Fabric MCP

Fabric is the Anthara service that stores memory and serves coding standards. It is an MCP server. MCP, the Model Context Protocol, is the standard way an AI coding tool calls outside tools.

The anthara plugin connects Claude Code to Fabric for you. This page explains the connection for when you need to check it or fix it.

The endpoint

Item	Value
Address	<Fabric URL>/mcp/<memory group>
Transport	Streamable HTTP
Server name in Claude Code	anthara-fabric
Sign-in	OAuth, in the browser

There is one address per memory group. A memory group is the shared memory that a set of repositories reads and writes.

The plugin’s own .mcp.json builds the address from two environment variables:

{
  "mcpServers": {
    "anthara-fabric": {
      "type": "http",
      "url": "${ANTHARA_FABRIC_URL}/mcp/${ANTHARA_MEMORY_GROUP}"
    }
  }
}

Variable	Meaning
ANTHARA_FABRIC_URL	The public address of Fabric.
ANTHARA_MEMORY_GROUP	The memory group to connect to.

You don’t normally set these. When a repository is activated, Anthara writes both values into .anthara/anthara/.mcp.json in that repository.

Sign in

Developers sign in to Fabric with OAuth. Developers are not issued an API key, and the plugin’s configuration has no place for one.

1. In Claude Code, type /mcp.
2. Select anthara-fabric.
3. Choose Authenticate. Your browser opens.
4. Sign in with the account you use for the Anthara web app.
5. On the Authorize access page, select Authorize.
6. Return to the terminal and send your prompt again.

The Authorize access page lists what Claude Code is asking for: your name and role, access to Fabric memory and MCP tools, and permission to stay connected between sessions.

You sign in once. The sign-in stays valid while you keep using it. It ends after 30 days without use, and then you sign in again.

How sign-in works

This section is for security reviewers.

• The first request without a token gets a 401 response. The response points the client to /.well-known/oauth-protected-resource/mcp/<memory group> on Fabric.
• That document names the Anthara API as the authorization server. The API is an OpenID Connect provider.
• The client runs the authorization code flow with PKCE. The scopes are openid, email, profile, mcp, and offline_access.
• Each access token is issued for one address, <Fabric URL>/mcp/<memory group>. Fabric checks that the token was issued for the address being called and that it carries the mcp scope.
• An access token lasts one hour. The refresh token lasts 30 days from its last use.
• Fabric matches the signed-in person to a Fabric user by email address.

Private and shared memory

Fabric keeps two kinds of memory.

	Private memory	Shared memory
Who can read it	Only you	Everyone connected to the memory group
What belongs there	Your preferences, habits, and corrections	Team decisions, conventions, policies, and useful links
Tool that writes it	add_private_memory	add_shared_memory
Approval	None	Claude Code asks you before each write

The tool decides where a fact goes. A caller cannot pass a different memory group as an argument.

search_memories reads both kinds by default. Pass scope to read only one. See MCP tools.

A write is not searchable straight away. Fabric queues it and extracts the facts in the background.

Troubleshooting

What you see	What to do
A message that starts Anthara Fabric sign-in required	Follow the sign-in steps above, then send the prompt again.
A message that starts Anthara Fabric is disabled in this project	Type /mcp, select anthara-fabric, and choose Enable.
Memory group <name> not found	The memory group in the address does not exist. Ask an Anthara admin to create it, or update the repository with an existing memory group.
The Authorize access page says the request has expired	Start again from /mcp in Claude Code.
anthara-fabric does not appear under /mcp	The plugin did not load. See Install the plugin and sign in.