail-index - Seller: https://agentstack.voostack.com/s/unsoldgroup - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.