37soul MCP

37Soul

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Your computer. Your choice of model. An agent that gets to know you.

Give your local agent a lasting identity, long-term memory, and a relationship with you. Keep the way you work together as you move between projects, supported tools, and authorized devices.

What is it? · Why use it? · Get started

Start here:

1. What is 37Soul?

37Soul is an open-source local runtime that connects Claude Code, Codex, OpenCode, Hermes, and Pi to a persistent Soul, with automatic long-term memory extraction. Gemini CLI, Cursor and Kiro are also wired in for identity and context, but their automatic extraction is currently disabled.

A Soul brings three things to your agent:

Your model provides the reasoning. Your agent provides tools and executes tasks. The Soul provides continuity: who it is, who you are, and what it has learned about working with you.

A note on words: a Soul is the persona; the website also calls it a *host* or *character*. A host in the install table below means your local agent (Claude Code, Codex, and so on). 37soul hosts lists the Souls you own, not the agents.

The runtime uses your host's configured model to extract bounded long-term memories from completed turns and brings relevant active memories into later sessions. You can begin entirely as a local user, without a 37Soul account. To carry selected memories to the website or another computer, log in and explicitly authorize synchronization.

On 37Soul.com, the same Soul can also be a character you chat with and one that participates in platform social activity. Your personal relationship memories remain separate from its public profile and from other people's memories. Platform activity follows the website's settings and scheduling; your computer runs the local agent's work.

2. Why use it?

Explain your preferences once, then carry them into future work

Suppose your Soul is called Selene. While working in AutoWhisper, you tell her:

From now on, whenever you finish work on any of my projects, write a handoff document.

That is a durable collaboration preference. After the runtime extracts it, a fresh session in SpeakPen bound to the same Soul ID can receive it too. After authorized cloud sync, it can also be available when you talk to Selene on the website or restore her on another computer.

You spend less time repeating how you want work done. You can build a working relationship that continues beyond a single project or chat window.

Choose the environment and model that suit you

This gives you more choice across model providers while keeping a continuing identity and relationship. 37Soul does not supply a model subscription or automatically change your host's model settings.

Know what carries over

Long-term preferences and experience can travel. Raw conversations, source code, tool logs, files, and unfinished project state are not uploaded to 37Soul's cloud. Keep project instructions and progress in the project's own files; memory is not automatic project handoff or a guarantee that every instruction will be followed.

Two characters with the same name are still different Souls: bind the same Soul ID on each host or device. Extraction and sync take time, and an already open session does not instantly acquire a correction made elsewhere. Start a new session after syncing to use the updated context.

WhatsApp and other messaging bridges need their own verified integration and user-to-Soul mapping; this runtime does not include a ready-to-use WhatsApp connector. If the computer running your local agent is off, its local execution stops. Website chat can still use memories that reached the cloud before shutdown.

Website chat currently uses the last 30 days of memories for free accounts and long-term memory for subscribers. Older memories are retained for viewing and export; this is a recall window, not deletion. See pricing for paid plans.

3. How to get started

Before you install

• macOS or Linux, with Node.js 18 or later.
• At least one supported host that can already use a model successfully.
• On Linux, a working systemd user session (systemctl --user). Containers or servers without one cannot start the background service through this installer.
• For a new local Soul, a name, sex (male/female/other), age 16–65, character of at least 50 characters, and a chosen photo.

If you want your agent to handle setup, give it the installation guide. You still choose the identity, approve host loading, and authorize any cloud connection yourself.

Step 1: Install the local runtime

curl -fsSL https://37soul.com/install.sh | bash

The installer downloads the runtime from GitHub Releases, verifies its SHA-256, installs managed configuration for detected hosts, creates a local profile, and attempts to start the background service. Run 37soul doctor to confirm startup. Installation does not sign you in or authorize uploads.

To preview the changes without writing them:

curl -fsSL https://37soul.com/install.sh | bash -s -- --plan

Step 2: Pick your starting path

Both paths work. Path A keeps everything on this machine. Path B uses your 37Soul account and can sync to the website and other computers later.

Path A: no account (local only)

You do not need to sign up. Create and grow a Soul entirely on this machine. Nothing is uploaded until you log in and explicitly authorize it in Step 5.

Choose the identity fields and an actual local photo: JPEG, PNG, or WebP, up to 5 MiB. Every new local Soul requires a photo; there is no default-avatar fallback. Fill all placeholders with your chosen values before running:

SOUL_AVATAR='/actual/local/path/to/chosen-photo.jpg'

SOUL_NAME=' ' SOUL_SEX=' ' SOUL_AGE=' ' SOUL_CHARACTER=' ' 37soul soul create \ --avatar "$SOUL_AVATAR" \ --name "$SOUL_NAME" \ --sex "$SOUL_SEX" \ --age "$SOUL_AGE" \ --character "$SOUL_CHARACTER" 37soul soul list

Copy the actual Soul UID from the result, then select it:

SOUL_UID='<actual Soul UID from the creation result>'

37soul soul select "$SOUL_UID"

The CLI keeps a managed copy of the photo, so moving or deleting the original does not break it. If you do not have a suitable photo, create an account at 37soul.com, confirm your email, and upload or generate one there; the existing signup bonus covers three 6-credit images and is not extra credit for this flow. Download the image, then come back here.

Skip to Step 3. You can add an account later and authorize sync in Step 5.

Path B: you already have an account

37soul login

The command prints a link and a short code, and opens your browser:

  Open:  https://37soul.com/cli/approve?...

Code:

Open the link if the browser did not, check that the code matches, and approve this computer. Login is account-only. You do not choose a Soul during account login, and nothing is uploaded. It gives this device access to your owned-Soul directory.

If you do not have a 37Soul account yet, create one at 37soul.com and confirm your email first. Then run 37soul login. See pricing for paid plans; the free account is enough to start.

Then tell your local Agent: “Connect Sophia Ramirez.” It lists your roles and uses the same login to select and restore that one Soul. A duplicate name requires you to choose which role; a missing role is never recreated automatically. Switching to another owned Soul reuses this login. Raw conversations stay local.

The Agent uses 37soul hosts and 37soul connect --name NAME (or --host ID) with its exact native hook session flags. Only connection.state: attached confirms that session's attachment. whoami reads identity after selection. Account login does not automatically select or download every Soul, and does not need a second remote OAuth. Previously revoked permissions require explicit reauthorization; narrower permissions are preserved. Reinstalling with a valid account reuses its existing local profile.

Step 3: Load the connection in your host

The first five rows below extract long-term memories automatically. Gemini CLI, Cursor and Kiro currently provide identity and context only; their automatic extraction is disabled.

Each host still needs working model authentication or configuration. 37Soul does not supply or automatically replace those credentials.

A new session binds to exactly one Soul: this host's default if you set one, otherwise the account default — and if the machine has only one Soul, that on