How to connect Attio to Claude Code

1. 1. Enable Attio in Metorial

   In your Metorial portal, enable the Attio MCP server and sign in with the account that owns the data. Access stays governed by your team policies.

2. 2. Add the server over HTTP

   Add --scope user to use it in every project.

   Copy

   claude mcp add --transport http metorial <your-magic-mcp-url>

3. 3. Sign in

   Run /mcp, select Metorial and sign in to load Attio tools.

• Delete Note: Permanently delete a note.
• Update Record: Update an existing record's attribute values.
• List Tasks: List tasks with optional filters for assignee, completion status, and linked records.
• Search Records: Fuzzy search across records in one or more objects.
• Create Comment: Create a new comment on a record, list entry, or within an existing thread.
• List Objects: List all objects (data types) in the workspace, including built-in objects like People and Companies, and any custom objects.
• List Notes: List notes, optionally filtered by a specific record.
• Update Task: Update an existing task's deadline, completion status, linked records, or assignees.
• Create Task: Create a new task in the workspace.
• Add List Entry: Add a record to a list as an entry, or update an existing entry using upsert.
• Update List Entry: Update attribute values on an existing list entry.
• Get Record: Retrieve a single record from any Attio object (People, Companies, Deals, or custom objects) by its ID.
• Create Note: Create a new note attached to a record.
• Query Records: Query and filter records from any Attio object using structured filters.
• List Attributes: List all attribute definitions for an object or list.
• And 9 more on the Attio MCP server page.

• Attio tools appear as mcp__metorial__<tool>. Use that name in permission rules to allow or deny a tool.
• Run /mcp to see whether Metorial is connected and to sign in again.
• Claude Code warns when a tool result passes 10,000 tokens and caps it at 25,000 by default. Raise the cap with MAX_MCP_OUTPUT_TOKENS.
• Pre-approve trusted Attio tools with allow rules in your settings so Claude Code stops asking each time.

claude mcp list shows "Needs authentication"

Run /mcp, select Metorial, and sign in. If sign-in keeps failing, choose Clear authentication in the same menu and sign in again.

A teammate sees "Pending approval"

Servers shared through a project .mcp.json need approval. Run claude in the project and approve Metorial when asked.

Large tool results are cut off

Claude Code limits MCP tool output to 25,000 tokens by default. Raise it with the MAX_MCP_OUTPUT_TOKENS environment variable.

Based on the Claude Code MCP documentation.