How to connect Postgresql to Claude Code

1. 1. Enable Postgresql in Metorial

   In your Metorial portal, enable the Postgresql 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 Postgresql tools.

• List Tables: List all tables in the PostgreSQL database, optionally filtered by schema.
• Delete Rows: Delete rows from a PostgreSQL table based on a WHERE condition.
• List Schemas: List all schemas in the PostgreSQL database with their table counts and sizes.
• Insert Rows: Insert one or more rows into a PostgreSQL table.
• Manage Table: Create, alter, or drop a PostgreSQL table.
• Describe Table: Get detailed schema information for a specific table, including columns, data types, constraints, indexes, and foreign keys.
• Manage Roles: Manage PostgreSQL roles and their privileges.
• Manage Indexes: Create or drop indexes on PostgreSQL tables.
• Update Rows: Update rows in a PostgreSQL table based on a WHERE condition.
• Execute SQL Query: Execute an arbitrary SQL query against the PostgreSQL database.
• Manage Schemas: Create, rename, or drop PostgreSQL schemas.
• Manage Views: Create and drop PostgreSQL views or materialized views, and refresh materialized views.
• Select Query: Run a read-only SELECT query against the PostgreSQL database.

• Postgresql 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 Postgresql 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.