postgres-mcp

Instructions

Args:
    schema: Schema name to list tables from (default: public)
    
Returns:
    List of tables with name and type

Implementation Reference

• postgres_mcp/server.py:145-163 (handler)

  MCP tool handler for 'list_tables'. Fetches tables using PostgresClient and formats output using TableSummary models.

  @mcp.tool()
  @handle_db_error
  def list_tables(schema: str = "public") -> dict:
      """List all tables in a specific schema.
      
      Args:
          schema: Schema name to list tables from (default: public)
          
      Returns:
          List of tables with name and type
      """
      client = get_client()
      tables = client.list_tables(schema)
      
      return {
          "schema": schema,
          "tables": [TableSummary.from_row(t).model_dump() for t in tables],
      }

• postgres_mcp/models.py:34-50 (schema)

  Pydantic model defining the output schema for table summaries in list_tables response.

  class TableSummary(BaseModel):
      """Table info for list responses."""
      
      model_config = {"populate_by_name": True}
      
      name: str
      type: str = "BASE TABLE"
      schema_name: str = "public"
      
      @classmethod
      def from_row(cls, row: dict) -> "TableSummary":
          return cls(
              name=row.get("table_name", ""),
              type=row.get("table_type", "BASE TABLE"),
              schema_name=row.get("table_schema", "public"),
          )

• postgres_mcp/server.py:145-145 (registration)

  FastMCP decorator registering the list_tables function as an MCP tool.

  @mcp.tool()

• postgres_mcp/postgres_client.py:203-221 (helper)

  Core implementation in PostgresClient that queries information_schema.tables to list tables in a schema.

  def list_tables(self, schema: str = "public") -> list[dict]:
      """List all tables in a schema.
      
      Args:
          schema: Schema name (default: public)
          
      Returns:
          List of table dicts
      """
      query = """
          SELECT table_name, table_type, table_schema
          FROM information_schema.tables 
          WHERE table_schema = %s
          ORDER BY table_name
      """
      with self.get_cursor() as cursor:
          cursor.execute(query, (schema,))
          return [dict(row) for row in cursor.fetchall()]