PostgreSQL

PostgreSQL MCP Server for Cloudflare Workers

Available Tools

21 tools available in the PostgreSQL MCP server. Each tool can be called by AI assistants to perform specific actions.

postgresql_database_info

Get information about the connected database.

Returns comprehensive database information including:

PostgreSQL version
Database name and size
Current user and schema
Server encoding and timezone
Connection limits and active connections

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    }
  }
}

postgresql_list_extensions

List installed PostgreSQL extensions.

Returns all extensions currently installed in the database.

Returns: List of extensions with:

Extension name and version
Schema where installed
Description

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    }
  }
}

postgresql_table_stats

Get statistics for a table.

Returns detailed statistics about table usage and maintenance.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: Table statistics including:

Live and dead tuple counts
Last vacuum/analyze timestamps
Sequential and index scan counts
Insert/update/delete counts

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_functions

List functions and procedures in a schema.

Args:

schema: Schema name (default: 'public')

Returns: List of functions with:

Function name and type (function, procedure, aggregate, window)
Arguments and return type
Volatility (IMMUTABLE, STABLE, VOLATILE)
Language (SQL, plpgsql, etc.)

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_get_function

Get the full definition of a function or procedure.

Args:

name: Function name (required)
schema: Schema name (default: 'public')

Returns: Complete function definition including:

CREATE FUNCTION statement
All parameters and return type
Function body

{
  "type": "object",
  "required": [
    "name"
  ],
  "properties": {
    "name": {
      "type": "string",
      "description": "Function name"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_triggers

List triggers on a table or all triggers in a schema.

Args:

table: Table name (optional - if omitted, lists all triggers in schema)
schema: Schema name (default: 'public')

Returns: List of triggers with:

Trigger name and table
Event (INSERT, UPDATE, DELETE, TRUNCATE)
Timing (BEFORE, AFTER, INSTEAD OF)
Level (ROW, STATEMENT)
Associated function

{
  "type": "object",
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name (optional)"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_sequences

List all sequences in a schema.

Args:

schema: Schema name (default: 'public')

Returns: List of sequences with:

Sequence name and data type
Start, min, max values
Increment and cycle settings
Current/last value
Owner table (if serial/identity column)

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_roles

List database roles.

Returns all user-created roles (excluding system roles starting with pg_).

Returns: List of roles with:

Role name and capabilities
Login/superuser/createdb permissions
Connection limit
Role memberships

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    }
  }
}

postgresql_list_privileges

List privileges granted on a table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: List of privileges with:

Grantee (role name)
Privilege type (SELECT, INSERT, UPDATE, DELETE, etc.)
Whether privilege is grantable

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_connections

List active database connections.

Returns all active connections to the current database.

Returns: List of connections with:

Process ID (pid)
User and application name
Client address and port
Connection state and current query
Wait events (if blocking)

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    }
  }
}

postgresql_get_settings

Get PostgreSQL configuration settings.

Args:

pattern: Filter settings by name pattern (optional) e.g., 'work_mem', 'shared', 'log'

Returns: List of settings with:

Setting name
Current value
Description

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "pattern": {
      "type": "string",
      "description": "Filter pattern for setting names"
    }
  }
}

postgresql_query

Execute a read-only SQL query (SELECT, WITH, EXPLAIN, SHOW).

This tool is for querying data from the database. It only allows read operations for safety. Use postgresql_execute for write operations.

Args:

sql: The SQL query to execute (must be SELECT, WITH, EXPLAIN, or SHOW)
params: Optional array of parameters for parameterized queries (prevents SQL injection)
format: Response format ('json', 'markdown', or 'table')

Examples:

SELECT * FROM users WHERE active = $1
WITH cte AS (SELECT ...) SELECT * FROM cte
SHOW search_path

Returns: Query results with rows, row count, column info, and execution time.

{
  "type": "object",
  "required": [
    "sql"
  ],
  "properties": {
    "sql": {
      "type": "string",
      "description": "SQL query to execute (SELECT, WITH, EXPLAIN, SHOW only)"
    },
    "format": {
      "enum": [
        "json",
        "markdown",
        "table"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "params": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Query parameters (for $1, $2, etc.)"
    }
  }
}

postgresql_execute

Execute a write SQL command (INSERT, UPDATE, DELETE, CREATE, ALTER, DROP, etc.).

This tool executes commands that modify the database. Use with caution. For safety, always use parameterized queries to prevent SQL injection.

Args:

sql: The SQL command to execute
params: Optional array of parameters for parameterized queries

Examples:

INSERT INTO users (name, email) VALUES ($1, $2)
UPDATE users SET active = $1 WHERE id = $2
DELETE FROM users WHERE id = $1
CREATE TABLE new_table (id serial PRIMARY KEY, name text)

Returns: Command result with affected row count and execution time.

{
  "type": "object",
  "required": [
    "sql"
  ],
  "properties": {
    "sql": {
      "type": "string",
      "description": "SQL command to execute"
    },
    "params": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Query parameters (for $1, $2, etc.)"
    }
  }
}

postgresql_explain

Get the execution plan for a SQL query.

Analyzes how PostgreSQL will execute the query without actually running it. Use ANALYZE option to execute the query and see actual timings.

Args:

sql: The SQL query to explain
params: Optional query parameters
analyze: Run the query and show actual timings (default: false)
buffers: Show buffer usage information (requires analyze)
format: Output format ('json' or 'text')

Returns: Query execution plan showing:

Scan types (sequential, index, etc.)
Join strategies
Cost estimates
Actual timings (if analyze=true)

{
  "type": "object",
  "required": [
    "sql"
  ],
  "properties": {
    "sql": {
      "type": "string",
      "description": "SQL query to explain"
    },
    "format": {
      "enum": [
        "json",
        "text"
      ],
      "type": "string",
      "default": "json",
      "description": "Output format"
    },
    "params": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Query parameters"
    },
    "analyze": {
      "type": "boolean",
      "default": false,
      "description": "Execute query and show actual timings"
    },
    "buffers": {
      "type": "boolean",
      "default": false,
      "description": "Show buffer usage (requires analyze)"
    }
  }
}

postgresql_list_schemas

List all database schemas.

Returns all user-created schemas in the database, excluding system schemas (pg_catalog, information_schema, pg_toast).

Returns: List of schemas with name and owner.

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    }
  }
}

postgresql_list_tables

List all tables in a schema.

Returns tables, views, and foreign tables with size information.

Args:

schema: Schema name (default: 'public')
format: Response format

Returns: List of tables with:

Table name and type (BASE TABLE, VIEW, FOREIGN TABLE)
Estimated row count
Total size, table size, index size

{
  "type": "object",
  "properties": {
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_describe_table

Get complete information about a table.

Returns detailed information including columns, indexes, constraints, and foreign keys for the specified table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: Complete table structure:

Table info (type, size, row estimate)
All columns with types, nullability, defaults
All indexes with columns and types
All constraints (PK, FK, UNIQUE, CHECK)
Foreign key relationships

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_columns

List all columns in a table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: List of columns with:

Column name and position
Data type with precision/length
Nullability and default value
Identity/generated column info
Comments

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_indexes

List all indexes on a table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: List of indexes with:

Index name and type (btree, hash, gin, gist, etc.)
Indexed columns
Unique/primary flags
Index size
Full definition

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_constraints

List all constraints on a table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: List of constraints:

PRIMARY KEY
FOREIGN KEY (with references)
UNIQUE
CHECK
EXCLUSION

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}

postgresql_list_foreign_keys

List all foreign keys for a table.

Args:

table: Table name (required)
schema: Schema name (default: 'public')

Returns: List of foreign keys with:

Constraint name
Local columns
Referenced table and columns
ON UPDATE and ON DELETE actions

{
  "type": "object",
  "required": [
    "table"
  ],
  "properties": {
    "table": {
      "type": "string",
      "description": "Table name"
    },
    "format": {
      "enum": [
        "json",
        "markdown"
      ],
      "type": "string",
      "default": "json",
      "description": "Response format"
    },
    "schema": {
      "type": "string",
      "default": "public",
      "description": "Schema name"
    }
  }
}