corresync

Getting started

Install to first answer, in four clear steps.

Install corr, sign in to an account you control, register the local MCP server with your agent, and ask something that spans every inbox and calendar you connected. Outlook Web sign-in stays browser-owned; API and standards grants stay behind your OS keyring. Agents never receive Corresync-managed credentials, and the MCP connection is local stdio—no hosted relay.

Start at step 1 Check your provider first

  1. Install corr

    Pick your platform. Installing gives you the corr command—no account is added and nothing signs in until you do.

    Linux

    curl -LsSf https://corresync.org/install.sh | sh

    The script is short—review install.sh first if you like. Prefer packages? Every release also ships .deb, .rpm, and .apk, and Homebrew works on Linux too.

    macOS · Homebrew

    brew install nkiyohara/corresync/corresync

    Homebrew builds the tagged source of the latest release.

    Windows · Scoop

    scoop bucket add corresync https://github.com/nkiyohara/scoop-corresync
scoop install corresync/corresync

    Prefer not to use Scoop? Download the release .zip directly and verify its checksum before extracting. Corresync never asks you to weaken an execution policy or organization script restriction.

    Verify

    corr --version

    Optional · keep standalone installs current

    corr config set updates.auto_install true

    Interactive starts already check quietly and show the right update command. This opt-in automatically installs only signed, verified standalone releases; Homebrew, Scoop, and WinGet stay under their package manager. Updates never run during MCP tool calls, configuration changes, or machine-readable output, and become active on the next corr start.

    macOS binaries are not yet notarized and Windows binaries are not yet Authenticode-signed—verify downloads instead of overriding Gatekeeper or SmartScreen. Direct archives, packages, checksums, and signed provenance are available on the release page.

  2. Choose an account, then sign in

    Corresync starts with no provider selected. It uses your address only to gather credential-free evidence, adds the route you choose, and authenticates only after a separate account-specific command.

    For Outlook Web, corr setup can select the first-party browser route when the evidence is strong enough. Discovery and account addition never open that browser. The next auth login command starts sign-in for exactly the alias you name.

    Using Gmail? Corresync is still preparing its official Google OAuth application for verification, so guided Google connection is not available yet. For now, connect your agent directly to Google’s official Workspace MCP servers.

    Compare provider routes · see how sign-in ownership works

    Outlook Web · guided setup

    corr setup you@example.com --alias personal
corr auth login --account personal
corr doctor --account personal

    Gmail · temporary connection path

    Use Google’s official Workspace MCP setup guide. The service is currently a Google Developer Preview and has its own Google Cloud and OAuth setup requirements.

  3. Connect the agent you already use

    One command registers Corresync as a local stdio MCP server in the client’s own configuration, with absolute paths and no remote endpoint. Restart the client afterwards.

    Codex

    corr mcp setup codex

    Verify with codex mcp get corresync.

    Claude Code

    corr mcp setup claude-code

    User or project scope; verify with claude mcp get corresync.

    GitHub Copilot CLI

    corr mcp setup github-copilot

    Verify with copilot mcp get corresync.

    Gemini CLI

    corr mcp setup gemini-cli

    Verify with gemini mcp list.

    Qwen Code

    corr mcp setup qwen-code

    Verify with qwen mcp list.

    Qoder

    corr mcp setup qoder

    Verify with qodercli mcp list.

    Kimi Code CLI

    corr mcp config kimi-code

    Prints the registration to add to Kimi’s MCP configuration.

    Any MCP client

    corr mcp serve

    Generic stdio transport—point any client at this command.

    Every client reaches the same 40 narrow tools and two read-only monitor resources—see what agents can and cannot do. Codex and Claude Code users can also install the bundled plugin and Agent Skill.

  4. Ask across everything

    Reads span accounts without merging them; writes are deliberately different. Try these first:

    • “Search every account for the message from Ana about the quarterly plan.”
    • “What’s on all my calendars tomorrow morning?”
    • “Draft a reply to Ana—I’ll review the preview before anything sends.”

    Each result keeps its account and provider, and a failed route surfaces as an explicit partial failure instead of hiding what succeeded.

    When the agent—or you—asks to send, Corresync returns a review of the exact message. Only approving that exact payload (same account, recipients, and bytes) commits it: --approve in the CLI, or the separate mail_send_commit tool over MCP. Approval is short-lived and single-use.

    review before effect 
    $ corr mail send --account work \
    --to ana@example.invalid \
    --subject 'Quarterly plan' \
    --body-file reply.txt

REVIEW · send new message
  account   work · microsoft-owa
  to        ana@example.invalid
  body      text/plain · 412 B

Nothing sent.

$ corr mail send … --approve
SENT · one attempt · review 9f2c1a…

Where next

Go deeper when you need to.

Providers and limits

What each route can and cannot do, stated per capability. Compare routes.

The safety model

Credentials, isolation, preview→commit, and what is deliberately absent. Read the guarantees.

Everything you can do

Mail, calendar, agents, scripting, import, and monitoring in plain language. Tour the features.

Before you connect a sensitive account: provider routes ship with deterministic synthetic contract coverage and remain live-unobserved until a separately authorized, recorded observation exists.

How evidence works

That’s the whole loop

Install, sign in, connect, ask.

Everything else is detail you can read when you want it.

Read the safety model See everything you can do