MCP

The Walrus Memory MCP server exposes your portable Walrus Memory as Model Context Protocol tools, so an AI agent can decide when to save and recall memories on its own. It works with any MCP-aware client, and on Claude Code, Codex, Cursor, and Antigravity it can be installed as a plugin that adds automatic memory through lifecycle hooks.

MCP Vs plugin

There are two ways to use Walrus Memory. The difference is whether you also get the lifecycle hooks:

Component	Plugin	MCP-only
Walrus Memory MCP: memory tools (memwal_remember, memwal_recall, …)	✓	✓
Lifecycle hooks: automatic recall/save reminders	✓	✗

• MCP-only gives the agent the memory tools. Because the tool descriptions encourage proactive use, the agent already saves and recalls on its own; you just do not get the hooks. Available on every MCP client.
• Plugin bundles the MCP server and lifecycle hooks that reinforce the behavior (for example, preferring Walrus Memory over a client's built-in memory). Available on Claude Code, Codex, Antigravity, and Cursor.

note

The proactive behavior comes from the tool layer, so it works on both installation paths. The plugin hooks add reinforcement on the clients that support them.

Available tools

Tool	Description
memwal_remember	Save a durable fact for the user (preference, decision, constraint, identity).
memwal_remember_bulk	Save several distinct facts in one call.
memwal_recall	Semantic search across stored memories for relevant context.
memwal_analyze	Extract and save multiple facts from a passage of text.
memwal_restore	Rebuild the search index from Walrus when recall is unexpectedly empty.
memwal_health	Fast connectivity check (no search or decryption).
memwal_login	Connect this client to your account through browser wallet sign-in.
memwal_logout	Remove the saved credentials from this machine.

See Reference for full parameters, CLI flags, and transports.

How it works

The npm package (@mysten-incubation/memwal-mcp) runs locally next to your MCP client and bridges every memory tool call to the Walrus Memory relayer, which handles embeddings, Seal encryption, and Walrus storage.

• First run (no credentials): the server still starts and exposes memwal_login, so the agent signs you in inline instead of failing with a vague startup error. The login tool returns a clickable URL (valid 5 minutes); after you approve in the browser, the next tool call picks up the credentials automatically.
• Credential file: login writes ~/.memwal/credentials.json (mode 0600) containing your delegate key and account metadata. The delegate private key is a sensitive, long-lived credential; treat it like an API key.
• Local vs remote tools: the package handles memwal_login / memwal_logout locally (they never reach the relayer) and forwards all memory tools (memwal_remember, memwal_recall, …) to the relayer over an authenticated session.
• Logout deletes only the local credential file. To fully revoke access, also remove the delegate key from the dashboard.

See Reference for the credential file contents, transports (stdio vs HTTP), and runtime safety details.

Client-specific setup

Claude Code

Plugin (automatic memory) or MCP-only

Codex

Plugin (automatic memory) or MCP-only

Cursor

Plugin or MCP-only

Claude Desktop

MCP-only

Antigravity

Plugin or MCP-only

OpenCode

MCP-only

Reference

Tools, CLI flags, transports, self-hosting

Verify your setup

Ask the agent in any conversation:

What MCP tools do you have available?

You should see the memwal_* tools. Then state a durable fact (for example, a preferred package manager) and confirm the agent saves it with memwal_remember and recalls it in a later session.

Quick recovery

If memwal_recall returns nothing although you saved before (a new machine, a fresh relayer, or after switching servers), run memwal_restore <namespace> to rebuild the search index from the durable Walrus blobs, then recall again.