Fabric MCP Gateway

The Fabric MCP Gateway turns your entire Fabric instance into a single MCP server. Instead of configuring each tool separately in every AI client, you connect once to Fabric and get access to everything — your projects, documents, workspaces, workflows, and all your connected MCP servers — through one URL.

Why Use the Gateway?

Quick Setup

1. Create an API Key

Go to Settings → API Keys and create a new key. Copy the key — it starts with fab_.

2. Configure Your Client

{
  "mcpServers": {
    "fabric": {
      "url": "https://your-fabric.com/api/mcp-gateway",
      "headers": {
        "Authorization": "Bearer fab_xxxx_xxxxxxxxxx"
      }
    }
  }
}

{
  "servers": {
    "fabric": {
      "url": "https://your-fabric.com/api/mcp-gateway",
      "headers": {
        "Authorization": "Bearer fab_xxxx_xxxxxxxxxx"
      }
    }
  }
}

Endpoint: POST https://your-fabric.com/api/mcp-gateway
Auth:     Authorization: Bearer fab_xxxx_xxxxxxxxxx
Protocol: MCP 2025-03-26 (Streamable HTTP)

3. Organization Context (Optional)

To scope all tools to a specific organization, add the X-Organization-Id header:

{
  "headers": {
    "Authorization": "Bearer fab_xxxx_xxxxxxxxxx",
    "X-Organization-Id": "your-org-id"
  }
}

Or use fabric_switch_organization after connecting to switch context dynamically.

What Tools Are Available?

When your client connects, it receives two categories of tools:

Platform Tools (Always Available)

These give the AI direct access to your Fabric data — no extra setup needed:

Connected Server Tools (Require Authority)

Every MCP server you've connected in Settings → MCP Servers becomes available, namespaced by server name:

linear__list_issues       → List issues from your Linear connection
linear__create_issue      → Create an issue in Linear
github__list_repos        → List repos from your GitHub connection
slack__send_message       → Send a message via your Slack connection
notion__search            → Search your Notion workspace
fizzy__get_cards          → Get cards from Fizzy boards

Per-User Tool Visibility

Each user only sees tools from MCP servers they personally connected in their current context:

• User A connected Fizzy only → sees fizzy__* tools
• User B connected Linear + Fizzy → sees linear__* + fizzy__* tools
• In org context → sees tools from servers connected within that organization
• Personal connections never appear in org context, and vice versa

Runtime Authority

Connected server tools are protected by runtime authority — a Pipes-style session-scoped authorization model. This means:

1. Credentials are persistent — your MCP server connections stay configured
2. Runtime access is ephemeral — AI agents must request temporary permission before using tools
3. Approval is human-only — agents can request authority, but only humans can approve it

The Authority Flow

Authority Tools

Authority Metadata in tools/list

Connected tools include metadata indicating their authority status:

{
  "name": "linear__list_issues",
  "description": "[Linear] List issues",
  "_meta": {
    "requiresAuthority": true,
    "authorityStatus": "granted",
    "providerKey": "linear"
  }
}

For more details, see Runtime Authority.

Example Conversations

Cross-Platform Project Sync

"Show me the features in the Acme project, then create a Linear issue for each one that doesn't have a corresponding ticket"

The AI will:

1. fabric_list_projects → find Acme
2. fabric_list_documents → get feature docs
3. fabric_request_authority for Linear (WRITE)
4. Wait for your approval in Fabric UI
5. linear__list_issues → compare with features
6. linear__create_issue → create missing tickets

Knowledge Base Search

"Search the engineering workspace for our database migration strategy and summarize the key decisions"

The AI will:

1. fabric_list_workspaces → find engineering workspace
2. fabric_query_workspace → semantic search for "database migration strategy"
3. Return a summary based on the matching document chunks

Workflow Execution

"Run the weekly report workflow and send the output to #team-updates on Slack"

The AI will:

1. fabric_list_workflows → find weekly report
2. fabric_execute_workflow → trigger it
3. fabric_get_workflow_execution → wait for completion
4. fabric_request_authority for Slack (WRITE)
5. slack__send_message → post the results

Protocol Details

The gateway implements the MCP 2025-03-26 Streamable HTTP transport:

Session Management

• Sessions are created automatically on first request
• Session ID is returned in the Mcp-Session-Id response header
• Sessions last 24 hours
• Active authority sessions are completed when the gateway session ends

Authentication

Next Steps